Atlas upper compound slide modification

[iron man]

I have been wanting to do this for a long time and the right part come up for grabs and I thought now would be a good time. As you can see in the photo I have two compounds the lower one is a stock 10 inch Atlas that broke in half as they frequently do. The other is a Atlas 12 inch commercial lathe compound that was for sale on this forum ( thanks Rick ) at a very reasonable price. The second problem is Atlas made a very short lower slide that offers very little support if for some reason you go past the slide as you most likely will and the tool catches the compound has had so much material removed and there is no support the compound snaps at the T slot. Plus the compound is so narrow and the dovetails are a little shallow the compound often rocks during cutting. Some guys have removed the compound made a spacer and use there QCTH without it so there is no give. ... Let's see if we cant fix that.

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Since the commercial compound is off of a 12 inch lathe it is thicker I set it up in my band saw and cut off the dove tails. This is good cast iron and cuts like butter.

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If your a purest of Atlas lathes please turn away this is after the cut I will mill the rest of the dovetail off. The casting will still be thicker in key areas because I will keep the tollerance tighter.

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For the second part I got a piece stressproof I wanted cast iron but could not find any locally and I wanted to get started so stressproof machines easyier than cold rolled and its stronger so I started in.

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Here I faced and bored the part I should mention the shaft is 5 1/4 in dia. it makes it an inch longer.

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Here I took it over to my modified wood to metal bandsaw and cut out the shape.

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I took the part over to my modified GO 727 mini mill and finished the shape I just cant leave any machine in its stock form it seems.

 

[Dranreb]

Interesting...I'll be watching this, as I do have a slotted cross slide that's much more rigid but a stiffer compound would be more useful to me..

Bernard

 

[iron man]

Well here we go milling out the main part getting ready for the dove tail.

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Now I started with a 45 degree cutter and cut out some of the material it seems that the 45 cuts easyier I then go back to a 60 degree and just clean up it is a LOT easyier on these mini mills. The dovetails are also cut to a ful depth the same as they are on the lower slide for greater contact area.

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Here is the 60 degree finishing up the rest of the cut.

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Here is the finished part I need to sink the screw and the nut to gain clearance for the compound. The stock Atlas has a groove cut down the middle that does absolutly nothing but gathers chips and weakends the compound. They also make the dove tail off center so when you crank in it will tend to cock the compound mine will be centered and since it is 3 times stronger the groove will be useful and will not affect the strength for what I am doing.

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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.

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As you can see the original has the nut off center to the dove tail and to the clearance slot this was in one wreck from the previous owner resulting in a chiped dove tail and broken compound when I got the lathe in the 80's I bought a new compound I think it was $80 bucks back then!!

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Here is where the modification on the GO 727 comes in handy I had enough clearance to drill the holes for the lock downs worked very nice.

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Now after dialing in on the remaining dovetail surface I started in taking out material for the dovetail I remove only what is need for clearance 10 thousands is as good as a mile for air gap.

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Here I am cutting the dove tail all went very well.

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All done I cut down the center of the casting to straighten it up a bit for clearance again just enough for clearance and that is it!

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Drilled the holes for the dove tail adjustments tapped 10-32.

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Here it is side by side with a stock unit notice how much wider it is and what I really like is I now have a nice flat spot that I can set my dial indicator on and I can now put on my home grown QCTH without a shim or without milling a all ready weak compound. The new one is 100 thousands thicker at the T slot thanks to careful measuring I also have a deeper dove tail.

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Clearance is tight but as I said an few thousands in this case are as good as a mile the part is still thicker everywhere compared to the stock compound.

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I left all material thick enough for strength here I just counter sunk a hole for the Acme nut hold down it probably is not needed since it fits in a tight pocket now but I put it in anyway.

 

[stevecmo]

Wow, very impressive! I bet that will make a ton of difference.

 

[Dave Smith]

Very nice work Ray and a good improvement----Dave

 

[Smudgemo]

Neat project, Ray. Out of curiosity, where'd you get the micrometer carriage stop? It looks like the one Tom Griffin made plans for on his website Tom's Techniques that I've started making. It looks really nice, too.

-Ryan

 

[iron man]

I made a cap out of a piece of 5/16 x 1 1/2 CR bar stock I installed a 1/2 x 3/8 bronze bushing it I also installed a South bend 1 1/2" direct read dial its bigger easyier to read so if I turn it one thousands I will only cut off one thousands not 2 off the total diameter. looks like I am ready for paint! be right back...

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Look here I saved the cast iron pieces I cut off the dove tail of the tool compound and made a gib out of it this.

 

[iron man]

I hate waiting for paint to dry specially this paint takes about a month to get really hard. But well worth the time it probably took as long to explain it as it did to make it. It has a much wider stance and does not wiggle around anymore it will be stronger the entire range of use. Cast iron would work fine for the compound slide I just was in to big of a hurry to get started!! This should never ever crack or break I have made steel compounds before and they work fine but this cast one saved a lot of machine work and it mills about like brass or bronze.

I have $25 in the whole project got to love that!! The dove tails and the drilling and tapping are the most intense moments the thought of breaking a mill cutter or breaking a tap or drill bit is heart breaking this did not happen but is always stressfull. the stressproof could be hardened I choose not to because it does not need it. I have made taps out of it before so it can be made to get really hard but it machines much better than cold rolled otherwise I would have just used CR bar stock. Thanks for lookin and any comments or questions always glade to help. Ray

 

[iron man]

Neat project, Ray. Out of curiosity, where'd you get the micrometer carriage stop? It looks like the one Tom Griffin made plans for on his website Tom's Techniques that I've started making. It looks really nice, too.

-Ryan

I made that from scratch never saw an artical before I made it I just needed one and started in there handy when you make your own dials.. Thanks Ray

 

[pdentrem]

Very nice! For the same reasons I too made a new top slide, and I also thought of the upper swivel but I ended up selling my Atlas and bought a over all bigger and better lathe. Nothing wrong with the Atlas, within it's limits, just wanted better.
Pierre