DELTA only 9C type Electric Pitbike 20" BMX Wheel

[F&P]

Here's my latest project, a 1000W star wound brushless ebike motor in a 20" BMX wheel with a standard 12fet controller beefed up to 55Amps (about 2kw) and the motor re-wired in DELTA only, gives great torque and goes about 50 to 60kph. Picture shows battery bag up high, but now it has a lower hung alluminium box seen in youtube video below.

I also changed the small 3 phase cables that enter the wheel, as they were getting way too hot for delta, so I pulled them out and used 2 heavier 6mm sq (9-10AWG) cables and the 5 hall wires in the original entry side and then grinded a slot in the other side on the shaft and ran another 6mm sq (9-10AWG) cable out the other side under the bearing and it all worked a treat.

Would go even better if I used a stanbdard BMX bike in Delta.



See Youtube link below of the little power slides, not bad for 48V at 55Amps in pure delta in a heavy pitbike. Even better with my 8 Year Old 30kg boy on it who it was actaully built for.
need better batts, have 12V / 10ah SLA's at present but will go for "Lithium" something when they get cheaper.

[youtube]ncQCdolZ0VU[/youtube]

Matt

 

[bzhwindtalker]

wow it must be big fun for the young one ! I wish my dad built me one at 8^^

 

[Hyena]

motor re-wired in DELTA only, gives great torque and goes about 50 to 60kph

Cool, but why rewired in delta ? For a pitbike you'd want the extra torque from star wiring wouldn't you ? Or did you want the higher top speed ?

 

[F&P]

Yes lots of fun and sadly dad uses it more than the kids.

Delta is much better for this Pitbike, as in star it might have a bit more torque from start but as it only goes about 25 to 30kph in star the current draw drops off very quickly and so does the power. In Delta it keeps on drawing 55Amps and therefore really powers on even at 30kph and allows for much beter power slides. I will eventually put in a relay system to switch from star to delta, especially for beginers.

Apart from that for me I wouldn't bother with star at all with the 20" BMW wheel as it has enough power anyway as you can see in the video.

Matt