Why Will This Not Work?

[JPG]

The straight edge determines the straightness of a 'line' across the surface.

A .005 dip along a single line could be greater when referenced to a higher point(corner?).

Remount the dial indicator to a 'flat' piece of MDF.

Mount two straight pieces to each long side of the table.

using the straight edge, make sure the side pieces top surfaces are as coplaner as you can make them(shim them).

Slide the mdf with indicator on those side pieces.

Not perfect, but at least the reference(the side pieces) will not vary much.

[beatnik]

I agree, sounds like a twist in the table.

[dusty]

The straight edge determines the straightness of a 'line' across the surface.

A .005 dip along a single line could be greater when referenced to a higher point(corner?).

Remount the dial indicator to a 'flat' piece of MDF.

Mount two straight pieces to each long side of the table.

using the straight edge, make sure the side pieces top surfaces are as coplaner as you can make them(shim them).

Slide the mdf with indicator on those side pieces.

Not perfect, but at least the reference(the side pieces) will not vary much.

This might have been a misleading statement on my part. For the most part, I cannot slide a .001" feeler under the straight edge.

[dusty]

The straight edge determines the straightness of a 'line' across the surface.

A .005 dip along a single line could be greater when referenced to a higher point(corner?).

Remount the dial indicator to a 'flat' piece of MDF.

Mount two straight pieces to each long side of the table.

using the straight edge, make sure the side pieces top surfaces are as coplaner as you can make them(shim them).

Slide the mdf with indicator on those side pieces.

Not perfect, but at least the reference(the side pieces) will not vary much.

I am going to give this a try. It won't happen, however, for a day or two. I now have all three of my table assemblies dismantled.

I was asked by Shopsmith to make some measurements and to do what they needed I had to loosen all the trunnion bolts (to remove a stress that they might be producing).

I went one step further and removed all the trunnions completely.

I provided all of the numbers to Shopsmith yesterday and today received confirmation from Shopsmith that none of my tables are "out-of-spec".

As I reassemble, I will be making measurements to see if I can determine whether or not the tables get "twisted" in the assembly process. I have identified bosses that I feel need to be shimmed.

["Wild Bad Bob"]

OH Dusty, just make some saw dust, you arnt sending men to Mars!!! IMHO!!!LOL

[dusty]

Needs to be refined but it does work!

[ATTACH]25934[/ATTACH]

[ATTACH]25935[/ATTACH]

[ATTACH]25936[/ATTACH]

This is really a take off on a suggestion by JPG --post #11 this thread.

[charlese]

By golly! you sure have "stick to itism" Congratulations, Dusty!

Although your interests differ from mine, you certainly have a lot of machine adjustment ideas, and search for solutions until one is found. I am impressed by your ability to listen to other ideas and bring one to fruition.

[dusty]

By golly! you sure have "stick to itism" Congratulations, Dusty!

Although your interests differ from mine, you certainly have a lot of machine adjustment ideas, and search for solutions until one is found. I am impressed by your ability to listen to other ideas and bring one to fruition.

Thank you for the kind words, Charlese.

I am not so good at making fine furniture, as you are, but I do enjoy working with the equipment.

The Shopsmith often gets a bum wrap when discussing accuracy and repeatability. With my back ground, I just can not let that go unchallenged. The machine is capable of far more than it is advertised to be.

I will never create or cause to be created a precision replacement for this wood working machine but I have fun casting doubts into the path of the naysayer.

I don't have a lot of money to spend on this sort of entertainment (wife calls it nonsense) but I got a lot of stuff laying around. I just need to find ways to utilize it. I sure wish that I had been more of a scavenger when I worked in manufacturing. I know now that the trash barrel back then was really a "gold mine"; especially in the job shop.

[keakap]

... Moving Starrett 36" Straight Edge to all of the horizontal and vertical lines in the attached drawing and measuring the gap reveals no gap greater than .005".

BUT, if I relocate the straight edge to the diagonals and make those same measurements (with a feeler gauge), I have gaps in some locations as great as .012"-.014"....[ATTACH]25929[/ATTACH]

I had similar indications with my old table, where I got fairly reasonable readings with a perfect straightedge lain in "Ortho" planes, yet way outta whack errors measuring diagonally.
I then found that I had a high point at the lower left (in your drawing) of the insert opening, where the straight meets the arc.
I subsequently discovered, having an overabundance of time on my hands, that if I stood the 36" straightedge on edge and placed it's exact mid-point on that high "point", I could actually spin the S-E on that point, and it would spin for two or more complete revolutions before friction caused movement of the S-E enough off the point to where it touched elsewhere, and stopped.
Made for an interesting video.
The table was replaced, btw.