Variable speed motor for my 110V mill/drill?

Wondering if anyone has any suggestions for putting a variable speed motor controller on my little 110V mill/drill. The belts are a bastard to adjust for different speeds... it would sure be nice to just turn a dial and still get reasonably good torque w/ a reasonable amount of speed variablility. And, I'm doing a CNC conversion soon, so this would really be a + (especially if it has an an analog input for adjusting speed).

I've seen a lot of Variable Frequency Drivess on ebay for 3ph stuff... wish I had a big mill with that kind of motor... but my mill/drill will have to do for now.

What about 110V 1ph? What kind of motor controller and who are good sources? Is this even a good idea?

Thanks a million

Single phase squirrel cage AC motors like your 110V motor can *not* be speed controlled. So if you want speed control, you are looking at swapping the motor, or else going to a variable pulley. I'm not going to comment on the variable pulley method. If you decide to swap motors, you can go 2 ways: DC or 3 phase AC. There have been lots of designs for speed controlling a DC motor used to control a treadmill, suggest googling. A 1 hp 3 phase motor that will bolt on may work for you, and may cost less than you think. Suggest you start looking around your area (or posting where you are!) and watching ebay.

GWE

stag wrote:

Hey, thanks... I don't have 3ph in my shop though. Will the VFD's w/

220 1ph-in/220 3ph-out work in this situation? Or, are rotary phase converters the only option w/ machine tools? In that case, I'd just scrap the thing and buy a full-size Bridgeport anyhow.

Thanks again...

Sure, they'll work. - GWE

Between this and the CNC conversion, you're better off starting with a used Bridgeport. The conversion is easier and cheaper in the end, and certainly much more capable.

I have a Smith mill/lathe that I have a 1/2 hp D.C. motor and controler and it works real well. I got the motor and controler from a place in Cestline, Ohio

?ViewItem&category=71393&item=7512179049&rd=1 They don't have a motor listed on ebay, but they do have a controler list for $25.00. I was at there location Saturday and I think they had a couple

1/2 hp motors. They are a recycler so stock comes and goes. I think there phone number is 419-683-3535. I have gotten a lot of stuff from them, both from ebay and at there location.

JIm Geib Mansfield, Ohio

I been researching the same thing for a benchtop lathe and have found a few googling and a few in the yahoo groups for the 9x20 lathe group and some in the lathemaster group.

They use lesson treadmill dc motor (2 hp inverter type) with a Hatachi vfd type controler. I don't have the links handy, sorry

Jack

Google: 9x20 dc motor

stag wrote:

I recently bought a junk Atlas lathe that had a 2 HP DC motor and a big variable speed controller attached to the side of the bench. I have seen similar items go on ebay recently for about $150, sometimes less.

- - Rex Burkheimer WM Automotive Fort Worth TX

jackK wrote:

Not only will the above work, there are lots of cheap 3 phase motors around. And Dealers Electric has some pretty cheap VFDs. The really nice thing about the VFD is that it will (should) accept the command from your CNC control. If you already know what kind of control you plan to buy contact the seller and see what kind of signal it puts out for speed control. Then make sure the VFD you buy will accept that type of command. Cheers, Eric R Snow

Noise! Power = noise. Look at any carbon conmutator motor such as on your

3/8 drill or shop vac or sewing machine motors. But since you will be converting to NC, you should include servo control and a servo motor which will give you nice, quiet, power under full load or not.

Wayne

And you can get a VFD that runs on 120v up to 1/2 hp. see

A 1/2 hp 3-ph motor will be cheap on eBay.

Randy

Hi Stag,

Re the VFD, that is exactly how many are used: they allow you to BOTH convert 1ph to 3ph AND to vary the speed of the 3ph motor (within limits).

But my question to you is: if you can afford to "scrap" the mill-drill and buy a full-sized Bridgeport (or Bridgeport-sized mill), why would you attempt to do a CNC conversion on the mill-drill? A CNC conversion is an expensive undertaking, both in dollars and in labor. Frankly, I see that investment wasted on a mere mill-drill. The inability to accurately re-position on the Z-axis (assuming yours is a round-column mill-drill) would be enough for me to scrap the idea of adding CNC to a mill-drill. Other limitations would be machining capacity (the spindle-to-column and spindle-to-table dimensions are typically limiting on a mill-drill).

Don't get me wrong, I'm not a "mill-drill basher." I have one myself and understand why people buy them. But if you have the space for a full mill and the disposable income for a full mill, then I would recommend buying a full mill and then adding your CNC conversion. In the end you will have a MUCH more capable (and valuable) machine.

Regards, Michael

If you switch to a DC motor, I have a suitable Minarik controllers for $35 to $55

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