Tablesaw binding on rips

[Burt Alcantara]

I use my tablesaw about 3 times a month. Mostly to cut 2" slabs for turning. Recently, I tried to rip a 2x4, something I do fairly often. The piece got about 6" in then stopped moving. The saw did not make any noise. I thought I hit an extremely hard knot or even a bolt. When I tried to let up the 2x4 shot back. Fortunately for me, I always stand to the side of rips.

I checked for verticality and it was dead on.

Tried this a number of times with different 2x4s with the same result. Finally, I gingerly fed it to the blade very, very slowly and was able to execute the rip. However, the saw was vibrating like a an unbalanced washing machine. Well, not that bad but it would have failed the nickel test.

My crosscuts went without incident.

This blade is old. I'm thinking it may be getting dull. Could this be the problem?

Burt

[Hal Flynt]

Questions/comments

Do you have a splitter?
Is your fence parallel to the blade?
Is the end hitting an out feed table?

It sounds like something is pinching. Internal forces within the 2x4's may be closing the kerf ahead of the blade and pinching the blade or opening at the kerf creating side pressure between the fence and the blade. Blade sharpness can't make the above worse.

Personally ripping a 2x4 makes me nervous for the above reasons. I like to crosscut first and then rip or joint the edge to go against the fence to reduce the binding /pinching.

Now you know why it's best to stand clear of the kick back zone, glad you weren't injured.

[Matt Day]

Do you have a splitter?

[David DeCristoforo]

"This blade is old. I'm thinking it may be getting dull. Could this be the problem?"

You may have answered your own question. In case I'm being too "obscure", the answer is yes, this could be the problem. Even if the wood is binding on the blade, a fresh blade can still cut unless the binding gets too extreme. It sounds to me like your old dull blade is overheating and warping which is what is causing the binding, the vibration and the kickback.

[Alan Schwabacher]

If you rip something like a 2x4 that has not been jointed, it is next to impossible to keep it from shifting as it slides past the blade. This can result in jamming the blade and/or kickback. A dull blade can also be a problem, since it will heat up much more, and may distort while hot. This heating is made worse if you are ripping with a blade having a large number of teeth.

If you need to rip stock that might be warped or twisted, a bandsaw is safest, or a straight line rip jig for the tablesaw is helpful. It provides a straight edge to slide against your fence, so you can make a straight cut even if your stock is not straight. Tage Frid's books describe a simple one, or you can get something called a "joint'r clamp".

[Greg Funk]

If you are only making it 6" into multiple 2x4's before binding your blade is the likely culprit. Time to invest in a new 24-30 tooth ripping blade.

[Burt Alcantara]

What is not clear is I cut about 4 lengths of 8' 2x4s just last week and they ripped just fine.

I've never used a splitter as all splitters that came with all of the guards I have were too fussy and created more problems then they solved.

Since I do both ripping and crosscutting, neither of which is more critical then what I'm doing now, what are some blade suggestions?

I believe my current blade is a Freud combo of some sort a red LUxxxxx.

I did notice one thing that is different. Sometimes my fence jumps off the table when I lock it down. That problems seems to be getting worse and I'm not sure how to fix it.

Thanks for all the suggestions,
Burt

[Ian Welford]

All the comments are valid a new blade's a good investment or send the one you've got for sharpening pronto!
You can also get one way wheels to help. These rotate in only one direction- you screw them to the top of the rip fence and they hold down onto of the board. If you put one at the rear of the saw blade it stops kick back by locking up at the first hint of trouble. I bought mine ( on honeymoon in the USA 14 years ago) from Cascade? I seem to recall.

Like you I had a kickback and a 10" long sliver of beech embedded its self into the concrete block wall . I make it a rule never to stand in the "flight line" as anyone can have a slip up!

I do find it a bit scary seeing some stuff over here in UK which shows tabel saws without splitters, seems a bit suicidal to me for what its worth!

[Randy Denby]

This is nothing to do with Burts post and I'm not implying he is doing what I did....I was just thinking back to when I started woodworking in the mid 70's. I cant believe I didnt have any kickbacks ripping 2x4's before I realized the importance of straight stock against the fence or the knowledge of stressed wood. I mean, I would check it by eyeball, but I know they werent all that straight. I do remember the saw jamming a couple of times. My underpowered shopsmith probably saved me as I could hold it while turning off the saw. I pretty much know I aint holding against the power of this cabinet saw... I also know my Biesemyer splitter has saved me alot, from stressed wood. This is the main reason I want a saw with a true riving knife.

[Henry Cavanaugh]

I would lock your fence next to the mitre track and and see if the fence is parallel to the track. Its better to be wider after the blade if its going to be off. You cut last week fine tells me that your using construction grade 2x4 which means some will me warped. As stated above you MUST joint to get a straight edge or use the jig mentioned above. Shorter pieces will be easier to get straight. I was black and blue for a long time due to kickback. Its very dangerous.

[scott spencer]

The fence alignment is pretty critical....check into that.

At the very least, give your blade a good cleaning, and double check your alignment and flushness of the insert. Spray the blade with some degreaser and hit it with a brass brush or tooth brush, then wipe it down. If that doesn't help a sharpening and/or blade replacement might be in order. Sounds like you've got an LU83 or LU84 50T combo (TK and full kerf respectively). The Freud's Industrial line are as good as any, as are choices from Infinity, Forrest, Ridge Carbide, Tenryu, Delta's industrial, and DeWalt's series 40 and 60. TK's are recommended for saws < 3hp.

Alan mentioned something that entered my mind too...an unjointed board that's not flat or straight will be much harder to rip and may catch on something.

[Pat Germain]

... what are some blade suggestions?

After reading so many rave reviews, I bit the bullet recently and coughed up close to $100 for a 40-Tooth Forrest Woodworker II. Man, was it worth it! I'm sure there are many blades out there which work very well. However, I've used many a blade on my TS over the years and none of them came close to the WWII. This is the first blade I've used where there's more resistance from the wood dragging across the waxed TS surface than from the cut itself; and that's with oak. It's like I've got a plasma cutter on my TS.

If you can afford it, I would recommend trying a WWII. They sometimes go on sale on Amazon.com. Of course, they weren't on sale when I needed a new blade.

[David DeCristoforo]

"I did notice one thing that is different. Sometimes my fence jumps off the table when I lock it down. That problems seems to be getting worse and I'm not sure how to fix it."

???? What kind of saw do you have where the fence "jumps off the table"? This alone can account for your binding because when it "jumps off the table" it can also "get out of whack". Between this (apparently crappy fence system) and your dull blade, it's a wonder you can cut any wood at all! Besides a new blade, you might want to consider upgrading the fence to a baby bess or something that will stay put (and in adjustment). Or maybe you need to get a "real" saw....:rolleyes:

[Burt Alcantara]

My saw is a General 85-150 (???) left-tilt. I believe the fence is a Bessy copy. One thing I don't like is when I move it then lock it, it moves. I tried this on the SawStop. Now that's a fence!

However, I probably need to do a complete alignment, cleaning and sacrificial chicken then retest the blade. I'm sure it needs sharpening but I'd like to get a replacement before I send it out.

Remember, I don't do critical cuts. So far, the saw has served me very well. No complaints, except for this recent binding problem.

Burt

[Gary Curtis]

How does this sound? My General 350, with a 5HP motor stalled in a sheet of 3/4 playwood. The saw was brand new, as was the blade.

My mistake was feeding it from the far left corner of the ply sheet. Which indicates that the wood wasn't being fed perfectly square with the rip fence, and thus coming at an angle to the blade. Check your fence alignment!

Gary Curtis

[Mike Cutler]

My saw is a General 85-150 (???) left-tilt. I believe the fence is a Bessy copy. One thing I don't like is when I move it then lock it, it moves. I tried this on the SawStop. Now that's a fence!

However, I probably need to do a complete alignment, cleaning and sacrificial chicken then retest the blade. I'm sure it needs sharpening but I'd like to get a replacement before I send it out.

Remember, I don't do critical cuts. So far, the saw has served me very well. No complaints, except for this recent binding problem.

Burt

Burt.

Your General has a cam lock lever mechanism that applies pressure to a teflon pad that is between the cam mechanism, and the fence. General used a very high quality epoxy paint on that front rail, and your teflon pad is now either slipping on the paint, or is missing. Cut a piece of 400 grit sandpaper the size of the teflon pad and attach it to the teflon pad with double sided sticky tape, and your fence should stop moving on you, unless you apply a lot of leverage.

The blade you are using is may be trashed. The vibration is indicative of an overheated blade that is "potato chipping" as it heats up. It may not show up in a crosscut due to the minimum length of time the blade is in the wood, a rip is altogether different. Go to a dedicated full kerf rip blade, and realign your fence.
The General "Bies" copy is not a very good copy of the Biesmeyer Fence. The metal plate(s) that the set screws act against to align the fence, are of a lesser quailty steel that has poor modulus characteristics, and fatigues very quickly. I've pretty much given up on my General fence, and use the old Xacta Fence off my Jet. I have an Excalibur to replace it, but I just haven't gotten around to it.
I apologize for criticizing your fence, but I have the same one, and have had to overcome it's shortcomings.

[Clint Winterhalter]

Burt,
Everyone has given you great advice...

I think its time to:
swap / sharpen the blade.
Tweak the fence / get is true / fix the movement problem
While your at it clean / wax the table
Adjust the insert
Check the out feed table etc.
Buy a jointer ;)....:DI know the saw does what you need it to do most of the time. For your safety you should spend some time tuning it up once in awhile! General makes nice machines, it should be back in top shape in no time!

Good Luck
Clint

[Mike Null]

Adjsut and align the fence. Find or make a good straight edge for ripping.

The WWII is the best tool I've bought in years.

[Burt Alcantara]

Alright. I've been slacking too long. I will do all of the things that are outlined. I'll end up with a better and safer saw.

Many thanks to you guys for excellent information and support!
Burt

[Frank Stolten]

You've already been given a lot of advice about how to correct you're ripping problem. I'm sure if you follow it you'll again be able to rip satisfactorily.

You also need to address the safety issue. Ripping without some kind of device to control wood movement i.e. featherboards, board buddies, grip-tite, splitter, etc is, as you've already experienced, a potentially serious accident just waiting to happen. I understand why you removed the cumbersome blade guard, I did the same with mine. I don't know what kind of saw you have but there are after-market splitters available from Delta and Biesemeyer that just snap in place and are easily removed. As a less costly alternative, you could easily make your own at very little cost. Here are a couple of articles that describe how to do it.

http://www.sawmillcreek.org/showthread.php?t=37761
http://webpages.charter.net/harkerhome/WWShop/splitter.html

You also could do a web search and probably come up with other splitter designs. I've made my own in the past and, when I sold my contractor's saw, made sure the new owner understood the splitter's function and why it was important to keep it installed as much as possible.

I think a lot of times we get so focused on woodworking technique that we don't think enough about the most important part....how to do it safely.

[Brad Naylor]

The fence is a Bessy copy.
Burt

Am I right in thinking that 'bessy' fences are long ones reaching beyond the blade?

If so, this is at least part of the problem. Ideally the fence should only extend maybe an inch past the FRONT of the blade for ripping. This will help prevent the stock binding behind the blade, particularly if a splitter or riving knife is fitted.

It also sounds as if your blade is blunt.

Cheers
Brad

[John D. Thompson]

Sounds to me like you may have deposited some pitch on your blade last week when you were ripping those other 2X4s.

Still, I am with the camp that recommends a fresh blade.

It is a sort of onerous task but, if you are going to rip pine, a quick wax of the blade can help. The problem is that you have to do it VERY often.

Having several rippers in rotation through a bath of pitch remover may be your best bet.

JT

[Michael Schwartz]

1. Tune your saw

The saw and fence system need to be in perfect alignment. Align the miter gauge slot with the blade, and check your arbor flange, and blades for runout. Then adjust your fence for parrelel, offsetting it by at least 1/64 out at the end, so that there is more room at the back of the blade than there is at the front.

2 Setup

For any kind of ripping you need a spitter or riving knife. This will prevent the wood from closing up on the blade, and help keeping you from steering it away from the fence by accident. You can make one out of wood and fit it into a zero clearence insert, or if the one that came with your saw is long lost, or problematic, invest in an after-market one.

A spiiter will work wonders to help prevent many situations that could lead to a kickback, but you may wan't to use Anti Kickback Fingers in addition to the splitter, they do get in the way, but again an inconvience is better than having a 2x4 hit you in the gut at 100 MPH.

Use fetherboards, Theese will keep your work tight up aginst the fence, and help keep a board from kicking back. Downword presure fetherboards clamped to the fence are also advisable.

3 Blade

Use a clean well lubercated sharp blade that is apropriate for the cut your are making. For 8/4 lumber a rip specific blade is advisable. For 4/4 lumber a combination blade will work. Invest in a top of the line combo blade, such as the forrest WW2, if you only use the saw a few times a month, a top of the line blade will last a lifetime, and if they get dull, you can have them resharpened a number of times.

Keep the blade clean, cutting wood will leave deposits of pitch and resins on the blade which will cause it to drag. A good cleaning can bring a blade that seems dull back to life.

Lubricate the blade with a non sillicon blade/cutterhead lubercant. These will not affect wood-finishes.

Signs of dullness or alignment issues are slowness of cutting, burning, and rough surfaces.


4 Lumber and Stock preperation.

Never rip a rough edge on a tablesaw. Always dress it with a jointer, strait edge with a skillsaw, or router, or a strait line rip sled on a tablesaw. If you wan't to rip with a rough edge use a banDsaw. Even the tricks where you run it up aginst the fence with a level etc... are dangerous.

[glenn bradley]

I'm late but, that sounds like a pinch due to stress relief. I use a splitter EVERY time it is possible. If I've got a board with a really bad case of stress and I have to use it I rip on the BS and correct the edge on the TS.

[Eddie Darby]

I've never used a splitter as all splitters that came with all of the guards I have were too fussy and created more problems then they solved.
Thanks for all the suggestions,
Burt

Micro-jig sell a nice easy to use splitter, that can be easily removed, if needed. You can get it at Lee Valley or Woodcraft , etc.


http://www.microjig.com/MJ%20Splitter.htm

http://www.woodcraft.com/search/search.aspx?query=splitter

http://www.leevalley.com/wood/page.aspx?c=2&p=51151&cat=1,41080,41165