Delta 34-350 motor and pulley issues

[Karl Card]

I have a delta 34-350 and it came with the 3 phase 7.5 hp motor. Well I took the motor out because I do not have 3 phase service and took the pulley off and was looking for another motor. Well I came across a baldor 7.5 hp single phase motor, well worth the money and I really want it bad, dont ask if I need it, I just want it.. The only problem is that my pulley has a bore of 1 1/8 and the new motor has a stem of 1 3/8. So I am thinking of having the pulley bored out depending on cost. I thought about buying a new pulley but am not having much luck in finding a 4 V-belt pulley with the bore I need. The wall thickness beteen the bottom of the V belt slot and the bore is 5/8 of an inch thick. I would only need about 1/8 inch of that. Does anyone know i that is safe?

[Bruce Wrenn]

It would be cheaper and quicker to have shaft of new motor turned down to desired size on lathe (between centers.) Then using milling machine, cut a new key way. Should take about an hour shop time. First take a file and see if you can scratch shaft. If you can't, then it's hardened and would require cobalt / carbide cutters. Remember you only need to reduce size of shaft where sheave goes. To bore out a sheave, you chuck it in a three jaw chuck on lathe and then bore it out. Next you have to broach a key way into it, which is a simple operation. I personally would reduce shaft size. To turn shaft, you would have to remove it from motor, and most likely remove bearings.

[Jerry Bruette]

You should be able to buy a sheave with a taper lock bushing from either McMaster or Grainger. You'll have to provide them with the pulley diameter and the groove size..."A" groove "B" groove etc. or if the belts are fractional horse power size.

The diameter of the sheave is measured on the pitch diameter for all belts except fractional horse power belts. But I don't think the actual O.D. would make that much difference.

I wouldn't change the NEMA dimensions on a motor because it will have only one purpose. Along with the idea that you may not have the knowledge to take a motor apart and reassemble it properly.

If you need more help with this project you can PM me.

Jerry

[Karl Card]

You guys make it sound so easy... which is a good thing. I have friend who has a friend who owns a machine shop and he is looking into seeing if this person will do the turning. I realize different parts of the country have different rates but I am assuming I would be safe to say 100 bucks should get the shaft turned and motor put back together..??!!!!

[Jerry Bruette]

Karl

The taper lock and sheave is easy, and probably cheaper than turning the moter shaft. Consider this, if your custom turned motor ever takes a dump you'll have to get another custom turned motor. If you get a taper lock and sheave it'll fit every motor of the same NEMA frame size and you only pay for it one time.

PM me I'll walk you through this process.

Jerry

[Don Jarvie]

Look into buying 2 new pulleys that are the same size for the outside diameter and the same width so the belts will run pararell with each other. Get one to fit the motor and one for the saw.

I'm going this route for my PM 66 because my motor swap now has a 5/8 shaft and the pulley to match the 5/8 shaft won't match the arbor one.

Check Surplus Center and McMaster Carr. It maybe easier and quicker than fooling with the shafts, etc.