Main Table Alignment Fun

2bits · Post by **2bits** » Tue Jan 31, 2012 6:30 pm

robinson46176 wrote:Precision table adjuster on the right.

[ATTACH]15966[/ATTACH]

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I like farmers approach. If it don't work right, Get a bigger Hammer:D

Culprit · Post by **Culprit** » Tue Jan 31, 2012 7:21 pm

"If you can't fix it with a hammer, you have an electrical problem."

- Mechanical Engineer's Creed

JPG · Post by **JPG** » Tue Jan 31, 2012 9:22 pm

jm51 wrote:Just a thought but does the table HAVE to be connected to the Shopsmith for alignment?

Loosen the bolts then have the main table upside down in a jig that will firmly hold the table and the tubes. Once they're going nowhere, tighten the bolts.

If it's still out of alignment, the jig needs work.

Geez! It is bad enough to adjust to the variability of the carriage, headstock, table tubes, trunion, quill bore. . .

Adding the creation of a jig that replicates all those aberrations? I do not think so!

beeg · Post by **beeg** » Tue Jan 31, 2012 10:36 pm

It's EASY to align the table. The hard part is tightening the bolts so they don't move the table.

algale · Post by **algale** » Tue Jan 31, 2012 10:41 pm

beeg wrote:It's EASY to align the table. The hard part is tightening the bolts so they don't move the table.

Ain't that the truth!

JPG · Post by **JPG** » Tue Jan 31, 2012 10:41 pm

beeg wrote:It's EASY to align the table. The hard part is tightening the bolts so they don't move the table.

Double washers??? Like the miter gauge last week.

eagleta2 · Post by **eagleta2** » Wed Feb 01, 2012 12:40 am

I recently went through this also...

Here was my procedure... align, check, tighten, check, swear, loosen, throw wrench, repeat.

So I got to thinking...do you guys think this would work?

Get a piece of flat bar with a ground face that would lock into miter slot with a set screw and stick up about .500 above table surface. Then have an 8" piece of tooling plate that is known to be square made to connect to shaft on head stock and lock on with a setscrew. On the opposite end of tooling plate there would be two cutouts whereby you could securely clamp this plate to the bar that is locked into the miter slot.

Then wouldn't the table be clamped securely and maintain perfect alignment as you tighten the front trunnion bolts?

Please help me think through the pros and cons of this and let me know if you think it will work. Maybe I can have some machinist friends Fab one up for testing...

Thanks
Geo

algale · Post by **algale** » Wed Feb 01, 2012 7:22 am

JPG40504 wrote:Double washers??? Like the miter gauge last week.

That's just simple enough to work!

algale · Post by **algale** » Wed Feb 01, 2012 7:27 am

eagleta2 wrote:I recently went through this also...

Here was my procedure... align, check, tighten, check, swear, loosen, throw wrench, repeat.

So I got to thinking...do you guys think this would work?

Get a piece of flat bar with a ground face that would lock into miter slot with a set screw and stick up about .500 above table surface. Then have an 8" piece of tooling plate that is known to be square made to connect to shaft on head stock and lock on with a setscrew. On the opposite end of tooling plate there would be two cutouts whereby you could securely clamp this plate to the bar that is locked into the miter slot.

Then wouldn't the table be clamped securely and maintain perfect alignment as you tighten the front trunnion bolts?

Please help me think through the pros and cons of this and let me know if you think it will work. Maybe I can have some machinist friends Fab one up for testing...

Thanks
Geo

This is somewhat similar in principle to the technique Dusty uses, although his is a piece of aluminum stock that he backs up against the fence and then this is bought up to the blade. The problem with this, I think, is that there's nothing to prevent the slight rotation of the table as the bolts are tightened. As has been observed above, it isn't that hard to align the table with the bolts loose, the devil is in tightening the bolts and maintaining that alignment.

EDIT: I re-read your thread and I see the difference. You make provision for clamping the piece in the miter bar to the piece connected to the arbor. I think that this might work. However, I would be concerned about imparting the twisting force of the table, as you crank down the trunnion bolts, to the spindle. The spindle and its bearing might not like it.

pennview · Post by **pennview** » Wed Feb 01, 2012 8:05 am

Algale, yes you need to use your eyes and ears when making test cuts after aligning the saw, but preventing kick back is not the only benefit or purpose of alignment. And, aligning the blade and fence to the miter slots is not the end of the alignment process. Test cuts tell you if you got the set up right, otherwise you learn when cutting wood for a project.

If the back of the blade is closer to the fence than the front, you risk kickback or burning the sawn edge. If it's the other way round, the wood pulls away from the fence and you won't get a straight cut. If you force the wood against the fence, you get burning.

How far out of line you must be to risk a kick back is not a fixed amount. It depends on the width of the carbide tip and the thickness of the plate or body of the saw.

If the blade is not perpendicular to the miter gauge, you indeed get a wide kerf, but you also get increased chip out and a ragged cut and scoring along the cut line. Part of the set up also is to ensure the blade is perpendicular to the saw table. Simply flipping the board over and putting the sawn edges together shows the accuracy of this part of your alignment. If the blade is not perpendicular to the miter gauge, you get an angled cut. Flipping the board over and putting the sawn edges together demonstrates if you got this alignment right.

Test cuts point out the accuracy or flaws in your set up.