I just returned from visiting my brother-in-law in the hospital. He cut off 4 fingers in a table saw accident yesterday.
Now i am very scared. I am going to get a blade guard. Any recommendations for a blade guard for the Powermatic 66? I religiously use a splitter already.
With wobbly knees,
dave
Replies
Dave,
To start, almost any blade guard on the market today, if used and set up correctly will help to protect you from harm. You have two options: either store bought, or shop built. Which ever one you choose, make sure it has dust collection capabilities.
As far as store bought, the model from Penn State Industries (see image below) (http://www.pennstateindustries.com) is probably the least expensive at $200, This is a solid performer with dust collection and the ability to be mounted either on the saw's table wing or from the ceiling. *Note: This is almost identical to the Exaktor overarm guard - different color.)
If you choose to build one yourself, plans are easily found on the web under shop built over arm guard. Check the Fine Woodworking archive as well.
If you need any help in design or set up, please feel free to ask!
View Image
Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.
Edited 12/2/2003 11:29:22 PM ET by Jackie Chan
I also have one of those over-table guards, but seldom use it because it doesn't allow for ripping narrow pieces which I do a lot. Otherwise, it's a pretty good solution and, like you, I always use a splitter. Seems as though there really isn't a good all-round solution.
Standard guards don't suit cutting thin strips but it's not difficult to make a guard/featherboard to make cutting strips safe. My learning days in woodworking were during college summers employed in a wood shop where fortunately for me the owner was very safety concious and had a good training and safety program. I spent weeks cutting 1/4 inch strips of yellow cedar and black walnut - millions of feet. The boss had made a guard/featherboard that clamped across the table from the right side and attached to the fence. I just had to push the wood through - couldn't even see the blade, and just about impossible to cut myself.
I recall the beginnings of my tablesaw experience when a piece of plywood began to kickback and then suddenly flew up into the air and away from the saw. The boss had been watching me and when the kickback started he had kicked the board up and out of my hands. He said "Don't use the saw again until I have spent a few hours with you". He trained me well.
In that shop hand outlines with fingers missing were painted in red on the saw tables to keep us thinking safety.
Jim,
To rip narrow stock with the over arm guard protectively in place, you will need to fabricate an auxiliary L-shaped fence and a modified push block.
The L-fence can be constructed from two pieces of plywood or melamine. One piece is 3/4" x 6" x 24", and the second is 3/4" x (the height of your table saw's stock fence) x 24". Screw the table saw height piece to the long edge of the other creating a right angle. This auxillary fence should then be clamped to the stock fence so that it extends two inches past the blade's center point. Be sure that it is secure - best to use two clamps. (See enclosed graphic)
The push block should be made out of 1/2" plywood - 6" x 9". On the side of the left rear corner screw a piece of scrap (1/2" x 1.5" x 1"). Mount some sort of handle to the top of the block (a block of wood or even a large dowel in a block will work), locating it as close to center as possible while still being able to clear the clamps on the fence.
Use a paste wax to slick up the bottom of the push block and other plywood rubbing surfaces.
You are now ready to cut some wood! Use a ruler to measure the distance from the blade to the aux. fence for cutting width.
On most commercial over arm guards, the blade shroud can telescope left to right. Move it over so that there is no less than one inch from the blade to the cover (on fence side). You are now able to rip wood into 1.5" strips (width of cover to the blade + width of push block hook). Using a feather board with a hold down mounted on top of it is highly recommended. (see enclosed graphic)
If you have any questions, please feel free to ask!
Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.
Edited 12/4/2003 12:02:50 AM ET by Jackie Chan
Edited 12/4/2003 12:04:11 AM ET by Jackie Chan
Thanks, Dan, very nice of you to go to the trouble of dealing with MY guard and ripping concern. I'll give that a serious try next time I've got some narrow pieces to cut. I note that you've drawn a left-side setup...how did you know I had a PM-66? Jim
The other option for production ripping of thin pieces is using the Grip-Tite system. Go to the 6,7,8 pics on this page:http://www.woodshopdemos.com/grpti-2.htm
With this system, your hands never go close to the blade, and the Grip-Tites guard the blade. You use your next piece of stock to push though the currently "working" piece of stock, and just keep pushing that way until the last piece is in, then use a scrap piece to finish off with. I have seen this demonstrated with pieces as narrow as 1/4" being produced in rapid, clean, safe fashion. It's the safest way I've seen to rip narrow pieces between the blade and fence.forestgirl Another proud member of the "I Rocked With ToolDoc Club" .... :>) -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
I don't believe the Grip-Tite system is the 'other' option fg. It's surely just one that might be considered? The safest method I've come across to rip multiples of thick or thin stuff is a power feeder added to a powerful saw, i.e., 5- 7 HP and up-- the power feeder being a tool generally beyond the budget of most amateurs.
The GripTite system seems to have some attractions, but I don't think I'd spend much time with it as it seems to be an attempt to sidestep the fundamental safety option of the short style rip fence, riving knife, and crown guard.
No-one (that I can recall in this thread, so I may be mistaken) has mentioned using a short rip fence for ripping, whether it be for wide or thin stuff, allied to a decent riving knife and crown guard-- items and options not available or fitted to US style saws, although I think Venecia mentioned these latter items. Slainte.Website
What exactly is a crown guard?
Dave, a crown guard is a device attached directly to the riving knife (in most cases) and can help in preventing the wood being thrown back at the operator. In a potential kickback circumstance the crown guard can provide last moment panic movement to turn off the machine.
The riving knife resembles a US style splitter but is much more substantial and attached directly to the rise and fall mechanism of the saw blade. It looks as you should be able to see in the attached image. Slainte.Website
So how does it shut off the machine? Is there an electrical connection?
dave, a riving knife doesn't shut off the machine, but it--- along with a decent crown guard--- does have a significant role in reducing the chance of kickback, as the lively discussion since my last visit here illustrates. Slainte.Website
Slainte
I agree that no one mentioned a riving knife, crown guard and short fence. But if you go to post # 6 you will see I posted a picture of all those on my saw and mentioned with all the "goodies" I added.
I was pointing out to the poster that even with all the added goodies, 110% attention should be given and the "lane kept clear" in response to I believe post # 5. I suppose I should have stated what these things are as most don't seem to know. ha.. ha...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
You did broach that subject indirectly, sarge. I failed to open your attached images to note that you had started that conversational thread. My fault. I'm not very good at opening attached images for one reason or another. Sorry. Slainte.Website
Sgain
Slainte, are you OK? Sorry.... I've never seen you use that word. This teaching thing seems to be honing the jagged edge. Next thing you know you'll be apoligizing to the chap you put on his *ss during a rugby match. ha.. ha...
As far as you not being good at opening things, I dis-agree. You seem to be "world-class" at opening malt beverages. Apologies not necessary as hopefully a few might have learned something here. Your comment to Scrit was "on target" about opening up something that has been covered time and time again. There always seems to be a new audience though. Like teaching, they come and they go. As soon as you think you have the word out, a new group shows up to take the place of the graduates. I'm just glad I was in one of those groups and came away wiser.
Your article in the Dec. Furniture&Cabinet-Making should be on the stands soon. Looking forward to it. BTW, did you end up selling the Wadkins before you returned or did you ship it over? Just curious..
Regards...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
Yep, Sarge, I did sell the Wadkin in the US. Far too big and heavy to ship over, and it probably needs a different motor. Wadkin kit is as common as muck in these parts anyway so it'd be easy enough to buy a secondhand one.
Funnily enough, when I walked into the workshop at my new job I was surrounded by Wadkin machinery, including a CP12 version of my saw which was the bigger CP16. Apart from the saw I had in the US I hadn't used Wadkin kit in ten years, but it was just like riding a bike--- all the knobs and controls are right where I expect them to be, ha, ha.
You're correct, I've seen a lot of names come and go in this forum over the years and there always seems to be a new audience coming through.
Enjoy the article. It's not a 'how to' thing, more of an aid to selecting a type or style of drawer making for the job in hand. I'll nip that saying sorry thing in the bud, then, eh? You prefer my pungent, in-yer-face character, ha, ha? Lots of Heineken Cup rugby to watch this weekend-- about six game on the telly, so that'll keep me busy and mostly out of mischief. Slainte.Website
Slainte
" You prefer my pungent, "in-yer-face" character"?
Yep, the humor is needed on ocassion. I expect the smooth, well versed WW knowledge to come from Richard Jones as in F&C and when answering a serious question here. But Sgain Dubh carries a "black-handled" knife ready for a little fun and a bar-room brawl if it breaks out. ha..ha...
Regards...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
I have some vague recollection of you describing the stack dado as, " inspired lunacy". I always wondered what it is about the dado blades that make you all so leary of it. If you take off less than 1/4 " at a time, and the blade is on the other side of the board, exactly why is it so dangerous?
Frank
You quoted me pretty closely from about four years ago Frank. I think I said the words, "Desperately inspired lunacy," and I'm pretty sure I was refering in particular to the technique of creating coves and the like by passing the wood at an angle over a blade using an angled piece of wood cramped to the table as a fence. I tried that trick once at the behest of a well meaning shop mate, and I won't be trying it again in a hurry. I'm already missing the ends of a couple of fingers, and I'd like to hang on to the ones that are left, ha, ha.
The lively discussion since your post seems to address most of the concerns about using a dado blade and I don't think I have much to add, except to say that those tools do have something of a reputation for causing injury. Still, similar blades are run in spindle moulders, but in that case there is usually added guarding and tunnelling rigged up. Most saw operators using dado blades seem reluctant to create similar guarding, but that might be due to the 'hurry-up' nature of the job in hand, or maybe a lack of appreciation for the inherent dangers of using such a tool. Slainte.Website
felder have a nice unit with a vacuum hose outlet on the top, you might have to make a bracket for it. Feel bad for your bud, but thats why there is a guard, if only to tell you where the blade is!
Dave,
This may is not relevant to your question but how did he manage to cut off "4 " fingers? I can see cutting off 1 or 2 but 4 takes some doing. Was it extreme carelessness or extreme bad luck? This is not morbid curiosity - knowing the precise mechanism helps me to be safer when using my own saw.
Like most woodworkers, I took the guard off my saw and even though I am not advocating this, it does force me to keep my attention riveted on the saw blade at all times. With a guard in place, I wonder if I would have a false sense of security about the saw. Just a thought.
This is one of my personal nightmares, amputation. I've got near a couple of times but been lucky to come away with only stitches to show, thank goodness. I feel genuinely sorry for your buddy.
A relative of mine who makes furniture advised me when I set up shop to always have the telephone number of the local Emergency Room together with the location (hospital), name and phone number of the nearest microsurgeon in the area by the phone. Mind you, he also keeps a couple of bags of frozen peas in the shop icebox so that if an accident does occur he can pick-up the amputated parts wrap them in ice and hopefully have them reattached in due course.... **** PLEASE NOTE: I stand corrected on this one, having been told that you must NEVER freeze the amputated parts, just wrap them up in a clean cloth and take them along to the ER. It also stands to reason that you should not attempt to drive there yourself ****
Perhaps this is a timely reminder to all of us, pro and amateur alike, to think about safety before we make that cut. After all, guards are there for a purpose.
For what it's worth there is this site with a good home made design for an overhead crown guard, although I personally think that this parallelogram linkage guard is pretty neat. For those who want to learn a bit more about safe working with circular saw benches, take a look at this PDF on the HSE website. Yes, I know the site is not American, and it certainly seems to contradict what Uncle Norm does, but the advice given there is first class (it also shows how to use overhead crown guards safely).
Scrit
Edited 12/3/2003 11:14:59 AM ET by Scrit
Edited 12/4/2003 7:09:39 AM ET by Scrit
Edited 12/4/2003 7:10:39 AM ET by Scrit
Call 911 imediatley!!! Do not drive your self or have someone else drive you let the pro's do that.Do not use frozen peas or wrap them around the amputated part,frozen parts can't be re-attached.Place them in a clean bag or towel ( middle of paper towel roll). Wrap loosely then wait for ambulence.
JR
"With a gaurd in place, I wonder if I would have a false sense of security"?
I got these little built-on and home-made goodies and I don't have a false sense of security. I keep 110% attention to the saw, stock and where my body parts are in relation to the saw. I need those fingers if I decide to be a concert pianist when I grow up. :>)
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
I saw the photos you posted in response to Dave's accident discussion. The photos are dark and hard to see. Would you take some more pictures and post them where we can all find them? I notice you are using a BT3000 like mine and I am always interested in safer ways to cut wood. Perhaps a discussion of the use and purpose would be in order.
Sarge, I was going to say somethin' too -- for instance "Hey, guy, set up those halogens when you're picture-taking. Your stuff is wonderful and we want to see it in all the best detail!" Do you have some halogen work lights?forestgirl Another proud member of the "I Rocked With ToolDoc Club" .... :>) you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
FG
"Do you have any halogens"?
How many thousand candle-power do you want? ha..ha...
The only time I tried to use them I was using a cheap polariod. Everything came up amber. I'm not to much of a photographer. I could try the halogen with the better 35mm auto I started using. Don't know what will happen as I probably won't invest in an expensive camera.
Regards...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
genr8r
So, I'm a lousy photograper, huh! ha.. ha... I won't have time to take any new pics before the first of the year. I'm in the middle of our annual "build 400 toys for needy kids with donated scraps" project. The 14 of us (used to be 6) are getting to the 300 mark, so I may finish soon this year. We may have enough time with the extra people and scraps to go over 400. This is a my immediate priority.
If you will e-mail your mailing address, I will put them in an envelope and mail them though. I have a few others that might be helpful for your intended purpose. Yep, it's a BT-3000 for sure with a few gut and surface modifications. My best friend is a mechanical engineer and my BIl is a shop foreman in the machinist shop at Delta Air Lines. We did a "wee" bit of modification with what is a good basic design that needed beefing.
If you have questions, ask. I have time to check the forum in the morning b-4 I go to my part-time job. I also get on late after finishing in the shop. Getting through earlier this year with the extra people. Used to be a 2 AM every nite deal.
As I stated, any questions you have feel free to ask. How I got the small shop refrigerator mounted in the base is the only secret I will keep. It's not there anymore in lieu of dust collection, so it will remain a "classified secret". ha..ha....
Regards...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
What he actually did is not entirely clear. When I saw him he was just coming awake after 11 hrs of hand surgery. It wasn't the time to ask.
If you dont want the gory details stop reading now!
He cut off thumb and all 3 fingers but pinky. Middle finger has been reattached in what he describes as a permanently defiant pose. Because the body went into shock and restricted blood flow to his extremity there is risk he will still lose the pinky; though right now that seems unlikely. There is talk of attaching his big toe in place of the missing thumb.
How did he do it? I'm not entirely sure but here is the little i know. His adult son says the accident occurred while performing a drop cut. I suspect that means he rotated the board down onto the blade. I do not know if the blade was higher than he thought or if he was the victim of some kind of kickback; i expect the latter but really do not know yet.
How many times i have experienced an accident or heard of an accident where it happened knowing full it was going to be trouble. . . I find myself wanting to say to myself and immediate family that this happened cause he did something that i would never do. Seems like a dangerously slippery slope . . . He has way more woodworking experience than me. Worked as a pro in his younger years.
Somehow he walked to the neighbor's afterwards to get help. His son went back afterwards and collected fingers and bone for the hospital.
Thanks for letting me "process" a bit here on the forum. Kind of like cheap therapy!
dave
Edited 12/10/2003 12:14:53 AM ET by dave
Every time I read or hear of one of these things I feel ill. I don't know if I feel worse for the unfortunate injured person or for myself, wondering if such a thing will ever happen.
We all tell ourselves we don't take chances, but these things happen so fast, so unexpectedly while we think we are under control.
And it is so very often on the table saw that these disasters happen. I dislike the TS so much, I do all the ripping I can possibly accomplish on my bandsaw. But there are some operations that only the table saw can properly do.
I guess we all have our own tales of near misses, real events, etc, all so fast it was like a rifle shot.
(shudder)
VL
Like you, I use my bandsaw for as many ripping operations as possible. I use Timberwolf blades and a quality fence, and I get great cuts with no drift. I then clean up the slightly rough edge with my router or a planer.
Also like you, I dislike table saws very much. Especially North American designs. The Euro-style saws are absolutely better, with their riving knives, but they are very pricey. I looked into Felders a while back, but they run about $5,000 minimum. Rojek, another good Euro saw, is a little less expensive, but will still cost you $3,500 by the time it's outfitted.
Unlike you, I do not own a table saw. I make all kinds of furniture and cabinets, and I find I can do everything without the table saw. I use a Festool system instead. This system does wonderful rips, cross-cuts, and allows compound angles and tapers -- all done with near-total safety and great dust collection.
I'm only saying this to emphasize that, for people who dislike the table saw, there is no absolute reason to own one.
Mathew,
You misunderstood. I DO have a table saw, and I use it all the time. Although mostly for crosscutting and miter cuts.
I also use it for ripping and "partial" ripping. However, I never use it for ripping rough stock. That's done on the band saw. The band saw is such a CALM thing compared to the violence of the TS. I'm really surprised that the band saw isn't generally recognized as the preferable way of doing this.
Compared to ripping rough stock, I find ripping to final size on the TS a relatively easy operation for removing the final 1/16" rough edge left by the bandsaw on stock too thin (less than 3/4") to run through the planer.
VL
Venicia
Why isn't the bandsaw more popular than the table saw? Probably because people buy a bandsaw and keep the cheap and nasty blade which comes with it forever after (as their one and only blade), or they try to make a 14in bandsaw do cuts that really need a much bigger saw, or they just never learn how to set it up properly. Either way they have some bad experiences with a bandsaw and never quite get over them, after all, aren't power tools just supposed to just work?..... To make a bandsaw perform well takes a little bit of time to learn how to use it, decent quality blades in a variety of pitches and widths (in the UK Dure-Edge, in the USA Suffolk Saw), possibly decent quality after-market guides (e.g. Carter) and patience when using it. A basic table saw is ready to go almost straight out of the box with a lot less variables to think about. Don't get me wrong, I feel that the time spent learning about the bandsaw will repay itself time and again in the years to come, but many people (mistakenly) think that the bandsaw is inaccurate, ornery and just too much trouble to deal with. Me - if I were to make furniture only from solid timber I could happily live without either a table saw or a crosscut saw - so long as I could keep the bandsaw.
Scrit
Edited 12/7/2003 11:48:11 AM ET by Scrit
Given what is known, it isn't too difficult to reconstruct the likely scenario that led to this accident.
A "drop cut" usually involves placing the back end of the board, the end nearest the operator, on the saw's table and then lowering the front end of the board down onto the blade. To do this manuever, one hand has to be holding the front end of the stock. If the board is pulled backwards by the saw blade, the hand goes with it and gets pulled right across the blade.
In this case the operator was probably holding the side of the stock with all of his fingers crosswise to the blade, which is why there was so much damage. The pinky survived only because the hand would have rotated at the wrist as it came backward and the pinky pivoted out of the way.
A compounding factor is the fact that there was a very good chance that the blade would grab the board. The wood strikes the blade's teeth right at the top of their arc, when the teeth have the highest velocity in the horizontal direction. Any wobble of the poorly supported board would cause the saw teeth to grab and further dig in. The force and direction of the grabbing would be identical to the result of ordinary kickback and, once started, be totally uncontrolable.
I can't concieve of any guard or pusher that would make doing a drop cut safe. The lesson from this is that certain operations are simply too dangerous to attempt.
John W.
Edited 12/4/2003 6:07:43 PM ET by JohnW
John
Presumably a drop cut is performed where you want to cut a slot in the middle of a board. Smarter would be to place the board on the table and raise the saw into it — similar process to making a zero clearance insert
Ian,
Raising the blade is possibly a slightly less risky option but it still has a strong potential for kickback unless you use a stop block and hold downs.
Another problem with raising the blade into the board is that it is difficult to hold the board firmly with only one hand while reaching down with the other hand to crank the blade upward. Also, because you are reaching down, your face and shoulders come into the line of fire of a kickback.
Generally the cut from using this method is a bit rough and burned because the board doesn't move for several seconds as the blade is raised and you then need to stand up and reposition your hands before feeding the board.
I've raised the blade often to cut zero clearance inserts, but I wouldn't try it with a bigger piece of wood when there are safer if slower alternatives.
John W.
John
If the project calls for a cut in the middle of a board my reaction is to break out the jig saw. However, if you must use the table saw what are your options apart from clamping the board to the table and raising the blade?
Ian
Ian
Can't see how trying to make an upward plunge cut with your head at the same height as the workpiece whilst you raise the blade is going to feel all that safe. In order to make the plunge cut you'd need to remove the riving knife, which in turn introduces the possibility of kickback if the workpiece is hooked up by the rising teeth. Also, if you make a plunge cut too slowly (or without good dust extraction) the blade will probably scorch the workpiece.
I do use a Bosch hand-held power saw which has a plunge cut facility - the advice there is to make the plunge cut then immediately start moving the saw forwards on the track. It should be noted that this type of saw has a spring-actuated riving knife which pops down as soon as you have moved forwards by about 10mm (3/8in). Now if you could invert your saw and fit a sprung riving knife.....
This thread is moving away from the hazards of operating without a blade guard to a "how to" primer on using a table saw to make plunge cuts. Apart from making zero clearance inserts I can't think of where you would want to do this when a jig saw is sooo much safer. However, I remain curious.
As to blade guards, I've seen an article somewhere on fitting a guard to a saw that raises and lowers with the blade. I think they are standard on euopean saws. Is there a Knot head who knows?
Ian
It is always best to examine one's working practices. If you weigh-up the risks of carrying out a particular procedure (such as making a plunge cut on a table saw) and come to the conclusion that the procedure(s) you are using places you in a potentially harmful situation, then surely it is time to look at whether there is an alternative, safer way of making the cut OR whether the design of the piece shouldn't be changed to accommodate safer working practices? This is almost a daily question for many professional woodworkers - when one stops asking questions dangerous practices are surely just round the corner. Personally I can't see a safe way to make such a cut on a tablesaw, guarded or not, but then that's my personal take on the situation (BTW the plunge saw was bought for flooring work where plunge cuts are de rigeur)
Ian,
I don't think there is a practical way to safely make a plunge or drop cut on a tablesaw. I don't even like raising the blade into a zero clearance insert and I'm not overly cautious about a lot of operations, the mechanics of the cut are just bad.
Using a jigsaw, a router, or a bandsaw, if the cut allows it, is the way to go with power tools. With hand tools, I'd make the cut with a keyhole saw started in a small drilled hole, followed by a ripsaw once the cut was long enough to take the blade.
John W.
"I don't think there is a practical way to safely make a plunge or drop cut on a tablesaw. I don't even like raising the blade into a zero clearance insert and I'm not overly cautious about a lot of operations, the mechanics of the cut are just bad."
Amen.
VL
Just a side note on a safer method of making zero clearance inserts by raising the blade into it on the table saw...
The insert is first milled to the proper shape and thickness - and finger holes are drilled for easy removal. With the insert in place, slide the rip fence over it so that the first 1/3rd is covered. Now, clamp a scrap piece of 3/4" plywood to the fence so that it is sitting flush on the table top and the insert - The scrap plywood should be long enough so that there is no chance that the blade will impact any of the clamps! The blade can now be raised up into the insert. This set up insures that no hands are near the blade during the up cut, and that the insert is rendered movement and launch proof. Keep the plywood aux. fence around for making future inserts.
If anyone has any questions, please feel free to ask!
(Tip: if you've forgotten to drill finger access holes, and are having trouble removing an uncut insert - don't try poking it up from underneath, you may nick yourself on a blade tooth, or at the very least get all greasy from the saw's lubricated parts. The easiest way to remove the insert is to drill a small hole, no more than 3/16" into the top of the insert, twist a small screw into the hole with your fingers, and use it as a handle to pull the insert up.) Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.
Dan,
Good solution, I'll use it in the future.
John W.
Dan, the inserts I have the most trouble with are the 45* inserts, due to the blade not dropping down low enough to get the blank in the throat. With 90* insert blanks, I can mount my 6" dado blade and get the starting slot. With 45* insert blank, however, the groove ends up in the wrong place. What a pain. Any ideas?forestgirl Another proud member of the "I Rocked With ToolDoc Club" .... :>) you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Would it make sense to chisel out a slot on the bottom of the insert for the blade to fit into and then raise the blade the rest of the way?
Or how about a jig that would hold the insert 3/4" up and 3/4" over (or whatever the actual measurement would be on your saw) from its intended position while starting the slot.
I tried making a starting slot by hand, pretty much a mess, but having the new insert set up just a little high would probably work. Ah! Just had an idea -- could plane down a regular insert with a wide slot in it to sit below the table top so it's just even with the top of the blade at its lowest position, put the new blank on top of it, slide the fence over and make a starting cut. I'm gonna try it!!!!forestgirl Another proud member of the "I Rocked With ToolDoc Club" .... :>) you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
FG
That will work for a vertical blade but I think the slot wouldn't be in the right place if the blade were tipped.
John W.
Hmmmm, if that's the case, I'll be back to lowering the insert onto the spinning blade from a safe distance behind the saw. Yuck.forestgirl Another proud member of the "I Rocked With ToolDoc Club" .... :>) you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
FG,
I think somebody already asked this, but why not route or dado a groove on the bottom of the insert to give yourself enough clearance for the fully lowered blade at 45 degrees? The groove can be wide and just deep enough to clear the blade, it doesn't have to be a close fit since it doesn't go all the way through the insert.
John W.
Edited 12/11/2003 4:38:36 PM ET by JohnW
I like that idea! Mostly because I thought of it last night after I went to bed.
Don't bother trying to figure out where the slot needs to be on the bottom of the insert, just relieve the whole area where it could be.
My General cabinet saw does'nt clear the bottom of the inserts at 90* .I make all my inserts in Baltic ply .I have found the easiest way is to rout out the underside then lift the blade through.The back of the insert has a locating pin and I hold the front down with a push stick.Then I shellac and wax the top face
Forest Girl,
I use a 60* sign making bit mounted in a plunge router. This gives the necessary clearance needed for 45* upwards plunge. It is possible to use the jig that I described in a previous post http://forums.taunton.com/tp-knots/messages?msg=11293.14 to score the bottom of the insert blank using your standard table saw blade. It is also possible to use the same jig, clamped solidly to the saw's top, to up plunge the insert. The caveat to using the jig in both cases, is that it must be offset. The mathematical equation is escaping me at the moment that determines the amount of off set. The off set amount is the measure between the blade at 90* (with the installed stock insert), tilting the blade to 45* and measure the distance of the movement - if the blade tilts left take measurements from the right side of the blade (visa versa for right tilting blades).
You'll only have to take this measurement once, and then you'll always know the amount to off set the insert for the future. If you use both thin and regular kerf blades, you'll need to take a new measurement for the alternate blade.
The graphic didn't post - check in below for the post with the graphic!
If you have any questions, please feel free to ask!
Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.
Edited 12/12/2003 1:13:48 AM ET by Jackie Chan
Hey, Dan, thanks! That little graphic above really helps. I'll check out the jig (again, as it was addressed to me originally) tomorrow. I don't remember if I saw it when you originally posted it. I might convert it to .jpg and repost it here, if it's ok with you. It'll be more a more manageable size.forestgirl Another proud member of the "I Rocked With ToolDoc Club" .... :>) you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Here is the graphic missing from my previous post.
Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.
Hi Dave,
I had an unfortunate incident at my table saw on July 31 of this year when I amputated about 1/8" from my left index finger and reshaped my left long finger a bit at the tip - I posted here about that incident if anyone should remember. I spent about 1.5 hours in reconstructive surgery so I can sympathize entirely with your friend. I am quite sure his outlook on things is quite bleak at the moment - mine was with the uncertainty of what would be left and how much function it would have. Realizing how fortunate I was and that my damage was nowhere near as severe as his, it still might help him to know that I am making a very good recovery. The fingers are still somewhat numb and may take years to "wake up" if ever, but they do not hurt and are quite useful. I was a classically trained guitarist and played professionally for a number of years and I was, of course, concerned about the permanent changes the amputation would make to my life (it was my fingering hand). After a great deal of work and plain old stubborness I can report that once again I can play in an acceptable fashion. I sincerely miss that 1/8" and I will never reach the level that I once attained, but I can still enjoy the instrument which is the most important thing to me anyway.
I was rather embarassed to post my experience here originally but I did so in the hope that it might keep one person from taking a chance and making a less than safe cut. Whether it did so or not I will never know but I can say for a fact that I now think very carefully about every cut I make. If I need to make a jig to more safely cut a 4" piece of stock I will spend whatever time it takes to do that. I sincerely hope your friend makes as full a recovery as is possible but please let him know that he WILL adjust to the changes although it will take time and patience on his part. The human body is an amazing piece of architecture - as is the human mind. If he keeps his outlook as optimistic as possible everthing will work out OK in the end.
Be safe,Ken
Dave,
Sorry to hear about your brother-inlaw. FWW's website actually had an article that I found useful when I myself was looking for a better blade guard solution to the stock version that came with my saw. Here is the link: http://www.taunton.com/finewoodworking/pages/w00130.asp
--Rob
That scares the hell out of me, too!
A couple of years ago I read about an article in Fine Woodworking that described an emergency stop devise that was being tested and developed at the time. If I remember it correctly, a small electrical current or signal was sent through the blade and when it got interrupted - by a finger for example - a steel rod was jammed into the blade stopping it immediately. They showed a test on a hot dog wiener and the blade stopped after breaking the skin. It wasn't on the market yet but I've told myself I would retrofit my table saw with one when they came out.
Has anyone else out there heard or read anything about this or did I just dream it?
On another note, I just bought a bandsaw this year and use that now for many of the operations I would have had to do on the table saw before. That may not really be a solution but it does reduce the inherent risks of a circular saw. When I do use the table saw I AWAYS use a sled or push block. My hand NEVER crosses the blade.
Does anyone have an opinion about this "safety" device? It looks good to me.
http://shop.woodcraft.com/Woodcraft/product_family.asp?family%5Fid=4393&gift=False&0=dept%2Easp%2Cdept%5Fid%3D10000%26Tree%3D%2CDepartments&1=dept%2Easp%2Cdept%5Fid%3D1046%26menu%5Fid%3D%26Tree%3D0%2CPower%20Tool%20Accessories&2=dept%2Easp%2Cdept%5Fid%3D2166%26menu%5Fid%3D%26Tree%3D1%2CTable%20Saw%20Accessories&3=dept%2Easp%2Cdept%5Fid%3D1093%26menu%5Fid%3D%26Tree%3D2%2CTable%20Saw%20Safety&Gift=False&mscssid=00A3F68F4B2EC4EDF9C87E6FC71EE2D6
VL
It looks like to me that if your cutting long stock it will get in the way of your feather boards you may want on the saw. For very short stock it may be ok but you will have to remove the saw guard to use it exposing the blade when the cut is finished. I don't think this is a good design at all.
Tony
We already have enough youth, how about a fountain of smarts.
Tony,
It's hard to tell from the picture just how the device functions. I agree it DOES appear that the blade is exposed after the cut. I would like to see it in action. It certainly does appear to keep the operator's hands protected from the blade during cutting.
But many people operate their saws without guards. And for certain operations on a contractor's saw the guard MUST be removed.
The only properly designed guards/splitters are crown guard assemblies and riving knives as found on (mostly European) cabinet saws. They never have to be removed for any sawing operation.
VL
Venicia
"They never have to be removed for any operation".
They do for non-through cuts and dadoes. Nothing is perfect. :>)
Regards...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
Sarge,
The riving knife is not removed and that is by far, the most important part of the assembly. Most crown guards which attach to the riving knife are very easy to remove and put back on.
I believe that "conventional" blade guard/splitters on most saws do not get used as much as they should because they are a pain to remove and re-attach (as silly as such an excuse is). Conventional assemblies are just about the only kind that can be fitted to a contractor's saw. But riving knife assemblies could be fitted to every cabinet saw. It is very hard to understand (other than economics - and savings can't be much) why the inferior type comes as standard equipment with so many.
VL
Venicia
I hate to disagree, but I have to in this case. The riving knife is removed for all non-through cuts and dadoes (which is a non-through cut). Stop and think about it. How would a piece of stock on a non-through cut go throuh the riving knife? The stock is not completely cut. The top of the stock will hit the riving knife and not allow the stock to be advanced any farther!
If you will go to post #6, I posted two pictures of my riving knife, crown gaurd and Euro short-fence on my saw. I have been using a riving knife for two years and added the home-made removable crown guard and short fence (learned from Sgain Dubh) for a year and a half.
What you stated about the riving knife and crown gaurd is very true. If you are not familar with the Euro short-fence, you need to at least be aware of it's presence also, as it can be added to both contractor and cabinet saws. You were correct about the riving knife not being adapted to an American saw without considerable modification.
I will re-post a pic of what I did in post #6 as a refresher.
Regards...
sarge..jt
Proud member of the : "I Rocked With ToolDoc Club" .... :>)
Edited 12/5/2003 12:32:52 AM ET by SARGE
Sarge,
In my experience, the riving knife does not extend higher than the top of the blade. I did a Google search for "riving knife." Take a look at the first three matches.
http://www.safetyline.wa.gov.au/pagebin/guidothr0007.htm
http://benchmark.20m.com/tools/HammerB3/B3RivingKnife/hammerb3_rivingknife.html
http://www.safetyline.wa.gov.au/pagebin/guidothr0007.htm
VL
Sorry,
I posted the same URL twice. Here's the third.
http://www.workcover.tas.gov.au/attach/sa017spdf.pdf
Venicia
The Saftey site states that the knife needs to go as far as practical forward. The BenchMark and WorkCover site both show it going slightly higher than the blade and forward. If you look at post #32 for Sgain, his goes over the blade several teeth. Mine goes over the blade for several teeth. Sgain was trained on Euro saws over 30 years ago and he has always used a riving knife.
The height and how far forward it goes has no bearing on what function the riving knive does. It is the same as a splitter, with the exception it is directly attached to the arbor mechanism and moves with the blade. If you tilt the blade, the riving knife tilts with it. When you raise and lower the blade, the riving knife raises and lowers with it and never changes it's distance to the blade. This is contrary to a splitter as it is in a fixed position. When you lower the blade, it stays put and is light-miles away from the blade. The crown gaurd is on top. It is either attached to the riving knife, or is independent. Either way, it's function is to stop the stock from flying up in a kick-back.
It is important that the knife is placed within 1/16" of the teeth and no farther that 1/8" regardless of how high the knife is and how far forward it goes. With the close relationship, it would be difficult to get a finger in between. The biggest danger in kick-back is the rear rising teeth. They are the culprits in 90% of kick-backs.
That's where the crown gaurd comes in. It prevents stock from going up. A riving knife could curl completely over the top of the blade and serve as a crown gaurd. But the crown is usually wider and made of wood or plastic to help absorb and disperse impact of upward flying stock. Less chance of it coming un-attached from the arbor with that dispersion.
The Safety site states the knife should be as wide as the plate of the blade. I disagree with that also. It should be as wide as the kerf of the teeth. If it is not, you will get pinch that will lead to kick-back. I have two riving knives custom made. One is 3/32" for Thin Kerf blades and one is 1/8" for regular blades. If I change blades, you flirt with kick-back by leaving a 3/32" riving knife mated to a 1/8" blade.
To the original point, you cannot defy physics by not removing a riving knife to do a non-through cut. It is impossible. On most Euro saws the arbor shaft will not not allow dado blades. This eliminates that problem, but on non-through cuts it has to be removed to make them. The choice is either remove it, or don't make the non-through cut!
As I stated to you once, I am not an expert on finish. But, we have hit a subject here that I do have a "wee" bit of knowledge about. ha.. ha...
Have a good day...
sarge..jt
Proud member of the : "I Rocked With ToolDoc Club" .... :>)
Edited 12/5/2003 2:38:51 AM ET by SARGE
Folks,
I have a Delta cabinet TS (basically a light dutyUnisaw with a 2hp motor) . It still has the original guard, splitter, pawls. Is there an aftermaket riving knife/ crown guard that will fit it? I rarely ever do dados on the TS.
Thanks
Frank
Frank
There is no riving knife to fit you saw. The way the Euro saws are set up to accomodate them is totally different from any of our American saws internal guts. The riving knife rides with the tilt-raise-lower mechanism and you would have to highly modify or custom make a mechanism that would work on your saw.
There are some after-market crown devices available. I'm sure someone will post them as I have the situation covered personally and haven't paid to much attention to that aspect.
Have a good day, Frank...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
Well, I guess I am stuck with what I have. i do have a short fence for ripping.
Thanks
Frank
The short fence is one of the best things I ever picked up. Got interested in it as Sgain explained it a couple of years ago to me. Built one that removes from my long fence in seconds. I always use it with the exception of larger panels. It took some getting use to the feel, but once I did there's no turning back. I spent an entire Sunday morning running rips till I got the touch. Well spent 4 hours.
Maybe someday someone will put an American design on the market with riving knife and crown gaurd at a reasonable price. If I was not semi-retired and 20 years younger, I would consider it as I have the financial backing. I think it would take the market by storm. Saw-Stop would have been better off to do that than what they did in my opinion. Not too many rushing out for Saw-Stops that I've noticed.
Evening Frank...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
Sarge, ever asked why us Europeans aren't keen on dado sets? I do use one from time to time as a trenching head on a crosscut saw, where the cutting action of the saw ensures that the workpiece is pressed agaist the fence and where I hold the workpice down to the table with cramps, but it's a long time since I used one on a table saw - I'm just tobbo fond of my "weenies". The thought of using one on an underpowered table saw just gives me the jitters.
As for riving knives, in the UK the HSE recommends that riving knives are wider than the thickness of the saw plate, but narrower than the kerf. That is certainly how may last three saws have advised in their handbooks (a Wadkin and two Altendorfs). The HSE instruction sheet #16 is here: http://www.hse.gov.uk/pubns/wis16.pdf
To quote you, "... you cannot defy physics by not removing a riving knife to do a non-through cut. It is impossible ..... ... on non-through cuts it has to be removed to make them. The choice is either remove it, or don't make the non-through cut!" Precisely! Surely if the making of a cut requires the removal of safety equipment (i.e. the riving knife) it is time to stop and ask yourself if there isn't another, safer, solution. I can think of several, e.g. power jigsaw, plunge-cut hand circular saw, etc.
Regards
Scrit
Scrit
"Ever asked why us Europeans aren't keen on dado sets"?
Nah, don't have to ask. All you have to do is experience the feel of a piece of stock going across a dado head when you have the depth set too deep. Common sense takes charge and at that point you know the answer from your own experience. I have an excellent stacked dado set that doesn't get used. When I did, I was having to set each pass 1/16" to feel comfortable. That takes forever to do a 1/2" dado. I just cut dadoes with a router and guide jig now. Takes about 3 or 4 minutes with a plunge and several passes.
That surprises me they recommend having the knife thicker than the plate (which makes sense) but slightly narrower than the kerf. Why??? I custom machined my own riving knives. I made one 3/32" exact for a thin-kerf blade and one 1/8" for the 1/8" blade. I find that if you make it narrower, it will have a tendency to bind. Especially if you have stock that is too wet and has a tendency to close back on the rear rising teeth.
This theory would have the riving knife actually separatating the stock slightly if the knife is narrower than the kerf. Common sense tells me that a knife the same width as the kerf would eliminate that task and allow the knife to insure the stock doesn't close back and pinch the rear rising teeth. I think I will stick with my theory till someone can explain why I should make it narrower than the kerf. I called my best friend who is a mechanical engineer this morning to see if I was missing something. We may be missing something, but he agreed.
Have to agree about better ways to do non-through cuts. I am a 30 year hobbyiest and have found a few. I don't have any dead-lines, so this is not an issue with me or will I allow it to be. Like I said, I might want to be a concert pianist when I grow up. I'll need those "pinkies". ha..ha...
Regards...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
Sarge,
My experience with table saws is limited. I didn't know that some riving knife implementations rise above the top of the blade. As you have described, on such a machine, the knife would have to be removed to do partial cuts.
On machines where the knife is at or below the top of the blade, the knife need not be removed. That's been my frame of reference.
The knife, of course must not bind in the kerf. We had a machine with several knives made for blades which we didn't have. The most useful knife was actually thicker than the kerf by a hair. It didn't seem to impede the board and the kerf never closed in the cut behind the blade.
The same laws of physics apply in my little shop as yours. However, I've been working on this tool that utilizes string theory and quantum principles. It seems, in theory, if we do the cuts in the 7th dimension on the opposite end of a temporary worm hole, the job emerges from the 9th dimension after traversing a black hole and actually is finished before we start. That's actually a big problem, as it's hard to do "heirloom" work. Instead of making things that my descendants will inherit, the objects wind up in my ancestors' homes. Working on that.
VL
Venicia
Ha.. ha... I'll leave the string and quantum thing to you as I have the agenda full of Xmas toys for the needy. :>)
You were on the right track with the riving knife and crown, just needed a little fine-tuning on the hows. Sam Maloof told me once that "nobody knows everything about this craft". I have been doing it for a long time and learn something new each day. That's where I'm counting on you to teach me some of those ghastly finishing techniques that I deplore. (I'd rather build) You guys are helping me immensely over there.
Have a good day...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
On most Euro saws the arbor shaft will not not allow dado blades. This eliminates that problem, but on non-through cuts it has to be removed to make them. The choice is either remove it, or don't make the non-through cut!
Sarge.. I hate to disagree with you, but on this one point I gotta point out the short sightedness of the legislation that's forced the short arbour on euro saws. For sure, it renders stack head cutters impossible to fit; a half baked attempt at making saws safer. The alternative forced on us is to either use a router to make the cut, or revert to multiple passes on the saw, moving the fence by less than the kerf width for every pass. Personally I fail to see how either alternative is any safer than a single pass on a properly set up table saw... Other than that, I'm right with you; canna do a non through cut with anythin but the bare blade. Mike Wallace
Stay safe....Have fun
Mike
I don't think the problem is so much with the stacked dado as with the depth people will attempt on it. Try making a pass set at over 1/4" with a 3/4" dado stack in oak, ash, hickory or hard maple with a U.S. contractor saw that usually has a under-powered 1 1/2 HP motor. These saws make up the majority of we WW's have here. To much stock, to little torque and the only true sharp cutting teeth on a stack are on the outside. Add the fact that the smaller blade slows the rpm that those fewer teeth are cutting. You have just brewed trouble.
I feel confident using 1/16" depths, but it takes forever. In lieu, I use a router jig and straight bit. I can make 3 or 4 quick passes in less than 2 minutes. This is my solution to my personal interpretation of where I need to go with this.
There are those that will tell you it's no danger at all and they do it all the time. So be it. You are free to cross-cut or rip with a dado stack if you wish. It puts me in no personal danger. It isn't illegal in the U.S.. If it's not illegal, we are free to do as we chose. I just don't personally chose to over-ride what I consider common sense with im-patience or dead-lines. If I go to the hospital, I intend to just be a visitor, not a patient. ha..ha...
Regards...
sarge..jt
Proud member of the : "I Rocked With ToolDoc Club" .... :>)
Edited 12/6/2003 10:32:51 PM ET by SARGE
I have a pretty anemic 2 hp saw. Cutting 1/4 at a time in walnut or cherry probably might slow it down a bit. I am still not clear on why it is dangerous.
I am not arguing that it isn't dangerous. I just don't understand why it is.
Visualize the bites those 2 tooth chippers are taking compared to a 50 tooth blade and add to that the idea of the wood moving away from the fence(no riving knife),jamming all those teeth in a 3/4wide by 1/2 deep kerf.It is an interesting way to go from hand to HANDburger!
Frank
I saw you had asked Sgain and was hoping Sgain would answer this. And he will when he gets through with that Heineken Rugby on the telly this week-end. ha.. ha..
Jako started and I will go into a little more detail. Keep in mind this is my theory. Theory is just that, theory. Not necessarily right or wrong. The theory of a 30 year hobbyiest by choice as opposed to a 30 year professional furniture-maker is sometimes not given the same validity. That's why I was hoping Sgain would answer your question.
First, I will state you could go two life-times and never get a kick-back with a dado. Or, you could on the first attempt. There are normal risk with any machinery. Here's why I think you go beyond normal risk with a dado.
My Freud Super Dado has two outside cutting blades. They have 20 teeth each. The inside chippers have 4 teeth. (Cheaper sets have two as jako mentioned). The outside teeth are responsible for the true cutting of the ouside defined lines of a say, 3/4" dado. The inside chippers responsiblity is to basically "knock the crap" out of the inside waste between those two defined lines and remove it.
With a 6" or 8" dado you reduce the size of the normal blade. That means those outside 20 toothers are making contact less than a standard 10" or 12" blade. Much less. That covers 1/4" (two 1/8" outside cutters). The inside chippers with their 2 or 4 teeth are responsible for the remaining 1/2" of the similtaneous 3/4" cut.
Soft-wood, maybe. Lets say we are using hard-wood. With successive small bites, m-a-y-b-e... Get in a hurry and set the depth deeper. We are asking the dado to cut a 3/4" swath cross-grain (most of the time) with two slicers and 4 or 5 punchers. No over-head gaurd, no splitter or riving knife and the chance that that hard-wood has grain direction changes we can't see on the surface.
When kick-back occurs, it happens so fast you have no clue what happened. Things twist, jump, jerk and launch. Anything can happen as it is totally un-predicatable. Hands and wrist can move with the stock that has been disrupted. You might get lucky, you might not. You have no gaurds what-so-ever except "keeping the lane clear". That is very important on a rip cut as the tendency is for the stock to go straight back. On cross-cut kick-back it can go anywhere. (It can on rip also) No gaurds at all are in place. You're on your own. Good Luck...
Like I said, you might go a life-time and it never happen. You could put "Sugar Ray Leonard" (light-weight) in the ring with "Lennox Lewis" and chances are he can out-manuever and avoid the heavy-weight. In his prime he dances and stays out of reach. One mistake...... Just one.. all the lucky charms won't avoid getting KO'ed or TKO'ed. End of story...
As I said, this is a personal choice. I feel more confident with using a plunge router and jig making succesive passes. I have got a razor sharp slicing edge making contact with my dado at all times and I don't bite off more than the router and bit will chew. I have a clean dado with one pass of a shoulder plane on the bottom of the cut.
By the time I can set up a dado stack and make the successive passes I believe are necessary. Clean the bottom and side-walls as a dado is usually rougher than I accept, I have it done with the router and am working on something else. My mind is at ease as I don't have the after-thoughts of just crossing a mine-field. ha..ha..
Keep in mind this is my theory. Others may vary. I'm just a hobbyiest. We each can make our choices in a democracy. Ain't it great!!
Have a good day, Frank...
sarge..jt
Proud member of the : "I Rocked With ToolDoc Club" .... :>)
Edited 12/7/2003 1:03:08 PM ET by SARGE
Frank,
Apologies for butting in, but here are some additional thoughts. The reason for a splitter/riving knife is to keep the timber from moving away from the fence and onto the back end of the spinning circular blade. You know all this.... The danger this prevents is that this part of the blade is spinning up and, at top, at the operator. It's just a matter of direction of force. You don't want it at you. The dado blade is always working such that its top teeth are in contact with the timber. That's how you get the depth of dado you have measured up from the table. That means the spinning blade will always have a fairly appreciable force directing the timber toward the operator. A fairly effective launching mechanism. (In my opinion, this is true even with four-bladed chipper sets; the greater danger is the wider the dado one attempts to cut.)
Imagine if you were trenching a fairly deep dado, removing a lot at a time. Then imagine letting go of your workpiece. It would be pushed at you at fairly high velocity. Conceptually, it's just a silly thing to try. If you are creeping up on your depth in small increments, the force will hopefully be withing the physical limits you can control. For a beginner who doesn't yet appreciate kickback, or who hasn't been reading the dark knife's rants and rails, or who has only seen Norm do it first pass to full depth, who knows. Just my two cents. By the way, you do good work.
Cheers,
Greg
Thanks Greg and Sarge. It sounds like something that can be done in tiny passes and probably with a featherboard. Better yet use a router.
Frank
It has always been a wonder to me that people use table saws to cut dadoes. I've seen woodworking TV shows where the "woodworker" passes his hand right over the blade. Just unbelievable.
I think what happens is that novice woodworkers buy stack dado cutters because they are in the catalogues. Then they try them and see that, yes they do make dados- easily and rapidly. If I was in a production shop I wouldn't cut a dozen dados 1/8th at a time with a router.
That is why folks use dado cutters
Just out of interest a couple of years ago I saw a carpenter on a subdivision gang cutting rafter birds mouths with the biggest dado I've ever seen. On a skilsaw,it cut 3 1/2 wide by at least 1 inch in one pass ! I have never seen anything like it again always wonder how long he survived
Jako
Maffell in Germany make machines such as that - scares the heck out of me thinking about them
Scrit
I use a dado set all the time to cut dados, grooves and rabbets on the table saw. Yes, my right hand passes right over the blade to keep the panel firmly pressed down. But, I use my jointer push pads which gives me a great no-slip grip...works nice.
There are several different designs of riving knife. I have had two different European saws. The first had a riving knife that did not project above the height of the saw blade and was no impediment to cutting rebates, grooves, etc. The crown guard was positioned separately on an arm. My second machine is fitted with a riving knife which does project above the saw blade. Its crown guard is then attached to the back edge of the riving knife. Both riving knives move up and down and on an angle with the saw. The essential feature about riving knives is that there is very little distance between the back side of the blade and the knife, and the knife is the same thickness as the saw kerf (or only slightly less).
I suggest that the reference given in an earlier post in this thread (http://www.safetyline.wa.gov.au/pagebin/pg000377.htm)
be compulsory reading for everyone who uses woodworking machines (of any description). It's an excellent site and while it relates to a commercial environment the principles are the same for everyone. In truth if you can't do the job with appropriate guards (either those provided with the machine or else fabricated in your own shop) just maybe it's time to think about getting the desired result by a different method. As attested to by others in this thread, losing the fingers or worse is not a lot of fun and the flow-on consequences to the woodworker who makes the judgement error can be dire indeed.
Ted
No, your not crazy <G>, such a device really does exist. It's called a SawStop .
Scrit
Thanks!
This sounds like the best solution of all. I hope the others clicked on the site. I will seriously consider this in 2004! Anybody in the market for a 5 yr. old Jet contractors saw?
My concern with the SawStop device, scrit, is that it only addresses the issue of sticking your 'weenie' up against the rotating blade--- it senses soft flesh (or your 'hot-dog') and stops instantly, or so they say. So, however hard your 'weenie' is at that particular moment, and what it's doing up there in the first place is nobodies business, but----- whatever, it's taken care of, ha, ha, ha.
But it doesn't seem to address the issue of kickback which is most often caused by wood pinching on the rear upcutting teeth as they emerge from the table. Wood pinching tight at that point ain't a weenie, so how does the SawStop device know that a kick-back is about to occur and prevent it?
It's my experience that woodworkers that get into trouble on a bench or table saw tend to experience kick-back situations more often than weenie-whacking situations. I just watched a student today get very close to dealing with kickback as the wood rose up the blade at the back, but none of his weenies were anywhere near the blade-- No call for the SawStop technology there that I could see, but the danger was real. Slainte. Website
Kick back would be a different issue altogether. For that I would recommend tuning the table saw; making sure the arbor and mount are parallel to the slots and the rip fence parallel to the blade. That's not a one time adjustment either - should be checked periodically. I also use a zero clearance insert with a split. A lot of rip cuts can also be made on the band saw and that would eliminate the problem of kick back altogether.
I don't think there's any one thing that's totally fail safe. Woodworking is inherently dangerous but sharing ideas and experience on sites like this can go a long way in helping.
It is indeed a different issue Ray. I agree that the SawStop device might contribute to reduced wheenie whacking, but as I said before, how could it reduce the incidence of probably the most common saw table accident, i.e., kickback--- if it might contribute at all?
The tuning of a table or bench saw is a regular weekly, or even daily routine maintenance procedure in a busy workshop which every working woodworker understands from their earliest days, and is undertaken as required. It always has been a fundamental part of the job along with maintaining and tuning all the other machinery in a busy workshop. Slainte.Website
I don't know if anyone responded but I think I saw the "SawStop" Saws have riving knives on them.
I don't think the SawStop makers intend for it to replace good working habits but to keep us all from having to replace our fingers if something happens.
I think you might be right on the riving knife addition, Derek. Your post jogged a memory of one being a part of the design. If that's the case, then the SawStop technology might have gone a long way towards addressing two safety issues. Slainte.Website
1)Well, I remembered the quote at least, albeit out of context.
2)Back to riving knives:
Ok, so there is no way to rig a riving knife to the trunnions/ nether regions of the saw so that it will rise and fall with the blade. However, 90% of what I cut is 3/4. So why can't I go to a machinist and have him fabricate a knife that allows a 1" above the table cut? Would this be worth the effort?
3)By the way. It seems kind of dicy to cross cut against the shorter fence.
Edited 12/8/2003 11:03:41 PM ET by BISCARDI
Frank
I'm sure Sgain will respond to question #3, but I will add this. The short fence is for ripping. The last person I saw that used a fence for cross-cutting had to replace the fence. When the stock kicked after it twisted on the surface of the fence somehow (who knows as slow motion wasn't activated) it ripped the fence completely off the saw and bent the internal components.
He was fortunate just to suffer a broken wrist, but it could have been worse. He was lucky. So, even though the dado stack is a personal choice I will ask you to think twice before using a RIP fence to cross-cut. I'm not telling you what to do, I just like you well enough to hate to see you get injured.
The person I saw do it will Never, Never again use a rip fence to cross-cut. Even though that was years ago, I know that for a fact. How? That person was ME !!
Regards...
sarge..jt
P.S. I do use the fence to do larger panels. I made my short fence to fit over the long fence. It removes in seconds with the turn of two T-hanldle that attach to the top track of the fence. Remove the short fence on large panels. This is a safe approach as all the friction suface of the panel makes the cut similar to a rip cut..
Proud member of the : "I Rocked With ToolDoc Club" .... :>)
Edited 12/9/2003 1:09:41 AM ET by SARGE
As Sarge correctly states, the short fence is used solely for ripping. If you want to use it for crosscutting it is normal to pull it back behind the leading teeth of the blade (I was taught that it should be the same distance back from the blade that the piece is wide - or use a spacer block attached to the face of the fence) and use it as a length stop. If you don't do this there is a possibility that the material will bind between the blade and the fence whilst making the cut. The mitre guide, or better if you have one the sliding table, is then used to make the cut. If making lots of short pieces you should also consider making up a taper guide which goes just behind the blade/riving knife - this will push small cut pieces away from the line of the blade - especially important on sliding table saws where the slider can pick-up a piece and pull it back into contact with the rising teeth on the blade. The ricochets are..... interesting! <G>
Long fences running front to back on a machine are probably only safe where you are cutting materials which are unlikely to bind or twist apart under cutting as a result of tensions being released, e.g. panel materials such as MDF, chipboard (melamine), plywood, etc.
Again, Frank, it's been some time between my visits here, and there's been quite a bit of discussion that should go some way to answering the questions you posed.
"So why can't I go to a machinist and have him fabricate a knife that allows a 1" above the table cut?"
You could, but US style saws are configured somewhat differently to European type saws. I've seen quite a few tips and articles describing making your own 'splitter' that fits into the throat plate-- everything from gluing in a milled piece of wood into a kerf in the plate cut in line directly behind the line of the saw-blade, to jamming a drill bit into a hole bored into the table saw insert (throat plate) in line with the saw blade plate-- the latter I feel is a bit iffy in concept, but there ya go!
Responding to your point 3, I'd find cross-cutting using a US style long fence more disconcerting than using a short fence for the job. There's lots of opportunity for wood to get jammed between the fence and the blade resulting in kick-back, and a long fence adds to the chances of it happening. I only use the short fence as a length stop for cross cutting, as described by scrit earlier.
Anyway,there have been plenty of answers and good discussion on cross cutting operations to your questions, so I'll not add further confusion to it. Slainte.Website
Sgian
My response was merely in answer to a question posted. I agree that the SawStop will not save you from a kickback. Personally, as I work in the UK, my approach is to use the short rip fence and a riving knife for ripping stock, with push sticks/push blocks so that my hands are never nearer to the blade than 12in (and frequently not even that near). My saw (an Altendorf) has a suspended crown guard as standard and the rip fence has a sliding fence plate to allow use as both short and long fence depending on application. It is set up with a small amount of freeboard (toe out, i.e. NOT parallel to the blade) to reduce the possibility of binding, this is per the manufacturer's recommendations. I rotate my blades through the saw doctor regularly to ensure that I almost never have a blunt blade, and with 7-1/2HP on tap the saw has enough power to cope with most things. I rarely experience kickbacks. But then I do tend to use the bandsaw for deep ripping as it is inherently safer than the circular saw.
Scrit
scrit, I knew why you posted your response. I too work in the UK---- again--- after nearly a decade living and working in the US. I'm more than familiar with both European style and American style woodworking, including table saws.
I'm a through and through Wadkin type myself, and even insisted on owning a 9 HP Wadkin sliding table monster for my own business whilst living in the US. Most Americans, certainly not at this level anyway, have ever seen anything remotely like it in action and have no idea how much destructive power such a tool has.
As I can tell you know, when you're dealing with that kind of horse power the idea of removing guards doesn't even enter your head, unless you're extremely ignorant and/or stupid, but most visitors and contributors to this forum are working with small saws-- 5 hp and less.
However, your post seemed like a good opportunity to open up the discussion into a wider area-- one that's been covered here several times before, but one worth airing again for the delectation of newer visitors/woodworkers and contributors, ha, ha. Slainte.
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Edited 12/5/2003 5:18:16 PM ET by Sgian Dubh
I think it is always important to listen to that inner voice you sometimes hear that says, "this is nutso, I shouldn't do it."
Occasionally the inner voice gets turned off by fatigue or haste or (worse of all) both; time to get out of the shop.
Also, if you can't figure out how to do it safely with power tools, ask yourself if there is a hand tool that would be safer.
Dave,
Sorry to hear of the accident. I use a Delta Uniguard on my Unisaw. It's not perfect, but works way better than the standard guard it came with. It's a split design so you can swing up one side of the guard if you are intent on cutting narrow strips like another post complained about. I built a little jig that allows you to cut precise, repeatable narrow strips off the outside of the board, which I think is much safer. I think I saw the basic design in Wood magazine. I don't know if it will immediately bolt to a PM66, but it looks pretty easy to modify.
Mike
Dave,
Please tell your brother in law how very sorry I am that he had this accident. I'm pulling for him; and I'm hopeful that he will recover enough use of his hand to enable him to get back into the shop, or to do whatever else he wants.
Alan
Edited 12/3/2003 8:47:32 PM ET by Alan
Dave,
Sorry to hear about your brother-in-law. I had a friend do something similar so I looked around and bought a Brett Guard for my Powermatic 66. I thought the parallelogram type might tend to ride up over my fingers if my hand pushed into the blade. The Brett Guard is fixed and seems fairly solid. I also have the optional dust collector hookup. It is one of the more expensive ones out there, but I wanted the sturdiest one I could find.
Good Luck,
Max2
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