Monday, June 25, 2012

MiniCycle V2 and DethWhacker

A few weeks ago, MiniCycle V1 was completed and Tom, Shane, Charles, and I went to the garage to do some time trials. This thing is TINY. Due to impatience, we used the old battery from DethScooter, a 26.4V (8S) 4.4 Ah pack I built in September 2011. Also due to impatience, the battery was wedged into a space between the motor controller and the rider's crotch. Not exactly the ideal place to have a battery malfunction. Regardless of battery position and rider vulnerability, the bike had some killer initial acceleration (watch the video) but not a huge top speed, probably about 20 mph.
lol
Tiny and Chibi
Right-side-up videography by Charles Guan.

To fix the problem of the slightly lower than desired top speed, I built another battery pack that would a) go faster and b) fit better into the frame. The pack is 33V nominal (10S) and 4.4Ah. 




Please ignore scorch marks on negative terminal.


Couldn't find heat shrink big enough. Kapton tape and foam to the rescue!


Fits perfectly!
video



The bike was tested in the Stata Center basement and will hopefully do some garage runs later this summer with the wattmeter and right-side-up video camera.

And now on to the home improvement portion of our show post. Today's task: make the Black and Decker weed whacker a little less... awful. The stock battery was a 18v 1Ah NiCd that supplied about 10 minutes of underwhelming plant mutilation. Sometimes it cut all the way through the plant and didn't just knock it over... Sometimes. Regardless, the first iteration of DethWhacker (named as an homage to DethScooter) uses a 19.8v 2.2Ah battery and is actually kind of terrifying.




video