Right on! We're all working toward the same thing, Electric Motorcycle
Excellence! When figuring drive wheel circumference you can use the mark,
roll and measure technique or, I think Dia x Pi = Cir ( that's off the top
of my pointy head) Double check me. Later, Bob
----- Original Message -----
From: "lyle sloan" <[EMAIL PROTECTED]>
To: "ElectricMotorcycles" <listserv@electricmotorcycles.net>
Sent: Tuesday, September 04, 2007 7:34 PM
Subject: Re: [ElectricMotorcycles] Zee science of EM was (Throw another
Etekon the barbie)
Repeating what I had said earlier in another post, I
find taht alot of the times I witness ppl using the ev
calculators but not "see"ing the math and how it
interrelates. So I have been working on a couple of
graphs trying to illustrate the max performance ranges
or limits for the newbies. I wanted to keep it simple
enough by FOCUSING on single gear performance range at
a set voltage (and not delve into battery/voltage
switching and/or transmissions, yet). As the
following graph is intended to show, the max amperage
of the circuit will determine the max Torque at the
wheel at a set gear ratio. Also, the max voltage of
the circuit is the max RPM at the wheel at the set
gear ratio. Then the cycle's and rider's weight and
all the other aspects are plotted for
amps/torque/force needed to MAINTAINING each given
speed. (Acceleration is intended to be a different
discussion and graph with times squared. not shown nor
ready for discussion at this time)
http://electricmotorcycles.net/uploads/wordpress/2007/09/4-to-1-gear-ratio-to-torque-to-mph.JPG
So after Mike's post, I though it would be interesting
to throw in the ETEK heat performance as a sort of
graduated color scale on top of the graph with my best
"guess"-timation for the ETEK. Which I say is the
green zone from the continuous HP @ 93 amps to stall
and anything above that is a yellow and red zones.
The yels and reds are gonna have to be found out how
long we can stay in each zone. I basically took the
guess taht 180 is the red zone.
http://electricmotorcycles.net/uploads/wordpress/2007/09/mikes-amp-torq-gear-to-mph-graph.JPG
Unfortunately, when I tried calculating Mike's max
speed range for the circumference, I came up with a
max speed of 132mph. But I am willing to bet that the
plotted/actual force to maintain speed is gonna be
greater than the etek can sustain at Mike's given
weight and gearing. (Or I messed up his circumference)
I would like the rest of the EM list to check my math
to see where I messed up (if I did) and if possible
the pro and cons of theses illustrations to be used
for the site.
Thanks in advance. I am pretty sure the fur is gonna
fly, but I am willing to stand with my illustrations
unless of course I see a suitable counter argument to
refine a point or two.
Lyle
--- lyle sloan wrote:
Man, this parallels what I was thinking. Except I
wanted to show it in a graph. I will post as soon
as
I get mike's info
----Andrew Wowk wrote:
> Say you are pulling 200 amps with one etek running
> at any voltage:
>
> 200 * .033 ohms (terminal resistance) = 6.6v * 200
=
> 1320 watts in heat that
> one etek must dissipate without frying.
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