I've got an Alltrax 4845, and a big contactor (maybe 300A?) I got off
ebay. I decided to go big to give room for possible upgrades. I was also
worried about the possibility of welded contacts! For now I'm using 3
Hawker/Enersys SBS60s that I bought surplus. They seem to have good
capacity left. The motor is a compound (but I think 'mostly' series)
snowblower motor off my Elec-Trak. If I gave it a bit of help it got
going but I really had to crank the throttle. I do have the Alltrax
'held back' with I think 300A max and 58% max throttle allowed.
Mechanically, my throttle doesn't quite peg out the potbox yet. After
scooting around the yard just a few seconds at rather low speeds, I saw
some smoke coming from the motor; brushes I think (hope). So I must
definitely be over amping. No, I didn't have any instruments connected
yet. Maybe I'll try again this weekend on flat pavement and take some data.
I'm not too surprised. I had originally calculated 45MPH top speed based
on specs from the ICE R75. But I assumed the top transmission gear was
1:1, but it's 1:1.5, so now my theoretical top is like 75MPH. So at low
speeds my RPMs have to be really really low and it may be just too much.
My gear (rear end) ratio is actually 37/11. I figure 5 MPH is only about
200 RPM. So it's either supersize the motor or gear down. I figure using
a transmission will let me easily test out 4 or 5 ratios and be the
easiest to install.
Dang, it has gone so well so far, but I guess I'm really just getting
started.
- Steve
damon henry wrote:
What controller are you using? The alternative to a different gear
ratio is more amps :-) It's possible that once you get moving a bit
you will feel the gear ratio you already is fine. If you have a
contactor that is rated for the job you can test this by hooking a
battery straight to the motor through the contactor. Try 12 volts
first, then 24 etc... This will give you an indication of what kind
of acceleration you can achieve with your current setup. Just be sure
that the contactor is up to the task otherwise you may be going for a
longer ride than you intended with no way to turn the motorcycle off :-(
damon
