I had the opportunity to get a 24” bandsaw that supposedly works for $100. It appears to be 30 years old and in good physical shape. My stepgrandfather, Ernie knows a guy that knows a guy, etc. Anyways he said something to me at Thanksgiving and he told me he would have bought it but he couldn’t use it in his garage. I asked him why, is it 220? He said it was 3 phase. I replied that we have 3 phase at school and want a large bandsaw. So he called the guy back and said I would get it at Christmas.
I don’t know how they got it in a pickup to begin with, probably a fork since it came from a factory. But Ernie had a hoist in his garage so that is how he got it out. I used a solid surface pallet from the cabinet supplier and a pallet jack to load it. Had to winch it into the trailer. Was told it weighs 800#. It took 4 of us to get it on the pallet, 800# my foot, more like 1G.
Anyways, got it home and then the next day wiped off the motor plate. Wouldn’t you guess 440v. Good thing it was just me an a maintenance worker, because I said some school inappropriate choice words. Our shop doesn’t have 440 power.
Here’s the question i have for the LJ’s that are good with electrical motors.
The motor is a 5hp, 3ph 440v 1150rpm with what appears to be either 1” or 1 1/8” shaft, about 3” long and a 1/4” key. The motor is about the size of a lear jet engine (exaggerating a little) but not much.
I have 2 motors that I can get my hands on that are 5hp, 3ph 220v, 1750 rpm, with the shaft measurements the same as the original. The motor is smaller in size and building a bracket out of some angle or blocks of wood to make it the right height isn’t a problem.
Can I use the 1750rpm motor? With my limited electrical background, wouldn’t it just spin faster. Maybe wear out the bearings a little quicker?
Or am I better off just selling to get my money back? I will post pics later this week.
Thanks for any suggestions or comments.
7 comments so far
dennis mitchell
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3791 posts in 1207 days
posted 299 days ago
It sounds like a gem. I’d love one of those old monsters. Call an electrician if you have to. To buy a saw like that new is probably in the $4000.00 range.
-- http://www.woodsongsfurniture.com
bentlyj
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783 posts in 363 days
posted 299 days ago
Couldn’t you change pully sizes to make the rpm you want?
EEngineer
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274 posts in 506 days
posted 298 days ago
Definitely find an electrician that is good with motors. You may be able to use the original motor. Some were able to be rewired for 220 or 440. They do this by splitting the windings for each phase – to run 440, you wire both windings for each phase in series; for 220, you wire the windings for each phase in parallel. To determine if this is the case and rewire it, you really need to open the motor up and look at the wiring already in place.
As for motor RPM differences – these can usually be solved with different size pulleys. I wouldn’t just substitute the new motors. The difference in motor speeds, 1750/1150 = 1.52, will give you about 1 1/2 times the linear cutting speed on the bandsaw. This would be a lot more concern than any increased wear on the bearings. Somebody with more experience on bandsaws can tell you what this means practically but the most obvious concerns would be increased blade wear and possibly dangerous operation with increased linear cutting speed.
I once helped a friend replace a motor on his old table saw. It originally had a 1750 RPM motor with a 5” on the motor and a 2” pulley on the blade arbor. This gave about 1750 X (5/2) = 4375 RPM at the blade. The manual for this saw gave the specs for blade RPM at 4500 RPM – pretty close. For the new motor at 3450 RPM we used a 2.5” pulley. This gave about 3450 X (2.5/2) = 4312 RPM at the blade – close enough.
-- "Find out what you cannot do and then go do it!"
FJPetruso
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163 posts in 603 days
posted 298 days ago
Since you’re in St.Louis you could talk to the fellows at MISSOURI ELECTRIC MOTOR Co., 3001 Delmar Blvd., St. Louis, MO 63103, (314) 535-6800 … We use them quite frequently at work.
-- Frank, Florissant, Missouri "The New Show-Me Woodshop"
Karson
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25797 posts in 1293 days
posted 298 days ago
I’d keep it and work on the motor. Usually motor guys change the power all the time. So I’d try that before I’d replace the motor.
I’d love to have that. I’ve got my own phase converters at home to use my 5hp 3 phase table saw, 220V.
-- What happens in the workshop stays in the workshop. No wait that doesn't sound right. Karson Southern Delaware karson_morrison@bigfoot.com †
tooldad
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454 posts in 608 days
posted 298 days ago
thanks guys. I have decided that we will take the motor off and take it to the motor company the school uses. I actually think it is MO Elec Co. One of the maint workers at school is semi-retired and I almost consider him family. He will help me get it off in between jobs. Sorry forgot to take pics today. But I will keep everyone updated. ONe of my students, also is an LJ, says it needs a paint job. Not that it needs one because it is bad, but because it is yellow and blue, and that is our rival school in the district’s colors. We are red, white, and black. So in the end it will get a paint job too!
FJPetruso
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163 posts in 603 days
posted 297 days ago
Yes, some call it MO Electric Motor Co. ... the abbreviated form of Missouri Electric Motor Co. It can be “googled” both ways. They specialize in re-winding electric motors & coils. They rewind motors & coils for some of our antiquated equipment here at the “Electric Company”. I seems as though I’ve worked on some of Dr. Frankenstein’s stuff at one time or another.
-- Frank, Florissant, Missouri "The New Show-Me Woodshop"