Dumore #5 motor type?

[RandyWilson]

On to the next project. A few years ago I purchased a dividing head from a gentleman living deep in the swamp. Along with the dividing head, I got a pallet of odds and ends. One of those was a metal box full of Dumore parts. Upon inspection it appears to be an old #5, and mostly complete. Frame, three spindles, a handful of arbors, pulleys, belts, stones.... the only thing missing is the motor and maybe some pulleys.

I'm trying to figure out what sort of motor this thing is supposed to have. And that is turning into a real problem. The best I can figure from old manuals and such, 1/2hp, 115V, 0-60hz AC/DC (huh????) 14000rpm.

Anyone have a clue what is supposed to be there, and where one would find such a motor?

 

[woodchucker]

I don't have a dumore, I have a Themac, but I doubt the motor RPM would be 14k.

 

[JimDawson]

Those used a brushed motor (AC/DC universal motor), much like a basic hand router motor. They were speed controlled by carbon pile rheostat.

 

[Janderso]

This Dumore is 15,500 RPM

Dumore tool post grinder Model 11-011 fully operational and serviced. | eBay

<p>Dumore tool post grinder Model 11-011.</p><p>Excellent Working condition.</p><p>Bought and serviced before used. We bought for one specific job and now is up to sell.</p><p>Missing covers but is working like a champ. All tolerances are tight. Motor rotor and brushes like new. </p><p>Came with...

www.ebay.com

10,000 full load....

Dumore Tool Post Grinder 14-011 Model with accessories | eBay

This little guy SINGS! like a dentist drill! Now it will be yours.works great but the cord is ancient and very stiff.it should be replaced.

www.ebay.com

1,725 RPM

Dumore 18-011 Tool Post Grinder 115V 1/4HP | eBay

Attached is a 4" grinding cup.

www.ebay.com

 

[woodchucker]

This Dumore is 15,500 RPM

Dumore tool post grinder Model 11-011 fully operational and serviced. | eBay

<p>Dumore tool post grinder Model 11-011.</p><p>Excellent Working condition.</p><p>Bought and serviced before used. We bought for one specific job and now is up to sell.</p><p>Missing covers but is working like a champ. All tolerances are tight. Motor rotor and brushes like new. </p><p>Came with...

www.ebay.com

10,000 full load....

Dumore Tool Post Grinder 14-011 Model with accessories | eBay

This little guy SINGS! like a dentist drill! Now it will be yours.works great but the cord is ancient and very stiff.it should be replaced.

www.ebay.com

1,725 RPM

Dumore 18-011 Tool Post Grinder 115V 1/4HP | eBay

Attached is a 4" grinding cup.

www.ebay.com

But is the motor that high RPM??? I think the pulley drives the RPM. At least on mine you change pulleys to control speed.
The problem normally with very high speed motors is vibration and the brushes dance off the commutator and are not smooth enough.
At least that's my opinion and I'm sticking to it for the moment
Ok, I saw the badge on the motor... I'm an idiot. sorry for the jibberish.

 

[RandyWilson]

Interesting. So there is such a thing as a "universal" AC/DC motor? Guess I have much researching to do. Thanks!

 

[JimDawson]

Interesting. So there is such a thing as a "universal" AC/DC motor? Guess I have much researching to do. Thanks!

Almost all corded power tools have universal motors. They run just fine on AC or DC. Just to really throw a wrench in the works, most of the better battery power tools are 3 Phase.

 

[markba633csi]

Vacuum cleaner motors are often ac/dc also. Brush-type screamers, I call them
Also, older sewing machine motors are brush type- maybe adapt one of those for your grinder? Hmmm...

 

[RandyWilson]

I've been looking around. I happen to have a washing machine motor that is rated at 7/8hp 18000rpm. But as much as the world wants to convince me it's a universal motor, it smells strongly of three phase. But there are options.

While on the subject, does anyone know which way the grinder should spin? It would strike me that it should be against the work for maximum relative surface speed, but I saw one thing that suggested otherwise.

 

[JimDawson]

I've been looking around. I happen to have a washing machine motor that is rated at 7/8hp 18000rpm. But as much as the world wants to convince me it's a universal motor, it smells strongly of three phase. But there are options.

While on the subject, does anyone know which way the grinder should spin? It would strike me that it should be against the work for maximum relative surface speed, but I saw one thing that suggested otherwise.

I suspect that the washing machine motor is 3 phase. Modern washing machines are variable speed and are powered by VFDs. In fact it is most likely a BLDC (Brushless DC) motor. BLDC motors have an advantage in that they can produce near 100% torque from 0 up to their rated RPM.

I really don't think it makes a difference because the surface speed difference is so great. I does seem to make logical sense that the surfaces would turn opposite each other.