Shopsmith Forums

No one else interested? Really, Dusty, there are six pages and counting of replies. That's a decent amount of interest.

algale wrote: ↑Fri Dec 11, 2020 5:36 pm No one else interested? Really, Dusty, there are six pages and counting of replies. That's a decent amount of interest.

Dusty,

I second Alan's comments above. Your post has generated some definite interest. I haven't found a need to maintain alignment on an auxiliary table on the left & right side, but it may just be that I have never come across the application that demands it in my shop. If anyone has good justification for this double alignment of the auxiliary tables please share it to enlighten me. Please continue to share your findings on this investigation.

I will continue my quest and I will post any significant information that I learn as I go.

What I would like to hear from those who have extension tables that can not be exchanged is why.

Are the front and rear rails not in line? Are the table tops not co-planar? Are the diagonals not equal (meaning the tables are not square with one another.

All of this presupposes that the Main Table is done first and found to be in proper alignment with the blade. The Main Table is the key reference for the other tables. Among all else, the tubes must slide smoothly through all of the involved rails. Just saying that they are not interchangeable provides very little to go on.

I don't assemble the system and then begin taking measurements. I build from the Bench Tubes and Castings up while making measurements as I go.

Not having two extension tables, I can't give you the diagonal measurements you want, Dusty. Next time I'm in the shop (this weekend) I'll try to switch the extension from right to left and see if I can figure out what it was that didn't work.

Lack of 'meaningful' participation does NOT mean lack of INTEREST.

Dusty,

I have two tables and will set them up this weekend if I get the time. You want diagonal measurements?

Jack

claimdude wrote: ↑Sat Dec 12, 2020 9:25 am Dusty,

I have two tables and will set them up this weekend if I get the time. You want diagonal measurements?

Jack

Yes, I very much appreciate the effort.

I made some progress today on the Extension Table issue but I am not certain which way I moved - toward an under standing or away.

Measuring the various diagonals to verify tables square to one another seem to be promising. All of my early morning measurements were promising. Then it dawned on me tat I could mount the Main Table in the carriage and make measurements there. I would then have the Main Table and two Extension Tables. This would allow me to slide the carriage to the right, install table tubes and check table alignment. Now move the carriage to the left and check alignment. Had to tweaked the rails a bit but got that done. Now, back to the right side. Looks good.

Well since this exercise in all about swapping extension tables it seemed to be the right time.

Must now express out loud what I said there in the shop at this point.

No, they did not line up. No where near. Bent table rails - gotta be.

Dug out the seldom used log table rails, swapped the extension tables back to where they were originally aligned and installed the long table rails. This connects the Main Table to both of the Extension Tables - just like a normal set up but without a headstock.

Much to my surprise the carriage with Main Table mounted slides back and forth with ease and the Extension Table mate with the Main Table on both ends. Naturally - that is how they were aligned.
Next step has to be "swap extension tables" and ponder the results - but that will be another day. I gotta sleep on this.

dusty wrote: ↑Sat Dec 12, 2020 2:27 pm
Well since this exercise in all about swapping extension tables it seemed to be the right time.

Must now express out loud what I said there in the shop at this point.

No, they did not line up. No where near. Bent table rails - gotta be.

That's what I remember with my one extension table. Works great on one; when swapped to the other the tubes won't work. It isn't bent table rails.

Here's Nick's old Sawdust Session video showing how to align the extension table.
https://www.youtube.com/watch?v=EpuDalM ... e=emb_logo

He aligns it perfectly on the right side (video shot from backside of Shopsmith makes it look like left side in video). Just before the 12:00 mark he moves it to the other end. At the 14 minute mark he spins the machine around. Spends the next almost two minutes demonstrating that the table tubes wont slide through the extension table that he just swapped. And at the 15:48 mark he starts talking about the "secret" adjustment (anti-twist) screw under the headrest hat you purists hate and which the double tilt doesn't have. After adjusting that anti-twist screw, the tubes slide through the extension table fine. BUT, HE NEVER SWAPS THE TABLE BACK so we are left wondering whether, after the adjustment to the twist, does everything still lines up when he swaps the table back?

As one of those 'purists' I have no problem with this version of when to adjust that set 'secret' screw. A lot of non obvious compensation is occurring with the use of the 520 tubes etc.

Earlier (M5/500) procedures included main to aux table top coplaner and parallel to rails adjustments. The 520 rail/tube eliminates the need for those two adjustments as well as the independent mounting bolt/double nut being existent.

Where this purist has issues with adjusting that set screw is when one ignores the reason for the set screw adjustment and causes the way tubes to acquire a twist.

Note Nick mentioned that he misadjusted that set screw 1/4 turn so as to create the misalignment(l/r) in the first place.

So what he did was put the way tube twist back to normal(0° twist).(assuming correctness to begin with)

FWIW only if the way tubes have 0 twist will there be any possibility of l/r interchangeability.

So this purist only objects when all the things the 520 brings to this effort are NOT available.