sv27 VS UL-1 motors

[rockwerks]

How much difference? what are the differences?

[Fluid]

There are major differences, mostly the Kv. The SV motor has a low Kv, somewhere around 1500 rpm/volt. The UL-1 motor Kv is around 1900/2000. Since I don't know what amp draw is used by the makers to calculate Kv the values above are estimates.

You can swing a much larger prop with the SV motor, just at a lower rpm. It is better for larger or slower models - although if your model lets you swing a large enough prop it can equal the UL-1 in speed. You need to let the UL-1 motor wind out with a smaller prop to get maximum performance. Otherwise you will generate heat in the drive components without getting the speed you want.

I prefer the BJ26 motor if I need a lower Kv. It is of higher quality construction than the others (and you pay for this higher quality) and the Kv seems to be slightly higher than the SV. I can exceed the speed of the UL-1 motor when I run the BJ in larger hulls, and the temps are lower too. This is just what you'd expect considering their differences in Kv. It all boils down to what boat you are running and what your performance expectations are.



.

[sailr]

As an aside to this question, has anyone mix-matched the aquacraft/proboat esc's with these motors? In other words, can you use an aquacraft UL-1 esc with the proboat motor and vice-versa? I'm not sure why you couldn't unless there are big differences in the timing, pwm, etc. programmed into the controllers? I have a spec rigger I am building with a proboat motor but the proboat esc to too big to fit in the tub!

[Hydromaniac]

As an aside to this question, has anyone mix-matched the aquacraft/proboat esc's with these motors? In other words, can you use an aquacraft UL-1 esc with the proboat motor and vice-versa? I'm not sure why you couldn't unless there are big differences in the timing, pwm, etc. programmed into the controllers? I have a spec rigger I am building with a proboat motor but the proboat esc to too big to fit in the tub!

I have all three motors and esc's ( UL-1, BJ26 and SV 27) I have ran all of them together mixing all possible combinations with no problems, I have ran the SV27 esc and UL-1 motor together on a X442 prop and they ran fine no heat isuues at all, I agree with Mr Turner that a lot depends on the boat, I have ran these set ups in a light SSH and LSO boat. So far they have worked out just fine. I do however run a bit smaller prop then most guys. I prefer to let the motor hit full RPM and wind out a little later. It seems I get faster top end speed this way then running the largest prop I can.

[sailr]

Thanks Hydro! Good post! I'll rest easier tonight! Now back to the spec rigger setup! Yippee! In the beginning when Herb Stewart's and I were doing initial testing of brushless OPC tunnel setups, we kept going smaller and smaller and smaller on props until the motor 'came alive'. It was amazing how small we went.

Herb set SEVEN world records this year before his untimely passing.