# Atlas 10f Question



## Bill Rosselot (Sep 12, 2016)

Ok I've got an Atlas 10F and it is mid 50's I've taken it all apart and cleaned it and replaced most of the worn or broken parts.  There are two things that I still need to get but not in a big hurry is a 4 jaw and maybe a steady rest.  But my Question is the motor that came on the lathe was an ATLAS 3phase 1/2 hp. So I had a 1phase 1/2 hp laying around in the shop off of an old joiner.  But I've been told that it you need a reversing motor but if if you have a reversing motor and running it in reverse wont you turn the chuck off?  I know dumb question.  Also I do need to find a motor pulley the one that came with the lathe was broken.


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## westsailpat (Sep 12, 2016)

It will absolutely unscrew the chuck , every time I see one of our machines with a reversing switch it makes me wonder why someone would do that . Maybe I'm missing something ? OK It's a little early in the morning for me to figure forces and rotation , but just a simple taping operation would do it .  As for a new pulley McMaster Carr is hard to beat .


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## wa5cab (Sep 12, 2016)

Bill,

There are only a few operations where you might want or need to reverse the motor.  And if you do, and are using a chuck to hold the work piece, there is a risk of the chuck coming loose.  I wouldn't worry about a reversing switch.  The only operation I can recall that was common to the Atlas machines  years ago was if you were using the double turret cross slide, the parting off tool was commonly installed in the rear turrent.  If it was installed with the cutting edge up, you had to reverse the spindle rotation to use it.  The obvious work-around is to install it upside down.  But most operations where a shop would be making small parts with the double turret cross slide, the work was being held in a collet anyway.  So reversing the motor in those circumstances would have been safe.

On the motor pulley, they are still available new from Clausing.  And used ones can sometimes be found on eBay.  But they ain't cheap!  Part number (for 5/8" shaft diameter) is 10-428.  The part number for the 1/2" shaft diameter was 9-428 but production of those ended long ago.  They have been supplying a reducing bushing since the 1950's.  I haven't bought a 10-428 from Clausing but recently bought an M6-429 (for 6" lathe and early mills) and it was machined SS, not cast.  Which accounts for the price.  If you look in DOWNLOADS, you will find a reverse-engineered drawing for 10-428.  The person who did the drawing reported making one and said that it worked fine.


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## Bill Rosselot (Sep 12, 2016)

wa5cab said:


> Bill,
> 
> There are only a few operations where you might want or need to reverse the motor.  And if you do, and are using a chuck to hold the work piece, there is a risk of the chuck coming loose.  I wouldn't worry about a reversing switch.  The only operation I can recall that was common to the Atlas machines  years ago was if you were using the double turret cross slide, the parting off tool was commonly installed in the rear turrent.  If it was installed with the cutting edge up, you had to reverse the spindle rotation to use it.  The obvious work-around is to install it upside down.  But most operations where a shop would be making small parts with the double turret cross slide, the work was being held in a collet anyway.  So reversing the motor in those circumstances would have been safe.
> 
> On the motor pulley, they are still available new from Clausing.  And used ones can sometimes be found on eBay.  But they ain't cheap!  Part number (for 5/8" shaft diameter) is 10-428.  The part number for the 1/2" shaft diameter was 9-428 but production of those ended long ago.  They have been supplying a reducing bushing since the 1950's.  I haven't bought a 10-428 from Clausing but recently bought an M6-429 (for 6" lathe and early mills) and it was machined SS, not cast.  Which accounts for the price.  If you look in DOWNLOADS, you will find a reverse-engineered drawing for 10-428.  The person who did the drawing reported making one and said that it worked fine.




Thanks very much, I was being berated on another forum about how come I did not have a reversing motor on my lathe and I told everyone that it will spin the chuck off, I guess that is what I get for listing to guys that dont know anything about an Atlas.  I've been slowing getting things back together and working.  It is under power now and it the first time since 1970 or so.  I found a single pulley in my inventory that is the same size (DIA) as the small side of the original step pulley so I can go through that range of speeds but was planning on using some carbide insert tooling so I think I need all the speed ranges to dial in what works the best.


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## wrat (Sep 12, 2016)

Bill Rosselot said:


> Thanks very much, I was being berated on another forum about how come I did not have a reversing motor on my lathe and I told everyone that it will spin the chuck off, I guess that is what I get for listing to guys that dont know anything about an Atlas.



Just a little off-topic.....
Time after time, I have proven to myself that the spirit of camaraderie and brotherhood on this forum - or call it simple neighborly civility - is simply unsurpassed in the metal-moving world.  There are those can almost come close (until one questions the resident 'expert') and there are others that are simply abysmal (when one doesn't worship one of the resident 'experts').
This list, and its expertise, is thoughtful, patient, and forgiving.  That's why I try to mostly stay out of the way and simply don't tune in elsewhere, anymore.

Ohwell... back to friendly people that know what they're talking about....

Wrat


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## wa5cab (Sep 12, 2016)

Actually, even with HSS tooling, you really ought to have the B-step when machining small steel parts and just about anything in aluminum under about 3/4" diameter.


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## pollardd (Sep 20, 2016)

Another reason for going backwards is cutting metric threads.  But as mentioned above you will unscrew the chuck under power.
I have herd of people winding the machine backwards by hand when cutting metric threads that way they can leave the half nut engaged with the lead screw.
However I never thought of using a collet chuck. (Held in the Spindle Morse Taper with a draw bar)  It wouldn't come loose.
I'd be happier if I could physically lock out hitting reverse by accident if I had it.

I agree you will definitely need the higher speeds.  I don't bother with carbide tools and just grind up my own HSS tools which is more than adequate for the one off hobby stuff I do.
I spend most of my time on the larger motor pulley. 
Good luck finding the other parts you need.  I love my old machine and enjoy making stuff on it.  (wife thinks it is magic when I walk out with a replacement part for something  )

David


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## wa5cab (Sep 20, 2016)

That reminds me that I remembered the day before yesterday (while doing some grinding) that there is yet one more case where you should run the spindle in reverse.  And that is when doing OD grinding.  The reason is that with the spindle turning in forward, the direction of motion of the front of the work piece is downwards.  For at least one very good reason (you don't want to throw sparks up into the air in front of you) the front of the grinding wheel (the part against the work) is also moving downwards.  Even though you should be using a low spindle speed when grinding, it would still subtract from the grinding wheel RPM, which is undesirable.  Since you can't safely reverse the grinder, you need to reverse the spindle.


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