binding problems

[mcommushroom]

I've finished putting together my bt3100-1 and as this is my first TS I don't have enough experience to know what's normal here. Here's a couple of problems:

1. When I try to crosscut a 2x6, its very difficult if not impossible to cut off a small slice ( less that the blade to rip fence side of the guard). Cutting off a longer piece seems to work fine. What's going on here?

2. When ripping, I get binding at the back - not at the blade, but at the back end of the riving knife. This happens with 1x material.

3. The riving knife doesn't really look straight - maybe warped or curvey which, I imagine is causing 2. I tried bending it as suggested here, but haven't really had any luck and want to avoid making it worse. The whole riving knife alignment has been difficult because at some blade heights it seems to be in a good spot and at others it seems to cause binding.

Any help would be appreciated.
Thanks!

[jdschulteis]

When cross-cutting a thin slice from a 2x6, is your offcut getting stuck between the riving knife and the anti-kickback pawl? Try it with the blade guard removed. It's also a good idea to use a zero-clearance throat plate so that the offcut doesn't fall into the saw.

I think you're on the right track with your ripping problem. The riving knife should be flat--if yours isn't, get it replaced.

[mcommushroom]

Thanks for the reply. I'll try the crosscut without the guard just to see. Its binding and getting stuck before it even gets to the back of the blade. I think maybe because the 2x6 is not flat maybe its twisting and binding against the middle of the blade, but I'm not sure if that's a plausible scenario.

Is there a way to get the guard off the riving knife so I can see if its flat and try to flatten it?

[mcommushroom]

Just to close this out - the binding during a rip was resolved by moving one shim over to the right side. Works great now.

The crosscut was, I guess just dumb newbie stuff. Partway through the cut the 2x6 often would start to pull away from the crosscut fence and turn clockwise - just a hair. Enough to cause it to bind against the blade.

Are there some clamps I can get to use on the crosscut fence to hold the board tight against it?

All better now and I'm pretty happy with the setup and the saw overall.

[scorrpio]

The accessory kit for BT3 includes a miter fence clamp - I found one on ebay for $15 and use it all the time. Another option is to use a couple regular clamps to secure the piece.

It looks like too much of your 2x6 is hanging off the left side. You should slide SMT as far to the left as possible to provide adequate support - this might involve sliding front/rear rails all the way left as well. For extra long pieces, it is recommended to support with a sawhorse topped with something slick. Lee Valley sells UHMW tape that can be applied to surfaces to make them slippery.

[LarryG]

A critical point no one has raised.

The crosscut was, I guess just dumb newbie stuff. Partway through the cut the 2x6 often would start to pull away from the crosscut fence and turn clockwise - just a hair. Enough to cause it to bind against the blade.

Forgive me if you already know this, but I'd rather risk insulting someone's intelligence than see them get hurt: you're not using the SMT in combination with the rip fence, are you? I can't tell by your descriptions whether you are, but a clockwise rotation of the workpiece suggests this may be what you're doing. This is a fairly common mistake for first-time TS users, and it's almost a surefire recipe for kickback.

[mcommushroom]

Larry, No apologies needed - I need someone looking out for my safety. However, I am not using the rip fence and crosscut together. The rip fence is on the rails but way off to the side and not touching the work.

And actually, I have hardly any of the 2x6 hanging off to the left of the sled, its pretty much all to the right. When I slide it through the blade to shave off just a bit (maybe 1" to 1/2") the blade seems to be able to grab it a bit and sort of pull it away from the fence. The 2x6 starts to turn clockwise pivoting on the right most corner of the crosscut fence. Of course, I'm only holding the 2x6 against the fence with my hand - no clamp so maybe that's the problem.

Does this rotation indicate an alignment problem of some sort? Or just bad technique?

[scorrpio]

Ah, so the problem is opposite of what I thought. In this case, you should move your SMT so that miter fence tip is real close to the blade. When cutting short pieces, I usually set it about 1/8" from blade. Also, be sure that miter fence is properly tightened and snug against the popup tab - sometimes a heavy piece will cause the miter fence itself to rotate from its position if not properly tightened.

[LarryG]

Does this rotation indicate an alignment problem of some sort? Or just bad technique?

It probably just indicates that you need to hang onto your workpiece a little tighter. With a rotating saw blade, there is a natural tendency for the workpiece to self-feed toward the blade; i.e. the workpiece will move from left to right.

Also, related to scorrpio's last comment, the black plastic ends on the miter fence may not be all the way forward so they're precisely flush with the aluminum extrusion. Mine don't, and I seem to recall others reporting likewise. You need to take care to hold the workpiece tight against the aluminum part and ignore any gaps that may appear out at the plastic ends.

[scorrpio]

Plastic tips on miter fence are perfect fush with aluminum part when you originally set up the saw - but a few bumps and knock them off true fast.

For absolute best support, especially cutting real short piece, clamp a longer sacrificial board to the miter fence and use it to push your workpiece through blade.

[mcommushroom]

Thanks so much for your help everyone. I'll try and get some clamping and a miter fence extension setup. This website is great!