Replacing brushes? - Sullivan Dynatron.

[John Beardslee]

The pictures look like the wire is on the side near the end. Does it slide in a slot in the retainer and has a flat spring for pressure instead if a coil?

 

[Terry Keeley]

No, the wire is on the end of the brush, not on the side.

Something like this might work (ditch the spring) but coming from China who Knows when I'd get it:

https://www.amazon.ca/gp/product/B08HCRLFJQ/ref=ox_sc_act_title_2?smid=A1763YIMSAWL9Y&psc=1

 

[John Beardslee]

You should be able to get a 1/4 x 1/4 end feed at just about any length you want locally up there I would think. That’s a common size in DC applications.

 

[Mark Bullard]

Terry, I did not have a brush with a high copper content for a starter. But looking on the Helwig site I found a brush that will work. The shunt does come out of the side but there is a slot for the shunt to lay into so that it will come out on the back. The number is 13-H and I think thety were about $4.50 each. This brush has enough copper to last for a long time. Standard carbon brushes do not have enough copper to hold up.

 

[Terry Keeley]

Terry, I did not have a brush with a high copper content for a starter. But looking on the Helwig site I found a brush that will work. The shunt does come out of the side but there is a slot for the shunt to lay into so that it will come out on the back. The number is 13-H and I think thety were about $4.50 each. This brush has enough copper to last for a long time. Standard carbon brushes do not have enough copper to hold up.

Awsome, thanks! Dunno why I didn't see that one:

https://www.helwigcarbon.com/shop/13-h/

 

[David Bryant]

Finally wore them out, called and you have to buy the whole motor. WTF?

Anyone found a replacement or have a junker they could pull some from?

I just bit-the-bullet and purchased a new motor

 

[Terry Keeley]

My buddy Olly came through and gave me an old starter, it still had the sticker and Google came up with this: New mamco bp 12V dc motor E51964, bp-12-24

I sent them a request for a part # but for now I've got these (plus a better armature), thanks Mate!

 

[Terry Keeley]

 

[David Bryant]

nice!

 

[Timbo Whalen]

It’s been a lot of years but when I did one of mine I got them at ACE Hardware in their small parts boxes. The carbon part had to be sanded down to fit.
Thanks John

That's what I did, John.....those darn Hillman fastener drawers come in handy for all kinds of things.

 

[Timbo Whalen]

I just bit-the-bullet and purchased a new motor

Well, yeah!....you aerospace boys can afford that!

 

[RobertDoak]

The lathe method sure beats the drill and pencil eraser method..

 

[Mark Bullard]

For what its worth. The com ready did not need anything. It looks perfect to the the proper running commutation of brushes. That look that you see is from moisture in the air that makes the color you see. This does act as lubrication to the brushes and com. We will try and set this up in large DC motors by using a spray bottle of water and misting the com as the motor is running. The only time to turn is if you have groves wore into the com bars.

 

[rhomodel]

Mamco corporation (mamcomotors.com)sell the complete engines: they might be able to offer an all in one solution. I notice that my start engines start to wobble and then the anchor or stator wires short for some reason.

 

[Mark Bullard]

Here are a couple of pictures on a commutator on a large DC motor. Horsepower on the motor is 250 hp. Turning a com this big is not much of a problem but what we call undercutting it is a real pain. There are a lot of bars in the com. I spend about 3 to 4 hours cutting the slots.

 

[Ray Sametz]

Now those brushes might be 14 inches square.

 

[Brad Christy]

Here are a couple of pictures on a commutator on a large DC motor. Horsepower on the motor is 250 hp. Turning a com this big is not much of a problem but what we call undercutting it is a real pain. There are a lot of bars in the com. I spend about 3 to 4 hours cutting the slots. View attachment 285050View attachment 285051

Mark,

If, by "undercutting", you are referring to deburring between the bars, have you ever tried a PCD insert? They are fairly spendy, but they work really on low tensile strength materials like copper. There likely won't be enough of a burr to worry about. Just a thought.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

 

[Mark Bullard]

Mark,

If, by "undercutting", you are referring to deburring between the bars, have you ever tried a PCD insert? They are fairly spendy, but they work really on low tensile strength materials like copper. There likely won't be enough of a burr to worry about. Just a thought.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

Brad, When we undercut a com we cut the insulation from between the bars. This is most of the time a earth element called Mica. But on this com it was a molded very hard epoxy type material. After we turn the commutator we have to lower the mica between the bars so the brushes do not bounce when the motor is running. Brush bounce is very bad with a motor running at speed and under load. I built our undercutting machine many years ago. It consists of like balance waves with two ball slides controlled with oil metered air cylinders, or what we call air over oil control. One slide has a spindle with a motor driving it that we use very small saws. These saws are about 1/2" to 1" diameter with 0.010" to 0.050" wide. The bars slots are different on different motors brands When I have the slot lined up I will press a button and the slide that carries the spindle drive moves down. The other slide moves out. We adjust so the saw drop down into the slot and then the other slide cuts out the slot when it moves out. Release the button and everything goes home. We then turn to the next slot. Cycle time on this com was about 25 seconds per slot. And I had to go around it twice because of the material between the bars.

 

[SayMikey]

All right who is going to post a pic of there GROWLER. SOME OLD GUYS IN HERE lol

 

[Mark Bullard]

All right who is going to post a pic of there GROWLER. SOME OLD GUYS IN HERE lol

That's a good one Mike. I do have a couple of those too.