Casting starter & generator brush holders

[AdminJeff]

After rebuilding 100's of starter & generator brush holders and seeing what is available for replacements (they suck) I bit the bullet and decided have a casting made. I'm taking one for the team here. It's not cheap and is VERY time consuming, but these parts are failing more and more frequently, and somebody had to do it. All I can say is I'm glad I did well in most of my mechanical engineering classes. This is NOT easy. Round one is done as a proof of concept, but some adjustments still need to be made.

Here's the initial drawing. Lots of edits before we went to the mold. A couple important mods - I filled in the bottom of the often failing spring stantion for a little more support and made the brush wire screw (so often stripped) surface slightly thicker. I also drilled and tapped the 2 #6 mounting holes so it will be hyper easy to install these.
We're using zinc (as original) for the material.
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3D renderings

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First mold pop

Unfortunately the engineer made a mistake and the spring holder diameter is a bit too big, but everything else is good to go.
.
Fitment

As with most projects like this, it is time consuming, rarely works the first time, and the smallest details matter A LOT! Hopefully rev 2 will make the cut.

[Humblej]

Bravo!!!!!!

[jab35]

Jeff: Impressive effort, detail and design, thanks for sharing.

Any plans to bring an OEM-correct ignition lock cylinder to the marketplace in the future?

Thanks, jb

[Jerry VanOoteghem]

Very nice!

It may have been that the area under the spring mount was hollowed out in order to prevent shrink voids in that section, which might undermine the spring mount stud. This can happen in castings that have thick & thin sections. I had this issue in some bronze castings I had made. After the next iteration, maybe cut through that section to look for any internal flaws.

[AdminJeff]

Jeff: Impressive effort, detail and design, thanks for sharing.

Any plans to bring an OEM-correct ignition lock cylinder to the marketplace in the future?

Thanks, jb

I'll get right on that.

[AdminJeff]

Very nice!

It may have been that the area under the spring mount was hollowed out in order to prevent shrink voids in that section, which might undermine the spring mount stud. This can happen in castings that have thick & thin sections. I had this issue in some bronze castings I had made. After the next iteration, maybe cut through that section to look for any internal flaws.

Quite possibly, esp given the crappy pot metal used back in the day. Metallurgy and casting technology have made a couple advances since the 1920's so I'm really not too worried about it.

[Jerry VanOoteghem]

Very nice!

It may have been that the area under the spring mount was hollowed out in order to prevent shrink voids in that section, which might undermine the spring mount stud. This can happen in castings that have thick & thin sections. I had this issue in some bronze castings I had made. After the next iteration, maybe cut through that section to look for any internal flaws.

Quite possibly, esp given the crappy pot metal used back in the day.

Well, there's still a whole bunch of originals out there, still working after 100 years, so they couldn't have been too crappy.

[mcnallyf]

After rebuilding 100's of starter & generator brush holders and seeing what is available for replacements (they suck) I bit the bullet and decided have a casting made. I'm taking one for the team here. It's not cheap and is VERY time consuming, but these parts are failing more and more frequently, and somebody had to do it. All I can say is I'm glad I did well in most of my mechanical engineering classes. This is NOT easy. Round one is done as a proof of concept, but some adjustments still need to be made.

Here's the initial drawing. Lots of edits before we went to the mold. A couple important mods - I filled in the bottom of the often failing spring stantion for a little more support and made the brush wire screw (so often stripped) surface slightly thicker. I also drilled and tapped the 2 #6 mounting holes so it will be hyper easy to install these.
We're using zinc (as original) for the material.
.
IMG_2877.jpeg

3D renderings
IMG_2878.jpeg
IMG_2880.jpeg
.
First mold pop
IMG_2867.jpeg
Unfortunately the engineer made a mistake and the spring holder diameter is a bit too big, but everything else is good to go.
.
Fitment
IMG_2879.jpeg

As with most projects like this, it is time consuming, rarely works the first time, and the smallest details matter A LOT! Hopefully rev 2 will make the cut.

Have you tried 3d metal printing? I created a Solid Works model of the gooseneck (water outlet) and had it 3d printed in 316 stainless steel for $114.00 and got it seven days after I uploaded the model on the website. There are many places that offer 3d printing in metal and this looks like a perfect part for it. Check out jlc3dp.com or Xometry.com. You get a quote instantly upon uploading the model and choosing the material.

[AdminJeff]

3D printing is GREAT for prototyping (I use it all the time), but the financials for 3D metal printing don't work when you want 1000 parts....

I 3D printed my cutout/VR enclosures and all the electrical pieces before I produced 1000 of them in steel.

My Stewart speedo sender housing just cracked in 2 where the cable goes into it at the wheel, so that might be a candidate...

Jeff

[VinTin23]

Impressive!

[FATMAN]

I have some a few small brush holders, Bob if somebody needs just a couple

[1925 Touring]

Thank you for this great service, adminjeff! For the younger hobbyists such as myself, this sort of thing is what will keep the hobby going.