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Forgingnoob

Eerf grinder motor

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I need help finding the cheapest way to get my eerf grinder going I've been looking for a motor for weeks and the only thing I've found was a jet pump motor that doesn't fit.

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When I needed motors I like to go to an oldschool motor repair place and ask them.  They generally have some that folks dropped off and then left them when they found out how much the repair costs.  I've often gotten a good deal that way.

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2 hours ago, WayneCoeArtistBlacksmith.c said:

You will need a 56C face frame,  Are you going to have a single speed or use a VFD for variable speed? If so you will need a three phase motor.

Let me know if I can help you.

Wayne

I ordered a single phase 1hp 56c motor. Could I use a Variac as a veriable speed? I'm not too keen on electronic motors.

5 hours ago, ThomasPowers said:

When I needed motors I like to go to an oldschool motor repair place and ask them.  They generally have some that folks dropped off and then left them when they found out how much the repair costs.  I've often gotten a good deal that way.

The only place I know of around me that sells electric motors is Tractor supply Harbor Freight and a little RC shop.

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You will probably need at least a 1.5 hp motor.  Three phase does not mean "electronic".  Three phase just means that you have 3 phases of electricity rather than one.  Your house has single phase.  Three phase is generally and industrial application.  If you had 3 phase you would be paying industrial rates.  The VFD converts the single phase power 115v to 3 phase 230v power.  Many people who have grinders want the variable speed provided by the VFD. 

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The short answer is NO!   Have you ever seen any system with dual motors running the same shaft?

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58 minutes ago, ThomasPowers said:

The short answer is NO!   Have you ever seen any system with dual motors running the same shaft?

Not without lots of smoke and sparks!

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5 minutes ago, JHCC said:

Not without lots of smoke and sparks!

Stirring the stew a little here....they do stack motors to get higher torque but generally only those with digital drives so the multiple stages are perfectly phased with each other. It's becoming much more common to do this now that the cost of digital controls is dropping:  Lots of electric cars use stacked motors for example.  On your standard machine tool motor, the "slip" differential between any two motors would make them inefficient and possibly even battle each other.  Just wanted to bring up the difference so that, if the O.P. happened to run across a reference to stacked motors, he didn't think it was a pursuable option in this case.

The O.P. asked about a variac which is NOT a viable option either.  Speed control is going to have to come from either pulleys or a VFD on a 3 phase motor (which I would highly recommend, even though the cost is a bit painful).  Once you go VFD, it's hard to talk yourself into less in the future.

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That was the long answer, the cost of the control system would far outweigh the costs of the motor needed for his use.

And lets not forget the Jaguar with the 12 cylinder engine that was basically 2 six cylinder engined bolted in line...(got to see one last year at a gas station with the hood up!,sigh, drool, sigh)

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1 hour ago, ThomasPowers said:

And lets not forget the Jaguar with the 12 cylinder engine that was basically 2 six cylinder engined bolted in line...(got to see one last year at a gas station with the hood up!,sigh, drool, sigh)

Ever see the original Sherman tank motor set-up?  5 standard Chrysler 251 flatheads arranged around a central drive shaft via gearing to give an effective 30 cylinder motor.  Yes, it was a nightmare but a lot of guys were used to working on the individual motors from cars so could do some field repairs.  It also meant the needed new tooling was reduced to make the thing so there was less delay in production.  5244 lbs with radiator and clutch.

impwar57.jpg

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22 minutes ago, Kozzy said:

Ever see the original Sherman tank motor set-up?  5 standard Chrysler 251 flatheads arranged around a central drive shaft via gearing to give an effective 30 cylinder motor. 

Hook that up to your grinder, and you'll be doing some serious stock removal!

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Can you not use a motor from a domestic appliance? I regularly score motors from vacuum cleaners, washing machines, clothes driers, gardening tools, etc. some are even stepped or variable speed and all are compatable with the domestic power supply!

Kozzy, Thomas....google Tractor Pulling and check out the big boys toys.....half a dozen V8's don't half twist a chassis up! lol

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Smoggy; what motors do you have in the 1.5 to  2 HP range in your domestic appliances---and did you have to register them with the police?

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7 hours ago, ThomasPowers said:

The short answer is NO!  Have you ever seen any system with dual motors running the same shaft?

Do they make a differential for electric motors?

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With the exception of a few hand tools most domestic white goods and tools at the budget end of the market have a motor of about 1hp, (750w) ie 4" angle grinder, washing machine, etc, up market a bit and the motors get a bit bigger. But if he can't find 1.5-2hp then a 1-1.25hp is an option. At the end of the day it only means working slower for longer! How much power do you really need, I have a bench grinder here that is only 150w!

But a free scavanged motor could get it up an running while a bigger motor is sourced, and there is always gearing and abrasive choices.

.....or put it another way, a 1hp tool or no tool, how many HP does your file have!

(p.s. just checked the wifes "henry" vacuum cleaner, it's whisper quiet and she doesn't know I use it as a swarf vac......1200w or 1.6hp)

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Going cheap on a motor for a belt grinder is a false economy in my opinion.  If you don't get one rated as TEFC you are either going to have to build a filter box to keep the metal grindings out or replace your motor after the dust gets into the windings.  If you don't get at least a 3 speed pulley setup you will be letting yourself in for burned blades and ruined temper after heat treat (unless you plan on hand sanding after heat treat of course).  I have 1.5 HP on mine and can still stall it at times (but that may be a product of my VFD torque limiter and/or belt drive), so would recommend at least 1.5 HP.  You also need to decide whether you go with a 1750 RPM or 3600 RPM motor, which is directly related your drive system.

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A treadmill motor might work. And you'd get the variable speed control thrown in. Used treadmills can be found for fairly cheap - maybe even free. Of course I built a filter box for the motor on my home made belt grinder. The treadmill motor on it is rated at 2 hp and 7099 rpm.

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