On Mon, Dec 21, 2009 at 12:39 PM, Graham Allan
<allan physics umn edu> wrote:
So what would you say is the major factor in not getting stuck? Weight? I've tried either blowing or plowing my driveway with my E15 with dismal results. The driveway is probably around 30 degrees, downwards from the house, and when it comes time to reverse back up the hill one wheel will simply lose traction and spin. So I have given up for now (knowing mainly, I am missing something critical). I've had chains on the drive wheels but no extra weight, which is probably a big mis-step given the huge weight of blower or plow blade up front. But I was never convinced that weight alone would make the difference, given the open differential... hopefully I'm wrong on that?
How much do you have in the weight box (besides the additional 120 lbs of lead)?
Graham
On 12/20/2009 12:07 PM, Christopher Zach wrote:
Well, the snow is over. 20 inches, wet and heavy here in Relay.
Shoveling it would be very un-fun.
I'm glad I did some blowing yesterday during the storm, enough to make a
single-width path and turn-around up the driveway when it was about a
foot. Because blowing a full 20 inches of snow is tough. Easier to do
about 3/4 of a blower-width at a time when charging up the hill in L.
Putting the weight box plus 120 pounds of lead stops the wheel skipping
problem. The tractor can now blow up the 40 degree driveway in L and
keep it's chute full. Go too slow or too little snow and it can clog.
Today I widened the scope to the whole driveway. I also hooked up the
E-Meter to one half of one string to get it working again (since the
DC-DC exploded probably due to voltage spikes from the dead varistor).
When going full blast into a 20 inch pile of snow each string is pulling
200a. So the whole tractor+snowblower can pull a peak of 400 amps from
the pack.
I wonder at what point the wiring in the tractor will start to become a
factor.
This also explains why I need a >60ah pack. However the fact that these
30ah cells can put out 7C in 32 degree weather is pretty nice. I like them.
Right now the pack is on charge. When I looked a few minutes after
starting it was going at 10a per string (10.5/9.5) for a total charge
rate of 20a. So in 3 hours or so the pack should be full and I can
complete the top of the driveway (which includes the slush/snow from the
street plows). Then maybe I'll trundle over to the neighbors.
But overall I'd say tractor+blower+chains+weight box+120 pounds=will not
get stuck.
_______________________________________________
Elec-trak mailing list
Elec-trak cosmos phy tufts edu
https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak