Trouble getting square cross cuts

[djkert]

Hello All,

I just tried calibrating my Sears clone and am having a few problems getting the thing to cut square. The things I noticed are:

1.) There is some wiggle in the sliding table. If I tighten the screws underneath (the eccentric bolts?) to eliminate play the miter table becomes too tight and I cannot slide it.

2.) I align the miter fence up to 90 degrees and then tighten round clamp thingee. However, the fence always seems to slide a little bit to get just out of 90. How do people tighten these things while keeping it from moving?

3.) I thought it might be easier if I got the quick stop setup. However, every time I tried tightening the bolt behind it the quick stop would move. So, I could not get this to align square either.

Any help on this would be appreciated.

thanks,
Dennis

[LCHIEN]

Hello All,

I just tried calibrating my Sears clone and am having a few problems getting the thing to cut square. The things I noticed are:

1.) There is some wiggle in the sliding table. If I tighten the screws underneath (the eccentric bolts?) to eliminate play the miter table becomes too tight and I cannot slide it.

2.) I align the miter fence up to 90 degrees and then tighten round clamp thingee. However, the fence always seems to slide a little bit to get just out of 90. How do people tighten these things while keeping it from moving?

3.) I thought it might be easier if I got the quick stop setup. However, every time I tried tightening the bolt behind it the quick stop would move. So, I could not get this to align square either.

Any help on this would be appreciated.

thanks,
Dennis

Don't tighten the screw behind the quick stop - you can break the stop and this is a shoulderscrew the flip-up quickstop should be easy to flip and not held in place. Further the screw is a special eccentric shoulder screw, you turn the screw to move the quick stop forwards and backwards and you tighten the nut in the back to lock the QS in the position where the QS stops the miter fence in exactly the right spot. If you are turning the screw in the quick stop pivot, then you have likely un-calibrated the 90° position. Set the QS position using a T-qure or a drafting square betwen the miter fence an blade.

There has to be some very slight wiggle in the slide to allow the SMT to slide, The important thing is that it slide parallel to the blade.

I only tighten the knob that holds the miter fence as much as necessary to keep it from moving... for short pieces this is not very much since the miter fence is held at two places - the black pivot in the bottom in one of the holes (usualy the right side) on the SMT and the knob/screw. make sure the that is assemble correctly, e.g. bolt, SMT, fence holder, washer, knob... that's an ocassional cause for SMT problems.

[poolhound]

As Loring says you first need to get the table set accuratley parallel to the blade. It should easily be possible to get it tuned for an easy slide and zero slop.

You say the miter fence "slides" a little, can you be a bit mopre specific? If the miter fence wont hold tight first check the bolts assy as Loring suggests. SOmetimes the nut underneath has worn the groove so you cant tighten it properly. If you replace it with a T bolt things will improove.

Lastly check the miter table itslef you may have the dreaded crowned table. This means that the fence only really contacts the table in the center and you will always get a slight movement.

Mine has this problem and it drove me mad. I built some sleds (x-cut/miter/panel) and rarely use the SMT unless I need some weird angle. You could also make up a shooting board to tune your cuts but this will get tiresome if you have to do it for every one...

[pelligrini]

Waxing the SMT sliding bed will help quite a bit with the binding when tightening up the adjusting screws. Even a couple passes with just wax paper will let you adjust the alignment screws fairly tight.

I still get a bit of movement probelms at the fence, especially when using my long miter fence. It is even more problematic when crosscuting heavy and/or long pieces. I built a 90 degree stop block. It fastens to the table through the two rear holes on the table with 1/4" t nuts. Even crosscuting a 8' 2x4 won't move that fence now.

[djkert]

There has to be some very slight wiggle in the slide to allow the SMT to slide, The important thing is that it slide parallel to the blade.

See, that's what I don't understand. When I loosen the bolts enough to allow it to slide, the play is enough to knock my crosscuts out of square. The table is parallel to the blade, but I can wiggle it side to side. The only way I can deal with this is by sorting of pushing right at the front of the table when I set the fence and make sure I hold that pressure when I make my cut.

You say the miter fence "slides" a little, can you be a bit more specific?

I guess turns or twists is a better word than slides. I set my fence with a t-square so it is 90 to the blade. Then I tighten the fence. when I re-check it is may 1/16 off.

you turn the screw to move the quick stop forwards and backwards and you tighten the nut in the back to lock the QS in the position where the QS stops the miter fence in exactly the right spot.

I'll try it again, but when I tighten the nut it was moving the screw.

[dstenson]

Hey Dennis, you're not alone. I've got the Sears clone (Craftsman model #27413) and although I can get the smt really close to square, there is always enough play in it to throw it off, as well, when I tighten the miter fence, it causes a bow in the smt. So the cut is not square on either plane. Lacking any miter tracks, I built a crosscut sled that had it's two guide rails run along the outside edges of the table top.
http://picasaweb.google.com/dstenson...40264220823730 or http://picasaweb.google.com/lh/photo...eat=directlink

This at least provided me with a repeatable cut every time. I'm now adding two extension wings with miter tracks so that I can use a number of "standard" jigs and tools that will ride in the tracks.
Good luck, Devin.

[Black wallnut]

See, that's what I don't understand. When I loosen the bolts enough to allow it to slide, the play is enough to knock my crosscuts out of square. The table is parallel to the blade, but I can wiggle it side to side. The only way I can deal with this is by sorting of pushing right at the front of the table when I set the fence and make sure I hold that pressure when I make my cut.

The eccentric is rather steep so it takes a very fine touch between too loose and too tight. Remember to set alignment with the right rear and take up slack with only the left at the front and rear. You may find it easier to just use a hex driver from above.

I guess turns or twists is a better word than slides. I set my fence with a t-square so it is 90 to the blade. Then I tighten the fence. when I re-check it is may 1/16 off.

see comments above...it's called fine adjustment.

I'll try it again, but when I tighten the nut it was moving the screw.

For the quick stop tab the nut should be snug. After you have established the SMT fence to perpendicular to the blade set the quick stop with a screwdriver carefully. When in use be gentle so you do not disturb the setting. Check this evey now and then. Like at the start of a big project or after not using the saw for a while.

[shoottx]

Check to see if the Pivot is loose in the slot. I all of a sudden started having cross cut problems. I had the SMT tuned to a gnats A@@ and still had problems. It was a loose pivot. It allowed the SMT fence to teeter tooter on the hold down point,

Good luck

[LarryG]

The eccentric is rather steep so it takes a very fine touch between too loose and too tight.

Mark is exactly right with this statement. The difference between too loose and too tight is hair-trigger. More than once I have expressed it this way: when you get it close, and are making the last fine adjustment, don't think in terms of turning the adjuster, think in terms of applying pressure.

[jon_ramp]

I have a Craftsman 21829. I find that the quick release that hold the fence rails to the saw body tend to loosen up. Make sure those are also tight.

[Black wallnut]

If there is not enough adjustment in the left side eccentrics then either your SMT base is not parallel to the blade or your glides are worn. If the former adjust as needed. If the latter disassemble all four glides and spin them 180°.

[djkert]

OK. Thanks everybody for your help. I was able to get things pretty well under control. I played with the eccentric bolts until the play in my SMT was gone, and the table still slid . I wasn't able to get the quick stop setup correctly but I am not really worried about that. I'd feel more comfortable measuring every time anyway.

The problem with the fence turned out to be not the fence at all. I finally realized that rotating the blade caused it to get out of square. Once I noticed this, I changed the blade and the fence stayed in square when I rotated the blade. I havent tried making a cut and checking for square yet as I ran out of time but I am assuming this fixed the problem. Must have bent the played somewhere along the way . Could this have caused my rip cuts to pull away from the fence? I always assumed it was the riving knife.

Anyway, thanks again for all the great suggestions. It was a good learning experience if nothing else.

[LCHIEN]

OK. Thanks everybody for your help. I was able to get things pretty well under control. I played with the eccentric bolts until the play in my SMT was gone, and the table still slid . I wasn't able to get the quick stop setup correctly but I am not really worried about that. I'd feel more comfortable measuring every time anyway.

The problem with the fence turned out to be not the fence at all. I finally realized that rotating the blade caused it to get out of square. Once I noticed this, I changed the blade and the fence stayed in square when I rotated the blade. I havent tried making a cut and checking for square yet as I ran out of time but I am assuming this fixed the problem. Must have bent the played somewhere along the way . Could this have caused my rip cuts to pull away from the fence? I always assumed it was the riving knife.

Anyway, thanks again for all the great suggestions. It was a good learning experience if nothing else.

usually a blade with wobble cuts a wider kerf. (This is the method behind wobble dado blades). The bigger the wobble the wider the kerf. Not usually cutting off 90°.