Can you weld to the base of industrial motor?

Question

Can you weld to the base of industrial motor?

Answer 1

Depends on how you're talking.  Generally, the motors come with bolt holes for mounting, because a motor needs to be occasionally moved back for periodic maintenance.  Welding is pretty permanent.

If you're welding the motor mount to something and don't mind the loss of mobility, you should be fine.  You'll still need some sort of way of adjusting the motor or the load to insure the driveshaft is correctly aligned, or you'll have problems.  Be sure to calculate the strength of the weld including appropriate safety and cyclic factors to insure that the weld connection is at least as strong as the bolts it was designed to be held with.

If you're welding to any other part of the motor, you risk interfering with air flow causing the motor to overheat.  The welding heat could also weaken the case or damage internal components.

Answer 2

I wouldn't recommend it.

1) You may need to remove or replace the motor at some time. Taking the trouble to bolt the motor down makes more sense than welding.

2) Motor casings are often cast iron or cast aluminum. Welding either of these poses some technical problems. It's not recommended for amateurs.

In the case of cast iron, generally you need to use a filler metal that's *specifically designed for cast iron.* The large amounts of carbon, silicon, and manganese in cast iron make ordinary mild steel filler rods, extremely brittle and useless. You'll also need to preheat the entire piece to be welded to about 800-1,000 F to prevent stress cracks in the weld zone. Then you need to wrap the piece in an insulating blanket so it doesn't cool too quickly.

Even if you carry this process out perfectly, cracks are still possible.  

Brazing cast iron is relatively easy, though you still need to preheat to about 800-900 F. Also, this makes removing or replacing the motor rather difficult.

In the case of aluminum, most aluminum alloys (cast or otherwise)  can be welded with acceptable results, though some cannot. (In particular, one should be wary of welding high-strength, or precipitation-hardening aluminum alloys.)

TIG welding is the only way to go when it comes to aluminum, but TIG machines are somewhat expensive. TIG welding is more difficult and requires more skill and experience than other processes.

3) Constant vibration and variable operating stresses make fatigue a serious concern. Again, bolting the motor in place makes more sense here than welding, when one considers the problem of vibration.