please help again

[Sawatzky]

3 posts in 2 days and I am in need of help. I desparatley want my SMT to work properly! I don't need it all the time, but when I do I want it to work. I have adjusted everything according to the manual. I can assure you that it is parralel to the blade. My problem is that dumb fence. No matter how hard I tighten it, I can still move it out of alighment very easily. I think that is why my cuts are never square. I start out with the fence at 90 degrees, but the slightest pressure pushes out a degree or two. The pivot pin is in the correct hole. The washer is under the knob. I have done everything right according to this forum and it still moves when tightened. Is there anything else I can do or do I just need a new SMT?!

[LarryG]

I start out with the fence at 90 degrees, but the slightest pressure pushes out a degree or two.

If you literally mean it moves under the slightest pressure, something is definitely wrong somewhere. It's possible to move the SMT fence on my saw when its tightened down, but it takes a deliberate effort.

Try this experiment: take a strip of coarse sandpaper, 80 grit or so, fold it double with the grit side out, place it between the SMT table and fence, tighten the knob, see if that helps.

Also: are you sure it's the fence itself moving (confirmed by the orange pointer thingy on the backside now pointing to a different place from where it was), and not the sliding table itself rotating from side to side?

[Sawatzky]

It is definatley the fence moving. I do have to apply some pressure, but it does not lock down solid like others' seem to. I will try the sandpaper and see if that helps. I was thinking that perhaps waxing the SMT top would cause the fence to slip some. Might this be the case? If so, how do I get rid of the wax?

[big tim]

Having waxed it could very well be your problem, I would think that acetone, or paint thinner would remove the wax. You should not wax either the SMT or the fence. When you make 90 degree cuts, do you make use of the fence stop on the left edge of the SMT. If you do and you have the plastic pivot pin in the pivot hole on the right hand side of the SMT, I can't see how the fence could shift, even if the table was waxed. By the way, is the hold down bolt correctly positioned in the slot in the SMT. Is the fence lying flat on the SMT, no space between the bottom of the fence and the SMT?
Please check all these things.

Tim

[LCHIEN]

It's really a simple system.
I'm assuming from your description that the miter fence is moving in relation to the SMT, and that the SMT is fine with relation to the blade.

With two points of locking then there is almost no way the fence can move.
I'd check the two points of locking:
1) the black pivot, as you say must be in the groove in the bottom of the miter fence, sliding left to right but not forward or backwards. Once the knob is locked, it cannot slide sideways because its trapped by the pivot hole and by the knob locking the fence. I think you told us you are aboslutely sure its in the right hand pivot hole (and a snug fit)?

2) The knob - you said its in the right order - bolt, SMT, fence, washer then knob. Look on the flip side of the SMT and make sure the hex head of the bolt is trapped in the wider groove behind the slot thru the table. Two side of the hex should be parallel to and touching the groove. This keeps the bolt from turning. The bolt should be in contact with the groove and slot, no washers or anything under the bolt. The bolt head tightening against the groove is the friction that keeps the miter fence in place.
I hope you have the original bolt - if a longer bolt was substituted then the end of the bolt could be bottoming out on the knob (which is closed ended if I recall) preventing the bolt fom tightening up in the groove.
Check the SMT for crowning (e.g. is it deformed, not flat and extra high in the middle) although this in itself should not cause the miter fence to slide.

Its a very simple solid system, there's can't be too much wrong with it.

[Black wallnut]

About all that Loring left out is to make sure the black pivot is installed correctly. The "tab" need to fece the front of the fence.

As far as wax is concerned: I have ALWAYS waxed my SMT table but have NEVER waxed the SMT fence! IMNSHO to wax the rest of the saw and not the SMT table is just asking for problems, unless you always remove the SMT for any cuts other than cross cuts. The SMT by design sits slightly higer than the other table surfaces and cutting of sheet goods with an unwaxed SMT could prove to give poor rusults at the least. I can really feel a difference in feeding when my wax needs to be reapplied.

[pecker]

Occasionally my smt fence moves slightly off the quick stop when I am cutting heavier items.
Cleaning the bottom of the fence as well as the smt's top surface with denatured alcohol usually gets rid of the problem for awhile.
Also, using some 320 or 400 grit sandpaper on the two mating surfaces, to coarsen them a bit, helps too. Sand side to side...not lengthwise.

[leehljp]

I used to have some problems like this and then discovered it was a combination of my technique and an uncleaned blade.

This might not be your problem but I will list the solution to it as it was for me.

Technique:
1. Make sure everything is set properly - including the fence being tightened down while it is against the Quick stop on the left side.
2. Where do you push from? For short pieces, push from the fence with hand on the fence between the knob and the end near the blade. (But of course do not put your hand near the line of the blade). Pushing this way will put some pressure against the Quickstop and help hold it in place.
3. For longer pieces, push from the knob. For pieces sticking out beyond the fence on the left side, I put one hand on the knob and one on the fence on the left side to make sure I have a balanced steady grip and push.

Unclean Blades / resin build up and dull blades. This will cause just enough resistance to force the board back against the fence even tighter and this extra pressure can cause the fence to deflect from its 90°.

Cure for this - 1. clean blade; 2. smooth steady push; 3. hold board against the fence firmly. 4. Push steady and smoothly.

[crokett]

I second what Loring said about the bolt on the knob. When I got my saw I had problems with the fence moving and it was because the bolt was not seated correctly.

[gjat]

Sawatzky,
I'm very curious what exactly you are cutting, how big it is, and the cleanliness of your blade. These are the things I would check.
TECHNIQUE:
-Don't cut overly long lumber with SMT without properly having it supported on a slick surface. For example, if you're cutting a 5' 1x5 that hangs off 4', you are just asking for trouble.

-Make sure your blade is good and clean.

-Don't force the wood into the blade by pushing the wood too firmly. Let the saw cut.

-Push the center of the miter fence.

MECHANICAL:
-Check and make sure there are no bumps, chips, debris that is under the fence, the bottoms surface of the fence, AND the inside head of the bolt, and the inside bottom of the slot the head of the bolt goes against. It there is uneveness there, then the tension is not even accross the faces of the SMT and the fence, allowing the rocking.

-Use a star type lock washer under the head of the bolt so that it will grip the underneath of the SMT well.

-Add another washer between the knob and the top of the fence to make sure you aren't bottoming out the threads inside the knob and/or hitting the un-threaded shoulder of the bolt. I don't remember if the knob is threaded all the way through, or is closed. If it is closed on top, make sure there isn't foreign material in there keeping you from threading all the way down. If it is threaded all the way through, run a bolt all the way through to make sure there isn't an imperfection in the threads that won't let you tighten the knob all the way down.

[LCHIEN]

i agree with most everything giat says except the star washer. Since the head of the bolt is captured by the side of the groove the bolt is recessed into, there should be no way the head of the bolt will rotate. Putting a star washer or anything else will not help and can hurt by raising the bolt head to the point where it won't be grabbed by the sides of the groove.

Unless you are simply cutting a very long piece in which case you have a huge lever working against the fence, the most likely cause is that the knob is bottoming out on the end of the bolt before the bolt is tight.

[gjat]

i agree with most everything giat says except the star washer. Since the head of the bolt is captured by the side of the groove the bolt is recessed into, there should be no way the head of the bolt will rotate. Putting a star washer or anything else will not help and can hurt by raising the bolt head to the point where it won't be grabbed by the sides of the groove.

Unless you are simply cutting a very long piece in which case you have a huge lever working against the fence, the most likely cause is that the knob is bottoming out on the end of the bolt before the bolt is tight.

LCHEIN,
Tha
Those are good points, but...
He should check the star washer to make sure it doesn't raise the head beyond the walls of the groove. I don't think it can. Star washers are pretty thin.
The idea of the star washer, is to increase the friction between the bolt and the SMT table so it can't slide that 'little bit' and to help compensate for the surface irregularities between the bottom of the bolt head and the bottom of the SMT groove. The stars are all around the bolt head and should compress at the high spots and still grip at the low spots.

Though you are probablly right that the most likely problem is the knob bottoming out which an extra washer between the knob and top of fence should correct.

[Tom Miller]

I, too, have experienced the fence moving a few degrees away from the 90 degree stop while cutting. I basically fixed it with my sawing technique. Now, instead of wondering if the clamp is holding well enough, I always counter the force that would rotate the fence.

Here's my technique: I move the SMT through the cut by pushing on the back of the SMT (not the fence) with my right hand. With my left hand on the fence, I counter the force of the blade (which would pivot the fence off the stop) by pulling back on the fence, keeping it snugly against the stop, like so:






It also may be possible that your fence clamp is not clamping effectively because it's too tall compared to the fence, like so:





The gaps shown are greatly exaggerated. I'm not at my saw, right now, so I'm not 100% sure of this geometry.

Regards,
Tom

[Sawatzky]

Thank you all for all the tips! I did everything you all suggest, but still get a little play in the fence. But, I did figure out a simple way to fix all that! I just attatched a c clamp to the left edge of the fence to secure it to the table. That way I now have two clamps holding it down. Now it is secure as a rock! Don't know why I didn't that of that before!

[gjat]

Sawatzky,
It was a good question. I'm going to pay a bit more attention to what I'm doing. I may make some adjustments myself. I am careful how I push the SMT, but I think that's because it's still new to me. Even if it moves, it's 100% better than what I used to have so my standards are low, though I like the idea of clamping it just to make 'sure'.