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Do We All Agree

Posted: Thu Aug 04, 2016 7:49 am
by dusty
that when performing a Main Table Alignment the primary objective is to get the table properly oriented with respect to the saw blade. Properly oriented meaning that the blade is parallel (at all points equal distant) to the miter tracks.

Re: Do We All Agree

Posted: Thu Aug 04, 2016 7:52 am
by JPG
dusty wrote:that when performing a Main Table Alignment the one and only objective is to get the table properly oriented with respect to the saw blade. Properly oriented meaning that the blade is parallel (at all points equal distant) to the miter tracks.
'Alignment', absolutely!

There are other 'adjustments'.

Re: Do We All Agree

Posted: Thu Aug 04, 2016 8:45 am
by dusty
JPG wrote:
dusty wrote:that when performing a Main Table Alignment the primary objective is to get the table properly oriented with respect to the saw blade. Properly oriented meaning that the blade is parallel (at all points equal distant) to the miter tracks.
'Alignment', absolutely!

There are other 'adjustments'.
You are probably referring to "table tilt" and you are correct. They would be part of a procedure to achieve "complete table alignment". I rely on the "zero tilt" table stops only and tend to ignore the 45° stop. If I tilt the table I set it using other methods.

I also align the table so that the axis of rotation (of the main spindle) is at a specific location on the table. I am likely the only one to do this but it does come into play during drill press operations.

Re: Do We All Agree

Posted: Thu Aug 04, 2016 9:42 am
by Ed in Tampa
I also believe there can be a twist between the blade and table. This twist I believe is the reason the aux table can not be used on both ends of the Shopsmith in many cases.

The table can be perfectly aligned by your definition but the center axis of the head stock and center axis of the main table are not aligned.

Just thinking as I wrote this. I wonder what would happen if we used a plumb bob and right angle. One on the center line of the headstock and the angle on the main table. Are these two on the same plane? Or are they skewed from the other front or back.

Re: Do We All Agree

Posted: Thu Aug 04, 2016 12:12 pm
by charlese
dusty wrote:that when performing a Main Table Alignment the primary objective is to get the table properly oriented with respect to the saw blade. Properly oriented meaning that the blade is parallel (at all points equal distant) to the miter tracks.
Yes! Absolute agreement from this location. :D

Re: Do We All Agree

Posted: Thu Aug 04, 2016 1:17 pm
by dusty
Ed in Tampa wrote:I also believe there can be a twist between the blade and table. This twist I believe is the reason the aux table can not be used on both ends of the Shopsmith in many cases.

The table can be perfectly aligned by your definition but the center axis of the head stock and center axis of the main table are not aligned.

Just thinking as I wrote this. I wonder what would happen if we used a plumb bob and right angle. One on the center line of the headstock and the angle on the main table. Are these two on the same plane? Or are they skewed from the other front or back.
If the table is flat would there be a twist?

If there is a twist would that change the distance from the miter slot to the blade significantly?

A Graphic from a Different Thread Different Subject but same axis:

The dashed lines are the axis of rotation.

Re: Do We All Agree

Posted: Thu Aug 04, 2016 4:09 pm
by everettdavis
I believe we all agree on the purpose, yet suspect we have various ways of aligning things based on the reference tools we have, and the tolerances they can sustain.

Earlier this year I wrote a post titled "My method to the alignment" I took that and combined my thoughts and comments, adding one more section titled "A final check" and condensed it all into the attached PDF.

There are many folks here who are exceptionally talented and who achieve very tight tolerances in their masterful workmanship that have valuable knowledge and experience, who do it somewhat differently, or who have finer precision tools than I have access to, as they achieve alignment on their Shopsmith and other equipment.

Do we all agree? I think so.

Do we phrase it the same way, or use the same tools? Likely very similar.

To that discussion, I respectfully add the following PDF to this discussion.

Everett

Re: Do We All Agree

Posted: Thu Aug 04, 2016 4:36 pm
by dusty
Excellent paper. I can not take exception to anything said therein.

Re: Do We All Agree

Posted: Thu Aug 04, 2016 10:13 pm
by Ed in Tampa
dusty wrote:
Ed in Tampa wrote:I also believe there can be a twist between the blade and table. This twist I believe is the reason the aux table can not be used on both ends of the Shopsmith in many cases.

The table can be perfectly aligned by your definition but the center axis of the head stock and center axis of the main table are not aligned.

Just thinking as I wrote this. I wonder what would happen if we used a plumb bob and right angle. One on the center line of the headstock and the angle on the main table. Are these two on the same plane? Or are they skewed from the other front or back.
If the table is flat would there be a twist?

If there is a twist would that change the distance from the miter slot to the blade significantly?

A Graphic from a Different Thread Different Subject but same axis:

The dashed lines are the axis of rotation.
The twist would be in the way bars or the carriage or the main table support tubes, or in the trunnions. It would shift the table center line front or back and it could hold the main table so that is not perfectly level.

I know my table could be In perfect alignment but the aux table could not be installed on either end. I adjusted for the twist by using the set screw at the left end back side of way tube connector thatremoved the twist, I then readjusted my table to once again perfect and now my aux table goes on either end without binding the connector tubes.

I wish I had tried the plumb bob and framing square to see if it revealed the twist.

Re: Do We All Agree

Posted: Thu Aug 04, 2016 11:45 pm
by JPG
I have often stated my belief re way tube twist and that the purpose of that big set screw is to adjust it 'away'.

Yes that twist can make aux table use on both ends impossible.