neptronix wrote:Not sure where you got that.. on the ebike simulator, they list the pre 2013 motors and the current motors distinctly.. and 2013 is right around the time ezee switched to the thinner lams.. as well, the ezee motors simulated match the efficiency of a thin lam mac.. thus, we can safely assume the ones currently modeled are the current motors, yes?
Justin told me that the ezee motor on the older Motor-Simulator is based on 2008 data. As I said, simulate both for a certain work point along with the Trip-Simulator, and you will see a significant performance difference.
neptronix wrote:I don't know why the trip simulator is better. It can tell you more over a long period of time, but less information for a fixed period of time. I want to know what the fixed point is before i look at the long data.
The Trip-Simulator doesn't only carry updated motor data (along with the option to add Statorade), it also gives you the most accurate thermal data regarding temperature rise vs time (and you can tweak the motor's heat-transfer parameters as well), while the motor's simulator is a simple first-order model that doesn't account for wind cooling. The older motor simulator is also quite inaccurate for regen conditions.
You can also see the motor's kV, resistance, magnetic losses, and you can tweak any of them to learn better.
It's a way more accurate tool to know what performance you will get, but of course there is no two systems comparison, and you don't see the motor spec vs rpm graph.
neptronix wrote:Turn counts, pole counts, stator dimensions, and reduction ratios ( since we're talking about geared motors ) do determine the motor constant, AKA KV, but the KV doesn't say anything about motor performance. What happens under load does.... and the more copper and steel and magnets, the better, to put it simply
Phase resistance is not the end all value to look at. It may be a quarter lower due to something silly like measurement differences or one motor having thinner phase wires and a wimpy connector at the end. It can simply be that. Phase resistance is simply a value of how much resistance there is along the total length of copper. It is only a good figure for looking at two motors of the same stator dimensions. Even then, it won't give you the full picture.
I'll give you an example. The leafmotor versus a 35mm 9C clone with 0.5mm lams. The two motors could have identical phase resistance, being wound exactly the same. But the leafmotor produces 25% more continuous power.. just because we were thinking about phase currents and not factoring in the huge difference in eddy losses..
I don't talk about faulty connections or engineering design errors like too-thin phase wire leads into the motor's body. I talk only about it's optimal performance, assuming the proper phase-wires, correct air-gap spacing, etc...
The kV go along with the phase-resistance, hysteresis and eddy losses, which are the four parameters that define a motor in the trip-simulator.
Physically it's the kV divided by the square root of the Phase-resistance figure, that define the machine's power capability, so all H35XX motors have the exact performance but with either low kV and high resistance and vice versa. That figure stays constant within the same family of motors.
But, if I do this calculation for the H35 series with their wider 35mm stator and magnets, vs the narrower 27mm of the 9C+ 27XX, I will find both families have around the same net result of kV/sqrt(phase-resistance).
Since the Trip-Simulator calculates the motor performance only according to the four values, how come the H35 is more powerful?
It's actually around 35/27 more powerful, but there is no field to fill up for that. Only kV, resistance, hysteresis, and eddy.
So how does it know? Where do the 35mm vs the 27mm takes place in the calculations?
neptronix wrote:
I don't recommend the eZee. I just came here to tell you that i bought one to find out if it puts out equivalent power despite being 15% lighter. I may very well also have a MAC on order later on with a similar wind and identical wheel size for a friend. You wanted to know why the eZee was so expensive and i am curious too so i'm finding out.
I assume because the eZee is a much more reliable motor in mechanical terms.
Justin told me not long ago about a company in New-Zealand that manufactures electric off-road motorcycles which uses two ezee motors.
I would have assumed hub motors would break in short order on high-speed off-road trails (due to their high unsprung weight), but apparently the ezee doesn't.
I am now building a hard-tail MTB that has the ezee motor on it's rear wheel, and I plan to take it high-steep off road single tracks (but not aggressive ones). With less than 4Kg, and having it's clutch welded&locked, it should be the perfect off-road machine - mostly because of the regen capability, which I have already tested: You can glide -12% grade at 10Km/h and still recharge your battery quite well. You enter plug-braking only at standstill speeds - like 1-2km/h.