Hi Fellow Knotheads,
There are some good postings here and if we can prevent one accident it is well worth while.
I like the idea of putting pilot lights on power tool switches. Anyone out there know how to do this? If so, please share.
I had a near accident with my delta unisaw that I would like to share. First I had put a kicker plate over the on-off switch so I could shut off the saw with my knee. I had a cut out in the plate to stick my finger through to cut the saw on. I was helping a friend cut out a picture frame and had cut the 2 pieces, turned the saw off and was working on the saw table to check the fit. I was standing at the side of the table and my friend in front. Suddenly, the saw came on, shot my wood folding rule against the door and left us both with stained shorts and a surprised look on our faces. No injuries. What had happened was my friend had a set of car keys in his pocket and when he leaned against the front of the saw the keys in his pocket pushed through the recess on the switch and turned the saw on. I immediately fixed this by putting a pipe clamp over the on switch large enough to put my finger under it to turn on the switch. I plan to send this to FW with a photo and hope they will print it. A freak incident but could have resulted in a serious injury. If it happens once, it can happen again. Bob W
Replies
Bob,
Great story - good thing it all came out in the wash...(sorry, poor impulse control...)
My sense, given my own experience and that of others, is that the simplest solutions are often the best.
I've gotten into the habit, ever since my little thumb abruption (sp?) incident, of removing the safety every time I shut my machine down. It may take a little while before it's habit, but I don't even think about it anymore - I just do it. While I like a knee-height kickstop, it still doesn't address the issue of preventing an accidental restart, such as in your example, and the whole thing with the plate and the pipe clamp seems like an overly complex solution. It also robs you of a pipe clamp, and only addresses the accidental restart issue for that one machine. I have safeties on my jointer, planer, drill press, and belt/disc sander as well.
Anyway, FWIW, IMHO getting into the habit of pulling the safety after every single power-down is the best way to keep yourself safe, short of disconnecting the power source each time you shut down the machine. I'd be interested in your thoughts, and hope the advice is helpful whatever you choose to do.
Regards, and thanks for starting this thread,
Mitch
"I'm always humbled by how much I DON'T know..."
Edited 3/24/2005 12:38 pm ET by mvac
Hi Mitch Thanks for your contribution and comment. I am not sure what you mean by a safetie. What exactly are you doing? I'm always looking for an easier and better way short of unplugging my equipment. BobW
Some tools (like my Delta drill press) have a center "Key" on the switch. Pull that key out (It's a plastic insert) and you can't start the tool.Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
Hi Fellow Knotheads. So many of you have responded with alot of excellent suggestions and I'm certain there are some accidents waiting to happen that will not happen because of these comments. It does take a bit of time to type them but it's easier if you have all 10 digits,Right?
I have followed the guard and splitter comments with much interest. I have the overhead Delta which I will also admit is not on at all times. I use a splitter that can be pushed below the throat plate and has an antikickpawl on it. Not sure who makes it. I will rededicate myself to the guard.
A comment was made about the chopsaw and the danger of entrapment of small pieces. I have a solution for this. Make a right angle fence and place it on top of the factory fence and table,and clamp it on. Make a cut but stop short of cutting your auxillary fence in two. You now have a zero clearance set up for safely cutting small parts. Get a much cleaner cut also.
Thanks again to all of you for sharing. BobW
Thanks Mark, I have only one tool with that. Bob
Maybe it's time to re-think the whole concept of powered woodworking tools -- table saws, jointers, shapers, etc. It's only in woodworking that we shove material into powered cutting tools with our bare hands.
The same kind of cutting happens in metal working. Horizontal and vertical milling machines do pretty much the same tasks in metal. On those machines, you clamp the work piece securely to a table, and turn a handle that moves the table relative to the cutter. Or you have a computer program that does it all for you. Machinists don't risk their hands like woodworkers do.
-- J.S.
However, metal is a more predictable raw material...Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
> However, metal is a more predictable raw material...
True, and all the more reason to have the unpredictable material fed mechanically rather than by hand.
-- J.S.
I've seen plenty of machinist with mashed up or cut off fingers, it is about safety and attention to work. Not a slam, but the machine (table saw, drill, lathe, mill, computer, etc.) will only do what you allow it to do. Set up safety, be aware of your surroundings, double check and things should go well...but accidents do happen - we need to only do the things we should do to minimize them and the results from them. I am a school teacher and have taught woodworking, CAD, machine tool, as well as other industrial/career tech. classes.
Donkey
Yes, machinists do get hurt, too. And any machine can be used safely if you take a sufficient amount of care.
But the point still stands that the amount of care required to safely shove wood toward the blade of a Unisaw is a whole bunch more than what it takes to safely turn a crank on the end of the Benchmaster table.
-- J.S.
Dear Bob,
What you describe is properly addressed by industry as follows:
The START button is FULL SHROUDED, the STOP BUTTON is not. A Green light indicates OFF, and a Red light indicates running.
In the table saw here, have it setup with a GREEN colored fully shrouded START BUTTON which controls the contactor. It is, additionally in series with a key operated switch, the key being removable to block the START control circuit.
The STOP button is and industrial size MUSHROOM RED button, in an industrial enclosure which lies on the floor and is pushed by the foot to turn the saw off. The advantage of this type of STOP is that the STOP button can be easily moved to the usual operator locations for various kinds of cuts. Also, it is much more reliable than a mechanical means of activation.
The lights are not needed and are not put on a typical table saw aside from cost and space in the control box.
However, if you are making your own, controls, you could do it if you wanted to. In fact, there are illuminated industrial control buttons.
But those items are rather expensive for typical woodworking equipment, and other types of switches may not be proper for the application.
Also, it is possible that your saw might not be equipped with a true industrial grade magnetic contactor, but in fact with a manual contactor of low grade (as seen in much equipment nowdays). Those are not quite safe for such uses, would say.
Please check the contactor or switch, and electric wiring of your saw for adequacy and functioning to prevent a reoccurrence.
If your TS is 120V, you could simply plug the cord onto an outlet box that has a pilot light and its own ON/OFF switch, and use it as a disconnect for when the equipment is not in use, or wire an outlet/lamp combination into a typical house-hold wiring box.
Best of all.
-mbl-
Hi MBL, thank you for your reply. My saw is a 12 year old Delta unisaw that I bought new. It does have a magnetic switch and is set up somewhat like you describe. However the on switch(green) is only partially shrouded and the depth still allowed the keys in my friend's pocket to turn the switch on. The pipe clamp ( 1" ) solved the problem and all I have to do is stick my finger under the clamp and turn it on. Bob W
Outfeed tables, I've learned, are another great safety device. I no longer have to (or feel the need to) reach for a piece of stock falling behind the saw.
Push the stock through the blade.
Turn off the saw.
Walk around and grab the wood.
Turns out, my outfeed table also hides my motor and belt (since they hang out the back of my saw) - anoter bit of protection...
Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
Mark,
I'm looking to add an outfeed table to my table saw. Do you have pictures or suggestions of how you made yours? How did you mount it to the saw table, and did you cut miter slots through it to match the ones on the table?I recently saw an item at Woodpeckers that seems like it would help in creating an outfeed table: http://www.woodpeck.com/tableexthinge.html
Mine is a stand alone table. It's about 3/4" lower than the table saw so I don't need to cut miter slots.Here is a picture. I use mine as an assembly table as well - that explains the powerstrip and the shelf with the power handtools.2x6 legs, 2.4 frame - plenty of diagonal bracing - plywood top (currently unfinished) braced across and lengthwise... Screwed together with 3" drywall screws - pretty solid.Markhttp://www.pbase.com/durrenm/image/39076840.jpg
Measure it with a micrometer, mark it with chalk, cut it with an ax.
Hi Matthew, right- an out feed table is a fine addition to the saw and makes cutting much safer. I have two banks of storage drawers and then a maple block table top the same height as the saw. I cut slots in it to allow the miter gauge to travel over and put a vice on the far end. I now have another bench as well as a out feed table. Before that I had a folding outfeed table. Worked fine but I felt the space below was wasted. BobW
I think I read about a switch on this forum not too long ago that requires you to push and twist to start a machine. Hard to accidentally perform two functions at once.
Anyone remember that one?
Hi Wsplinter, I have never seen that switch but it is not human nature for people to change out switches just for "safety", especially if they have never had an accident but modify? You bet. There is a small section of the male brain that is labeled" FIX or MODIFY" it is close to the "remote control center" also. My bet is more would modify what they have. To make the knee shut off I mounted a piece of wood above the switch then used a plexiglas plate hinged to it with a cut out over the off switch. The 1 to 11/4" clamp them was fastened to the plate. Easy to cut on but never directly from the front. It also makes me think one more thought about safety when I turn on the saw. BobW
Edited 3/26/2005 2:35 pm ET by Bob
> it is close to the "remote control center" also....
Now that gives me an idea. How about a remote control -- the generic programmable kind -- and an IR sensor to start the saw? Maybe even enter a PIN number to start, any key to stop. And best of all, attach the remote to the push stick. ;-)
-- J.S.
Hi John,
you are getting closer all the time.
New point. I was in the shop the other day and my grandson, age 9, walked over to the chop saw and squezzed the handle. I heard the switch click but fortunately, the saw was unplugged. It could have been plugged in though.
Point-- Always lock down the saw and or pull the plug when not in use. You never know when someone, big or small, will squeeze the switch on. BobW
Edited 3/29/2005 7:55 pm ET by Bob
Dear woodend splinter,Have not heard of that one.However, would like to add that it would not be in the spirit of SAFETY.In industry, it is not uncommon a policy, to discourage false starts.Keep in mind that START is seldom an action that can not be delayed by a half a second or so, in the interest of safety.Many industry situations even call for interlocks before a START operation takes place, some of quite a complexity.However, for a table saw, twist and push switch would seem like an inconvenience.Note also that a 'twist to start switch' is not an uncommon switch. We have those in our cars in the form of a key to start the engine.-mbl-
Am familiar with interlocks. Am familiar with complex interlocks.
Some of our switches had a "bump" mode which allowed you to move or rotate a piece of equipment a small distance. Had to push and hold for 8 seconds to get it to run.
Even most circular saws have a button that has to be pushed before the saw will start. Can't see how preventing an unwanted action isn't in the spirit of safety.
BTW, way way back, cars had a pushbutton for a start switch. LOL
Edited 3/29/2005 8:36 pm ET by wooden splinter
Dear wooden splinter,Where it says "However, would like to add that it would not be in the spirit of SAFETY" was not correct.should say "it WOULD BE in the spirit of SAFETY".Apologies for the mis-type.Thanks for the clarification.(And yes, do now remember industrial push-buttons that worked in the turn-to-push mode, and had cars with starter push-buttons just as you say).Have a good day.-mbl-
I sure enjoy these safety topics. Glad they're taking off. The first one I read kinda died in the water.
That was probably the one I started. Was it something I "said"... :-)Doing a clean-up on my table saw and found that the upper pully (the one on the blade arbor) was just about to fall off! Those damn set screws don't want to stay set.
Not sure it was much of a safety issue however.Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
>> Not sure it was much of a safety issue however.Only if the clatter when it falls off gives you a heart attack.You say plural "setscrews". Are there two on this pulley or are you talking about setscrews in general? If there is only one, adding another at a 90 degree angle will help quite a bit. Are there flats milled on the shaft for the setscrews to land on? That also helps quite a bit. Loctite in the setscrew holes makes a big difference. Loctite between the shaft and the pulley will give you a damn near bulletproof installation, but you might start hating yourself if you ever needed to take the pulley off again.
Only one set screw on the blade arbor. The pulley is keyed and the set screw presses the key in.I put a "cheater bar" on the allen wrench (to add some torque) this time. With any luck it will hold.The pulley on the motor does not move.Thanks,
Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
Only one set screw on the blade arbor. The pulley is keyed and the set screw presses the key in.
************Mark, if the single set screw is deep-set within the threaded hole, you may try adding another Allen screw on top of it as a jam nut.Grind the end of it flat first, though, so it doesn't bugger the recessed hex head on the first one.Leon Jester
Might be worth your while to check the keyways on both the shaft and the pulley as well as the key. If its been vibrating for a while, the keyway could be enlarged (probably on the pulley). If that is the case, for the price of it, replace the pulley.
Just out of curiosity, does the table saw seem to have more vibration?
Since I tightened down the pully most of the vibration is gone. The keyweigh is the "half moon" shaped.Also per your previous comment, I don't know if the set screw hole is deep enough for two but I think that your suggestion is great.Thanks,
MarkThe saw has some unavoidable vibration. The weight of the moter keeps the tension on the belt - If I lock the motor in place, then I can't raise the blade past a certain height because everthing gets so tight the motor cant turn... (poor design)
Measure it with a micrometer, mark it with chalk, cut it with an ax.
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