Recent content by zappy

The gear ratio is 14t to 98T to start with and should give around 70km/hr top speed with good acceleration. Thanks to Pickle for letting me make a mess in his man cave, baby sitting my old lathe and welder and always helping out. He's funny too.

I am the 1st to admit scootzilla was crap and dangerous. It had 6000w, light switch type throttle control, a steep steering head angle, short wheelbase and cable rim caliper brakes operating on a plastic front wheel and my mates weigh up to 140kg and had 10 beers under their belt! I think the...

The backing iron shows some flux leakage in the high tech ( look the cap screw sticks to it ) test. The stator laminations are .5mm thick Rotor pole and weight

The motor core is about 4.7kg . So a fair bit of weight could be lost by discarding a lot of the motor chassis, if you can be bothered trying that hard. You could also make a aluminium centre hub to mount the magnetic disk/backing iron. The small integral fan starts to move a bit of air at...

Yes John , The kv is very close to 100rpm/volt and I should have put up the phase / phase resistance but I lost the scrap of paper and the motor and chassis is in a 3rd world country now. So that is very unhelpful. :oops: So the motor pulled about 8000rpm at 80volts for an extended period of...

This came about by a little 3kw golden motor arriving in the mail, from my big little brother. We have been on the look out for a suitable high quality mid drive motor for high performance down hill type bikes in the 8-12kw region that weigh in under 5kg. To keep things simple we wanted to use...

The dimensions are on the link. Inlet 9mm , outlet 7mm Zappy

Hi splinter, What KV did you pick? and for what pack voltage? Zappy

Good work cowardlyduck! The little fans make a big difference at slow speeds and for a quick cool down.(unvented stators after a good spanking stay very hot for a long time and can heat soak your magnets). At high speeds fans seem to make less difference. In Canberra at this time of year, high...

24s of A123 20ah prismatics. I have used a few ecrazyman 24fet controllers but have had a few reliability issues with blown fets(one just stopped today from plugging it into my 7000w killer kick scooter! :twisted: but I had just dropped it off the bench :cry: ) or usually a KEB 8KW Kelly...

Kareleski has PM me about installing computer fans into a magic pie, so I have put up a few old photos. I run 4 fans dimensions 50mm X 50mm by 10 mm thick, 12v run in series straight off the main battery pack voltage of 80v. They seem reliable even at 20volts. 5,6 or 8 fans could fit. You do...

Vasi said The version 1 cro lams are .5mm the version 2-3 cro lams are .35mm . For some sense of perspective, just as a comparison, I would just like to repeat the no load losses for a version 1 cro motor (at 10.6kg with no spokes or rim) and 79.2 volts(24s lifepo4) no load losses are around...

Vasalisk said I think you are right! 63 stator teeth. It looks very similar to a version 3 cro manufacturing style, only really big diameter. Thanks for sharing, have fun with this heavy beast. Zappy

This stuff can also help. The trade name is monkey cum(?). Zappy

Drawing of modified Cro motor flux stator ring. I have made 3 similar to this. Machining off the original spoke flanges and re drilling spoke holes seems like a bit of a hassle but this saves around 350grams and it doesn't really take very long. You also have the option for different spoke...