Hope someone can help me with my table saw problem. All of the sudden it is binding when I try to rip anything. It seems as if the blade is racked when I look down the line of the saw it seem the blade is off so when I cut the blade is cutting through the top of the wood and cutting again as it circles up the back(if that makes any sense). The saw is 2 hp and usally burns right through most stuff. But now I have to crawl things through. Blade is new, just racked. I don’t know if the motor got knocked off line or what. I am going to try to fix it tomorrow. Just looking for some tip or suggestions as to what the problem might be. Thanks for any input. Also the blade seems to be sit flush on the arbor. Thanks again.
Joe (with a slow running saw)
Replies
Hey, Joe, don't force it! Fix the problem before you rip any more wood.
OK, now I can breathe. You need to check whether the blade is parallel to the miter slot. As long as you're at it, you might as well confirm that the fence is parallel too, but the culprit is probably the blade being out of alignment. Time for a complete tune-up, then try again. Hope the blade didn't get bent or warped or anything.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
As Forestgirl said.......................STOP CUTTING.You have the perfect situation for kick back,and you don't want to experience that.Align your blade to miter slot and your fence as well.Don't use your present blade just in case it is bent,it will just give you a false reading.If you don't have another blade just take a piece of MDF,drill a 5/8" arbor hole in it and use that.Don't forget to check your arbour for runout.
Once you get all the alignment done replace the suspect blade and check it for runout.If you've been careful on all your other adjustments and you are still getting runout on the blade,place it in the round file and get a new one.
Brent
One more question, it turns out that that housing holding the motor got racked some how. And i fixed that problem this morning. Thank for the help. Now the blade and fence are perfectly paralell to the miter slot. But when I push stock through ( which now cuts beautifully) although the stock is cut well, meaning even. It doesn't ride along the fence the whole time. If I set to cut 6 inches for example the material starts thight against the fence but as it is push through it wanders farther and farther from the fence. This would make it seem that the fence is not paralell to the slot, but it is. And the strange thing is the cut comes out good, but the stock its touching the fence the whole way. Strange!?!?!?!?! If anyone can offer some advice I would appreciate it. Thank
Joe (with a well running but strange saw)
That is how a fence should be set IMO. Itshould have a slight toe out at the rear maybe .003 or so. The blade only cuts at the front. The toe out condition will help eliminate kick back and wont effect the cut other than help eliminating teeth marks on the piece also.
So your in good shape now. Buck Construction View Image
Artistry in Carpentry
Pgh, PA
I'm going to jump in and totally disagree with setting the fence 1/32" out at the back. Holy smokes. Personally, I set my fence perfectly parallel to the blade, and have no problems whatsoever. Plus, when I need to swap the fence to the other side, I can. If you feel compelled to toe the fence out, then keep it to the .003 suggested in the other post.
The fact that your stock is wandering noticeably away from the fence is not good. There's still something going on there. It's possible that somehow your technique is causing it (given the experience you had yesterday, a certain level of anxiety isn't surprising, LOL.)
To eliminate any technique problem, place a featherboard just in front (operator's end) of the blade to hold the stock against the fence as you rip, then push the stock straight through, against the table.
If that doesn't work, try it again with a different blade. Let us know how it goes.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Ther's really nothing wrong with having a fence toe-out as much as 1/32". In fact it guarantees a certain measure of safety against kickback.It's when the fence is toed-inward, that real danger can happen.
As for woodrat, measure your fence with a straightedge.The fence may simply not be straight.While you're at it, be sure your drive pulley and idler pulley(with belts) are also in a straight line. If not this will cause excess vibration and poor performance.
Ther's really nothing wrong with having a fence toe-out as much as 1/32". In fact it guarantees a certain measure of safety against kickback.It's when the fence is toed-inward, that real danger can happen.
I agree that toe-in is worse than toe-out, but if you are trying to do accurate, safe work, the fence has to be as close to parallel to the blade as possible.
I grew up with that "toe-out" idea, and 35 years of commercial experience has amply demonstrated to me that anything but dead parallel is a mistake. Having your fence toed out will pull your stock away from the fence, since the stock will follow the blade instead of the fence, and you will end up with tapered stock.
Try it with a piece about 6 feet long if you don't believe me. You can force the wood against the fence, but this makes the saw blade cut sideways, which is not a good idea.
Michael R
"You have to look for possibilities where there are none" Krenov
Edited 4/19/2005 1:34 pm ET by Woodwiz
Thank you Woodwiz! (I know, you didn't post that for me, but stil.....) I'm completely convinced that the whole toe-out idea is an archaic, useless habit that should be given an honorable funeral and disposed of. forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Just backing you up, actually. Sometimes experience carries some weight. It's pretty hard to butcher wood 60 hours a week for 35 years without learning something.
Here's a picture of why you don't want toe-out. It's exaggerated, but shows how the wood follows the line of cut established by the blade.
(Thanks for giving me an incentive to learn how to use "Paint". Now all I have to do is learn how to paste a sketch into a post. See? Still learning!)
Michael R
"You have to look for possibilities where there are none" Krenov
Edited 4/19/2005 3:17 pm ET by Woodwiz
"Just backing you up, actually." Yeah, I know, and thanks.
Glad you're having success with Paint. I think, though, that you and I have our differences about the whole "offset creates tapered cut" thing. (Didn't we go 'round and 'round with that awhile back?). I still think if you have a featherboard in front (operator's side) of the blade holding the stock to the near/front end of the fence, you will not get a tapered cut.
I s'pose some day I should offset my fence and test that theory. Your drawing assumes that the board moves away from the fence at the entry of the cut. If you stabilize the stock at the entry of the blade, as should be done, and your pushing force is parallel with the blade, the cut will be straight.
I suspect, too, that there's a physical difference between having a moving blade angled away from the fence, and a stationary fence toed out away from the blade. Purely instinctive, that one.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Edited 4/19/2005 5:21 pm ET by forestgirl
I still think if you have a featherboard in front (operator's side) of the blade holding the stock to the near/front end of the fence, you will not get a tapered cut.
My sketch reflects what actually happens, just exaggerated. The board can't help but to follow the cut line, rather than the fence. It cannot follow the fence without cutting sideways, as anyone who has ever tried to turn a circular saw has found out. Once you have the cut line started, they are real hard to turn because the wood keeps the blade on line, although very minor corrections are doable.
If you have just a tiny bit of toe-out and use a strong featherboard, what you are actually doing is forcing the blade to cut sideways on the offcut side, which it will do, to an extent, due to the overhang or set and the configuration of the teeth. Unfortunately, that sideways cutting occurs largely at the tail end of the cut, where the saw teeth are rising, which is one of the ways that kickbacks happen. (Take a look at your offcuts.) If you have more than just a few thousandths discrepancy, the board will have to move away from the fence because the saw blade can only cut sideways so much.
I haven't used a featherboard on a table saw in so long I can't remember (on the other hand, I sometimes have a hard time remembering yesterday.) The only time I have a problem getting a straight, parallel rip is when I've got a crooked edge to start with, or when drying defects cause problems.
You don't have to agree, of course, but if you are going to disagree, it might be interesting if you would try to refute my points. Of course, not being able to refute doesn't prove my case, but a successful refutation does disprove it and send me back to the "thinking board."
(Didn't we go 'round and 'round with that awhile back?).
I don't remember whether we went around over this or not. In any case, that's part of what the board is for -- comparing viewpoints and sharing information. And if it will result in a few people being more successful in their work and avoiding accidents, then it is effort well spent. And if I learn something, even better.
Your drawing assumes that the board moves away from the fence at the entry of the cut.
Either that, or it proves it. I try not to prove my conclusions by using my assumptions as proof. I think that's called begging the question.
Michael R
"You have to look for possibilities where there are none" Krenov
What's a Featherboard for? -- to hold the board to the fence at saw entry.The only reason to toe-out the fence is to be sure it is not toed in. Now that could be real trouble. If in doubt, Toe out, but just a hair.Bones (New meat here)
From what I remember from high school trigonometry, fence toe-out makes no sense. Certain not anything as large as 1/32". Maybe if you're trying to set a specific value, you'd list it as "0.00x inches, +/- 0.00x inches", so that it is never negative, but one should try to get as close to zero as one can.
With a deliberate toe-out, the blade and fence are non-parallel. If the piece is going through with the cut parallel to the blade (which is what you want, in order to both get a clean cut, and to avoid kick-back), then the piece will contact the fence at only one point- the nearest part of the fence to the operator. This being the case, it's near impossible to guide the piece into the blade, so that the first few inches of the cut will be clean.
I say set the fence parallel to the blade. If you don't want the fence contacting the piece on the outfeed side, then install an auxiliary fence that stops before reaching the outfeed side of the blade. This way, wood that may bow away from the blade when cut has some room to go before hitting the fence.
> I s'pose some day I should offset my fence and test that theory.
Or just mock it up with a straight piece and a shim clamped to the fence. That makes it easier to put it back right.
I agree with the as close to dead parallel as you can get it theory. I used a machine shop dial indicator that reads in 0.0001"'s. First I found the flattest place on the blade, marked it with a sharpie, and rotated the blade to always read from the indicator on the miter gauge to the marked spot on the blade. I got it within 0.0005". With a fresh blade, the saw makes surfaces that look like they came from a jointer.
-- J.S.
Following up on my response above, here is a sketch of the scenario I described. For those joining the conversation late, I do not believe you need to toe out your fence. This illustration is simply to show that a toed-out fence does not produce a tapered cut.
View Imageforestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I missed your artwork while I was writing my post.
What you ave illustrated is that if you start out with the board parallel to the cut line, then it will follow the cut line. But if the blade is not parallel to the fence,the cut line won't be parallel to the fence, and the board can't start out parallel to the fence, so why have a fence at all?
If you start out with the board parallel to the fence, and the cut line isn't parallel to the fence, then the board will still tend to follow the cut line, which can't be parallel to the edge of the board, so you get a tapered cut.
Am I making any progress? I can draw a more exaggerated example, if it would help.
How did you get your pics into your post? (I promise I won't tell anybody)
Howie, Good info. Thanks for the post.Michael R
"You have to look for possibilities where there are none" Krenov
"if you start out with the board parallel to the cut line, then it will follow the cut line." Why would you start out with the board anywhere but parallel with the cut line?
We're talking about a simple ripping operation here. I maintain that the drawing you provided is not representative of a toed-out fence, but rather representative of a blade that's cock-eyed, and an imaginary woodworker feeding in the direction of the blade. The mechanics of that are not what we're talking about here.
Take a deep breath, forget about your drawing for 10 minutes, and just sit and ponder the first drawing I provided. Is it not a correct representation of how we rip wood? Even given the fact that I don't practice the toeing-out set-up practice, there really is no difference between a parallel fence and a toed-out fence when you rip according to standard practice (again, as represented in the drawing). forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
"if you start out with the board parallel to the cut line, then it will follow the cut line." Why would you start out with the board anywhere but parallel with the cut line?
ponder the first drawing I provided. Is it not a correct representation of how we rip wood
No, it is definitely not, and that may be the key difference here. When you rip lumber, you start out with the wood tight to the infeed part of the fence, hence necessarily parallel to it. When you feed the wood, you keep the wood tight against the fence, especially at the point even with the front of the saw blade, and again, necessarily moving parallel to the fence. In your drawings, the wood is well away from the fence at the point where it needs to be tightest to it to maintain a consistent cut width.
Now if the blade and the fence are not parallel to each other, then the cut line can't be parallel to the fence because the cut line always wants to follow the line of the blade.
I maintain that the drawing you provided is not representative of a toed-out fence, but rather representative of a blade that's cock-eyed, and an imaginary woodworker feeding in the direction of the blade.
It's not a matter of which one is cockeyed. It only matters that they are not parallel with each other. Your own drawings clearly show the wood is not moving parallel to the fence, but rather at an angle to it. This will produce a relatively straight cut, because you are starting out with the cut line more or less parallel to the edge of the board. I used to cut plywood on a table saw without a fence a lot. But you lose precision that way. The purpose of keeping the wood tight to the fence is to control the width of the piece, and when the wood pulls away from the fence you lose that control, and your dimensions start to wander.
If you changed your drawing to show a starting position with the front corner of the wood tight to the fence at the point where the blade starts to cut as well as the rest of the way to the front of the fence, you would see that the cut line of the blade would go on a slant through the lumber.
WE all seem to agree that when you have a rip fence toed in, you get a bind. If you have a very slight toe-in, the blade will cut sideways enough to compensate for the toe-in, but if you have more than just a very few thousandths, the wood will bind. This is because the blade and the line of cut are not parallel to the fence. The blade wants to cut outwards in relation to the fence, and since it can't, the wood tries to move sideways into the fence. The fence, if it is a good one, isn't going to move either, so the wood binds up pretty quickly, with predictable results.
With the fence (or blade) toed out, is is the exact same principle, only in reverse. The wood wants to pull away from the fence instead of riding into it, and there is nothing to restrain it other than a featherboard or the saw operator. If there are more than a very few thousandths of toe-out, the wood can't be kept from moving away from the fence, just like it can't be kept from binding in the reverse case..
Your drawings clearly show that the wood can't move parallel to the fence, and at the same time parallel to a saw blade that is not parallel to the fence.
This might be a key question: If a piece of wood binds when the fence and blade are toed in relative to each other, what keep the exact same principle from applying to make the wood move away from the fence when they are toed out from each other?
I know I'm right, because I have physically demonstrated this any number of times. And I know you are an intelligent and avid woodworker. The interesting challenge is to show you what I know to be demonstrable truth without actually showing you on a saw. Maybe I'll try one more drawing if I can do it without repeating the same approach. I'll have to think a bit about it.
It might be worthy of note that "back in the day" when things weren't nearly as precise (Jet-lock fence, anyone") we used to determine whether the fence was parallel to the blade by looknig for an equal number of "upcut" blade marks as of "downcut" marks because this indicated that the blade was not rubbing more at the front or the back.
Now I did as you asked, and looked at your drawings and your argument, and I hope, answered them. I'd appreciate it if you would, in turn, make a real effort to understand my points before you try to refute them. You might also want to take a deep breath, and sit and ponder why so many people with substanial industrial experience agree with me, and why they disagree with you. I know that's argument from authority, and a logical fallacy, but it does carry some practical import, nonetheless.
I'm not fighting with you, and this isn't about winning or who's right. It's a fairly important safety issue, and it's about what is right. If I can convince you, I can probably convince some other folks at the same time, and those would both be good things. Michael R
"You have to look for possibilities where there are none" Krenov
Hey, Michael, I just got back in. So, what I'm thinking is -- we should take this to a separate thread, and leave the poor guy in peace who started this thread. I'm gonna grab a drink o' water, then I'll start a thread and try to recap. We can discuss this one some more.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
And (I know, I'm showing off, putting pictures in the thread. Sorry!) ----- the only time I've had a problem with a tapered cut, or burning for that matter, is when the force I was applying was in the wrong direction, pushing diagonally into the fence, which cants the opposite end away from the fence. Most noticeable when not using a featherboard. Someday, I'll be good enough, I won't always need the featherboard.
View Imageforestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
True, in the best set-up, the blade is parallel to the fence.
Based on woodrat's first post I didn't think he was an experienced woodworker, and so during an initial tune-up it's safer to have the fence toe out. You are correct that the wood has to be"forced" against the fence, but it takes minor pressure to do this for 1/32".
Cutting custom coves for crown molding on the tablesaw for example, really requires force to move the wood over the blade, and it often can be seen bending during this.
Only times I see that is when the board has a bow and the high side is against the fence.
Another...Joe
Ohhh, you're just not creative enough, LOL! I've had that happen with plywood of all things, totally operator error.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
It could simply be the stress in the wood releasing after the board is cut.As long as your splitter is well adjusted and the board clears the back of the blade don't worry about it.After all,as you say,the cut comes out perfect with a smooth ride thru the blade.What more could you ask for??
Joe, could you try running a longish piece of plywood through as for a rip cut, let us know if you have the same problem?forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Joe, assuming you are correct that the blade and the fence are dead parallel to the miter slots, are you using a roller stand on the infeed side of the saw? If you are, make sure the roller is at 90° to the fence. If the roller is askew it will make the board wander from the fence. You won't get it perfect, but get it reasonably close to perpendicular to the fence.
mike
Measure the blade thickness at the tip with a dial caliper. Then measure the kerf of cut stock. If the stock is more than 1/64" wider than the blade, you've got a blade running out of true.
This can be caused by the blade not mounted flat on the arbor flange, a bent arbor, or a bent blade.Before you rip again, be sure the fence is parallel to the blade, and even safer is to set it 1/32" out, to the right. For more info, see Kelly Mehler's "The Table Saw Handbook"
Adjusting the blade parallel to the miter slot doesn't need to cost you much.
Here is the low tech, low cost way to align a tablesaw that I learned maybe forty years ago and teach to my students now.
Make 3/4 x 3/4 x 12" hardwood stick. Drill a hole somewhat centered in one end and insert a brass #8 x 1" round head wood screw about half way. UNPLUG THE SAW. Raise the blade completely up. Clamp this board in your miter gauge (if you determine that there is some slop in your slot to miter gauge, use a playing card to take up the slop) so the screw head just about touches the blade at the front. Now rotate the blade by hand and determine which tooth is the closest. Adjust the screw in or out until it just touches this tooth. Mark this tooth. Rotate the blade so the tooth is now at the back of the table and move the miter gauge/stick assembly to the back and see if it touches the marked tooth to the same extent. If it doesn't, adjust the trunnion (if a contractor saw) or the tabletop (if a cabinet saw) until it does.
For a contractor saw, first use a small c-clamp on the rear trunnion and cradle to keep the assembly from moving. Then loosen the two rear trunnion bolts and one front trunnion bolt and use a stick to tap the trunnion until the blade and screw lightly touch. The blade does not move directly around the center so you will need to repeatedly go back to the front of the blade, readjust the screw, and then again measure the back. Be sure to check after tightening the trunnion as the trunnion frequently moves when being tightened.
The same adjustment gauge can be used to set the fence parallel to the miter slot. Slide the miter gauge to the front of the table and move the fence over to the screw head and insert a playing card between the screw head and the fence just so you can move the card as it touches both the fence and the screw head. Now move the miter gauge to the back of the table and see if you have the same feel when you insert the card. I like my fence absolutely parallel--if you want to have a slight opening to the fence, you can easily estimate the opening by adding a thickness of paper to the card.
I always show my students with a dial gauge that their adjustments are within .001 - .002.
You can also use the same gauge to measure blade runout by using a $5.00 feeler gauge.
Finally, after you are satisfied with the above adjustments, check the position of the splitter to make sure it is exactly in line with the blade.
Bottom line, there is no need to spend more than the $0.05 for the brass screw.
As to the issue of fence alignment, I keep my fence exactly parallel to the miter slot and blade. If the back is kicked out, the front is kicked in. This means that the board is entering the blade at angle and the longer the rip, the more the board will want to move away from the fence. I originally learned to always have the fence parallel and any pro's I know keep theirs parallel also. Blade manufacturers that I have talked to recommend a parallel fence, except for Forrest.
If a fence is pinched in, it will tend to direct the board into the back of the blade because the fence is moving the board that way. This can lead to kickback particularly if you are not using a splitter. However, if a board enters and exits the blade at ANY angle, there is potential for kickback. The safest procedure is to carefully align the blade to the miter slot and do the same for the fence. Also, use the splitter.
This forum post is now archived. Commenting has been disabled