RF-30 motor pulley on 7/8" shaft?

[RJSakowski]

Oh also, how hard is it to get off? If the pulley is blank on top, nowhere for the gear puller to push, how do you get it off? Is heat all I need?

A good question. I would loosen the set screw and hope that it came off with some gentle persuasion. A couple of oppoping wedges between the pulley and the motor housing should help. Barring that, I would consider drilling and tapping a 1/4" hole in the end of the pulley so I could jack it off with 1/4" screw.

 

[Harry Knutz]

Use some Kroil penetrating oil a couple of days before you get ready to pull the pulley.

 

[epanzella]

I too used a Baldor 3ph motor on my RF30 clone. Very happy with it. I left the step pullies and between the VFD and the pulley steps I get 60 to 3750 rpm. I have my VFD set for 30 to 90 hertz. I originally used 30 to 120 hertz but my spindle didn't sound happy at 5000 rpm.

 

[OTmachine]

Oh also, how hard is it to get off? If the pulley is blank on top, nowhere for the gear puller to push, how do you get it off? Is heat all I need?

I

Bearing separator and puller set

 

[bulgie]

Finally getting back to this project. Tonight I tried three things, all at once. Kroil, heat and a puller. Well, more Kroil, on top of what I applied months ago. Unfortunately no movement, but I did manage to break the pulley where the puller was pulling.

There was an 8 mm through-hole in the top, so I put in a 5/16" cap screw, for the puller to push on.

Anyway, now I am looking for a replacement pulley "stack" or whatever they call those things. The gap between the pulley and the motor is a tad narrow for my calipers, hard to know if I'm getting a good measurement, but I'm somewhat sure it's 25 mm! Here I thought I was going to have to bore it to 7/8, when in fact I would have had to shim it down to 7/8". If it wasn't broken that is.

I found this Grizzly replacement for their G1006 mill-drill, which sure looks like my Enco, almost identical. The Grizz website gives zero specs for ithe pulley though, unless I'm looking in the wrong place. No shaft diameter, pulley diameters, belt size... nothin.

It was $90 with free shipping, not cheap but I'll swallow that if it fits or can be made to fit. Wish me luck!

I got the VFD mounted, it's bolted to some 1.5" square tube that comes down from the ceiling joist. Above and a bit to the side of the mill. Should be fine, but it'll be easy to move it elsewhere if it ever gets in the way. Just two lag screws connecting the square tube to the joist, so I can remove one lagscrew and pivot the whole assembly up to the ceiling, the cables have enough slack.. It's out of the spray zone of chips and coolant, but it's in a wash-down enclosure anyway so I'm not worried.

Dang it I thought I might git 'er done today. Alas, it was not to be. I even knocked on wood, crossed my fingers and stroked my lucky rabbit's paw, but sometimes the universe has other plans.

 

[OTmachine]

I have brazed up and machined broken pulleys in the past. Good fix. Do you have a local welding shop?

 

[bulgie]

I have brazed up and machined broken pulleys in the past. Good fix. Do you have a local welding shop?

I can braze cast iron or steel, but this is cast aluminum.Do we know if it's even weldable? My alu welding experience is next to nil, but aren't some alloys considered unweldable?

Since the fracture surfaces on the aluminum are so rough, and fit perfectly together (no noticeable plastic deformation), it might be strong enough to epoxy it back together.

Anyway, fixing the broken pulley would only be useful if I could get it off this old motor I'm replacing. Maybe I could get it off with more time, technology and grunting, but I think I'm gonna wait to see if the Grizzly pulley I ordered is going to work. If it does, then I'm OK with scrapping this broken pulley along with the motor.

I'll offer this motor and pulley for sale cheap to a HM member if someone wants it. Free if you come pick it up at my house in Seattle, or else let's say $40 to cover the time it'll take me to build a proper shipping box for it, plus actual shipping. It's a 2 HP, single-phase, original equipment, manufacture date 2002, wired for 220V, can also run on 110V. Seems to run fine but no guarantee. When I ran it at the highest speed (something over 2000 rpm), torque was not great, had to take light cuts or it would slow down. Someone here thought it could be the Run capacitor going bad, which is easy to replace if that's the problem. But it did all the milling I needed it to do. I work mostly in steel and at lower rpms, torque seemed fine. Pics on request.

 

[Harry Knutz]

I can braze cast iron or steel, but this is cast aluminum.Do we know if it's even weldable? My alu welding experience is next to nil, but aren't some alloys considered unweldable?

Since the fracture surfaces on the aluminum are so rough, and fit perfectly together (no noticeable plastic deformation), it might be strong enough to epoxy it back together.

Anyway, fixing the broken pulley would only be useful if I could get it off this old motor I'm replacing. Maybe I could get it off with more time, technology and grunting, but I think I'm gonna wait to see if the Grizzly pulley I ordered is going to work. If it does, then I'm OK with scrapping this broken pulley along with the motor.

I'll offer this motor and pulley for sale cheap to a HM member if someone wants it. Free if you come pick it up at my house in Seattle, or else let's say $40 to cover the time it'll take me to build a proper shipping box for it, plus actual shipping. It's a 2 HP, single-phase, original equipment, manufacture date 2002, wired for 220V, can also run on 110V. Seems to run fine but no guarantee. When I ran it at the highest speed (something over 2000 rpm), torque was not great, had to take light cuts or it would slow down. Someone here thought it could be the Run capacitor going bad, which is easy to replace if that's the problem. But it did all the milling I needed it to do. I work mostly in steel and at lower rpms, torque seemed fine. Pics on request.

I heli-arced my neighbors cast aluminum wood stove legs, I don't think it was real quality alum, But that was years ago and it is still holding.

 

[bulgie]

Well I did get the pulley off. @RJSakowski in post #11 suggested tapping the end of the pulley and using a screw to push it off — I shoulda listened! The hole in the top was 8 mm, so it was pretty easy to tap it to 3/8" fine. The 3/8" screw by itself wasn't doing anything with the torque I had available without a cheaterbar, so I heated it up with a heat gun to maybe 150-200°F and applied still more Kroil, and then it came loose. Of course, it's still broken! Time will tell whether I try to fix it, or just replace it, the jury is out.



Since I got Kroil on the fractured surfaces, I might give it a nice long soak in the ultrasonic cleaner before trying to glue it back together.

The shaft turned out to be 22.0 mm. The part I was measuring at 25 mm previously was a step — I couldn't see the actual shaft when the pulley was mounted. So if I fix and use that one, I'll only have to bore it to 22.2 mm to fit my new 3-ph motor. 7/8" is only .009" bigger than 22 mm. Won't even have to deepen the keyway, I'll just shorten the key by .009"



Dunno if this will be of any interest to any of you guys, but since I asked the question, I figger I better tell the rest of the story.

 

[RJSakowski]

Well I did get the pulley off. @RJSakowski in post #11 suggested tapping the end of the pulley and using a screw to push it off — I shoulda listened! The hole in the top was 8 mm, so it was pretty easy to tap it to 3/8" fine. The 3/8" screw by itself wasn't doing anything with the torque I had available without a cheaterbar, so I heated it up with a heat gun to maybe 150-200°F and applied still more Kroil, and then it came loose. Of course, it's still broken! Time will tell whether I try to fix it, or just replace it, the jury is out.

View attachment 469707

Since I got Kroil on the fractured surfaces, I might give it a nice long soak in the ultrasonic cleaner before trying to glue it back together.

The shaft turned out to be 22.0 mm. The part I was measuring at 25 mm previously was a step — I couldn't see the actual shaft when the pulley was mounted. So if I fix and use that one, I'll only have to bore it to 22.2 mm to fit my new 3-ph motor. 7/8" is only .009" bigger than 22 mm. Won't even have to deepen the keyway, I'll just shorten the key by .009"

View attachment 469709

Dunno if this will be of any interest to any of you guys, but since I asked the question, I figger I better tell the rest of the story.

With a 3 phase motor and VFD, you may not need that pulley position. If you decide you do, I would be inclined to turn the broken part down and press fit a new pulley to the stub.