Extension tables

keakap · Post by **keakap** » Sun Aug 23, 2009 11:41 pm

[quote="JPG40504"]THANK YOU FOR THE DIMENSIONS!:)

WOULDN'T PLACING A 1/64" SHIM(.016...) BETWEEN THE "OLD" SPACER AND THE TABLE ALLOW ALIGNMENT WITH THE 'OTHER'(NEWER) 510 VERSION? THIS MOVES THE INNER WALL OF THE TABLE TUBE TO THE SAME DISTANCE FROM THE TABLE AS THE THINNER(NEWER) WALL TABLE TUBES.]

And now moves outer walls further from the table, rails further apart.
Pluses and minuses.
This is an odd situation. Table alignment may be the secondary concern.
The connector tubes align assemblies at the inner wall (away from the table) of the rail tubes (in this case automatically mis-aligning the outer walls).
The fence aligns against the outer wall.
The outer wall of the shimmed old would still be unaligned with the new, and with 1/64 front added to 1/64 rear, fence clamping now would be effected.

I know, it is hard to envision without seeing it up close and personal. It's probably hard to envision, too, how utterly annoying it is, having to remember and inject different work-arounds for almost every different setup (not to mention potentially dangerous).

If you had two pieces of wood, one 3" wide, the other 3-1/2", and put them down on the bench up against a straight edge, try to imagine how you are going to get anything to align with the front edges. Think of the pieces as segments of the outer walls of the rail tubes.

I believe I had already posted the dimensions in a different thread, earlier, and a list of sorts of the various problems the odd rails cause. There is no single 'fix' that I've been able to think up, other than rails that match. I'd love to find one. (Dusty almost had a fix worked out, but alas we found out the rails are different in more than one particular.)

Thanks for the idea, though!

iclark · Post by **iclark** » Mon Aug 24, 2009 1:47 am

keakap wrote:I believe I had already posted the dimensions in a different thread, earlier, and a list of sorts of the various problems the odd rails cause. There is no single 'fix' that I've been able to think up, other than rails that match. I'd love to find one. (Dusty almost had a fix worked out, but alas we found out the rails are different in more than one particular.)

the dimensions were in your post in #28 in this thread. thank you.

as a (very) naive suggestion: could you take some 3" wide shim material and slip it inside the thinner-wall tubes? spring steel would probably not lie close enough to the wall (unless you can temper it as a slotted cylinder), but some sheet brass might work nicely if it is formed around the right sized pipe before insertion. if I did the math right, a 3" wide strip would leave ~0.3" gap for the tightening screws.

care to expand on those other particulars?

JPG · Post by **JPG** » Mon Aug 24, 2009 1:47 am

You are correct. I overlooked the movement of the outer surface. That leaves us with inserting a 1/64" shim stock inside the 'new' tubes. Long (the length of the table tubes) and narrow! Method of retention? - super glue???? Bend around the ends????

JPG · Post by **JPG** » Mon Aug 24, 2009 1:50 am

iclark wrote:the dimensions were in your post in #28 in this thread. thank you.

as a (very) naive suggestion: could you take some 3" wide shim material and slip it inside the thinner-wall tubes? spring steel would probably not lie close enough to the wall (unless you can temper it as a slotted cylinder), but some sheet brass might work nicely if it is formed around the right sized pipe before insertion. if I did the math right, a 3" wide strip would leave ~0.3" gap for the tightening screws.

care to expand on those other particulars?

Since it is only needed against the inside of the outer wall, it need not be so wide. 1" would probably suffice!

iclark · Post by **iclark** » Mon Aug 24, 2009 2:47 am

JPG40504 wrote:Since it is only needed against the inside of the outer wall, it need not be so wide. 1" would probably suffice!

I was thinking that 1" wide might be harder to get to curve the right way and might require bonding to the inside of the tube to keep it in the right place.

3" would give you an inner sleeve with a slot for the tightening screws. 2" might be enough to guarantee that there is always a shim in the right place to tighten against without having to glue it in place.

keakap · Post by **keakap** » Mon Aug 24, 2009 9:59 pm

iclark wrote: as a (very) naive suggestion: could you take some 3" wide shim material and slip it inside the thinner-wall tubes? ...
care to expand on those other particulars?

Not naive at all, imho.
That was one option. I actually went looking for a suitable material, but not very hard, I'll admit. I didn't like the idea of mounting them permanently (looking to future options) and not mounting permanently raised my hackles, thinking of holding one in place with one hand and the other with the other hand, while trying to insert the connector with the other hand and then doing the same on the rear and hoping one or more didn't fall out before I made that rip cut...
Or gluing it to the connector tubes.
Yes, that would take care of a lot of things, but not all. And I actually do have "shims" that I can stick in there for one operation, if desperate.

Anyone who has the old style rails can tell you that there's not a lotta slop between the connector tubes and the rails. And with tables all of different size a small discrapancy can ruin your mood.

The particulars:
>the measurements: I recorded caliper readings; my analog caliper reads 1/64 per division. I saw no reason to go buy a better caliper or go into greater depth (no pun intended); but when I said, to illustrate the point, that one read 7/64 and the other read 6/64, I was "rounding off" somewhat. (for instance, "7/64" may actually have been 53/512). There were variations. My eyes started to cross when I got to the point of trying to interpolate what appeared to be a disparity of some 3.4 ten-thousandths and extrapolate that to the other variations, none of which matched. If the shim can't be perfect, why bother?

To this point, the biggest bummer is this: you just don't know from one setup to the next what will be in alignment.

>Eventually I want to move up to the 520 system. I do not now know what that will entail. I've asked SS support and am awaiting a reply. In the interim I don't want to mess up the one "new" set of rails I have.

>fence lock: the outer-rail-surface depth dimension, i.e. from your tummy against the front rail to hooking your fingers over the back of the rear rail
if the rails are shimmed to the table, this dimension will differ from the Main.

Seems like there was something else, but it escapes me now (do I hear applause??).

Cheers.

JPG · Post by **JPG** » Tue Aug 25, 2009 12:03 am

Any shimming done to 'correct' different wall thickness in the 'new' tables so as to be 'compatible' with older thicker wall table tubes would have to be done to ALL 'new' tables. This INCLUDES the main table!

iclark · Post by **iclark** » Tue Aug 25, 2009 1:55 am

keakap,

thanks for the reply. very informative.

Ivan

keakap · Post by **keakap** » Tue Aug 25, 2009 3:23 am

every responder- I appreciate your trying to understand and help. 'Tis a weird situation I'm in.

On the one hand I was SO glad to find why I was unable-- for decades-- to use the machine the way it shoulda been (i.e. I'm maybe not a complete idiot after all) and on the other hand sad to realize it could get no better.

I just bought at the wrong time, it seems. I have a piece of crap whose main purpose, it seems, is to irritate me, and produce a lot of firewood (not a bad thing in Santa Venetia, California, but useless here).

dusty · Post by **dusty** » Tue Aug 25, 2009 7:36 am

I have been silent in this discussion because I do not undertsand how wall thickness makes a difference. Keakap and I have worked this issue offline and we were unsuccessful obviously.

The location of the inner wall with respect to the edge of the table (machined platforms) or the diameter of the rails is not critical to table alignment. The rails simply need to be aligned so as to be in line with one another (outer edge). This can be done by shimming the rails when they are installed. Tedious, yes - impossible, no.

Will you be able to secure the tables in position on the rail? That may be another story.