Dumore D3 dental lathe restoration project

[skysoldier]

Amazon.com: HiLetgo 2000W PWM AC Motor Speed Control Module Dimmer Speed Regulator 50-220V Adjustable Voltage Regulator: Home Improvement

Amazon.com: HiLetgo 2000W PWM AC Motor Speed Control Module Dimmer Speed Regulator 50-220V Adjustable Voltage Regulator: Home Improvement

www.amazon.com

would something like this work???

 

[rjenkinsgb]

You have a "universal motor" - a series wound, commutator motor.
The same basic motor type is used commonly used in power tools. A "Drill speed controller" should work well.

This is the basic circuit concept for an electric drill speed control:
**broken link removed**

If you search "AC motor speed controller" on ebay you should find things something like this, for ready built ones:
**broken link removed**

The supposed 220V one would likely work fine anyway; they are probably the same unit regardless of being sold as 110V or 220/240.


Edit - Snap! Your last post had wrapped to another page and I didn't see it when writing the above.

 

[shortbus=]

Actually, after thinking about it and your prompt, I have decided to go with a modern speed controller. I would like one that could potentially fit inside the casing of the motor with a little rotating knob in the place where the old one was; now which one would work for the kind of motor I have? can you please tell me the characteristic/features I would have to look for please?

Are you in the States? The type of motor you have is called a "universal motor", just like in a corded electric drill or wood router. I'd go to Harbor Freight and get one of their router speed controls. Don't let the size fool you, inside the case is what you need to adapt to your motor base.

Harbor Freight Tools – Quality Tools at Discount Prices Since 1977

Harbor Freight buys their top quality tools from the same factories that supply our competitors. We cut out the middleman and pass the savings to you!

www.harborfreight.com

 

[skysoldier]

Are you in the States? The type of motor you have is called a "universal motor", just like in a corded electric drill or wood router. I'd go to Harbor Freight and get one of their router speed controls. Don't let the size fool you, inside the case is what you need to adapt to your motor base.

Harbor Freight Tools – Quality Tools at Discount Prices Since 1977

Harbor Freight buys their top quality tools from the same factories that supply our competitors. We cut out the middleman and pass the savings to you!

www.harborfreight.com

Yes Shortbus= I am in Tennesse! I saw that one at Harbor Freight too but did not know if It would work. Also was trying to find something that fits inside the shell to keep it looking as OEM possible ( if that is a thing lol)

 

[gophert]

Yes Shortbus= I am in Tennesse! I saw that one at Harbor Freight too but did not know if It would work. Also was trying to find something that fits inside the shell to keep it looking as OEM possible ( if that is a thing lol)

What shortbus is saying is, open up the plastic box from Harbor Freight and you will likely find s surprisingly small pcb that you can place inside or under the base of your lathe.

 

[skysoldier]

What shortbus is saying is, open up the plastic box from Harbor Freight and you will likely find s surprisingly small pcb that you can place inside or under the base of your lathe.

Oh ok thank you! I did't understand that! that makes sense. So is it a sort of "inline" PCB ?

 

[skysoldier]

Continuing to clean parts and removing rust from the hardware of the lathe; will post pictures pretty soon. Right now I ordered a spool of magnetic wire to replace the old armature coil winding as they are only from 1938...
Now, Do I need to wrap them in that cotton-like material or can I just use red varnish? https://www.amazon.com/gp/product/B00DGKDOHC/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1
will this be suitable?
Also, how do I know with side would be RED wire and the other Black starting from the coil itself???

 

[gophert]

Continuing to clean parts and removing rust from the hardware of the lathe; will post pictures pretty soon. Right now I ordered a spool of magnetic wire to replace the old armature coil winding as they are only from 1938...
Now, Do I need to wrap them in that cotton-like material or can I just use red varnish? https://www.amazon.com/gp/product/B00DGKDOHC/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1
will this be suitable?
Also, how do I know with side would be RED wire and the other Black starting from the coil itself???

No, no, no. We live in modern times and you simply order magnet wire from the store and the varnish is already on. You'll need to use a razor blade or 400 to 600 grit sandpaper to remove the varnish at the ends so you can make connections.

You need to be careful which direction you wind the coils - take photos of your existing mess and make it the exact same way.

Also, as someone said previously, when you order the magnet wire (so named because it already has varnish on it), make sure the wire is the same diameter as the existing copper wire. You'll need a micrometer or good caliper to measure the diameter of the copper wire.

 

[gophert]

Also, the point of the coils of wire is that the current flows along those coils. You cannot wind plain copper wire, let it touch and short out and cover it with varnish after the fact. That wouldn't work at all.

 

[gophert]

Here is an example of magnet wire. Sometimes the coating is red, green clear (like below) or any other crazy color the manufacturer has on hand that day. No, actually, it is all very well specified with coating type, thickness and data is available for how high of voltage the insulation can handle and bend radius without breaking the insulation and possibly corrosion resistance, and ...

I don't know this company - it was just the first hit on google with a nice photo.

Magnet Wire

Perfect for Winding Coils, Inductors, Transformers, Lighting, Ballasts, Relays & Timers, Motor Applications. Insulated with polyurethane and nylon.

powerwerx.com

 

[skysoldier]

No, no, no. We live in modern times and you simply order magnet wire from the store and the varnish is already on. You'll need to use a razor blade or 400 to 600 grit sandpaper to remove the varnish at the ends so you can make connections.

You need to be careful which direction you wind the coils - take photos of your existing mess and make it the exact same way.

Also, as someone said previously, when you order the magnet wire (so named because it already has varnish on it), make sure the wire is the same diameter as the existing copper wire. You'll need a micrometer or good caliper to measure the diameter of the copper wire.

Oh sweet, thanks again! I didn't know that modern magnet wire were already insulated. I did measure the wire at work ( I work on helicopters) with a micrometer on multiple spots to make sure the reading was constant. I took many many many pics just to be sure to re-do everything as it was.

 

[gophert]

You'll need a micrometer or good caliper to measure the diameter of the copper wire.

If you don't have a micrometer or caliper, take a piece of wire to a neighbor that wears short sleeve button-down shirts and khakis all summer. He is likely an engineer and has one of the two measuring devices and knows how to use it. You may have to stay and listen to his story about his dad's slide rule.

EDIT: unless you wear khakis and button-down short sleeve shirts all summer - then either take it to work or use the measuring tools in your basement.

 

[skysoldier]

Just a quick dumb question... the link you posted shows all wires that are "copper color or red" are they already coated and they look red or am you need to coat them again????

 

[skysoldier]

Now, from each winding coil there where "two" wires that were attached to the "metal" box where the carbon brushes where. and two where connected with each other, why??? I assume the other two wires from the other coil pack are attached to the power cable ( but now to the ECP)

 

[skysoldier]

If you don't have a micrometer or caliper, take a piece of wire to a neighbor that wears short sleeve button-down shirts and khakis all summer. He is likely an engineer and has one of the two measuring devices and knows how to use it. You may have to stay and listen to his story about his dad's slide rule.

EDIT: unless you wear khakis and button-down short sleeve shirts all summer - then either take it to work or use the measuring tools in your basement.

...how would you know?????? lol

 

[gophert]

...how would you know?????? lol

I've met several engineers in my life. I can pick them out of a crowd in a snap. They are the ones quickly looking out of the airplane window when the pilot announces a mechanical delay - like they might be the first one to spot the problem.

 

[skysoldier]

I've met several engineers in my life. I can pick them out of a crowd in a snap. They are the ones quickly looking out of the airplane window when the pilot announces a mechanical delay - like they might be the first one to spot the problem.

I can spot them at work... the only civilians, I am military lol jokes aside, thanks for the advice! I will post pictures of the clean-up as I go and as I install new wires and give it a new life. Quick OT the metal tag with all the info, how can I restore it? Was thinking of spray-paint it black and then either color the words with a paint-pen of with a piece of sand-paper make the letters appear again, what would you advice to do?

 

[gophert]

I can spot them at work... the only civilians, I am military lol jokes aside, thanks for the advice! I will post pictures of the clean-up as I go and as I install new wires and give it a new life. Quick OT the metal tag with all the info, how can I restore it? Was thinking of spray-paint it black and then either color the words with a paint-pen of with a piece of sand-paper make the letters appear again, what would you advice to do?

Post a photo of the tag.

 

[skysoldier]

Post a photo of the tag.

 

[skysoldier]

But it should be like this one