Compressor Motor Mount Problem

[Bill Adamsen]

Looking too closely during servicing a 5hp 1-phase Champion Compressor (I'd bought used a few years ago) indicated a flaw when the Baldor "explosion proof" motor was mounted. The motor's frame mount holes did not align with Champion's tank motor mount slots. Whoever did the mounting did what was probably the best they could at the time in the field, drilled new holes in the motor mounts frame, and got the thing working. On close examination, the motor pulley is neither parallel with the compressor pulley nor in alignment. Plus, they pushed the motor pulley so far "up" the motor shaft, that the pulley is rubbing on the guards. I was able to relocate the motor pulley, but now I'm considering alternatives for remounting the motor.

Alternatives


Measure carefully, drill new holes and machine new compressor mount slots - having done this previously it is not something I look forward to.
Build a mount interface (see attached drawing) which bolts to the motor and bolts to the compressor though with twice as many bolts.


Question ... I have some thick (3/4") plate aluminum (6061T6) which is about 12" by 15" ... more than enough for a single interface. Can I use this? Will there be any electrolytic or issues I'll encounter before the compressor wears out and needs replacing in a few years? The aluminum would be reasonably easy to machine. If I go with mild steel for the interface and get something perhaps the same thickness, can I drill and tap studs (use Loctite) for the motor bolts - as opposed to needing to recess the heads - which I'm not sure I could actually do. Is there a solution I haven't considered here? Thanks!

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[Dick Mahany]

I've made an aluminum interface plate similar to what you describe to adapt a dish antenna to a steel bumper. Was outside in the elements for several years and was just fine. I'd go with the 6061 if slotting/machining the steel isn't what you want to tackle.

[steven taggart]

Your drawing looks like something I would tackle. If your motor mount holes are not standard, I would probably drill holes in the fabricated piece to accommodate a standard mounted motor also, which will make changing motors out in the future much easier.

[Jerry Bruette]

Grainger sells adjustable motor mounts, all you need is the motor frame number to order. You wouldn't need studs or recessed heads and it has adjustment bolts for tensioning belts.

Jerry

[Bill Adamsen]

Great and easy solution ... thanks

[Bill Adamsen]

So ... being a cheapskate and impatient I simply forged ahead with my proposed solution. Attached are some photos of it in place. The first photo is actually upside down ... that is looking from bottom up. The two carriage bolts are actually there just to keep the properly tensioned plate from sliding back and loosening the belts. I drilled and tapped all the holes for 3/8" coarse, which was the original mount. Five of the eight bolts required, needed to be countersunk. I used a carbide bit in a router with a template collar and scrap board bolted to the aluminum adjuster plate. Used a forstner bit to set the correct holes for the template guide/bit combination and hogged out the aluminum. Actually looked pretty spiffy when done - and done is the operative word.

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