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Unimat motor

 

I recently acquired a Unimat SL Model DB 200.? Motor was a little noisy, so I disassembled it, cleaned it up and put it back together.? It runs well, but in CCW rotation.? I believe it should be clockwise.? I reversed the connections to the brushes, but it still runs CCW.? Any advice would be appreciated.
Thanks
Andrei
 

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Sounds like there is a short in the motor.?


Best Regards,
Andrei

mailto:calciu1@...
?
?

From: [email protected] <[email protected]> on behalf of ronparatore@... <ronparatore@...>
Sent: Tuesday, November 5, 2024 11:59 AM
To: [email protected] <[email protected]>
Subject: [Unimat] Unimat motor
?
I recently acquired a Unimat SL Model DB 200.? Motor was a little noisy, so I disassembled it, cleaned it up and put it back together.? It runs well, but in CCW rotation.? I believe it should be clockwise.? I reversed the connections to the brushes, but it still runs CCW.? Any advice would be appreciated.
Thanks
 

开云体育

Would it still run with a short? Is there any way to test it to locate or at least verify the short?
Thanks?



Sent from my Verizon, Samsung Galaxy smartphone


-------- Original message --------
From: Andrei Calciu <calciu1@...>
Date: 11/5/24 2:02 PM (GMT-05:00)
To: [email protected], ronparatore@...
Subject: Re: [Unimat] Unimat motor

Sounds like there is a short in the motor.?


Best Regards,
Andrei

mailto:calciu1@...
?
?
From: [email protected] <[email protected]> on behalf of ronparatore@... <ronparatore@...>
Sent: Tuesday, November 5, 2024 11:59 AM
To: [email protected] <[email protected]>
Subject: [Unimat] Unimat motor
?
I recently acquired a Unimat SL Model DB 200.? Motor was a little noisy, so I disassembled it, cleaned it up and put it back together.? It runs well, but in CCW rotation.? I believe it should be clockwise.? I reversed the connections to the brushes, but it still runs CCW.? Any advice would be appreciated.
Thanks
Andrei
 

开云体育

Ron, there are members with good knowledge of electricity and electronics.?

I was able to point to the short because I had?a motor that did the same and I had to dump it because the rewinding fees were more expensive than buying a replacement.?

Best Regards,
Andrei

mailto:calciu1@...
?
?

From: Ron Paratore <ronparatore@...>
Sent: Tuesday, November 5, 2024 4:39 PM
To: Andrei Calciu <calciu1@...>; [email protected] <[email protected]>
Subject: Re: [Unimat] Unimat motor
?
Would it still run with a short? Is there any way to test it to locate or at least verify the short?
Thanks?



Sent from my Verizon, Samsung Galaxy smartphone


-------- Original message --------
From: Andrei Calciu <calciu1@...>
Date: 11/5/24 2:02 PM (GMT-05:00)
To: [email protected], ronparatore@...
Subject: Re: [Unimat] Unimat motor

Sounds like there is a short in the motor.?


Best Regards,
Andrei

mailto:calciu1@...
?
?
From: [email protected] <[email protected]> on behalf of ronparatore@... <ronparatore@...>
Sent: Tuesday, November 5, 2024 11:59 AM
To: [email protected] <[email protected]>
Subject: [Unimat] Unimat motor
?
I recently acquired a Unimat SL Model DB 200.? Motor was a little noisy, so I disassembled it, cleaned it up and put it back together.? It runs well, but in CCW rotation.? I believe it should be clockwise.? I reversed the connections to the brushes, but it still runs CCW.? Any advice would be appreciated.
Thanks
 

On AC motors just reversing the power wires will do nothing except potentially exposing you to an electric shock because you reversed the line and neutral wires (This is not necessarily an issue on cords with non polarized AC plugs).
?
There are several types of motors used on Unimats, it would be nice to know exactly which type of motor you rebuilt.
?
Generally...
The only way I know to reverse the rotation direction is to reverse the wires to the rotor armature winding (the brushes).
Did you disconnect and reattach any wires inside the motor?
?
In the picture below the brushes would be located between the field windings (marked W1, W2, W3, W4) and the rotor armature (marked Rotor and Rotor1).
?
?
?
?
 

So you have the U90 motor.
A wiring diagram can be found here...
URL
?
More info can be found here...
URL
This page specifically mentions marking upon reassembly and reassembling the case the same way it was assembled originally.
?
There is a complete topic on this site about wiring the U90.
URL
?
 

I have converted my Unimat to 24 volt DC motors as have some others on this forum.
The beauty of this is that I now have variable speed and directional control as well as a very quiet motor. Direcinal control allows me to use power tapping on a production basis.
I will never go back to using a U90 motor again. For years we used to power tap holes using ?Bridgport vertical mill do to tapping.
Same principle here.
Dick
--
http://www.homemadetools.net/forum/?OFF-SET-tailstock-center-65965#post105972
?SMALL TURRET TOOL POST PLANS?
?LARGE TURRET TOOL POST PLANS
?MINI-LATHE CARRIAGE LOCK PLANS
?SMALL QC TOOL POST PLANS?
?QUICK CHANGE LATHE TURRET
?MINI LATHE COMPOUND PIVOT MODIFICATION
 

Hi Dick,
Could you please describe how you use the 24v motor and Unimat to do power tapping? Just asking for a friend...
Cheers,
James

On Thursday, November 7, 2024 at 07:37:54 PM PST, OldToolmaker via groups.io <old_toolmaker@...> wrote:


I have converted my Unimat to 24 volt DC motors as have some others on this forum.
The beauty of this is that I now have variable speed and directional control as well as a very quiet motor. Direcinal control allows me to use power tapping on a production basis.
I will never go back to using a U90 motor again. For years we used to power tap holes using ?Bridgport vertical mill do to tapping.
Same principle here.
Dick
--
http://www.homemadetools.net/ forum/?OFF- SET-tailstock-center-65965#post105972
?SMALL TURRET TOOL POST PLANS?
?LARGE TURRET TOOL POST PLANS
?MINI- LATHE CARRIAGE LOCK PLANS
?SMALL QC TOOL POST PLANS?
?QUICK CHANGE LATHE TURRET
?MINI LATHE COMPOUND PIVOT MODIFICATION
 

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Hi Gang:

I do power tapping most of the time. Most Bridgeports have 3 phase motors that reverse instantly. The radial arm drilling machines I've used also have a clutch reverse, slow in, fast out.

With a DC motor, reversing the current will reverse the rotation. It is a bit hard on the brushes, I see massive sparks on my Funky Power Tapper when it reverses:

Just yesterday I tapped 154 holes in Plexiglas in under a half hour. ( 10 seconds each with part changes ) The small electrical switch reversing the current, and the small yellow capacitors reduce the arcing that can weld the contacts. The motor is a 12 volt cordless drill with a variable DC power supply.

My big lathe, the Smithy Granite, has a 90 volt DC motor, and I can reverse it, but it really doesn't like it. Some day (??) I plan to replace it with a three phase motor.

Good luck, Carl.

On 11/8/2024 1:45 AM, james Pineda via groups.io wrote:

Hi Dick,
Could you please describe how you use the 24v motor and Unimat to do power tapping? Just asking for a friend...
Cheers,
James

On Thursday, November 7, 2024 at 07:37:54 PM PST, OldToolmaker via groups.io <old_toolmaker@...> wrote:


I have converted my Unimat to 24 volt DC motors as have some others on this forum.
The beauty of this is that I now have variable speed and directional control as well as a very quiet motor. Direcinal control allows me to use power tapping on a production basis.
I will never go back to using a U90 motor again. For years we used to power tap holes using ?Bridgport vertical mill do to tapping.
Same principle here.
Dick
--
forum/?OFF- SET-tailstock-center-65965#post105972
?SMALL TURRET TOOL POST PLANS?
?LARGE TURRET TOOL POST PLANS
?MINI- LATHE CARRIAGE LOCK PLANS
?SMALL QC TOOL POST PLANS?
?QUICK CHANGE LATHE TURRET
?MINI LATHE COMPOUND PIVOT MODIFICATION
 

Hi Carl,?
So, with the 3ph, do you just slam the drum switch through off to reverse? That just seems like a harsh thing to do. Not being critical here, just curious.
?
Tim
 

First of all, I only power tap through holes, never bottom tap. I reverse the spindle and back the tap out under power slowly.
I hope this explains the process. It works very well.
Dick
--
http://www.homemadetools.net/forum/?OFF-SET-tailstock-center-65965#post105972
?SMALL TURRET TOOL POST PLANS?
?LARGE TURRET TOOL POST PLANS
?MINI-LATHE CARRIAGE LOCK PLANS
?SMALL QC TOOL POST PLANS?
?QUICK CHANGE LATHE TURRET
?MINI LATHE COMPOUND PIVOT MODIFICATION
 

James,
As I said earlier, I can power tap through holes using ?the Unimat in a vertical mode similar to a drill press and very slows rpm , watch very carefully and stop then reverse rotation while backing out. This would not be possible if I did not have the ability to reverse direction and control rpm. This is all possible only because I have installed 24volt dc motors.
Dick
--
http://www.homemadetools.net/forum/?OFF-SET-tailstock-center-65965#post105972
?SMALL TURRET TOOL POST PLANS?
?LARGE TURRET TOOL POST PLANS
?MINI-LATHE CARRIAGE LOCK PLANS
?SMALL QC TOOL POST PLANS?
?QUICK CHANGE LATHE TURRET
?MINI LATHE COMPOUND PIVOT MODIFICATION

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