Powering 5.5KW (7.5hp) lathe with clutch

[J Tiers]

[QUOTE=strokersix;n1943889]Motor data plate on this lathe: Anything jump out as a problem? I'm curious why the amp rating isn't exactly half for 440v. Also noted 1165 rpm................../QUOTE]

Take a look at the power factor. It is higher for the lower voltage, so the difference in current is accounted for by that. (listed as "Cos" with the Greek theta). Lower power factor is more current

[strokersix]

I reconfigured the control transformer and motor connections in the peckerhead for 220v. Took a while for me to figure out exactly what I needed to do. Then it was easy to execute.

My static converter says 3-5hp and I already had a 3hp 3600rpm idler attached so I plugged it in to see what happens. It works great! Winds up the lathe motor in about a second.

I checked voltages while the lathe was running, spindle medium speed. 255, 230, 225 phase to phase. 190, 125, 125 to ground. Are these values of concern? I understand that it could be better balanced with capacitors but I'm inclined to just leave well enough alone. Seems to run just fine.

Thanks to all for suggestions!

[The Metal Butcher]

Sounds good to me. Nice work! Just waiting on heaters then?

[strokersix]

Heater module has what appears to be a trim adjustment on it. It's set at 20 now. I didn't touch it so don't know the adjustment range. If I overload, I'll try adjusting that first. Hopefully I won't need to as I cannot imagine needing full power on this lathe. Not trying to remove cubic metal, rather just utilize the size of the machine.

If this lathe becomes used frequently I'll probably VFD it. I love the VFD on my smaller lathe.

[tom_d]

I reconfigured the control transformer and motor connections in the peckerhead for 220v. Took a while for me to figure out exactly what I needed to do. Then it was easy to execute.

My static converter says 3-5hp and I already had a 3hp 3600rpm idler attached so I plugged it in to see what happens. It works great! Winds up the lathe motor in about a second.

I checked voltages while the lathe was running, spindle medium speed. 255, 230, 225 phase to phase. 190, 125, 125 to ground. Are these values of concern? I understand that it could be better balanced with capacitors but I'm inclined to just leave well enough alone. Seems to run just fine.

Thanks to all for suggestions!

My choice would have been a static converter in the 5-8hp range without an idler. Larger size as a safety factor. But, where you already had the 3-5hp unit hooked up to an idler then by all means go with that. The proof is in you reporting that it runs fine. If the converter doesn't struggle when bringing a large chuck up to a higher speed then all that's left to do now is start posting photos of the lathe in operation, and the projects you're working on!

[strokersix]

Thanks for the encouraging words! I'd like to bore the main line on v8 chevy blocks with this machine. Don't disparage, I know there are other ways to do the job...

[The Metal Butcher]

Heater module has what appears to be a trim adjustment on it. It's set at 20 now. I didn't touch it so don't know the adjustment range. If I overload, I'll try adjusting that first. Hopefully I won't need to as I cannot imagine needing full power on this lathe. Not trying to remove cubic metal, rather just utilize the size of the machine.

If this lathe becomes used frequently I'll probably VFD it. I love the VFD on my smaller lathe.

Well, a lot of motors are inefficient and need almost as much current at idle. For example I overheated with N27 heaters at idle, but N36s are fine.

I don't know if you'll feel the need as much with a clutch. You've got all the feel in the world for gentle starts, it's only speed control you gain.

My choice would have been a static converter in the 5-8hp range without an idler. Larger size as a safety factor. But, where you already had the 3-5hp unit hooked up to an idler then by all means go with that. The proof is in you reporting that it runs fine. If the converter doesn't struggle when bringing a large chuck up to a higher speed then all that's left to do now is start posting photos of the lathe in operation, and the projects you're working on!

Safety factor? What is the danger?

Clutch lathe, it won't struggle regardless.

Thanks for the encouraging words! I'd like to bore the main line on v8 chevy blocks with this machine. Don't disparage, I know there are other ways to do the job...

I'd love to see that!!

[DennisCA]

Nevermind

[JRouche]

It is hard to show hope with words.. I see it here. Thanks.. JR

[JRouche]

I have an unused GE 10hp Single Phase electric motor. It is not worth anything to me. Barter?

No chickens or goats lol although I love both those animals.

I put a pic up here before. Its the size of a 10 gallon trash can and weighs 145lbs.

Real 10hp electric motor, not 3 phase? LoL No way. Yeah. she is a beast.... JR