Maybe better called a Murbuchi... or even a Murbuchicek.
I set out this time to do things a little differently and come up with a motor that would have done a racer proud back in the day... and maybe even look sorta right for the period on the outside anyway.
First off, I sliced one of my favorite early Mabuchi 16D cans horizontally. After some cleaning and deburring, I got a rough can that's as close or closer than I've ever gotten one before. How close?... Well so close that the can tabs were sliced in half and both sides of those went right back together after brazing! Nobody is more surprised at this than I am.
Here's a shot after the brazing mess was cleaned up, and I soldered a pair of shims to the inside of the can's two radiused sides. The silver stuff you see is solder that got outside when I soldered those two shims in place.
This time I'm using a vintage Mura C-can endbell, and the shims will (after some figuring and measuring and figuring again... then hoping) make the Mura endbell a nice snug, but not too snug fit:
Now, lest you think I embarked on this journey out of some quixotic quest for cheap thrills alone, there's a functional reason for all this stuff... but I do like doing one-off things for the heck of it as well!
First off, the can is now shorter than a C-can in height. You can see that the endbell is proud of the can's flats, and it's hard to see, but it's not just a smidgen... it's enough to actually be a good thing in lowering the CoG of the motor, which would also help an intrepid scratchbuilder lower the CoG of an entire chassis.
Notice the radiused corners of the stock Mura endbell in the above and following pictures. Those will give you an idea of what we're talking about here. ou can also see the interior shim adapters for the Mura endbell, as well as where the can slice went right through the tabs. Oh and, I also had to match the can drilling to the existing holes on the Mura endbell. I hate doing that, but it came out fine this time (whew!):
Here's a shot of the business end of the can with a nice bearing soldered-in. More goodness about doing things this way is that the endbell end of the can is well-reinforced by having those shims soldered-in to the inside, and the drive end of the can is reinforced by the bearing having been soldered-in.
Of course, the magnets will be epoxied into the can as well which will further reinforce everything. The end result will be nearly as strong an the original uncut can for sure.
At this stage, I still haven't drilled the can end for mounting, but I did notch the can to help the chassis builder get a few more degrees of angle out of the motor:
An interior shot with the bearing soldered-in, and strengthening the whole shebang:
Next up, I first sanded the can down to get it pretty flat, and applied some JB Weld wherever needed to act as a coat of Bondo. Then that got sanded as well. I mean, fast is good, "custom" is good, but neat looking is good, too!
You'll also notice that the endbell top and bottom have been sanded flush to the can's flats. No sense in having a not-so-tall can if the endbell is hanging out... or down. Oh and, the endbell is now a perfect snug "snap fit" to the can. By the way, this is the 'bottom" of the can and you're seeing what small amount of the magnet tabs are left:
Next up, the can gets an undercoat of high-temp paint. The color doesn't matter, but it will serve two purposes. First it will give a smoother result, helping to fill-in even smaller details that the JB Weld can't do so well on. Second, JB Weld will often "telegraph" right through a top coat of paint. When the first coat of paint is wet-sanded (with #600), you get a smooth base, and one with the JB Weld sealed-in:
After a second finish coat of hi-temp wrinkle black, and the endbell sanded flush and fixing the loss of color where it was sanded, it's pretty much a finished can:
So, it's unique, strong and functional... plus significantly lighter than a Mura Green can. The other things here is that, installing a set of typical C-can magnets, you wind up with about a .580" "hole." Wel,l boy howdy, that sounds about perfect for a .560" diameter arm!
So, while the outside looks pretty vintage (and of course, this sort of can surgery was not unknown back then), the inside will be "vintage style."
Whatever you call it, this motor will be a nice -ooking bomb! Next up, installing the magnets so I can build/space/wind a "heart" for this beast.