Running wood backwards on a table saw. Always a bad idea, right? - Page 3 - Woodworking Talk - Woodworkers Forum
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post #41 of 55 Old 09-23-2013, 11:18 PM
where's my table saw?
 
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just to make it perfectly clear

I'm not advocating feeding the stock "backwards" from the rear of the machine. I'm referring to a partial cut, maybe past the rear of the blade with plenty of stock remaining to maintain fence registration. Once you lose contact with the fence, it won't matter what else you do, there will be an issue.

I was ripping a 2 X 6 today where I need to remove about 3/16" from an edge. The board was curved side to the blade and the blade lost contact in the curve, so I retracted the piece, moved the fence toward the blade another 1/8" and restarted the rip. It went as predicted, no issues.

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
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post #42 of 55 Old 09-23-2013, 11:37 PM
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Quote:
Originally Posted by woodnthings
I'm not advocating feeding the stock "backwards" from the rear of the machine. I'm referring to a partial cut, maybe past the rear of the blade with plenty of stock remaining to maintain fence registration. Once you lose contact with the fence, it won't matter what else you do, there will be an issue.

I was ripping a 2 X 6 today where I need to remove about 3/16" from an edge. The board was curved side to the blade and the blade lost contact in the curve, so I retracted the piece, moved the fence toward the blade another 1/8" and restarted the rip. It went as predicted, no issues.
I'm sure cabinetman will agree here. It's your fingers brother.

Just do us all a favor and if your going to make an instructional video please edit that part out for the novice woodworkers out there.
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post #43 of 55 Old 09-24-2013, 12:16 AM
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I have remained silent on this issue until now.

Most of my career was in computer programming or network communications. In that world we had the saying, "Never say Never". This discussion warrants an exception.

On the table saw, you should NEVER move wood backward through the cut.

Discussing the physics is beating a dead horse.

If it is necessary to make a partial cut, for any reason, hit the paddle switch with your knee and wait for the blade to stop. Then extract the piece and do what ever you need to do.

What's that? You don't have a paddle switch? Shame on you. They are so easy to build.

Use the right tool for the job.

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Remember that when we have the "BIG ONE" everything east of the Rockies falls into the ocean.
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post #44 of 55 Old 09-24-2013, 05:23 AM Thread Starter
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Quote:
Originally Posted by ryan50hrl View Post
Explain where the safety issue comes in using which forces act upon the wood in which directions....

Two things I can think of, with what's already been mentioned:

1) You give up some control of the work piece when you let it go the direction of cutting mechanism. It's easier to push the wood with the blade direction than against. We can agree that the blade's teeth do have some influence on the board's speed, regardless of board direction. If you move the wood with the blade direction, you have less control of it since you're already going in that direction. Going with the direction of the bit rotation is something we don't do with routers/shapers for the same reason. Moving with the blade direction can encourage the work piece to accelerate uncontrollably. I suppose if you were already moving the wood with the blade direction, you'd just call it "kick" instead of "kickback", since it's not really changing directions suddenly, only velocities.

2) Regardless of how well a fence/blade is aligned, simply changing board direction can change the position of the board in relation to the fence/blade.

Last edited by RobinDobbie; 09-24-2013 at 05:26 AM.
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post #45 of 55 Old 09-24-2013, 07:09 AM
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Gas can firmly in right hand............

Google or ask about climb cutting/milling.

One way of looking at it is..."It's what separates the men from boys"....do it without the proper equipment/experience and it can be read:"it's what separates fingers from hands".

But it is part of the discussion........maybe with an asterisk or something?But we climb cut on shapers "right often".And regularly do it with routers...handheld and table mounted.

Those who say it cannot be done shouldn't interrupt the people doing it.
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post #46 of 55 Old 09-24-2013, 07:28 AM
where's my table saw?
 
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right!

Framing contractors or others who have used a circular saw a great deal and in awkward places, climb cut often. I have a buddy who says he has more "mileage" on a circular saw going "backwards", than most folks do going forward..... and still has all the body parts he was born with. With experience comes skill, and climb cutting is not for the unskilled.

I've mangaged to launch a few workpieces on the router table ... unintentionally of course. Safety equipment, hold downs, proper standing position are very important. Having had those experiences, I am more skilled, than before....just sayin'

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
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post #47 of 55 Old 09-24-2013, 09:39 AM
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what i like about this thread is the fact that safety can be a good discussion topic. and that awareness of this type of table saw scenario has been made, to all readers.

i know i'll think twice about attempting that move - and will not do it!
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post #48 of 55 Old 09-24-2013, 11:54 AM
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It all comes down to experience, watching the video is proof that it "can" be done with no adverse consequences, he had a choice to make, shut the saw down and wait for the blade to stop, carry on, or pull the board back in a "safe" manner.

Personally I would have just continued the cut, but that is my choice, he chose to hold the board to the fence and push it back with his push stick, I doubt he would have done that if he did not feel comfortable doing it.

I agree having this discussion is a constructive exercise, however it could do without a few of the "holier than thou" attitudes.

“Everything we hear is an opinion, not a fact. Everything we see is a perspective, not the truth.”
― Marcus Aurelius
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post #49 of 55 Old 09-24-2013, 06:15 PM
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running backwards implies "cutting" ...?

I'm gonna throw another wrinkle into this can of worms., the Radial Arm Saw. Every cut you make on the RAS is a "climb cut" where the saw carriage wants to climb into the workpiece when you pull the saw from the rear to front as the manuals suggest is the safest procedure.

If you push the saw into the work from the front toward the fence another thing happens ... the work wants to lift off the table because the blade is rotating upwards. The safe operation of a RAS depends a great deal on the workpiece being firmly pressed down on the table, maintaining it position during the cut. When pulling the saw from the fence toward the front, the blade rotation helps press the work into the table as it enters the material.

I'm also going to suggest that anytime the workpiece loses registration the fence there may or may not be a issue/kickback, depending on the amount. Many, many times I have stopped the forward movement of the workpiece to regrip or reposition my hands and push block, it's just a normal thing you have to do. It's only very slightly different from withdrawing the work piece "backwards" however, it's still important that you maintain work to fence registration. The big difference is getting a secure hold on the workpiece without letting it change it's registration. That's where the safety issue comes to bear in my opinion. IF you lose control of the workpiece, bad things may happen, and I think that is where the confusion is about in this thread. Nobody is advocating feeding the work "backwards", rear to front, to make a cut. No cutting is occurring when you are withdrawing the work, in a controlled manner.

I'm not even advocating anyone who doesn't feel comfortable with this operation do it. As FrankC so aptly said, it's a matter of experience.

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)

Last edited by woodnthings; 09-25-2013 at 07:13 AM.
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post #50 of 55 Old 09-24-2013, 06:16 PM
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Quote:
Originally Posted by FrankC View Post

I agree having this discussion is a constructive exercise, however it could do without a few of the "holier than thou" attitudes.
Sorry that you see it as a "holier than thou" attitude. Some of us have very strong feelings towards safety. Those that are experienced that offer alternative reasoning about performing certain procedures may not take into consideration the skill level of some members.






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post #51 of 55 Old 09-25-2013, 06:59 AM
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lots of backing up here

Check out the video at about 11:00 minutes in. Interesting jig for making small beveled pieces on the tablesaw. Actually using the sled requires backing up every time, BUT the sled is held securely in position by the guide rails in the miter slots. It's all about maintaining the material in position, whether a sled or against the fence.


The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
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post #52 of 55 Old 09-25-2013, 07:16 PM
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I'm generally against pulling wood back when a spinning blade is involved. I was lucky back when I was inexperienced. Many years ago, I was cutting a 45 degree bevel on my original "skil" tablesaw and the wood suddenly kicked back with my hand on it, putting a shallow (but nasty) cut across my left index fingertip. I was extremely lucky. No disfigurement, just a small dead spot on the tip of my finger.

Anyway, I realized that I *do* pass wood backwards across the blade in one specific circumstance - when I'm cutting tenons without a jig or dado set.
I use my miter gauge and my fence and I pass my end of my wood over the blade repeatedly, forwards and backwards to remove the wood. I don't cut on the reverse. I've never had a problem, don't perceive any loss of control or kickback risk on this sort of cut.

Some folks feel comfortable doing more. I guess it's really up the woodworker and his/her feeling of control over the wood.

My departed father (an artist, not a woodworker) used to tell me that you can break the rules, but you have to learn the rules first and know which ones can be broken...
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post #53 of 55 Old 09-26-2013, 11:59 AM Thread Starter
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Just curious if maybe pretty much every table saw manual ever got it wrong in the general safety area where they state never to run wood backwards? And what's the gain, you saved 12 seconds? Seriously, if you feel that lucky, just go to Vegas. The risk:reward ratios are much better, there.

Last edited by RobinDobbie; 09-26-2013 at 12:03 PM.
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post #54 of 55 Old 09-26-2013, 01:53 PM
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Huh?

Quote:
Originally Posted by RobinDobbie View Post
Just curious if maybe pretty much every table saw manual ever got it wrong in the general safety area where they state never to run wood backwards? And what's the gain, you saved 12 seconds? Seriously, if you feel that lucky, just go to Vegas. The risk:reward ratios are much better, there.
You are the only person I've heard use this description ....run the wood backwards. It just isn't what's happening. You make a partial pass, and withdraw the piece in the open kerf that you've just made. You can leave the machine on or turn it off, which ever you choose, it's your choice, what ever you feel safer doing.

Obviously with it off, nothing "can" happen. With it still on something "may" happen, but in my experience, it has not. It's still your choice.

As I mentioned, every time you crosscut with a sled , you withdraw the work or the slde in the kerf made by the blade. I've not seen any online sled videos where a person is making multiple crosscuts who turns the machine off. I don't do it either. It's just not necessary, but it's still your choice.

Every time you make a crosscut on a RAS, the blade is in the kerf in the table or the saw won't cut all the way through. You are constantly moving the blade back and forth in the kerf each time you make a cut. I never turn my RAS off until I'm completely finished cutting all my pieces, especially when making multiples the same length using a stop block.

I not trying to convince you of anything, I'm merely pointing out what I do and why. It's always your choice how you use your saw.
Good Luck.

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
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post #55 of 55 Old 09-26-2013, 03:03 PM
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I not trying to convince you of anything, I'm merely pointing out what I do and why.
You are doing that over and over.






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