Rotary Phase Converter

[rabler]

Another thing is I my lathe is a big, hefty old gal with 16 speeds so I haven't felt a need for variable speed. And I actually enjoy handling her knobs to change gears.

Same thing, even though my CK has a VFD! I have a 4 position switch on the VFD enclosure on the back of the lathe. One position is for the RPM to be adjusted by a pot on the lathe front panel. The other three positions are 40, 60, and 80Hz. It stays on the 60Hz position, and I shift gears. With dual clutch and brake levers, mechanical is easy.

I also find that it makes me think a bit more about feeds and speeds, rather than just twisting a dial randomly.

 

[matthewsx]

So this is the motor in question.



I have a static phase converter on the way which I can use to build the rotary, but space is a concern. The manufacturer of the static converter https://www.northamericaphaseconverters.com/phase-converters/static-phase-converters/
Says not for use with motors pre-1965 so my body would be okay but this motor is 1947 I think.

What happens with older motors and static converters? Should I even risk hooking up the static since I have an idler motor and can do the rotary? Is it just the manufacturer trying to keep people from complaining when they try to use their worn out 1904 motor with their product?

Has anybody here actually lost a motor from running it on a static converter or a VFD?

Inquiring minds want to know.....

John

 

[Tim9]

I THINK….The warning for the static phase converter is to warn against “running” a pre-1965 motor using the static phase powering said motors. I’m assuming that you’ll build your RPC using another Three Phase Idler motor which is post 1965. That should not be a problem because in that usage then the static just gets used to start the idler motor and once the idler comes up to speed then the static is no longer even powering the idler… much less your pre-65 lathe. The idler is then powered using the capacitors and the 220 single phase circuit.
At that point, then your post 1965 3-phase idler is generating the 3-phase power for your pre -1965 Three Phase lathe motor.
I started a RPC build in which I used a static phase converter to get my 5-hp “Three Phase idler “ motor started up. I began this build about 2 months ago( and then fractured my pelvis) so I kind of forget the finer details but I’m pretty sure that my static converter is out of cycle once the motor gets up to speed.

 

[MrWhoopee]

I have tried to use my WNY SPC on my 1 hp 1963 SB Heavy 10L. Even with the selector switches set correctly it does not start the lathe properly. It labors and does not come up to speed. Having been warned that if the SPC doesn't drop out within 5 seconds that it may be damaged, I gave up trying. I now use the 2hp mill (1978), which starts perfectly, for an idler. Been thinking about trying to find a newer 2hp motor for the lathe.

 

[matthewsx]

Thanks, I was worried about space for the 3 phase motor I have but realized last night that it can go on the bottom shelf of the cabinet I wanted to put in that space next to the mill. I now have a clear path forward, never thought the problem would be the motor messing up the SPC, I guess they just built them heavier (better) back then....

John

 

[Ulma Doctor]

Thanks, I was worried about space for the 3 phase motor I have but realized last night that it can go on the bottom shelf of the cabinet I wanted to put in that space next to the mill. I now have a clear path forward, never thought the problem would be the motor messing up the SPC, I guess they just built them heavier (better) back then....

John

i really can't imagine why the Static converter won't work on a motor form the 60's
if anything the old motors had more copper in them

the only potential problem i could see is if cloth insulation was present in the motor, or possibly the fan cooling is insufficient

i have started motors from the 1920's on my static converter design without any ill effects-
i have not run them as an idler motor for a RPC so i can only speculate as to longevity