Guys,
I am trying to determine the best motor for a small scooter.
I am leaning towards doing a proof of concept with a 24V 600W
like the ones at cloud electric, and then maybe migrating to
something larger like a Perm PMG-080 or Mars E-Tek. I have a
few questions.
Are there design formulas that can give someone an idea of
how a motor will perform? For example, if I have a X pound
scooter (with rider and all) producing Y ft-lb of torque at
the wheel edge, how fast will it accelerate on level ground
and how fast, for example, on a M% grade. How would I
determine the top speed? Although I can calculate the change
in torque from motor shaft to tire edge with relatively straight
forward math, are there reasonable ways to estimate losses in the
drive train? Can I just apply a blanket N% loss for drive
train and say that is good enough? I lack access to the tools
to cut my own gears, so I am likely to start with chain drive to
the test vehicle, and then later move to something like a single
90 degree spline gear and perhaps later to one of the bicycle
grade CVTs (continuous variable transmission).
How do folks feel about brushed versus brushless? It seems brushed
motors are a lot cheaper, but need regularly examinations and replacement
every few hundred hours. Using this back and forth for work means
1-2 hours a day, and that means every few months replacing the brushes.
For a test design, I will likely consider a $100 motor an expendable
part of the learning process. For a real design, I want to make it last.
Janet
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