kerrystagmer

I run a 10hp with idler motor in the shop all the time as all my equiptment is 3 phase and when I moved to my home it became a must.

Non issue, works fine. If you can, I would strongly recommend oversizing as you will end up with other equiptment you want to run even if you dont have it now.

I put in a 3 phase panel right next to the single phase one and feed it from the converter box. We run about 10 different sanders and mills off the panel and just have to think about max HP running or starting at the same time. We are a 2 man shop so its not too hard but I am outgrowing it. I see a 15hp system in my near future.

A 10 hp rotary converter is usually rated for 10 hp MAX motor size for starting and can be used with 15hp of motors running all at the same time.

Be aware that many air compressors often dont have air unloaders and are hard starting. A top quality unit might have a clutch on the motor that allows it to come up to speed before engaging.

Personally I bought a 10hp thinking of a CNC mill or lathe as they usually are that size. I just bought a control box off of ebay from someone with high feedback and attached my own motor for the idler. I think it was under $500.00 and is now 6 years old with no issues. My incoming power here is horrid with spikes and line drops and still no 3 phase problems. I do turn off the breaker feeding it when not in use.

Mine are welded back together, a bit scary!

I assumed I would have to forge a new set as price quoted to me have been extremely high.

I dont think Lee's springs broke, I think it was the mount at the top where the height setting is. Must have given him quite a fright.