Mill motor recommendations and sources

mariner3302

mariner3302

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I have a Gorton 0-16A that currently has a 440v 3 phase motor. I have 220v 1 phase. I am not going to do anything with the mill other than small projects. I got the mill for $1000 and I like it. I posted a thread here looking for help with rewiring the motor but the general opinion is a different motor will be the most economical route. The mill uses a 2 speed motor, 1hp at 1800 rpm and 2hp at 3600 rpm. It has 10 speeds by pulley per motor rpm.
So, what options are out there to find a motor?
 
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Hi, I was wondering if you thought this motor would work with an appropriate VFD for my milling machine? The motor is inverter rated and 3600rpm. Would the VFD now run the motor from very slow up to 3600rpm with constant torque? That 3600 rpm at 2hp is the highest rated speed if I used the original pancake motor. The motor is inexpensive and ships free. I would just like to choose something and get it setup. Lots of projects, so little time! haha

https://www.automationdirect.com/ad...eneral_purpose/general_purpose/mtrp-002-3bd36

Thanks, Dan
 
Personally I’d want a 1800 rpm motor, even with a VFD, you can only turn it down so far.
 
I would go for the 3600 RPM (just to be contrary :) ). If you need the low-low speeds / lots of torque you can change speeds with your pulleys.
Would using an 1800 RPM limit your top spindle speed to half of what it was? That motor would work well with a VFD.

BTW, I've used automation direct many times for business. They have been great to work with.
 
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Top spindle speed with pulleys is 12000rpm using the original motors 2hp 3600rpm setting. I figured an inverter motor would allow the motor rpm to come down to 1800 which is the original motor's 1hp setting. At least that is what I have read, I have no first hand knowledge or experience with motors generally. What I am trying to do is keep the original motor's capability without the cost of using RPC's and transformers.
 
(Edited with corrections)

A VFD will run your motor at speeds above and below the "60Hz RPM" of the motor as you have read. Buffalo 21 mentioned that the motor will lose torque when it is slowed down. It actually loses available horse power when run slower but the effect is you have less cutting power.

But you can "gear down" using your pulleys to get most of that back by running the motor as fast as possible with the spindle in the range you want. I have a small gear-head mill and run it in two ranges, "fast" and "slow". The VFD gives me good variation within those ranges while keeping the available horse power.

Here is a curve off the inter-web. Slower than rated RPM, loses horse power, faster than rated RPM, torque goes down.


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As Reddinr, stated the true benefit to a VFD is when its used in conjunction with the pulley system of the mill, this allow speed adjustments and to be able to keep the torque and hp levels at the optimum for the work/process being done. A VFD, should never be considered as a way to never have to change belt position ever again.
 
I am totally ok with changing belt positions. My hope is to get max torque at 1800 and 3600 because that is giving me stock motor capabilities.

Using the VFD to control the spindle speed is not what I am looking to do.

I would set the motor to either 3600 or 1800 as necessary. Belt changes on this mill are ridiculously easy.
 
I edited my post with a couple of corrections. You will have a nice capability with that motor, belt changes and a VFD. One thing I've found with a VFD is that I can sometimes change the speed a little and improve some chatter issues I might be having on a cut.
 
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