Shopsmith Forums

JPG wrote: ↑Tue Jan 11, 2022 1:41 pm Consider that the smaller "500" table is more suitable in this application.

Thanks, I will keep that in mind. I didn't have a ~500 version handy to look at, mine is in the attic. I'll defer the table anyway, I have some other things I want to try. I don't really need the main table, but it is intriguing.

My estimate is 1-1/8" shorter way tubes than bench tubes for the version I want to make. I'm hoping I got this right for obvious reasons. There seems to be a bit of error tolerance using two Headrests. One of the old threads I found was by someone that made the mini too small for connecting SPTs, not a good outcome.

- David

DLB wrote: ↑Tue Jan 11, 2022 5:49 pm

JPG wrote: ↑Tue Jan 11, 2022 1:41 pm Consider that the smaller "500" table is more suitable in this application.

Thanks, I will keep that in mind. I didn't have a ~500 version handy to look at, mine is in the attic. I'll defer the table anyway, I have some other things I want to try. I don't really need the main table, but it is intriguing.

My estimate is 1-1/8" shorter way tubes than bench tubes for the version I want to make. I'm hoping I got this right for obvious reasons. There seems to be a bit of error tolerance using two Headrests. One of the old threads I found was by someone that made the mini too small for connecting SPTs, not a good outcome.

- David

I don't understand why 1 1/8" shorter ways. The production ways are 3/4" shorter than the bench tubes.

dusty wrote: ↑Wed Jan 12, 2022 7:06 am I don't understand why 1 1/8" shorter ways. The production ways are 3/4" shorter than the bench tubes.

I'm planning to assemble it from two Headrests, leftovers from a couple of upgrades. The production 3/4" difference isn't, I reckon, allocated evenly between Base and Headrest. More of it is due to the assembly at the Headrest end. I didn't determine the exact amounts, so I'm estimating. In writing this, I realize that I could have done better. The Headrest end has some variation, which is why I estimated. I should have determined the exact amount to allocate to the Base end which has virtually no variation, this would have been more accurate.

This is the other side of the coin from the way tubes not fitting all the way into the DT Base Arms (two Bases). To fit snug, those ways would be closer to the length of the bench tubes. I don't like that fit, but I recognize it is correct per the instructions. My Mark 7, made from upgrades, is that way. My shorty is not, the tubes are fitted so that all four tubes are bottomed out in their castings. I like that fit better.

- David

FWIW I sorta blindly(by feel) measured my Goldie(upright and assembled) and determined that the bench tubes need to be 7/8" longer than the way tubes. The way tubes enter the tie rod 1 7/8". The bench tubes enter the headrest about 2 1/4. The ends of the tiebar and the headrest casting are almost coincident(about 1/16" gap).

So (2 4/16 + 1/16 ) - (1 14/16) = 1 21/16 - 1 14/16 = 7/16



x 2 (both ends) = 7/8 difference in length. Way tubes shorter by 7/8".


?????

We differ by 1/8" each end. Yer way tubes into the base 2 3/8"???

JPG wrote: ↑Sat Jan 15, 2022 3:45 pm FWIW I sorta blindly(by feel) measured my Goldie(upright and assembled) and determined that the bench tubes need to be 7/8" longer than the way tubes. The way tubes enter the tie rod 1 7/8". The bench tubes enter the headrest about 2 1/4. The ends of the tiebar and the headrest casting are almost coincident(about 1/16" gap).

So (2 4/16 + 1/16 ) - (1 14/16) = 1 21/16 - 1 14/16 = 7/16



x 2 (both ends) = 7/8 difference in length. Way tubes shorter by 7/8".


?????

We differ by 1/8" each end. Yer way tubes into the base 2 3/8"???

That is 1/8" different shorter than production tubes. Why the difference???

JPG wrote: ↑Sat Jan 15, 2022 3:45 pm ...
?????

We differ by 1/8" each end. Yer way tubes into the base 2 3/8"???

Yes. My bench tubes are into the Headrests 2 3/8" to 2 7/16". Headrest accommodates a lot of variation here as long as it's on the plus side.

I don't have it working yet. I'm getting some twist in the whole bench when I lock the Headrests. Big setscrews are backed out for no contact.

- David

David - Big setscrews are what are adjusted to eliminate way tube twist. They NEED to be a bearing surface.

Dusty - The tube lengths are the result of the amount the tubes go into the head rest casting and tie rod and both parts of the right base casting. Since the headrest/tie rod differs from the hinged end, the resultant dimension difference between the way tubes and bench tubes is not the same as 'normal'.

JPG wrote: ↑Sun Jan 16, 2022 9:31 am David - Big setscrews are what are adjusted to eliminate way tube twist. They NEED to be a bearing surface.

Dusty - The tube lengths are the result of the amount the tubes go into the head rest casting and tie rod and both parts of the right base casting. Since the headrest/tie rod differs from the hinged end, the resultant dimension difference between the way tubes and bench tubes is not the same as 'normal'.

I understand all of that but unless the castings are different the insertion depth (at least on my three sets) are all the same. Now, I do not have a 500 so that may be the "gotcha".

DLB wrote: ↑Sun Jan 16, 2022 9:03 am

JPG wrote: ↑Sat Jan 15, 2022 3:45 pm ...
?????

We differ by 1/8" each end. Yer way tubes into the base 2 3/8"???

Yes. My bench tubes are into the Headrests 2 3/8" to 2 7/16". Headrest accommodates a lot of variation here as long as it's on the plus side.

I don't have it working yet. I'm getting some twist in the whole bench when I lock the Headrests. Big setscrews are backed out for no contact.

- David

Can you id the twisted tubes independent from the castings? Roll them across the floor.

Twisted pair and a single bent tube are not the same thing.

The twisted pair results from the ends not being in the same plane. Think wind in a piece of wood.