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Vevor motor

 

I bought the 7x14 Vevor? lathe with the 550w DC motor a will back. The motor doesn't have much power. I can stall it with my bare hands by grasping the 4" chuck. Is there a easy way to check out the motor to see if it is the problem. I have the motor out and sitting on the bench.
 

Is it brushed like the old ones?? Maybe those need attention.

On Friday, January 26th, 2024 at 3:06 PM, paul mcclintic via groups.io <cannontandem@...> wrote:

I bought the 7x14 Vevor? lathe with the 550w DC motor a will back. The motor doesn't have much power. I can stall it with my bare hands by grasping the 4" chuck. Is there a easy way to check out the motor to see if it is the problem. I have the motor out and sitting on the bench.

 

Did sit for a long time without using the lathe or in wet climate?

Dave?
 

The lathe sat for a while when I got it but it was in a reasonably dry basement. I did look at the brushes and they didn't look too bad. One had worn in well and the other was getting there.
 

I look at the brushes and sand the comutator.?
It can happen on motors that are used a lot to but just sitting will do too.
On will used some times you need to file between the copper plates I like use I die file as a curve ? file and is easier on small motors.

Here photo of a comutator.
 

When have look to if burnt.
At point nothing will help but new motor.

Dave?
 

To avoid leaving abrasive particles in the motor, filing is preferable to sanding. If you must sand, use old style, "flint" sandpaper; the? abrasive is not electrically conductive. The mica (insulation) between commutator segments should be lower than the copper segments. On larger? machines, a hacksaw blade is the appropriate tool; on small motors, an X-acto razor saw blade (without the handle) is the right size. Copious amounts of cheapest brake parts cleaner from an auto supply store help to get rid of debris.

Roy
 

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Restoring the commutators on vehicle dynamos.
(British cars probably from the 1940’s/50’s/60’s)

I recall this is what we did for dynamos on cars. Fellow engineers - Are motors the same? I really don’t know??

Anyway, —
When I was young, we used to ‘very delicately’ skimmed the commutators on a smallish lathe and finished off with a fine file (one used for brass I expect - Dad had separate files for brass) and finish off with fine emery cloth/paper.?
Slow speed and done very delicately. Then we got an old worn out full sized hacksaw blade and ground the end into a fat claw shape. We then carefully used the blade to pull along the black spacer material between the copper commutators to achieve the required undercut on the commutator. (Something like a fraction of a millimetre or 1/32”) The black spacing between the copper commutator sections (mica) seemed something like hard pitch. ?It’s 60+ years ago but I am sure that’s what we did. I can’t remember covering the motor to prevent the ingress of particles but it seems a great improvement. JFI, I recall the commutator on the starter motors were not undercut. Sorry I don’t know why, but definitely different.

I hope this is helpful.

Regards,




On 27 Jan 2024, at 03:27, Roy via groups.io <roylowenthal@...> wrote:

?To avoid leaving abrasive particles in the motor, filing is preferable to sanding. If you must sand, use old style, "flint" sandpaper; the? abrasive is not electrically conductive. The mica (insulation) between commutator segments should be lower than the copper segments. On larger? machines, a hacksaw blade is the appropriate tool; on small motors, an X-acto razor saw blade (without the handle) is the right size. Copious amounts of cheapest brake parts cleaner from an auto supply store help to get rid of debris.

Roy

 

DAVID WILLIAMS
12:11am? ?
Restoring the commutators on vehicle dynamos.
(British cars probably from the 1940’s/50’s/60’s)

I have books from 1941 that cover cars from 1930s and had same in book.
I repair my father's drill motors in 1960's? used in construction.? They used 8 hours 5 days drilling steel. I use book on redoing the comutators on a South Bend 9A. Learn lot on DC motors and generators.?
What you said was cover in book which had forgotten.??

Dave?
 

There were special lathes made for this that were very appropriately called "armature lathes."? The lathes were small and didn't have much power (didn't need much) but the swing was big enough to clear the armature.? Otherwise, they only needed to be substantial enough to turn the smaller diameter of the commutator which was only brass and you were only taking off maybe 0.010" anyway.? Some also had an "undercutter" feature which was like a little tiny saw blade to cut away some of the mica insulator to make sure it was below the surface of the brass.? My first lathe (way back when) was an armature lathe a friend had made from a kit in a high school shop class.? He had also designed and made a compound for it.? Powered with a washing machine motor.

Charles E. "Chuck" Kinzer

On Saturday, January 27, 2024 at 02:34:42 AM PST, davesmith1800 <davesmith1@...> wrote:


DAVID WILLIAMS
12:11am? ?
Restoring the commutators on vehicle dynamos.
(British cars probably from the 1940’s/50’s/60’s)

I have books from 1941 that cover cars from 1930s and had same in book.
I repair my father's drill motors in 1960's? used in construction.? They used 8 hours 5 days drilling steel. I use book on redoing the comutators on a South Bend 9A. Learn lot on DC motors and generators.?
What you said was cover in book which had forgotten.??

Dave?

 

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Craftsman sold a Lathe setup fro doing armatures , hey come up every once in a while on ebay . Had a jacobs chuck that screwed on the spindle , a Jacobs chuck live center I believe , a Mica undercutter & sopme misc parts .

I found 2 South Bend Lathe co publications on Armature work

its interesting that they made the lathe look red on one of the SB publications , my TruCut armature lathe is red .

animal

On 1/27/24 7:53 AM, Charles Kinzer wrote:

There were special lathes made for this that were very appropriately called "armature lathes."? The lathes were small and didn't have much power (didn't need much) but the swing was big enough to clear the armature.? Otherwise, they only needed to be substantial enough to turn the smaller diameter of the commutator which was only brass and you were only taking off maybe 0.010" anyway.? Some also had an "undercutter" feature which was like a little tiny saw blade to cut away some of the mica insulator to make sure it was below the surface of the brass.? My first lathe (way back when) was an armature lathe a friend had made from a kit in a high school shop class.? He had also designed and made a compound for it.? Powered with a washing machine motor.

Charles E. "Chuck" Kinzer

On Saturday, January 27, 2024 at 02:34:42 AM PST, davesmith1800 <davesmith1@...> wrote:


DAVID WILLIAMS
12:11am? ?
Restoring the commutators on vehicle dynamos.
(British cars probably from the 1940’s/50’s/60’s)

I have books from 1941 that cover cars from 1930s and had same in book.
I repair my father's drill motors in 1960's? used in construction.? They used 8 hours 5 days drilling steel. I use book on redoing the comutators on a South Bend 9A. Learn lot on DC motors and generators.?
What you said was cover in book which had forgotten.??

Dave?

 

Paul, the power is very low when the speed is turned low. You may want to try and hold it while someone slowly increase the speed. These motors have poor torque at low end.
 

The motor controller may not be adjusted correctly:? or the controller is a POS.? A good motor controller uses feedback to maintain the RPMs under load.

Or perhaps you don't know your own strength?? You should put it all back together again and see how your lathe works to actually cut metal.? Do you know for a fact that it's a problem?
 

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At the bottom of page 14, Bulletin 33-j, it says you can order RED or Grey as your color....



On 1/27/2024 2:16 PM, mike allen wrote:

Craftsman sold a Lathe setup fro doing armatures , hey come up every once in a while on ebay . Had a jacobs chuck that screwed on the spindle , a Jacobs chuck live center I believe , a Mica undercutter & sopme misc parts .

I found 2 South Bend Lathe co publications on Armature work

its interesting that they made the lathe look red on one of the SB publications , my TruCut armature lathe is red .

animal

On 1/27/24 7:53 AM, Charles Kinzer wrote:
There were special lathes made for this that were very appropriately called "armature lathes."? The lathes were small and didn't have much power (didn't need much) but the swing was big enough to clear the armature.? Otherwise, they only needed to be substantial enough to turn the smaller diameter of the commutator which was only brass and you were only taking off maybe 0.010" anyway.? Some also had an "undercutter" feature which was like a little tiny saw blade to cut away some of the mica insulator to make sure it was below the surface of the brass.? My first lathe (way back when) was an armature lathe a friend had made from a kit in a high school shop class.? He had also designed and made a compound for it.? Powered with a washing machine motor.

Charles E. "Chuck" Kinzer

On Saturday, January 27, 2024 at 02:34:42 AM PST, davesmith1800 <davesmith1@...> wrote:


DAVID WILLIAMS
12:11am? ?
Restoring the commutators on vehicle dynamos.
(British cars probably from the 1940’s/50’s/60’s)

I have books from 1941 that cover cars from 1930s and had same in book.
I repair my father's drill motors in 1960's? used in construction.? They used 8 hours 5 days drilling steel. I use book on redoing the comutators on a South Bend 9A. Learn lot on DC motors and generators.?
What you said was cover in book which had forgotten.??

Dave?


 

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??? ??? Thanks , that interestin . I have never seen a red one in the wild .

??? animal

On 1/27/24 2:25 PM, Jon Rus via groups.io wrote:

At the bottom of page 14, Bulletin 33-j, it says you can order RED or Grey as your color....



On 1/27/2024 2:16 PM, mike allen wrote:

Craftsman sold a Lathe setup fro doing armatures , hey come up every once in a while on ebay . Had a jacobs chuck that screwed on the spindle , a Jacobs chuck live center I believe , a Mica undercutter & sopme misc parts .

I found 2 South Bend Lathe co publications on Armature work

its interesting that they made the lathe look red on one of the SB publications , my TruCut armature lathe is red .

animal
 

Neat!

Do you know if there's a site that has any of the other service bulletins?

Roy

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