Main Table Tubes

[DLB]

Update - I've talked to SS engineering (Jim) last week and again today. Evidently my tubes were among the first out of a new lot, the first with a problem reported. But the problem is with the entire lot. It will take several weeks for me to get my replacements, in the interim SS is sending me new pins so that I can re-install my original tubes.

Order timing - I ordered this kit on February 21st and think I received it April 11th. If any readers have a similar purchase in this time frame I'd encourage you to measure these tubes on the bench before installing them. A smart phone with a level app, if available, can be substituted for the Wixie I used.

- David

[dusty]

If I understand the alleged problem is the result of non-compliant tubes.

If that is the claim, can you tell me what the defect is.

[DLB]

A straight line through the mounting holes needs to be, but is not, parallel to the flats of the racks. Those lines should be parallel within some tolerance, I'm estimating around +/- 0.5 degrees. The error on these tubes is 2.4 degrees. The error on my original tubes is 0.3 degrees.

Non-compliance gets sticky, but is usually the simplest explanation. Sometimes the buying entity does not effectively communicate the minimum requirements. Been there, done that.

- David

[dusty]

A straight line through the mounting holes needs to be, but is not, parallel to the flats of the racks. Those lines should be parallel within some tolerance, I'm estimating around +/- 0.5 degrees. The error on these tubes is 2.4 degrees. The error on my original tubes is 0.3 degrees.

Non-compliance gets sticky, but is usually the simplest explanation. Sometimes the buying entity does not effectively communicate the minimum requirements. Been there, done that.

- David

So the holes were not machined at the correct location with regard to the plane of the flats???

[dusty]

I zeroed my level on the bench top then laid the table legs on the bench top with a drill bit through the holes. Then, using a speed square across the flats in conjunction with the level I measure the flats to be about .2 degree off level with respect to the plane of the drill bit.

[DLB]

... So the holes were not machined at the correct location with regard to the plane of the flats???

That is correct.

I zeroed my level on the bench top then laid the table legs on the bench top with a drill bit through the holes. Then, using a square across the flats in conjunction with the level I measure the flats to be about .1 degrees off level with respect to the plane of the drill bit.

.

That sounds the same (functionally) to me as what I did, unless I'm missing something. I posted pictures of how I measured earlier in the thread when Ed (reible) asked about it. I measured other combinations, but in the pics I just showed an old tube compared to a new tube. The only difference I see in our setups is that I zeroed my level on the drill bit, which I think yields the identical result.

There's an obvious underlying question of what happened between the first ten years of DT/M7 production and now. I'm sure Jim knows, but he did not volunteer the information and I didn't ask. I got the impression of either a change in suppliers or a change in tooling employed, but I could be completely off on that. SS is 100% engaged in resolution of the problem, Jim described the process in detail and they are keeping a very close eye on it.

- David

[dusty]

I have had the double tilt installed for about three years. The tables goes up and down in either configuration with no problem at all. Obviously there are differences that have occurred over time.

Don't discard your old table legs. They can come in very handy, I use mine along with the Adjustable Stop Collars frequently.

[DLB]

I should have waited for your pictures to post, now I see. Our setups are functionally different, but only noticeable with the bad tubes. Set up more like yours:

New Tubes

IMG_7981.jpg (467.24 KiB) Viewed 12696 times

This looks good when in fact it isn't. The straight edge is not riding on the flats, but hitting one point on each tube. So your (Dusty's) case is normal, you can measure both flats at once only because they are in the same plane. But this version does not discriminate between good and bad. And it only measures the angle of the flats for good tubes.

In the next two photos the only thing I'm changing is the location of the straight edge to ride on each flat and circling where that puts the straight edge in relation to the other tube:

Right Flat

IMG_7982.jpg (564.79 KiB) Viewed 12696 times

Left Flat

IMG_7983.jpg (530.12 KiB) Viewed 12696 times

- David

[dusty]

WOW

I admit that I thought your estimate of 2.4 degrees was likely excessive. This makes it clear that I WAS WRONG.

[DLB]

I received a set of good double tilt main table tubes (aka Tie Bar Posts) and new tapered pins from Shopsmith yesterday. Measuring the four flats as described earlier in the thread, the worst was 0.2 degrees.

- David