Atlas upper compound slide modification

[Plasanator]

Not sure if I could watch him cut the compound again? gets me shaking too much.
I need a beer!

 

[kcoffield]

Really like it Ray. Noticed you mentioned the cross slide is next. I'm on with the cross slide project but would like to do something similar with the compound to accommodate the additional cross slide height. Was going to cast the iron bits myself. Had a couple questions for you.

Here it is nearly complete notice the differance in length compared to the stock one. When these started to break and I have seen a lot of them you would have thought Atlas would have fixed the problem but since they could sell more parts they just kept going with a bad design

What is the overall length you chose?

As you can see the original has the nut off center

.....and what was the rationale for why they did that?

Here it is side by side with a stock unit notice how much wider

What is the overall width? Is the dovetail width the same on the commercial version of the slide?

I'm not an Atlas aficionado so am not familiar with all the nuance differences between the models.

Best,
Kelly

 

[brino]

@kcoffield
Hi Kelly,

Just an FYI, unfortunately user @iron man hasn't been here in a almost two years:


Don't be surprised if you do NOT get a reply.......

-brino

 

[wa5cab]

I don't have a 10" or early 12" to measure. So all that I can tell you is the following.

The cross slide dovetail must be the same as the early and late taper attachments fit and the follow rest is the same. The gibs for the cross slide and the compound slide are the same so the lengths must be about the same. And the dimensions of the pintle (the inverted truncated cone on top of the cross slide must be the same as the same Milling Attachment fits.

However, the compound slide is not nearly as tall because the early 12" compound upper slide is the only part on the carriage assembly that is not the same as on the 10" version (not counting the longitudinal and cross feed interlock). So the 1" total difference in height between 10# and 12" was made up in the compound slide. On the so-called Commercial 12", the saddle is taller and heavier than the one on the 10" and early 12" was.

 

[pdentrem]

Not sure on what size lathe Kelly has.
On my 10” the gibs were the same on cross section but the cross slide gib was longer than the compound one. 4 screws vs 3 if my memory is not faulty.

Kelly here is my posting.

Replacement Compound slide for Atlas 10

I have started to make a replacement compound slide as my original cast iron one is a repaired one and I do not want to continue to use it. First you start with a block of steel and square it up. Yesterday I milled out the area for the nut for the screw and the majority of the metal where the...

www.hobby-machinist.com

Pierre

 

[kcoffield]

Just an FYI, unfortunately user @iron man hasn't been here in a almost two years:

Too bad. Thanks for letting know Brino.

The cross slide dovetail must be the same as the early and late taper attachments fit and the follow rest is the same. The gibs for the cross slide and the compound slide are the same so the lengths must be about the same. And the dimensions of the pintle (the inverted truncated cone on top of the cross slide must be the same as the same Milling Attachment fits...........However, the compound slide is not nearly as tall because the early 12" compound upper slide is the only part on the carriage assembly that is not the same as on the 10" version (not counting the longitudinal and cross feed interlock). So the 1" total difference in height between 10# and 12" was made up in the compound slide. On the so-called Commercial 12", the saddle is taller and heavier than the one on the 10" and early 12" was

Thanks for that Robert. Seemed like the dovetails would be the same. I guess I figured the 10" compound sat an inch lower and the even though the ways are thicker on the commercial, the head stock, tail stock, and carriage all sit on top the ways so I was guessing the commercial 12" compound was the same height as mine, albeit, apparently wider.

Not sure on what size lathe Kelly has. On my 10” the gibs were the same on cross section but the cross slide gib was longer than the compound one. 4 screws vs 3 if my memory is not faulty. Kelly here is my posting.

Pierre, My lathe is an earlier (circa 1937) 12" Craftsman. It's story is here....and thank you for the link to your custom compound.

New Caretaker of Two 12” Craftsman Lathes

Hi all, first post here. I’m the new caretaker of two 12” Craftsman lathes, one with a 42” bed and the other 54”. Though they recently came into my possession they are well known to me. The 42 is model 101.07403 number SN 16014 and the 54 is model 101.07403 SN 22500. The only place I’ve found...

www.hobby-machinist.com

I've read some comments about compound breakage. Dunno if the 10s are more prone to that or not. I'm thinking I only need about 1/4"-1/2" less height than my existing compound so I don't need the whole inch gained by the 10" compound. The used prices for compounds on the auction sites are pretty spendy and since I will likely modify it anyway, right now I'm thinking I'll probably just cast (iron) and machine my own tweener variant that most resembles the wider 12" commercial compound. I will take a look at a slightly longer base like iron mans build.

Still not sure I fully understand or buy into the reasoning for the lead screw being off center.

Here are the three. I dimensioned my existing compound.




Best,
Kelly

 

[wa5cab]

The only cases of compound breakage of the cast iron 10" and 3/8" bed 12" compound slides that I have ever heard of were breaking out the T-slot and were generally caused by crashes (Operator Headspace), using an inadequate T-nut such as one made on a lathe instead of a mill or one that was too short, and similar preventable mistakes. Note that I said cast iron only.