[Jerry Bowen]

In my previous thread about what does it mean by the term"an accurate table saw", as often happens the posts got somewhat off of subject.

Harry's post about the importance of setting a little off set at the out feed end of the fence seems to be SOP for properly setting a fence up.

This leads to another question that I don't have the answer to but would like some comment on. My limited experience has led to think that the chances of a kick back are pretty much diminished when a splitter is used and some means of keeping the material held down hard against the table so that it cannot raise up at the out feed end. Does that make sense or not. That has become my thinking and is accomplished with both a MJ splitter and the MJ Ripper.

Those safe guards along with being very alert as to the feel of the material as it is being cut and, as Harry reminded us, standing off to the side of line of the cut being made seems to me to be all that one can do in order to avoid being hurt by a kick back.

I try to pay attention to the splitter as it psses through the cut watching to see that is not being disturbed. If for any reason it moves or looks like it is being pinched, the cut is stopped and saw turned off immediately. I say that I watch the splitter, I have tos at that I have never had a problem yet using the splitter and keeping the material be ripped held down hard against the out feed end of the fence.

Early on I admit that I learned about serious kick backs the hard way and sure am aware of the potential dangers associated with using a table saw.

Like our friend Harry, I sure am an advocate of the MJ ripper by the way.

Jerry



Jerry

 

[coxhaus]

I think pinching a board is the worst thing you can do on a table saw. I do respect kickback and stand to one side or the other when cutting on my 3hp Unisaw. I have had a few kickbacks but none on my Unisaw. I had a board slung on my Unisaw when the cut off piece fell into the blade. It hit the cabinet door pretty hard.

When I took shop class in the sixties I learned on a Unisaw with no splitter which is exactly what I have now. I have no experience with a riveting knife or splitter.

I also feel like the more accurate you tune the table saw the less likely you will have kickback.

 

[RainMan 2.0]

I was being sarcastic about a year back about kickback, and refusing to use the splitter guard .
Well karma got me good . I was cross cutting a 2/6 and it started bouncing between the fence and blade . It was like slow motion as it spit out at 200 moh and caught me in the forearm .
After the blunt force trauma incident , it is still going numb as we speak . Wakes me up in the middle of the night , and I have to get up and move the arm around in rapid circles to get rid of the numbness .
Seen a guy on tv who had a piece of luggage fall from the overhead compartment in an airplane , it hit the side of his arm , and he had to have the arm amputated?
That kind of scared me

http://www.dailymail.co.uk/news/art...ATED-freak-injury-caused-falling-luggage.html

 

[denniswoody]

Kickback as pointed out is caused by pinching. Both the offcut and main piece can be pinched if proper technique is not used. It is critical to keep the board flush to the fence throughout the cut while maintaining steady non-stop pushing pressure. Never release the push stick until the cut is completed or the saw is turned off. If there is a bind keep the push stick engaged and turn the saw off with your free hand. When cross cutting the fence should not be used as a stop. It should be well away from the offcut. I use magnetic featherboards whenever possible to help keep the board against the fence. I also use the blade guard and pawls as much as possible. My saw does not have a proper riving knife.
Some people, including me, are of the opinion the saw blade should enter the wood on a downward angle so I set the blade well above the top of the board. Others prefer a lower blade, but IMO that applies more lateral pressure to the piece and contributes to the kickback problem.
Having said all this I have had a few kickbacks that fired the offcut across my shop and dented doors and walls. So vigilance and standing out of the line of fire is critical.

 

[DesertRatTom]

Had a piece of ply kick back on me a number of years ago. Smack in the solar plexis. Sore and brised for a month. That ply had a little curve to it. That's when I got religion about setting the fence out a tad and got a Grrripper. No kickbacks since then.

 

[JOAT]

Sophmore shop class, 1955, me 14 - and that was the first time we were allowed to use power tools, except for a power sander freshman year. Teacher showed us kickback on a huge table saw, and told us to stay out of line of the blade, so if it does occur, it will not hit you. No splitter on the saw. I still do not use a splitter or blade guard, do use push sticks and push blocks, still stand out of line with the blade, and have never had kickback. I like to use saw sleds too. Always be slightly afraid of tools that can bite you, so you will always be careful when using them.

 

[hawkeye10]

Talking about kickback got me thinking. I have a riving knife on my table saw so what is the difference between the riving knife and a splitter? I know what the splitter looks like but is there a difference in stopping kick back?

 

[Jerry Bowen]

Talking about kickback got me thinking. I have a riving knife on my table saw so what is the difference between the riving knife and a splitter? I know what the splitter looks like but is there a difference in stopping kick back?

What I understand is that the riving knife and spltter do the same thing whenthe blade is at 90 degree with the table. The the blade is tilted off of 90 degrees the riving knive goes with it and is still functional while the spligger only works at the 90 degree setting. I assume that I'm correct, but am not certai.

I do wonder why we are so careful to line the blade with the miter slots righ down to the thous, and once that is done we set the fence at an angle so that it won't bind at the out feed end. I'm probably so dense that I'm overlooking something, and need for womebody to explain it to me.

Seems like, and will soud crazy probably, but whay not set the blade at a slight offset at so that it runs just a tad out of line with the miter to accomplish the ame thing. I'm almost positive that this will bring some answers to my question as the problem with binding could not be remedied in such a simple manner.

My kick back lesson was with a very small piece of quarter inch stock that was about 2x5 inches. I hit me in the stomach area and caused a bulge about larger than a golf ball. Had the piece been pointed it would have gone right into my gut for sure.

Jerry

 

[Cherryville Chuck]

I was sawing a piece of 3/4" oak recently and about 1/2 way through the cut the cut part closed up and pinched the blade on my Unisaw. It just about stopped it before I managed to stop it. I knew what was happening as I had seen it before a few times so I was holding it down as hard as I could in the meantime so it didn't throw it. It got the blade hot enough that when I restarted the saw the saw wobbled so bad it nicked my standard table insert. It cooled quickly and returned to normal in a few seconds. We call that timber bound up here bit it is a form of tension in the wood. It can happen at any time so you need to be aware of it.

Years ago when I was around 30 a cousin had a small sawmill with an old D8 cat engine for power. We were sawing railroad ties and he had a green hemlock log that was large enough to get two #1s out of (7x9"). The upper end was close to a fork that had been cut off. The mill had a 52" head saw and it had a splitter just after it. About 1/2 way through splitting it in half the power unit bogged down almost to a stall and the saw ripped the log out from under the dogs on the carriage and tossed it about 8 feet through the air back onto the infeed deck. This was a green hemlock log about 18" in diameter and 8 feet long. He and I were both around 30, over 6' tall, and both over 200 lbs and the two of us couldn't lift that log. That's how much tension there can be in a piece of wood.

 

[boogalee]

Seems like, and will soud crazy probably, but whay not set the blade at a slight offset at so that it runs just a tad out of line with the miter to accomplish the ame thing. I'm almost positive that this will bring some answers to my question as the problem with binding could not be remedied in such a simple manner.
Jerry

Your miter slot should be square to the blade so you can cut 90° with a sled.

 

[Terry Q]

A splitter and riving knife are both suppose to prevent kickback. They both will tilt with the blade. The riving knife is set up to be at or slightly below the height of a blade and raises and lowers with the blade so you can use it when using push blocks like grippers or cross cut sleds.

Splitters are a fixed height and are generally longer, providing more protection if the boards try to pinch closed when cut. Splitters have to be removed when using sleds, or push blocks, or tenoning jigs, or dados, or any other partial thickness cut. The riving knife was suppose to be a solution to the problem of people not putting their splitters back on since riving knives don’t need to be removed.

When I take off my splitter (saw is pre riving knife) I try to use a micro jig mj splitter which is a short splitter that mounts to your zero clearance insert. Not perfect, but my anal self says it’s better than nothing.
http://www.rockler.com/micro-jig-mj...t=*Everything Ese in 'Power Tool Accessories'



In woodworking there is always more then one way to accomplish something.

 

[DaninVan]

"Seems like, and will soud crazy probably, but whay not set the blade at a slight offset at so that it runs just a tad out of line with the miter to accomplish the ame thing. I'm almost positive that this will bring some answers to my question as the problem with binding could not be remedied in such a simple manner."
-Jerry
I can't say for certain, but I think you'd end up with the material pulling away from the fence, but at the very least you'd likely get burn marks on your cut faces.
Certainly your miter cuts would be off; they depend on the blade being parallel to the miter slot.
Doing what you suggest wouldn't help with the pinching at the back of the blade between it and the fence; you'd simply create a wider kerf.

 

[Jerry Bowen]

"Seems like, and will soud crazy probably, but whay not set the blade at a slight offset at so that it runs just a tad out of line with the miter to accomplish the ame thing. I'm almost positive that this will bring some answers to my question as the problem with binding could not be remedied in such a simple manner."
-Jerry
I can't say for certain, but I think you'd end up with the material pulling away from the fence, but at the very least you'd likely get burn marks on your cut faces.
Certainly your miter cuts would be off; they depend on the blade being parallel to the miter slot.
Doing what you suggest wouldn't help with the pinching at the back of the blade between it and the fence; you'd simply create a wider kerf.

Makes sense to me Dan, I was pretty sure that I would get a good answer to my questions. Thanks, Jerry

 

[harrysin]

The safe way: fence set a midges wider at the out-feed, a splitter and a GRR-Ripper, achieve a perfect safe cut every time. If a GRR-Ripper isn't available then a magnetic feather-board is the next best thing, all this in my usual humble opinion of course.

 

[DaninVan]

Harry; I think Jerry is speaking in theoretical terms. The question is, in technical terms, whats the difference between having the fence offset by a few thou, and the blade being skewed by a few thou?

There's probably thousands of table saws out there, never mind skilsaws, with the blade skewed. Obviously not a desirable condition, but what effect is it exhibiting in actual use?
I know when my 8" circsaw blade starts to get dull it will pull to the right on a rip cut; I can feel it.

 

[RÖENTGEEP]

Some european TS has shorter fence to reduce the kick back possibility. :|

 

[coxhaus]

The safe way: fence set a midges wider at the out-feed, a splitter and a GRR-Ripper, achieve a perfect safe cut every time. If a GRR-Ripper isn't available then a magnetic feather-board is the next best thing, all this in my usual humble opinion of course.

That looks like a router table not a table saw to me.

I have a Grr-ripper which I use on my table saw with small pieces. It just bothers me to have my hand pass over the blade. I was taught 50 years ago in shop class never to have my hand closer than 6 inches to the blade.

 

[harrysin]

That looks like a router table not a table saw to me.

I have a Grr-ripper which I use on my table saw with small pieces. It just bothers me to have my hand pass over the blade. I was taught 50 years ago in shop class never to have my hand closer than 6 inches to the blade.

It certainly is a SAW table.