Andje said:
And we will definitely loose some power. Actually I have no idea if it's a linear relationship, so I again will bow to someone who can do the math (edit-look down, i trust lfp). Prbly have to wait for a dyno test for the final verdict though. And then a side by side race of a sensored and sensorless version at same V/A.
There's no need to wait for a dyno test to have a really good idea of what's going on. The motor KV/winding is directly proportional to the flux linkage. To a first order, we would indeed assume that the 30mm stator would have 30/35 = 86% of the flux linkage of a 35mm stack, and hence 86% of the power and torque capability.
Under that assumption, for the same winding, the 30mm should spin 16% FASTER than the 35mm stator. Now, the fact that Crystalyte supplied the HS sensored motors with a 6-turn rather than a 5turn wind implies that this was probably the case:
30/35 * 6/5 = 1.03, so basically by using a 6 rather than 5 turn stator Crystalyte can get within 3% of the V/rpm of the 35mm stack and pass it off as the same 40kph motor spec.
If the 30mm lamination is really super high-saturation-high-permeability-magic-panda-metal-alloy and behaved the same or better as the 35mm pot metal sensorless crap stator, then your 10x6 motors should be spinning at least 17% slower than the 12x5's in the sensorless wind.
So Luke, or Methods, or somebody, give us as exact as you can a spec for your motor KV. Take the unloaded RPM at a known volts, subtract off the I*R loss from the windings knowing the winding resistance and no-load current, then divide.
The 35mm 12x5 has a KV of 0.92 Rad/sec/volt
-Justin