How to Add a 3 Phase Motor and VFD to a 10x22 Lathe

[henryarnold]

This document provides information and schematics for adding a 3 phase motor and VFD to a Grizzly G0602 10x22 Lathe. It can be referenced for adding a motor and Teco VFD to any lathe.

   


  Installing a 3 Phase Motor and VFD_1_1.pdf (Size: 936.6 KB / Downloads: 132)

[EdK]

Henry,

Can you tell me this dimensions of the plastic box you used? I need one for my mill VFD. And where did you buy the box from?

Thanks,
Ed

[DaveH]

Henry,
Nicely documented and photographed.
Sometimes we don't always appreciate the time and effort that goes into making a document of this calibre - really a 1st class job


DaveH

[henryarnold]

(05-19-2012, 10:28 AM)EdAK Wrote: Henry,

Can you tell me this dimensions of the plastic box you used? I need one for my mill VFD. And where did you buy the box from?

Thanks,
Ed

Ed,
I used a plastic electrical junction box from Home Depot. They come in 3 sizes 6x6x4, 8x8x4, and 12x12x6. The one I used on my lathe is the 12x12x6 but I cut it down to 12x12x5 so that the VFD just pokes out the front panel. This box costs about $32. They are quite easy to modify and have some mounting ears that make it easy to mount. I noticed that Home Depot also carries a sprinkler timer enclosure which has a hinged door. This might make a good VFD enclosure.

Henry Arnold

[henryarnold]

(05-19-2012, 10:34 AM)DaveH Wrote: Henry,
Nicely documented and photographed.
Sometimes we don't always appreciate the time and effort that goes into making a document of this calibre - really a 1st class job


DaveH

Dave,
Thanks. I had this document from a couple of years ago. I didn't just create it. I like documenting things because my memory is bad and it helps me when I have to fix something later.
Henry

[DanH]

Ok a disclaimer right here, I am a newbe so please be nice.

Why go to all this work to switch to a 3 phase setup?I have a 12x36 lathe running 220V single phase, what would I gain by doing a similar mod? I know when I picked my lathe I though it was a plus that it was a single phase setup so I only had to plug it into the 220 outlet to get up and running. Having to switch the gear levers to change speed seems like not a big deal but keep in mind I am not an experienced machinist. In a home shop setup why go to 3 phase power?

This grasshopper seaks knowledge.

[Highpower]

That is a fair question Dan.
The reasons that I can think of off the top of my head are:

Smoother surface finishes.
Infinitely adjustable spindle speeds. *
Soft starts. *
Spindle braking. *
Instant spindle reversal.
* (With a VFD.)

3 phase motors run much more smoothly than single phase motors resulting in less vibration and better finishes. Switching gear levers is fine unless the speed you need falls in between the speeds available from the two closest gear positions. And being able to run the lathe below it's minimum "low gear" speed can be a real blessing when it comes to threading to a shoulder on a lathe if you don't have lightning reflexes. (I am in that group...)

The ramp up function of a VFD takes a lot of stress off of the machine when starting the spindle. Spinning up a heavy piece of stock instantly to 1500 RPM from a dead stop can get.... interesting. Slowly accelerating that mass up to full speed is a lot more comfortable for both the lathe and the operator.

Likewise being able to ramp down the speed or inject additional braking, keeps the chuck from spinning forever due to the momentum when the machine is turned off.

What else did I miss guys?

Obligatory pics of my lathe....

[EdK]

Changing the speed on the fly as you are turning a piece is very nice because as the diameter of the piece gets smaller you can turn up the speed without stopping to change belts and/or gears. Having variable speed on the fly saves time. Once you've had a machine with a VFD, you'd not want to be without it. YMMV

Ed

[DanH]

Thanks for the info guys. I am so new at this, I hope my questions don't seem too ridicules.

[EdK]

(05-20-2012, 09:53 AM)DanH Wrote: Thanks for the info guys. I am so new at this, I hope my questions don't seem too ridicules.

Dan,

Your questions are not ridiculous. We all started from knowing nothing about metalworking. We're just a little bit ahead of you, that's all. Your questions was actually a very good one since buying a 3-phase motor and VFD is not pocket change for most of us. You certainly don't need to convert your lathe if you are happy with the results you are getting. Hope this helps some.

Ed