Quote:
Originally Posted by Lizard
Dremeling a spur until it looks like the drive-key? That's ambitious :)
Where will the base fit then? I think there is no space inside the spur assembly (?)
Maybe make a CAD drawing and have it made by some CNC service. An M3 screw in a 4.5mm wide drive-key should be no big problem I think. The hole would have to be 2.5mm, that leaves a mm on each side. Even M4 could be okay considering that the drive key is 5mm wide near the center. 3.3mm hole would leave 0.6mm at each side at the top and 0.85mm near to the center. But that would probably require good material (not brittle and also not soft). Or use M3.5, but screws and taps are hard to find for those.
Or maybe go to a local machine shop or something and have them drill a hole into the motorshaft so that you can use the pin to mount it.
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Haha, yeah, sounds more like it has disaster written all over it... you're right, I think I should just drop by a Kfz Werkstatt here to see if someone can tap a M3 hole in it. Comparing the contact area to a regular pinion, together with the small set-screw, just doesn't give me a very comfortable feeling yet, and I'm worried it'll be too wobbly, given the shaft won't reach the hole in the 2nd plastic end-cap.
I'll keep the CNC service in mind, thanks, didn't even know those existed. As another backup plan for if the whole Cushdrive plan fails, I ordered the OFN40760 Center Gear Mount. It has a 8 mm bore, so needs a reducer (or 6 pole TP motor :)), but Ofna has 44T-49T plastic spurs to go with it, so it should still be nice, light and cheap. Also have a $10 30T 6mm bore pinion (steel, 82g...) on the way from aliexpress, which I could use as a spur on the GT2 tranny shaft. Increases gearing options a bit: 49/30 (max Ofna) gearing would yield 112 mph no-load and 54/30 (max Cushdrive) 124 mph - no idea whether the motor will like that though.
Also haven't decided yet on ESC. Still attracted to XL2 to keep the door to 8S open at later point.
