Increasing electric motor output shaft diameter, can I?

[tarbellb]

Looking for some experience in this field. I have never had to do something along these lines, not even sure its advisable or doable?

Situation:

I have a amazing 18" Delta Invicta wood planer from the 70's that I need to convert from 3ph to 1ph.

Currently it has a 7.5hp 3ph motor with a 1 1/8" diameter output shaft.

There was a option on this machine to run a 5hp 1ph motor, both 3750rpm.

Because my shop lacks 3ph, and I have researched do a VFD and its cost prohibitive, I am now looking at 5hp 1ph motors for sale.

Finding a 3750rpm, 1 1/8" diameter shaft 5hp 1ph electric motor has proven to be hard and expensive. BUT.. finding a 7/8" shaft is much more common.


Question:

Is there a easy or known way to convert a keyed 7/8" shaft to a 1 1/8" shaft?

Will this adversely effect the motor/machine?

Does it make sense to have one made?

Cost:
I can locate a 5hp Leeson w 7/8" for $250-300

1 1/8" for $500+


Reference:

Delta Invicta RC-51 18" planer
http://www.toolpartsdirect.com/delta-22-460-model-rc-51-20-planer.html

 

[The Cobbler]

should be able to buy a shaft bushing from someone like Macmaster Carr

 

[LXCam]

Exactly what cobbler said. Get the right hub or just get a new pulley.

 

[rlitman]

First off, single phase 7.5HP motors do exist. I know, because I have one on my compressor. Any reason you don't want to stick with the original power?

Second, I'm not sure a VFD is as cost prohibitive as you think.
Don't take this as a fully researched answer, but wouldn't something like this work for you?
https://www.amazon.com/dp/B010CJBVOC/?tag=atomicindus08-20

Third, if you change the shaft diameter, you're choosing a different NEMA frame. That will have different bolt locations, and may make mounting your new motor difficult.

1-1/8" shafts are used by 182T, 184T, 213 and 215 frame motors.
http://www.baldor.com/Shared/pdf/nema_chart_04.pdf
But they have different mounting hole locations.

edit, oh, and is the motor you have ODP or TEFC, and is the cheap Leeson you're looking at ODP? I ask, because an ODP motor on a planer will probably clog up with dust, and if you have a TEFC motor already, I'd suggest you stick with it.

 

[tarbellb]

Cobbler/LX- I looked on McMaster actually and did see shaft sleeves but nothing keyed?

Seems like it should use a key way? Or is that just extra insurance that it doesnt slip on the shaft?

As for a new pulley, not going to happen, its a very specialized pulley for running a triple belt for the cutter and a single belt for the powered table assist.

rlitman- Wow, thanks! I swear I searched all over for a VFD and even posted a few things in the VFD thread....but that looks like a possible candidate?

Most the VFDs in that power range are very misleading about what they could handle, or if it was 1ph<>3ph.