Saw alignment tolerable---unlikely cause

[sailor55330]

Finally, I have been able to align my 3100. If you've been reading the posts, then you know it's been a very challenging ordeal. every time I would try the 5-cut method to check alignment, I would be off approximately 1/8th of an inch over 12 inches. I was using sandpaper on the miter gauge, stop blocks and miter clamp and was still getting this phenomenon.

I took another look at the cuts that were being made and noticed 1 blade swirl in the wood. I had not stopped the wood during the feed so I was very surprised. I matched up several cuts and they all had the same mark at approximately the same point during the cuts. I then decided to feed a few more cuts through without the clamp to see if I could determine anything. Basically what was happening is the anti kick-back part of the blade guard (the sharp part with the points---not sure of the name) was causing the wood to shift ever so slightly when the were engaging--even while being held by a clamp. I could feel the board "catch" for just a second and then feed again.

To test this, I taped the anti-kickbacks together and secured then out of the way and proceeded to the 5-cut method. With 3 consecutive cuts, the boards were close enough that there was no difference to the naked eye and nothing noticeable could be felt by hand. I would guess that the difference was probably .001" or less. (I dont' have calipers, but I have gotten pretty familiar with a dial gauge and the travel necessary for .001 lately). I can tell you that it is close enough that movement of wood in joints will far surpass anything this small.

To confirm, I set the anti-kickbacks back into their orginal position and cut again----back to the 1/8th. So, I have repeatable results both ways. I ended up putting a small bolt through the existing holes and snugging them together to keep them out of the way of the work being fed. I know this is not an ideal solution, but as long as I am aware of the situation, I should be able to compensate for it. I haven't figured out a way to permanently remove the pieces yet, but that may come to me. Some of you refered to a Homer Simpson moment. I dont' really think this qualifies as it wasn't necessarily something I did wrong, but maybe something Ryobi did. As I said before, I'm not even sure the blade guard had ever been used based on the lack of marks on it. Maybe the springs are just too stiff?

Thanks again for the help

[LinuxRandal]

The antikickback pawls?

Those are one of the reasons, so many people like a Sharkgaurd.

You can search here, but I believe several people have dremeled them off, and I know I have read about others, just not using a gaurd. (at least until we convince them the Sharkgaurd is good)

[sailor55330]

Yes, Anit-Kickback pawls. The name was somewhere in my head, but I couldn't pull it out.

[phi1l]

Have you checked to make sure the riving knife is aligned with the blade, and that it is not loose? If you are using the thin kerf blade proper alignment is even more important. In fact, if the blade is thin enough and the knife thick enough, you may not be able to use that guard with that blade.

[sailor55330]

Yes, the riving knife is centered on the blade and approximately 1/8th above it. I can see where a thin kerf blade could potentially cause an issue. At this time, it is not.

[Bill in Buena Park]

Glad to see you were able to identify the problem.

...Maybe the springs are just too stiff?

I recommend you remove the springs, but leave the pawls - and dull them a bit; there is no need for them to be razor sharp. The spring on mine was tight enough, and the pawls sharp enough, to cause the pawls to leave deep scratches in a workpiece, so I cut out the springs and lightly sanded the pawls. I like the idea of the pawls being there for antikickback.

I second the recommendation to check the riving knife. If its shimmed a bit off in either direction, it may be enough to shift your workpiece a little.

[Eagan]

My own frustrations

Good morning

Reading this story inspired me to try aligning my own saw, something that never seems to go well.

I started from square one; took the saw off the base, made sure it was level and solid, and put it back together piece by piece.

I carefully measure the smt rails, using a 90 degree square and an incra ruler and got them right. Set the miter for 90 degrees and confirmed it was square with the blade and rip fence. Patting myself on the back for the ease of it all, I made a test cut on some plywood... which my try square told me was not square and my protracter agreed was a half degree off. Tried a couple more times with the same success.

Adjusted the miter fence a half degree off, tried my test cuts, and my try square and protracter tell me the cuts are 90 degrees...

Try the square on the miter fence to blade and rip fence; looks like they are each about a half degree off (what a surprise!). The square only hits the front of the blade and rip fence - can't blame the kickback pawls. Recheck my measurement everywhere... Rip fence to blade, rip fence to miter slots, blade to miter slots, blade to smt, rip fence to smt, can't find any problems... except that the smt only cuts square if it isn't...

Anyone got any theories?

[leehljp]

Good morning

Reading this story inspired me to try aligning my own saw, something that never seems to go well.

I started from square one; took the saw off the base, made sure it was level and solid, and put it back together piece by piece.

I carefully measure the smt rails, using a 90 degree square and an incra ruler and got them right. Set the miter for 90 degrees and confirmed it was square with the blade and rip fence. Patting myself on the back for the ease of it all, I made a test cut on some plywood... which my try square told me was not square and my protracter agreed was a half degree off. Tried a couple more times with the same success.

Adjusted the miter fence a half degree off, tried my test cuts, and my try square and protracter tell me the cuts are 90 degrees...

Try the square on the miter fence to blade and rip fence; looks like they are each about a half degree off (what a surprise!). The square only hits the front of the blade and rip fence - can't blame the kickback pawls. Recheck my measurement everywhere... Rip fence to blade, rip fence to miter slots, blade to miter slots, blade to smt, rip fence to smt, can't find any problems... except that the smt only cuts square if it isn't...

Anyone got any theories?

First, it will be less complicated by doing one step at a time. Twice you mentioned 1. miter fence, 2. blade and 3 rip fence. The rip fence and miter fence should not be compared to each other, although when in alignment they will be square.

1. The blade can't be changed so that is a given.

2. Align the Rip fence to the blade. Remember it has a two step locking mechanism. Work and align it. IF it is aligned with the blade, it will stay that way as it is moved on the rails. This has nothing to do with the SMT fence. IF it is out of alignment it is a rip fence problem.

3. Go through the procedures with the SMT and then the SMT fence and the blade.

IF both are in alignment with the blade, they will be alignment of each other. Compare alignments with the blade on each - separately. That way, you can figure out where the problem is.

Sometimes, people's feed technique causes the problems. Not saying that is your problem but just beware that it does.

Sailor found the problem to be with the pawls. Most people do alignment troubleshooting without the guard - in a bare bones situation. As parts are added after alignment, problems can be more easily detected. Doing it as a whole from the beginning is more complex and frustrating.

[pelligrini]

Finally, I have been able to align my 3100. If you've been reading the posts, then you know it's been a very challenging ordeal.

Glad you tracked it down. I know you were getting frustrated.

Another little drawback to the SMT that occurs to some is that there is sometimes a small amount of movement in the miter fence. It can often be tracked down to a loose pivot or the clamping mechanism. I'm not exactly sure how I solved my fence problem, but I did have a little amount of movement at one time.

If you're going to keep your BT you really ought to consider getting a Shark Guard. I love mine. I rarely used the OEM guard assembly. Mainly due to the pawls and it being a pain to take off and on, much unlike my Shark. Now that I finally got a dust collector last Summer the dust collection capabilities of the Shark make it even nicer to use.

[herb fellows]

As the Aussie's say, 'good on ya' Sailor! Certainly not a Homer Simpson situation. It's kind of like buying a car; every car works the same way, but after a while you figure out all the little idiosyncrasies that are particular to your car, whether by design flaw or whatever. Glad to hear you got it up and running.

[SARGE..g-47]

I've owned and run 6 table-saws since 1972. I only ran the anti-kickback pawls on the first until the day I had the shield raised to change the blade with the saw off. The shield dropped and the anti-kickback pawl hit my finger. 5 stitches with a gash almost to the bone.

Never since as I have removed it on each saw since from 1 1/2 HP to 5 HP. What it does is hold the stock down and I add a scrap on my rip fence and clamp it with a couple of quik-clamps to do that. It also keeps off-cuts from flying straight back and that is no problem if you initiate the first Rule I learned in HS Shop in 1963...

Keep the Lane Clear.. meaning never stand or move directly behind the blade while it is spinning. I have some nice size holes in a sheet rock wall 20' behind my TS (5 HP Cabinet) that emphasizes it's a Golden Rule worth adhering to. So.. not only keep the lane clear but clear the lane behind the blade of anything you don't want damaged. You may not have had an off-shoot yet but... if you run the saw enough you eventually will.

Good luck...

[sailor55330]

Interesting point as to doing the alignment process with out the blade guard in place. I too, did that BUT I put the blade guard back on for safety before making test cuts. So, I guess because I was attempting to be safety conscious, I was actually doing myself a disservice in terms of alignment.

Also, FWIW, this wasn't in the manuals......

[mpc]

Eagan - from reading your post, it sounds like you are using the front aluminum rail as a reference point to set the SMT, fence, etc. Did I read that correctly? If so, that's why you're seeing issues. The Ryobi BT3 saws align differently from almost every other table saw out there.

Most other saws use the miter slot in the table top as the reference (after all, you can't move it). Everything else, including the blade and its support structure, are aligned to the miter slot. Folks with such experience sometimes look at the Ryobi BT3 saws and decide the front rail is a logical reference point, assuming the Ryobi factory made the blade perpendicular to the rail. Nope.

On the BT3 saws... the blade angle is not readily adjustable. Thus it becomes the reference point for all other adjustments. It may or may not be (is likely not) 90 degrees relative to the front fence, and, given how everything else is aligned, that angle doesn't have to be 90 degrees. Nor is it perfectly parallel to the edges of the tabletop. Using those edges as a reference to calibrate the miter table, fence, add-on miter slots, etc. is incorrect. Only a few folks "lucked out" with blades that happen to be exactly parallel to the saw top.

To align the BT3 saws, first install a quality blade. (saw unplugged of course) Turn it by and and make sure it runs true... if there is perceptible wobble at the blade teeth then either something in the saw arbor is bent, the blade is bent, the blade support washers and the arbor spacers may be uneven or more likely a bit of sawdust/junk is stuck in there. Once the blade runs true, mark one tooth. Use that as a reference point. Rotate the blade to put it at the front of the saw... measure from it to the SMT base. Rotate that tooth to the rear and measure the SMT base again. Why use one tooth? Just in case the blade isn't 100% true... and because the individual blade teeth (or the blade's body) may not be identical in thickness. I use a flat spot between the teeth as my reference point actually so I'm not running my square against the carbide.

mpc

edit: oh yeah, like other folks, I've given up on the factory anti-kickback pawls. They scratched the wood as others noted. I just tape them "up" behind the blade guard; I haven't tried removing the spring. I did grind the tips down/flatter but that didn't help much... thus the taping. I long ago modded the stock blade guard to accept a 1" sump-pump drain hose that "T"s into my dust port hose. It wasn't until after I did that mod that I learned about the Shark Guard.

[Norm in Fujino]

I consider myself a pretty careful sawyer, and I've been rid of the anti-kickback pawls and blade guard since the first year. One thing I absolutely won't get rid of, though, is the riving knife that I made. It's kind of like the sharkguard, or a Felder type riving knife, but the only time it leaves the saw is for dado cuts. It is great for all kinds or normal through cuts and non-through cuts using the regular blades and will probably stop 99% of kickbacks (of course there are other dangers it doesn't protect against; I have to take responsibility for those).

[Hoover]

The saw blade should be a thin kerf to match with the riving knife.