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Herblf
08-12-2005, 01:17 AM
recently acquired an Atlas V42 lathe (nearly as old as I am)in real good shape! Working fine ,cuts threads but no QC - it seems to me
that it is slightly underpowered -has 1/3 hp
old GE motor 1725rpm,v-belts and die cast gears -mounts a 8" Craftsman 4 jaw chuck (bought separately) have turned out some nice tools and pieces Would like some input about increase the HP to 1/2 1725rpm Is it feasible,has it been done,was the original
motor this small? have the room to fit the larger motor easily !! any thoughts gratefully accepted !!

JCHannum
08-12-2005, 08:00 AM
Some of the old 1/3 HP motors will out run a modern day 1/2 or 3/4 HP motor. If you are having problems with stalling, a 1/2 HP motor will not be too big.

One of the weaker links in these lathes is the leadscrew drive box. A jamup can damage the bevel gears before the belt slips.

Rustystud
08-12-2005, 09:03 AM
Herblf:

Have you considered a 3 phase motor with a VFD. Under 1 hP they are relatively inexpensive. It would give you the flexability to have varible speeds with each gear. Down to about 15% and up to about 175%. You can do this to the touch of a button. I converted my 3 hp single phase lathe from 3 hp 1 phase to 5 1/2 hp 3 phase and added a Westinghouse FM-100-205 VFD. Have not regreted it one bit and have not looked back since. It has plenty of torque and I can slow down the back gear to 12 RPMs or speed it up to 200 RPMS. In high gear I can slow it down to 1200 or speed it up to 3800. There unlimited numbers of speeds between.
Good Luck Rustystud

Al Messer
08-13-2005, 09:01 AM
Just my two cents, but I'd stick with the original motor or one rated the same as it could be possible to over power and strip some teeth from the alloy gears and then you'd really be in trouble.

Tim Clarke
08-13-2005, 02:17 PM
With the old 10" Atlas I have, the drive belt has always slipped before I ran out of power in the motor. 1/2 hp will be plenty. Actually 1/3 may work very well for you.

The motor on mine hangs from the rear of the factory stand, and I usually let the weight of the motor provide tension on the belt. This way, the belt will slip before anything gets damaged. The small step of the motor pulley doesn't allow for a very long wrap of the drive belt, so if you do need more power for things like drilling large holes, I then tighten the belt with the adjuster bolt.

The relatively light construction of the Atlas/Craftsman won't allow you to take heavy cuts, anyway. Too much flex in the carriage/crosslide/compound/toolpost assy. This is not to say that you can't do a lot of work with one, because I have. But light cuts are in order, and make sure your tools are sharp.

Regards, Tim

Al Messer
08-14-2005, 06:34 PM
Hey, Tim! Would you say that an Atlas will teach you to be a Machinist, not a "Hogger"? Mine sure did!!

egpace
08-14-2005, 06:46 PM
To all,
Just a little side note. While watching a show on the History Channel about the Manhatten Project (A-Bomb), I noticed, in one scene, what looked to be a 10" Atlas Lathe in the background. I wish they had held the camera in that spot for a little longer. I thought it was kind of interesting that an Atlas lathe played some sort of roll, however small, in ending WWII.
Ed http://bbs.homeshopmachinist.net//smile.gif

herbf
08-18-2005, 07:27 PM
<font face="Verdana, Arial" size="2">Originally posted by Rustystud:
Have you considered a 3 phase motor with a VFD. Under 1 hP they are relatively inexpensive. Good Luck Rustystud </font>

VFD= ???
What price range do you consider as inexpensive for this mod?
Where can we find more info on a unit under 1HP?