Best RPC out there?

Howdy. I'm new to this forum so excuse me if this has been posted before but a quick search did not turn anything up. I'm in the market for a rotary phase converter to power a Bridgeport Mill I have recently acquired. (1 hp). Could I take time and build one to save a few bucks? Probably. Do I have the time to do this? No. Essentially I'm looking to trade time for money so I can move on with other projects in the pipeline. A quick web search brought up a number of manufacturers (TEMCo, Phase-A-Matic, American Rotary, Des-co Industries, etc.) so my question is, does anyone have experience with any of these and if so, who builds the best one? Where's the best value for money? In life, you always pay for what you get, sometimes you get what you pay for! Thanks

Most folks probably won't have used more than a couple types, so I don't know how much you'll get on comparisons.

If you are looking for customer testimonials, I have an Arco that is about 25 years old, and it does very nicely. Of course, it's the only commercial one I have used, so a comparison this is not.

The Phase-a-Matic I'd be leery of. They may be fine. But pictures of the innards of the PaM static converters showed them to be of very cheap construction, barely adequate. Simply per guilt by association, with NO proof or direct knowledge, I'd suppose the RPCs to be similarly cheesey.

If you don't mind me asking, why a rotary?

If it will be your only machine, and you want a plug-n-play solution, a solid state
VFD *might* be a better solution for you.

Jim

im with both the above. i run my 1 hp bp on a home brew rpc and it does work good but. a vfd would make it more like a vary drive instead of a step pulley that it is. at the time my caps were the only thing out of pocket so i went with it. i would not recommend static.

I guess I'm not educated enough about the choice of a VFD. This machine will be used for occasional dinking around and from what I've read and seen on SPC's, I've ruled those out. What would a VFD do for me and how do they compare cost wise to RPC's? Educate me! Thanks.

A VFD is the way to go for an out of the box solution on a Bridgeport, especially on a step pulley drive model

Here are some I have helped with:
simple drive and simple installation: try a Hitachi L100
beter torque contol and still simple: try a Hitachi SJ200

you can see these drives at: www.driveswarehouse.com I am not associated with either company. You can also find other brands that are equally as good.

You want a model that accepts single phase 230 volt input and puts out three phase 230 volts. They may say 240 volts but it is the same VFD.
You connect the VFD DIRECTLY TO THE BRIDGEPORT MOTOR. Do not pass through the Bridgeport Drum Switch. Next you wire the existing Bridgeport drum switch to control the VFD. then you take the short form of the installation guide and follow the steps to program and start up the VFD. The only other thing is you might want a power switch, such as a disconnect, mounted before the VFD so you can power it down when not in use.
I can provide you with a connection diagram for a Hitachi SJ200 connected to a Bridgeport.

This sounds hard but is not. It is no harder than wiring in a purchased RPC and dealing with the shortcomings of a commercial RPC. It works very well for one machine and is my preferred method although I have a good RPC.

That would be outstanding. I appreciate your help. A connection diagram for the SJ200 would be great. I plan on getting this project going sometime after the holidays. I hope to have the 230V run to garage by that time and I could have the VFD by then. Can you send it to me off line? Thanks.
Charlie

Charlie,


Here is thumbnail, just double click on it to get full screen and you can print it. It may need to be "landscape" as I have not tried it yet. I will also put in a thumbnail of the orginal Bridgeport Drum Switch connections for your reference.

Be sure to remove any jumpers from the row where you connect the VFD as there is one on the orginal drawing. YOu do not need any jumpers on the drum switch. This is an easy installation.
I have the circuit sized for a 2 hp VFD. The 30- amp circuit was what another user had but you only need a 20 amp circuit to run the mill. If you use a 1.5 hp VFD you will need to put 15 amp fuses in the Disconnect. You need the disconnect so you can power down the VFD when not in use. I get a 30 amp disconnect switch from my local home center for about $20.

"The Phase-a-Matic I'd be leery of. They may be fine. But pictures of the innards of the PaM static converters showed them to be of very cheap construction, barely adequate. Simply per guilt by association, with NO proof or direct knowledge, I'd suppose the RPCs to be similarly cheesey."

An acquaintance disassembled a PaM rotary, which confirmed your supposition.

According to his observations, there appeared to be a simple modification to the rotor, which may have been intended to increase the resistance in the squirrel-cage rotor by removing some of the cast-in low resistance material which forms the shorted turns in the rotor.

Best Value in a Rotary Phase Converter

To find the best value in a rotary phase converter, look for the following and ask each manufacturer the following:

1. Where is their idler motor made. While there are a few good foreign motors out there, It it too hard to tell anymore what is actually made in China and what is not. A few of the motors made in the USA are Lincoln (Kay Ind. uses this I believe) and Baldor (American Rotary uses these).

2. Is the motor a custom motor, no shaft, or is it a modified stock motor, shaft on or shaft cut off my the phase converter manufacturer.

3. Does the RPC have a built in starter, and what brand?

4. Does the voltage come balanced? and to what %? 5%, 10%? You want at least closer to 5% for a good current balance, long life and quiet running.

5. Lastly, call the manufacturer, some of those companies you mentioned above don't even answer there phone. So don't expect them to when something goes wrong. I have a lot experience with American Rotary (they also carry VFD's and Digital Phase Converters so they can give you an unbiased opinion about which is the best for your application), so I can recommend them, but do your own research. You probably can't go wrong with either a drive or a rotary.

Don