Detroit Electric Controller Rebuild

[Eclector]

I've recently acquired a 1932 Detroit Electric Model 97. The controller needs to be cleaned up but also, I'd like to replace some of the plates and some of the fingers need help. Are there any resources for controller parts? OR Is there anyone out there who rebuilds these? 

[rotus8]

Check out the March 2022 issue of the Antique Electric Vehicles Newsletter. I have an article in that issue on making contact fingers for my '17 Model 68, it may be helpful to you. The March 2018 issue of the newsletter has an excellent (and somewhat humorous) article by Haakon McCallum on recreating controller segments. I believe that back issues of the newsletter can be purchased from Blanche Gordon <blanche@rose.net>.

 

The Electric Vehicle Museum http://www.electricvehiclemuseum.org/  has scanned blueprints for the controller that are very helpful in recreating the parts for your restoration. Good Luck!

 

One other little detail that may be useful - the Detroit Electric owner's literature says that the controller segments should be lubricated with whale oil, not something readily available today. I researched and found that Jojoba Oil, made from desert plants and available as an ingredient for cosmetics, is chemically identical to whale oil. It is not actually an oil, but a liquid wax.

 

Edited May 9, 2022 by rotus8 (see edit history)

[Akstraw]

I rebuilt my own last summer, just like yours.  I had to make a few parts from copper sheet, and fabricate the missing felt oiler.  Not aware of any off-the -shelf replacements.  Yours doesn’t appear to be in too bad of shape.  It looks like it needs cleaning up more than anything.

[Eclector]

6 hours ago, Akstraw said:

I rebuilt my own last summer, just like yours.  I had to make a few parts from copper sheet, and fabricate the missing felt oiler.  Not aware of any off-the -shelf replacements.  Yours doesn’t appear to be in too bad of shape.  It looks like it needs cleaning up more than anything.

Actually, I didn't post a photo for you to see the condition. The plates in mine are pretty severely chewed up from arcing. There's some aftermarket fingers that don't look all that great. My oiler is in place but I definitely need to replace the felt. What did you use for that? 

[Akstraw]

Sorry, I mistook the first photo as being yours.  I used the 100% wool hard felt from McMaster Carr for the oiler.  I also got my copper sheet stock from there.   To form the plates, you can make a pair of hardwood dies and form the copper in a press or vise.  I did not have to make any fingers, though I did touch up the contact surfaces on a few.  Achieving the right degree of 'springy-ness' will be important on the fingers.  I think solid copper is too malleable for this; though perhaps there is an alloy that would work just right.  In the second photo above, it looks new copper contact tips are riveted to the original arms, which seems like a sound alternative.

[rotus8]

 

I made the fingers from a combination of copper and phosphor bronze. The tips of the fingers are 3/16" copper I formed with a die and punch I created, forming in a hydraulic press.

The spring is three layers of .0162" copper to create a flexible conductor, plus one layer of .032" phospher bronze to make the springiness. I 3D printed a jig to drill the mounting and rivet holes in the pieces. Then attached them together with 1/8" copper rivets.

It only took me about a month :).

 

 

Edited June 7, 2022 by rotus8 (see edit history)

[Eclector]

Rotus8, thank you so much! I just saw your article in the newsletter. Awesome job! I don't personally have access to some of the machine tools so I may have to explore other options. 

 

Akstraw, I'll attach a photo of my controller. Looks like you did a great job on yours. McMaster Carr is a great resource. I'll check it out. Would you happen to have a stock number or thickness that you used for the felt?  

[Akstraw]

The Felt that I used was F10, 1/8” thick.  Part 2842T21.  I didn’t put all that much thought into it.  I think I used what I had lying around.  Seemed to be just fine, though.

[Akstraw]

The Felt that I used was F10, 1/8” thick.  Part 2842T21.  I didn’t put all that much thought into it.  I think I used what I had lying around.  Seemed to be just fine, though.