Rigidity in an Atlas 10F lathe -HELP-

[Moderatemixed]

If your lathe is not equipped with a variable speed motor/control, why not just record all the speeds on a chart/plaque? I did that for my 9" Monarch

It has a 2Hp DC motor with variable speed..... and I’m almost done making installing the RPM gage. Otherwise, yes. Valid point!


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[shadetreedad]

Moderatemixed,

First off, that is a beautiful machine. You'll have a lifetime of fun/satisfaction with it.

Regarding the stand offs, I know there are machinists who will disagree but I three pointed my Atlas lathe with 2.5” risers on the headstock end and a single center point on the tailstock. Since I move my lathe around in a small shop on a bench with wheels this allows the lathe to have a “natural” levelness. I can take .025” cuts in steel with no issues. In aluminum .050” easily. I suppose if I took much deeper cuts there could be a problem with bed flex, but I haven't noticed any. I do use razor sharp 3/8” or 1/2” HSS bits. An AXA tool holder is perfect for that 10” lathe. Also, a singe piece plinth on the cross slide (replacing the compound) will make for a much more rigid setup. I made mine out of round stock aluminum. Same height as the compound.

Mike

 

[Nutfarmer]

Nice job on the lathe rebuild. It sure is pretty. At risk of sounding like a broken record ,loose the carbide and grind some high speed steel. There is an excellent write up by one of the members here on how to grind a lathe tool bit. With a honed edge on hss you will be amazed at how much better the atlas will perform. One other item to check is if the bearing plates on the saddle were reshimed after the bed was ground. Regrinding the bed will change the clearance between the under side of the bed and the bearing plates. Also the saddle may need to be scraped in on the reground bed. Do the simplest thing first and try a sharp high speed tool bit. Good luck. The members around here are great at helping out. Let us know how it turns out.

 

[mattthemuppet2]

But everyone starts out a beginner.

that is for sure! No truer words spoken. I started with a weird old jewelers lathe and upgraded to an Atlas 618, so you're well ahead of me - at least you don't have to worry about wear and tear being the problem.

take your time and play around. Start with the easiest materials to machine first (candles?) and work up from there. First time I ever cut some threads I used PVC pipe. Before you know it several years will have passed and you'll be offering advice to people who are in the exact same situation you are now

 

[Moderatemixed]

Moderatemixed,

First off, that is a beautiful machine. You'll have a lifetime of fun/satisfaction with it.

Regarding the stand offs, I know there are machinists who will disagree but I three pointed my Atlas lathe with 2.5” risers on the headstock end and a single center point on the tailstock. Since I move my lathe around in a small shop on a bench with wheels this allows the lathe to have a “natural” levelness. I can take .025” cuts in steel with no issues. In aluminum .050” easily. I suppose if I took much deeper cuts there could be a problem with bed flex, but I haven't noticed any. I do use razor sharp 3/8” or 1/2” HSS bits. An AXA tool holder is perfect for that 10” lathe. Also, a singe piece plinth on the cross slide (replacing the compound) will make for a much more rigid setup. I made mine out of round stock aluminum. Same height as the compound.

Mike

Would you happen to have a picture of the “plinth”, and perhaps some dimensions? Hearing that you are able to make cuts like that gives me faith and further drives me to find the source of my rigidity loss. Thanks for the comments and for taking the time.

Derek


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[gerritv]

The plinth is basically a big block of steel, same height as your compound but bolted to the cross slide. Stefan G, Rob Renzetti both have YT videos on how they made theirs.
Here is mine on a 10x22. Not quite wide enough, will be widening the base soon. In your case a tall piece of round steel the diameter of the base will be all you can do.
No doubt somone will pipe up and say 'but then you can't thread' which might be true from the usual North American approach but in EU it is normal to plunge straight in for fine threads (which is pretty much anything less than 13tpi) so not really an issue.

I still think you should just bolt the lathe to a 7 or in wide u channel

 

[shadetreedad]

Mine is aluminum. Took a few hours to make. I think it's 4" diameter. Very simple and works great. It is the same height as my compound. So, if I use the same tool holders there is no need to adjust them. I really only use the compound if cutting a taper or threading "larger" items. If it's a small diameter I just thread straight in with the cross slide.
Mike

 

[pdentrem]

My lathe was set up the same way.
Everything I can see does not point to anything that can cause your dancing to the vibs except for the tool. When I had my Atlas, I used HSS tooling with carbide coming to play on hard metals. I typically used tools with a small radius and sharp. The parting tool and some form tools caused chatter, but kind of expected.
Pierre

 

[Moderatemixed]

My lathe was set up the same way.
Everything I can see does not point to anything that can cause your dancing to the vibs except for the tool. When I had my Atlas, I used HSS tooling with carbide coming to play on hard metals. I typically used tools with a small radius and sharp. The parting tool and some form tools caused chatter, but kind of expected.
Pierre


View attachment 324928

Hey Pierre. Looking at the feet of your lathe you have put it on those plates. I can’t quite see from the pic but are there feet at each corner of each plate? It appears that your lathe would have then 8 points of contact, and 4 solid bolt downs. Mine only has the 4 bolt downs which might be part of my problem. Your lathe is beautiful, by the way. Thanks for the input and any further would be appreciated.

Cheers

Derek


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[Moderatemixed]

Mine is aluminum. Took a few hours to make. I think it's 4" diameter. Very simple and works great. It is the same height as my compound. So, if I use the same tool holders there is no need to adjust them. I really only use the compound if cutting a taper or threading "larger" items. If it's a small diameter I just thread straight in with the cross slide.
Mike
View attachment 324909

Ok great! Thanks for the pic. and for the associated insight.


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