Short Term, Budget Friendly, 3 Phase Options

MyLilMule

MyLilMule

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I have a Series 1, 2HP Bridgeport with a variable speed head on which I am just beginning the restoration.

I currently do not have 3 phase power in my workshop. The plan WAS to get a 5HP rotary phase converter from American Rotary (my preferred manufacturer). However, I am looking for some possible short term, more budget friendly alternatives.

Reason being, I do not want to invest $800 in a phase converter, to find that in a year, I add a 5HP lathe to the mix and end up needing a bigger phase converter. So to bide my time until I make that decision one way or another, I want to find if there are any alternatives that are MUCH less expensive.

I'm open to ideas that will let me run the mill, even at reduced HP, for the short term (1 year) until I have either decided against adding a bigger lathe or not, at which time, I'll get an appropriately sized RPC.

If the answer is "no" then I'll bit the bullet and get the American Rotary unit.
 
Would you ever be running the mill and lathe at the same time? I personally never have with my machines... If not, I'd just get a phase converter that meets the needs of the highest HP machine you expect to have and use it for both.
 
Static Phase Converter.
phaseconverterusa.com

SCM03-1 - 3 Hp HD SCM series Static phase converter

phaseconverterusa.com

Like you, I bought one to fill the gap until I got my 7.5 hp rotary. Once I got my RPC, I quickly grew tired of the whine. Then my wife saw the electric bill. The RPC is in mothballs and I've been using the SPC ever since.

edit: Anyone want to buy a 7.5 hp RPC?
 
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I picked up a rotary phase converter on facebook market place. I don't do face book, but my neighbor keeps an eye out for equipment for me.
It's a cedarburg. I paid $75, no capacitors.. for my surface grinder it's been great.

Now, I am not saying go out and buy new, it is $950 new.

but since you are restoring, look around you have time... and maybe the machinist gods will be friendly to you.
 
Building your own RPC can be much more economical than purchasing a commercially made unit. It is not that difficult to build one and there is a lot of good information on this forum to help you along.
Food for thought.
Ted
 
MrWhoopee said:
Static Phase Converter.
phaseconverterusa.com

SCM03-1 - 3 Hp HD SCM series Static phase converter

phaseconverterusa.com

Like you, I bought one to fill the gap until I got my 7.5 hp rotary. Once I got my RPC, I quickly grew tired of the whine. Then my wife saw the electric bill. The RPC is in mothballs and I've been using the SPC ever since.

edit: Anyone want to buy a 7.5 hp RPC?
Click to expand...
That looks interesting. I'll have to do some research on it.
 
talvare said:
Building your own RPC can be much more economical than purchasing a commercially made unit. It is not that difficult to build one and there is a lot of good information on this forum to help you along.
Food for thought.
Ted
Click to expand...
Not really interested in that option. Yes, I am certain I could build one. But I would rather spend my time rebuilding a vintage piece of machinery and using it, than this. I've also spend decades building my own computers, but as age and wisdom have creeped in over the years, now I just buy Apple Macbooks.
 
So several options as outlined above, static converter is inexpensive for short term, you loose some Hp. You can buy an RPC box for not much more and then just find a motor (1750 RPM) locally and save about 2/3rds the cost of a new RPC. You just hook-up the 3 phase motor. A 5 Hp RPC will run a 2 Hp 3 phase motor, so somewhat limited for all the work. There are inexpensive VFD's (2 Hp) that could be used, and just use a simple switch to control the inputs for the run command. They can be had for as little as $100 for a generic brand with cryptic instructions sold on Amazon/eBay, or something like a Teco 2 or 3 Hp single phase input L510-202-H1-U will run around $200, the 3 Hp typically is $275 but link below is $217. The VFD's are pretty simple to setup, direct connect to the motor and in your case leave it a 60 Hz and use the mechanical Reeves drive. Check availability/inventory of the drives before doing on-line purchase, many vendors are out of stock and often do not have a due date for restocking. The drives have also gone up in price about 30% from 2-3 years ago.

shop.powerandcontrol.com

L510-203-H1-U TECO 3 HP 230V 1-Phase Input 10.5 Drive Amps C

shop.powerandcontrol.com
www.ebay.com

CP-7 Pro-Line 7.5HP Rotary Phase Converter Control Panel - Loaded with Features | eBay

Add your own motor and make a rotary phase converter. Rotary Phase Converters. 7.5HP Pro-Line Rotary Phase Converter CP-7. Static Phase Converters. Digital Phase Converters. Easy / Light Motor Loads - up to 5HP.
www.ebay.com
 
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I would go with a static converter then. You will be only getting about 2/3rds the power out of your motor this way, but this will buy you some time until you decide on what size RPC to go with.
 
I have a vari-speed 2HP Bridgeport at well. I run mine from a VFD and am glad I do. There are many times when hi range is a little too fast and rather than switching into low range I simply slow down the VFD. To be honest, I can't even remember the last time I dropped into low range...

Another consideration is you might end up with a flat belt drive lathe, like a South Bend, and I REALLY love having the VFD on mine! It really comes in handy being able to tweak the speed on the fly. I have a single phase motor on my larger SB 15" and it's not nearly as nice to run.

Just a couple of things to consider before you make a decision.

Ted
 
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