Converting 3-phase Enco 91000 drill/mill to single phase

JPMacG

JPMacG

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I have the opportunity to buy an Enco 91000 drill/mill from a local guy for a reasonable price. The problem is that it has a three-phase motor and I want to use it in my my basement, where 3-phase is not available.

I did a quick Google search and it appears that converters (electronic and motor-generator) are expensive - more expensive than the Enco that I want to buy. It also appears that static converters, while less expensive, are not the best idea.

So, what have others done? I'm thinking the best solution might be to swap in a single phase motor. Is the Enco motor a custom job or will I be able to find one to fit? How much might I have to pay?

Thanks!
 
JPMacG said:
I have the opportunity to buy an Enco 91000 drill/mill from a local guy for a reasonable price. The problem is that it has a three-phase motor and I want to use it in my my basement, where 3-phase is not available.

I did a quick Google search and it appears that converters (electronic and motor-generator) are expensive - more expensive than the Enco that I want to buy. It also appears that static converters, while less expensive, are not the best idea.

So, what have others done? I'm thinking the best solution might be to swap in a single phase motor. Is the Enco motor a custom job or will I be able to find one to fit? How much might I have to pay?

Thanks!
Click to expand...

Static converters work fine as long as you understand that you must derate the motor and that they convert the motor, not the power. They are easy to build: you just need some capacitors and a relay. It is also not hard to build a rotary converter using a surplus three-phase motor (plus capacitors and relay).

In any case it is unlikely that there is anything custom about the motor on the Enco.
 
JPMacG said:
I have the opportunity to buy an Enco 91000 drill/mill from a local guy for a reasonable price. The problem is that it has a three-phase motor and I want to use it in my my basement, where 3-phase is not available.

I did a quick Google search and it appears that converters (electronic and motor-generator) are expensive - more expensive than the Enco that I want to buy. It also appears that static converters, while less expensive, are not the best idea.

So, what have others done? I'm thinking the best solution might be to swap in a single phase motor. Is the Enco motor a custom job or will I be able to find one to fit? How much might I have to pay?

Thanks!
Click to expand...

I think that if the mill is a good fit for your shop and a very good price then buy it---you can figure the motor out later---get the bargain when it is available---you can always swap the motor to single phase ---just may need to make some brackets and use link belt--if it is a pulley drive---I've done it with a big drill press----it maybe that other members can help you use the 3 phase motor inexpensively----but get your bargain---Dave
 
You can get a Huanyang VFD for around $135 which will make you glad it's a three phase motor. It accepts a single phase input.
 
Thanks for the responses. The VFD looks like a nice solution. Will the VFD give me the ability to change speed electronically without changing the belt? Or is the motor going to overheat or something at frequencies other than 60 Hz?

The seller is asking $900 and he is including a vise, rotary table, clamps, a collet quick change arm, a set of collets and some end mills. Unfortunately I won't be able to hear it run as he doesn't have 3-phase power either. There is some surface rust on the circular column and the XY table. I don't think that is a show stopper.

Please let me know if I am wrong in my thinking. I am a novice - this will be my first mill.
 
JPMacG said:
Thanks for the responses. The VFD looks like a nice solution. Will the VFD give me the ability to change speed electronically without changing the belt? Or is the motor going to overheat or something at frequencies other than 60 Hz?

The seller is asking $900 and he is including a vise, rotary table, clamps, a collet quick change arm, a set of collets and some end mills. Unfortunately I won't be able to hear it run as he doesn't have 3-phase power either. There is some surface rust on the circular column and the XY table. I don't think that is a show stopper.

Please let me know if I am wrong in my thinking. I am a novice - this will be my first mill.
Click to expand...

If you are willing to spend the money the VFD is the way to go.
 
JPMacG said:
The VFD looks like a nice solution. Will the VFD give me the ability to change speed electronically without changing the belt? Or is the motor going to overheat or something at frequencies other than 60 Hz?
Click to expand...
Yes, you can change speeds without belt changes unless you need to go to very low speeds. You'll learn what's best and you can keep belt changes to a minimum. You won't see overheating unless you try to run a heavy load at very low RPM, I keep it between 40 and 80 hz.

Is it a 2 speed motor?

You'll need to follow the rules that apply to all VFDs, don't break the connection between the VFD and the motor while powered up (no use of the machine switch).
 
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You can also do a static converter for about 50 bucks. Between the two I would do a vfd but SC wont take more then 20min and your running.
 
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