*shirt* my browser crashed.. I'll try to be brief this time
Ah so your son isn't growing any longer.. that's nice,
that means we can stick with the 450 lbs you mentioned.
That changes the above calculation to yield a 9:1 ratio for the ~9% slope (5 degree)
if you could measure the steepest hill the kart has to climb more or less flawless- and frequently,
we can dial that further in towards a better number even.
your phone GPS might be all that's needed
(measure the altitude at it's peak and it's base, be sure to have a strong gps signal so the error margin isn't at 15ft or so
; then measure the rolling distance between the two spots,
so we can average the slope of that hill)
As far as heat goes.. yes ALL motors produce heat, usually between 10 and 20% of their power is transformed to heat,
for a 1300W motor you can safely expect 130-260W of thermal output which is quite significant.
I'd say it's time to adjust once the motor gets too hot to touch (~60°C [ 140F I think])
if it has neodymium magnets it must not heat up past 80°C (176F?) since at that point you cook off the magnetic field and weaken the magnets thus reducing it's torque and mechanical power and producing more and more heat...
if it's gott ferric magnets you gain a bit of tolerance but at 120°C (248 F I guess)
chances are you start boiling off the insulation from the coil and eventually end up with a short.
So yeah.. a classic "hands on" approach (literally) can tell you if you need to take precautions already.
by lowering the gear ratio, since a quicker turning motor can wick off it's heat more easily (moves air quiker
)
The uphill speed isn't really a matter of gear ratio though;
a perfect motor has it's peak torque at 0rpm and at it's peak rpm zero torque;
so it dials in it's rpm according to the load and torque required.
so an ideal 1300W motor would pull the 500lbs up that 9% slope at 15 mph,
no matter if geared 4:1 or 10:1
Downside: there aint no perfect motors available..
so real world values WILL vary! (still gives a good clue though)
Anyways, upgrading the motor..
yes might be the best thing to do,
unfortunately that's not exactly cheap.
I'd suggest a 3kW goldenmotor (it's fairly priced at 288 USD )
and a matching kellycontroller (cheaper than the one goldenmotor suggests
)
still you'd have to spend ~500 dollars to set this up, which is still a significant amount.
I'd pass on more amazon/ebay chinese products tbh.. they're nice to play with,
and certainly can do alot, but since there's nearly no real datasheet or any reliable information,
it's getting quite nasty around the edges and finding their true limits is more often than not tedious and sometimes disillusioning.
(like buying a 1800W motorkit, finding the controller cannot even provide more than 1400W of electrical power, and the motor running at 78% efficiency making it in fact a 1.1kW mechanical power motor is kind of a kick in the ba..sement)
'sid
PS gov gave some slack, and it's now worsening slightly again...
I'll spare political comments, but allow me to say I'm glad I live in germany,
quite a good place to be in times like these.
