So when you get snowed-in, you can't do much of anything except... MAKE A MOTOR! 
This is a little project I've been wanting to do for a while, so I seized the opportunity. I have some "roughly 26D sized" Mabuchis with very nice arms and sooper-dooper ceramic magnets... like a solid 20% stronger than Arcos on my meter, think modern D magnets for strength comparison. I cracked one open and got busy, putting in a few hours last night, and finishing up this morning.
First things first. These motors are a little longer than your stock Mabuchi 26D, but shorter and skinnier. Rather than shorten the can/magnets and that whole mess, I figured to let the motor tell me what to do, instead of the other way around as things often go. Can got sanded, drilled for screws, the rear bushing flange sanded flush to the bushing, and the magnet-stop-dimples filled with solder, after which I gave it a nice coat of "Hammered Gold". The magnets got installed where I needed them to be and then a bit of epoxy to keep them from sliding around.
For the endbell, I used a Champion 26D endbell. It had to be taken down a little on the top and bottom flats, as well as both radius sides. Afterwards, I installed post sleeves ("protectors"), soldered the brush tubes to the hoods, and clearanced the inside for the new comutator.
Time to build an arm! I shortened the stock arm by four lams to get it under .500" long, pressed the shaft forward for "endbell drive", cut tail and comm, spacers and powder-coated it. After coming out of the oven, I installed a Tradeship comutator and started looking at patterns. I figured that with such strong magnets, I could either increase the airgap or just do a little hotter wind... so why fight it?... I went with a healthy #28. Trying out patterns, this arm wanted a "reverse wind", so that's how I went.
The arm balanced right up with no drama, so I could go right to final assembly. When you build the arm for the setup, it's a snap to get everything sitting nice. All that was left to do was to wind a set of .015" springs and let her rip.
For a rough visual on the size comparison between this motor (I call it "NUBUCHI" 
) and a regular 26D:
The motor runs beautifully and has a really... er... "muscular" sound and feel while running. Current draw is right at around 1.5 amps no load at 6VDC, dropping to around 1 amp at 12VDC. It's a good sign when current draw drops at higher revs from what I've seen. It at least means that the springs are "in the ballpark" tension-wise, and that nothing ugly is going on in there. "NUBUCHI" is a "howling" success... and I do mean "howling"!
-john
Hope for foul weather. 
