Slowing Down An Atlas

[cdhknives]

Say I wanted to cut the slowest leadscrew speed down even slower...for feedrates useful in drilling and milling stainless steel with a drill bit in a boring toolpost and milling with the mill attachment. The power cross slide is particularly fast for facing operations as well. I have a QC gear box already, so do the correct gears exist for something like 1/2 or 1/4 speeds (to simplify threading, an even multiple is desired) to the leadscrew? If I could cut it in half or 1/4, threading would still be possible by multiplying the required thread by 2 or 4 as applicable to find the correct selection on the QC levers.

 

[pebbleworm]

A hand crank? A useful gadget I found out about when I was using a Unimat. Lots of plans and drawings are out there for different machines. It wouldn't fly in a production shop, but as Mr. Sparey says in the Amateur's Lathe, a lot of us are using a too small machine to the last gasp of its' capabilities. You could also change the motor and jackshaft pulley sizes.

 

[bill stupak]

Here is a link to all the speeds available.
www.machinistweb.com/forum/showthread.php?t=2711
Scroll down to Rob's reply. I plan on doing the same thing and am shooting for .002' per rev

Bill

 

[cdhknives]

Changing the motor pulleys would not help, I want to change the spindle/leadscrew ratio to 1/2 to 1/4 the current slowest rate so I can set up autofeed drilling with 2 hands free to pump oil and air into the hole. This stuff work hardens so fast I hate to stop a cut as restarting means breaking through a hardened skin...at least that is what it feels like.

 

[cdhknives]

Exactly Bill, the slowest feedrate on the standard QC gear box is like .0042"/rev...fine for turning but too fast for boring and facing.

 

[VSAncona]

If you can find a copy of the original Atlas quick change gearbox manual, it has pages of charts with the gears needed for different feed rates. I swapped out a couple gears on mine and got the feed rate down to .00144".

 

[yendor]

There is a copy of the QCGB Gear Setup Manual in the Thread Link posted above.

On the LAST Line of the Threading Chart it lists the combinations required for a .001 Feed Rate which is the equivalent of 1000 TPI.

The PDF Link is on the 2nd page of the linked thread.

 

[outsider347]

I can t get into the link to find the slowdown gear combo
Available anywhere else?
tks
ed

 

[Rob]

You can find it here.

http://www.flywheelmachinetools.com/Data/Atlas10QCgearsetups.pdf

 

[cdhknives]

It looks like the sliding gear [IN] halves the QCGB already...quick and easy! Thanks! Now to look for change gears...