Re: (ET) Go Cart power alternative

[Jim Coate <jbc coate org>]

Excellent idea! You didn't say how much "older" the kids are, but one
example in the 5th & 6th grade range is the B*E*S*T program that Lee
talks about on the EV list from time to time - it sounds like the kids
really get into it (http://www.bestoutreach.com/). Or if they are a bit
older can look at "electrathons" for inspiration & component ideas.

A few thoughts on parts... First, please don't use Sam's Club or any
other flooded batteries - use *sealed* batteries. If and when the cart
gets tipped over, you don't want acid to be spilling. AGM batteries,
like the Hawkers that Chirs Z has been enjoying, would be a top notch
choice, but more than you may need, depending on age of kids and
speed/acceleration desired. Gel-cell batteries don't dish up the same
type of currents but would still do well for reasonable speeds - and are
much more common being used in UPSs and wheelchairs. You may find a
battery dealer, computer department, etc. with used but still good ones
they'd be happy to donate.

Second, make sure the set up includes an appropriate fuse or breaker -
rated for DC use. Might also start with a very low current limit until
the bugs are worked out and then go to a slightly bigger size.

As for the motor, an E15/E20 motor strikes me as being on the big/heavy
side. Also having the separate field winding makes finding a controller
harder and one more thing to hook up right. If you had some ET motors
just sitting around, then may as well us it. But if seeking out
something from scratch, a somewhat smaller permanent magnet motor would
do nicely.

For the controller, could either use a simple contactor setup (like the
ET) or an electronic controller. The EV suppliers sell a 'gas pedal'
with the variable resistor inside to connect to the controller.

Some high school kids I know in upstate NY built an electric go-kart
(and "Greased Lightning" car for their schools' performance of "Grease!"
:-) I'll see if I can find the info on where the motor/controller came
from as it sounded like a good deal.


Solid Technologies wrote:
> 
> All,
>   I work with Royal Rangers at a local church here in Colorado Springs (I
> mostly work with the 7-year-old Ranger Kids).  I was talking with the
> Outpost Senior Commander this evening and found out about a new older-boy
> program for Saturday evenings that involves go carts - building them 
> from a
> pile of parts.  Well, I mentioned that we should have (at least) one that
> uses electic power vs. an ICE (quieter, less maintenance, etc.).  So, the
> request for the group is specifying and tracking down an appropriate
> configuration.  My initial thoughts are:
>   Motor: From an E-15/E-20 (where can I get one?)
>   Contoller: I think I've seen someone selling one (who/where?)
>   Speed pedal: Spring loaded gas pedal linked to a variable resistor?
>   Batteries: Maybe a set from the local Sam's Club (or maybe a set of 3 
> ___
> that I've seen a couple of notes on).  Or maybe a set of 4 @ 12V for more
> speed?
>   Charger: I have a spare 36V, but if we go 48V then what?
> 
> Input please.
> 
> Thanks,
> --joe


_________
Jim Coate
1992 Chevy S-10
1970s Elec-Trak E20
http://www.eeevee.com