Main table ribbing

[dusty]

Thanks to everyone for their contributions to this thread. The entire series of posts has been most helpful.

I should have been a bit more patient though. I read the posts this morning and when I got out in the shop I decided to check something I read rather than start another Christmas gift.

Someone had reported that their table bound and screached when it was tilted. I checked mine and yes it made some noise and it was tighter in some positions than others but I tried to make it better. Incidently, there was no way I was going to put a $20 between the crossbar ribs and the rear trunnion. I could not get a .0015 feeler gauge in there.

Aaah, this is why it binds a little and makes some scratching noises. I'll just loosen those bolts, slip that twenty in place and we'll have this thing fine tuned.....the Nick would do it.

Well, it is done and done right but I sure went through some steps that have not been previously discussed. For some reason, after loosening the bolts, the table was some bound up I could hardly move it at all. I don't know what happened but somehow between the trunnions and the tilt locking mechanism I had it all seized.

I removed the bolts (all four are the same size) and there are spacers (thich flat washers) under each. I kept track of which went where but that turned out to be unnecessary (I think).

With the trunnions completely removed (the entire table mechanism upside down on the workbench) I started to reassemble and inspect.

The trunnions are not scratched all that bad but when they are moved back and forth on their respective axis, they do screech a bit. I cleaned and was again tempted to wax but did not. They now swing quietly, except for a slight noise caused by the tilt angle indicator rubbing on the trunnion. Loosen two screws, get that out of the way and we're ready to put this puppy back together.

Now, follow the instructions and all will go well...and it did. We're back in service with the alignments as good as they ever were and the table makes very little noise when tilted. Whatever it is, I'll take care of it the next time I'm here.

I did come out of all this with one question. Why must this procedure begin with the $20 under the ribs of the rear trunnion. In fact, why are there no .005 spacers to position both trunnions with clearance.

It has been fun.

[Nick]

Just passed on your suggestion to provide a .005" feeler gauge for table alignment, Dusty, and I'm happy to tell you that the good folks on the New Product Committee pounced on your idea. If our owners don't want to use their own $20 bills, we are only too happy to provide a substitute. We have just ordered a shipment of "Andy Jackson Alignment Tools" from the United States Mint, and will shortly be selling them for $29.95, plus shipping and handling.

With all good wishes,

[dusty]

The Alignment Tool is probably a very good idea and being as I am about tools I will probably acquire one if it is anything more than a set of feeler gauges. But, my question was really "Why are permanent spacers (.005 or more) NOT used to provide a means of permanent clearance between the crossbar ribs and the trunnions. I would have already tried it but I haven't found an appropriate spacer material.

[Nick]

The purpose of the temporary shim, Dusty, is too provide a very small amount of clearance between the trunnions and the crossbar after the table is aligned. Otherwise, the table will bind when you try to tilt it. You cannot leave this shim in place; we cannot install a permanent shim here in the factory for the very same reason that you cannot leave a feeler gauge in place between the valves and the valve lifters when you set the valve clearance on an engine. The only purpose of the dollar bill/shim/feeler gauge is to set a .005" clearance; it must be removed after the alignment procedure or there will be no clearance.

By the way, we do offer .005" shims and for a whole lot less than $29.95. Even less than $20! See page 37 of the latest catalog, #521934. This dado shim set comes with several .005" shims as well as other sizes.

[Ed in Tampa]

Nick
I think you missed Dusty's point. If there should be .005 clearance between the trunion and the crossbar why not put a .005 shim/washer on the piviot to insure the clearance?

Of course the clearance wouldn't be maintained where the washer contacts both parts but it rub area would be so small it would be inconsequential. If need be, the washer/shim could be nylon or that slippery plastic.

I think the shim/washer idea would do two things. First insure and maintain a proper clearance between the crossbar/trunion. Secondly it would tend to remove any slop in the table.

Ed

[Nick]

Doesn't work that way, Ed. Even if you had a shim in the pivot, you would still need to insert a temporary .005" shim between the back trunnion and the crossbar ribs to properly set the clearance when doing the table alignment.

With all good wishes,

[dusty]

Ed;

I had the same question (as you see in the thread) and some doubt that I had communicated my thoughts about the $20 alignment procedure being replaced by a permanent shim.

I set out to convince myself that I could use a shim. I was almost so convinced that I about tore down the table that I had worked so long to get aligned so well.

Sit and stare at the detailed drawing with the proposed shim location in mind. The $20 holds the trunnion and the table tie bar apart (by the thickness of the $20 bill).

The shims that I wanted to install were on the shaft that the trunions swivel on. In that location, the shims would actually reduce the clearance rather than insure adequate clearance.

To put the shims on the other side of the trunnions would require that the shim be trapped between the tie bar and the trunnions. This is the very space where we are attempting to elimate drag (friction).

My table moves between vertical and horizontal as easy as when it was new. The table alignments have never been closer. I have learned to leave a good thing be.

I thank SS and everyone who has contributed to this thread. They don't know it but their inputs have all served to reinstill in me the confidence that I had in my SS before I was laid up. That long time away created in me some doubt about my using the SS any more. I no longer have that doubt.

My next significant project is an oak hope chest for my oldest granddaugther.

[hfmann]

I thank SS and everyone who has contributed to this thread. They don't know it but their inputs have all served to reinstill in me the confidence that I had in my SS before I was laid up. That long time away created in me some doubt about my using the SS any more. I no longer have that doubt.

Ditto here Dusty. As I've been slowly returning to this woodworking hobby, I'm been "hanging out" in some of the other woodworking forums. The discussions a lot of those folks have about precision had me wondering if a "mobile" unit like my SS could hold the tolerances so many seek. I'm anxious to get out there now and rekindle my woodworking efforts. I've been away too long. Thanks everyone!

Hal

[Bruce]

Also check the mounting bolt holes in the trunnions. All four bolt holes should be the same size. If two holes are 3/8" dia and the other two are 1/2" dia, you may have a bad run that got past us many years back. When the table is tightened down, the improperly machined trunnions pull the table out of true. Send us the trunnions; we'll check them; and if necessary, replace them.

Nick,
When I had trouble getting my table to stay in alignment, I decided to check the mounting holes. It looks like I got one of the bad ones. The holes on the front trunnion are 1/2 inch and those on the rear are 3/8 inch. Bummer! What does it take to remove the trunnions?

Bruce