Figuring motor speed for Coulter crank planer

The brochure for my Coulter crank planer discusses the factory motor drive, but doesn't mention motor RPM or pulley size. It does list specs for line shaft drive, with a countershaft speed of 350 RPM and driving/driven pulleys of 12" and 20" respectively. That comes out to 210 RPM at the input shaft.

The motor that came on the machine is 1200 RPM, with a 5" pulley. That works out to an input shaft speed of 300 RPM. It's not the original motor, it's locked up, and it's 208 volts only (which I don't have in the shop), so eventually I'll be replacing it.

Measuring from the catalog illustration and scaling from the known dimension (20" driven pulley) it would seem that they are showing an 8" motor pulley on the motor drive setup. That would require a very slow motor... of course, it could just be artistic license on the part of the illustrator, but an 8" pulley would provide better belt grip over a 5" one.

What's the slowest-speed old 3 phase motor you all have seen? Dad's phase generator was a 5 hp GE that was 850 RPM... that's the slowest I can remember seeing.

If anyone has an appropriate old 3 HP, 3 phase, 1200 RPM (or slower) that they would part with, give me a shout.

Thanks,
Andy

Sent from my SM-G950U using Tapatalk

My 1917 ten horse Westinghouse is also a tad under 900

Pretty much standard 8 pole motor, shouldn't be too difficult to find. I have a few about the place but I'm not parting with them and too far away anyway.

PDW