Building/modifying An Atlas Th42

Nice motor and controller. Any idea what the speed of the motor is?

David
 
Don't know. Its not marked on the motor.

But, most treadmill motors I can find on google seem to run anywhere from 4000 rpm to 6000 rpm.

I'm gonna need a tach to go with that controller it seems......
 
The Chinese tend to be quite optimistic about their horsepower ratings. But honest HP is HP. And in general, permanent magnet DC motors tend to be smaller than the equivalent single phase AC motor. The controller probably has the ability to limit torque but you don't have the information necessary to modify it. The reed switch most likely supplies the tachometer signal - nothing to do with a deadman function. The speed control is probably connected to the blue wire. And may take it's supply from the red wire.
 
I'd be a little leery of putting a motor with that much power on an Atlas. They were usually made with 1/3hp motors, so putting something that could deliver that much power-and torque- is kind of like putting a Corvette engine in a Corvair. Yeah, you can do it, but if you start to really put some muscle in it, something gonna give. And it won't be pretty. Well, actually it would be pretty. Pretty expensive. The gears are pot metal and not designed to take that kind of power. The Atlas is a light duty machine and can do a lot, as many here already know. But trying to make it do the work of a heavy is sure to cause problems. You will be tempted to make it do things it was never intended to do. If you really need that much power, get a lathe built to handle it.
 
wa5cab said:
The Chinese tend to be quite optimistic about their horsepower ratings. But honest HP is HP. And in general, permanent magnet DC motors tend to be smaller than the equivalent single phase AC motor. The controller probably has the ability to limit torque but you don't have the information necessary to modify it. The reed switch most likely supplies the tachometer signal - nothing to do with a deadman function. The speed control is probably connected to the blue wire. And may take it's supply from the red wire.
Click to expand...
Reed switch on the treadmill is a kill switch. Lanyard from a magnet key goes to the runner/walker and if you get "tossed" it kills the motor.

That's what I was thinking of using like a dead man or quick kill switch. Yank the magnet off the reed switch, lathe stops. I'm just leery of having a lanyard attached to me with the lathe running. Seems like it could cause the very accident I would be trying to mitigate....

I check on the optimism. The motor is rated 1.5 continuous, I assume the 2.65 HP is a peak and unlikely to actually see it.

:)
 
fgduncan said:
I'd be a little leery of putting a motor with that much power on an Atlas. They were usually made with 1/3hp motors, so putting something that could deliver that much power-and torque- is kind of like putting a Corvette engine in a Corvair. Yeah, you can do it, but if you start to really put some muscle in it, something gonna give. And it won't be pretty. Well, actually it would be pretty. Pretty expensive. The gears are pot metal and not designed to take that kind of power. The Atlas is a light duty machine and can do a lot, as many here already know. But trying to make it do the work of a heavy is sure to cause problems. You will be tempted to make it do things it was never intended to do. If you really need that much power, get a lathe built to handle it.
Click to expand...
Its not a matter of needing that much power as that I have this available (and at no cost). The treadmill is likely going out on spring cleaning and I thought I might be able to make use of the components. Really, its not something that hasn't been done before, lots of guys have threads and YouTube's up on it.

Its not like i have great plans for huge projects. Just a little turning here and there of things like axle spacers, fuel sump adapters and such small items. A variable motor might make it a bit more enjoyable and possibly a fun project in its own right.

:)
 
Great White I have an Atlas 618 and quite frankly have never looked at the motor HP. I purchased it from a guy way back in the 70's and it has served me well. The jack shaft seems to have a couple of detents on it to allow me to adjust the belt tension differently. So far if I have gotten into trouble the belt just slips. I don't do any heavy stuff, mostly brass and aluminum.

David
 
OK (on the kill switch). I was just going by what was printed on the system wiring diagram. And I agree about not wanting a lanyard around my wrist while running the lathe.

I would keep the motor. And find a controller rated 1/2 or 3/4 HP and made for industrial use. That often means that the START-STOP and Speed functions are already remoteable. You do need to find out what the max rated RPM of it is, though. Or arbitrarily limit it to 1800 or 2000 RPM, which is pretty sure to be safe. And don't think that a variable speed motor means you only need a single step pulley. The rated speed range of the lathe as stock is about 40:1. You don't want to exceed the maximum RPM of any of the lathe components on the high end but if you have the motor RPM at the high end 2000 RPM, the low end would have the motor RPm at about 50. That's less than 1 RPS and the motor will probably overheat.
 
For now, I think I'll just pull the treadmill apart a d work on getting the motor running independently. I've got a few ideas I'd like to try on it first.

I'll leave the lathe alone for now. I'll just play around with building a controller and seeing what the motor will do.

Then maybe later it will go on the lathe.
 
Here's a cut and paste from a 1945 Atlas Catalog Motors Section.

Note:
1/3rd HP is the Standard Duty
1/2 HP is the Heavy Duty Motor.

Adding more HP beyond the Mfg recommendation will just allow you to break thing faster and into more expensive pieces.

Motor.jpg
 
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