It's Alive!! (Rotary Phase Converter for Lathe)

[MtnBiker]

Now that some much needed shop organization was done I got around to installing our rotary phase converter. Picked up a lathe a few months ago from an estate sale. What was supposed to be 5 hp turned out to be 7.5hp dual speed. VFD was pretty much out and unfortunately the price break between American Rotary's 10hp and 15hp was a lot. Decided to spend just a little more and get their ADX-20 to future proof a bit.

I thought it was a very easy install after reading the manual twice and watching some YouTube.



With only one 3-phase machine right now I just picked up a fused 3-phase switch on Ebay. If we get more tools and a load center I'd still want the switch so we don't accidentally start the RPC under load.

We'll be installing some kind of chip shielding before someone asks about that. Expecting a glut of post Covid plexiglass any day now.

Now that we have 3-phase we needed to plan out how to get power to the lathe. We need the ability to roll our shop's gantry crane out of the garage and onto the driveway in order to offload our trailer. Our primary use case is 4x8 plate steel for the CNC plasma. But we also wanted to maximize floorspace vs putting all the tools on the perimeter of the shop to make room for the crane.



We needed a way to disconnect and move the power source so the gantry could roll out the door. No way to run permanent conduit on the floor and can't run overhead because of the garage door.



Picked up a really burley L14-30 extension cord for RV's. Has a NEMA locking connection. We cut it in half and wired each end into the switch and lathe. Now it's easy to disconnect and I get to put the lathe where I want it. Concerns about code aside, this will work really well for us.



Got everything wired. Motor turns the right direction. The lathe is alive!

Thoughts on the American Rotary RPC?

Easy install. Custom Baldor generator that runs really quiet. My kid turned it on then asked when it starts to spin. Couldn't believe a piece of machinery that big could be so quiet. If the stats are to be believed, this thing makes really clean 3-phase power. Will run everything from a CNC machine to an air compressor. Seems like a nice piece of kit.

Oh, one other detail. If you need to strip 6 gauge wire pick up one of these if you don't already have an extra large size stripper:



This is a coax cable stripper. Coax is the same size as 6 gauge. It's handy for coax too. You just attach and spin...the blade cuts the insulation perfectly every time. Super simple.

 

[markba633csi]

I like your Osama- where is it made?
-Mark

 

[MtnBiker]

Made in Taiwan by Shen Jey (no longer in business). Very very similar in design and specification to the current Eisen 1640G which are made by Win Ho in Taiwan.

Outside of a few exterior differences (like control placement) this is essentially the same machine as ABOM's Victor (in 40inch vs his 60 inch form factor). Millport also branded the same machine from Shen Jey.

I've had pretty good luck so far getting parts from Eisen. Sterling machinery had a few new old stock available about a month ago. Still on the original pallets. It was a slightly newer model. Would be a stormin deal I think.

Oh...and I grew up thinking the 633csi was the coolest car around.

 

[jwmay]

I installed an American Rotary 20 hp unit for a coworker. I wish I'd have known about that coax cable device you've got. Afaik, he never had trouble out of it, and seemed as happy as a stoic gentleman allows.

I'm a little confused about one thing though. Iirc, the directions tell you to leave the RPC on all the time. Are you intending to turn it off and on as a practice? You said something about accidentally turning it on under load. Anyhow, if it were me, I'd leave it running. Your electric bill will be cheaper, and the unit will last your lifetime.

 

[MtnBiker]

The American Rotary documentation says frequent stops and starts are harder on the rotary phase converter than steady operation. I can't quantify "frequent" but my guess is a full-time shop shouldn't switch an RPC on/off every time a worker fires up a 3-ph tool. We're at the side-hustle stage and we might use the lathe a few times a week. Kind of just freaks me out to keep it running for days without using it. The RPC at idle only draws about 650 watts. Not a ton. We'll probably limit on/off cycle to once per day on the days we use it.

Appreciate the comment jwmay. I do want to keep this thing running for long time.

 

[MtnBiker]

Another pro tip...the 3-ph disconnects can be had pretty cheap on the used market. The fuses are also inexpensive. I'm using 25 amp fuses as the Lathe maxes out at 19 amps. The 25's are a smaller form factor and don't fit directly. The 25's need these rudely expensive adaptors that I didn't budget for (about $18 apiece x 3 - fit on both sides of the fuse). Kind of a bummer - a load center would have been about the same price all up.

 

[Ulma Doctor]

There is no need to run the RPC when no 3 phase load is demanded.
Don’t worry about starting or stopping the RPC a couple times a day, just don’t try to start and stop more than twice an hour if you can avoid it.
There is no magic happening inside the RPC, the real killer is high heat inside the start capacitor(s)
The idler motor will turn at sufficient speeds to get full use of the cooling fan.
External cooling will extend the service like of just about any motor that has high demand

 

[tjb]

Wise choice on the American Rotary RPC. I bought one a while back for my mill and lathe - both 3-phase. Totally satisfied with the product.

Something you might want to consider if you end up with more 3-phase equipment is feeding the 3-phase power into a breaker subpanel. In my setup, my main panel feeds the RPC, which feeds a 3-phase subpanel, which feeds 3-phase wall outlets. I started with two pieces of equipment but now have three. In addition, I have a somewhat dedicated separate area in my shop for equipment that is being worked on. I have four circuits coming out of my subpanel. Three go into the machine shop area, and the fourth goes where I would be working on equipment. Makes life easy without the need to cram everything in or run heavy duty 3-phase drop cords.

Regards,
Terry

P.S.: Nice lathe.

 

[MtnBiker]

...Something you might want to consider if you end up with more 3-phase equipment is feeding the 3-phase power into a breaker subpanel. ...

Regards,
Terry

P.S.: Nice lathe.

Agree. I'd put the panel downstream from the disconnect if I got more 3-ph gear. Easy peasy.

And thanks. Looking forward the round stuff.

 

[mksj]

Coming along very nicely, and you are very fortunately to have a single owner lathe that was very well cared for. Really a gem of a lathe for the price.

Just a general reminder, I do not recommend using plexiglass (acrylic) plastic for anything that might be exposed to stress or impact because it cracks and shatters very easily. If you can get some polycarbonate (Lexan) it will not craze around holes and is almost unbreakable from impact. The fey times I have used plexiglass I have always regretted it and it ended up either breaking during fabrication or broke around the mounting holes. Recently made a hand chip shield for my lathe, I had a small scrap piece of plexiglass and it snapped in two with almost no pressure when bending it after heating. Switched to 1/4" polycarbonate and it worked much better and I do not have to worry if something hits it. I also made a 1/4" polycarbonate chip shield for my mill, if an endmill shatters, I have the added security that the plastic won't shatter if hit by it.