Motor help for NWG...

SpeedyGonzales

SpeedyGonzales

Active Member
Greetings,

I started casually looking for a motor for a no weld grinder...

I have a few questions being that I know little about electric motors...

* I need an AC motor... if a seller does not disclose whether a motor is AC or DC, is there a way to tell the difference just by appearance?

DC motors seem too look like big tubes with no contours or parts that 'protrude'. AC Motors seem to have burls that stick out in which the electricity grows in all kinds of different directions (that's a joke)... but how will I know?

* How will I know if the motor will run on 110 standard wiring? Does the motor voltage number reveal this?

* I think I want 1750 RPM's correct? I found a motor with two speeds (1750 and 3500 or whatever). Would this be of benefit?

* The arbor needs to be 1/2" or 5/8" correct?

* What's this TEFC blarney?

Thanks, any input is helpful... I know I need a 1 phase motor and not 3 or more...
 
The motor plate will say AC or DC. There are so many kinds out there just looking wont always be right.
The plate again will tell you. Most will say something like 110/220v which means both.
Get the fasternone.
5/8"
TEFC = totally enclosed fan cooled
 
That motor could work depending upon operating conditions, but certainly presents some obstacles.

The main problem is that it has the open drip-proof enclosure, not the TEFC.
Some people come up with rather ingenious methods to have the open enclosure live under dusty conditions, from using pantyhose to building filtered enclosures. Still, the better option is to use a TEFC, as it is actually designed for harsher operating conditions.
Like yourself, I consider myself very handicapped concerning most things electrical. But I personally have tried a couple of the above "make it work" methods. The problem with most "fix-it" modifications is keeping dust out while still allowing the motor to stay cool.


Another thing to consider with this particular motor is the electrical requirements. While 2 horsepower is great to have, it's certainly not needed.
A better option is to use a 1.0 or 1.5 HP motor. One horsepower being the minimum, with 1.5 being the max that the typical household circuits can operate.
For this (2 HP) motor to operate on 110, you're probably going to need an upgraded electrical circuit, assuming you do not already have one. Or if you have the ability to operate on a 220 circuit, that would be much better. Either way, you need more than the typical household 110 circuit if you want to use a 2 HP motor.
The cost of installing electrical upgrades can really add up if you do not do it yourself.

Even if you can satisfy the electrical requirements, you still have the enclosure issue. To me, it doesn't make good economical sense to invest in a new motor, only to have it soon go out because it was designed for different operating conditions.
 
What length of shaft has to be sticking out of the motor? I found a 5/8" that only sticks out 1 1/16" Would that be enough for a 4 step pully?... Since the pulleys are so wide, I don't know if there's enough shaft length coming out of the motor for the set screw to tighten it.
 
That shaft is long enough for a pulley.
A drip proof motor will allow metal dust to enter the windings and build up around the magnetic points and brushes. Even if you bow it out the some of the metal dust will weld to the parts and continue to build up until it shorts out. The same thing happens to VFD controllers.
 
Neighbor,

Measure a 4 step pully so you will know what will work for you. A trip to a motor supplier in your vicinity would pay benefits. They should have the pulleys on display. Hold out for the TEFC motor. Open motors will not last any time in a grinder environment. Look for something of at least 1 1/2 hp. Two or three hp is even better.

Good luck, Fred
 
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