determining motor kv rating

[morewattsnow]

Is there a way to determine a brushless motors kv rating once the label is gone, as in the case of a Neu motor? I have a 1527 1.5D that consistently underperforms in any hull I put it in. Just got an Eagle Tree data logger but haven't figured it out yet. Thanks.

[martin]

Why dont you look up Neu motor specs, Isnt the 1527 1.5D motor 1500kv. Martin.

[morewattsnow]

Yeah, a 1527 1.5D is 1500 kv, but what I want to know is there any way to measure the resistance of the windings (or something like that) to determine the actual kv of a particular motor. As I said, this motor is extremely unimpressive on 6s so I'm wondering if it was mislabeled at the factory.

[Fluid]

There are several Kv checkers available. You really need to measure the new motor first - before damage - then compare. But it can give you an idea.

http://www.hobbyking.com/hobbyking/s...dProduct=10335

How are you propping the 1527/1.5D and in what hull?


.

[morewattsnow]

Running it in a homebuilt rigger with the tub being 31" long. I've built nitro riggers before with good success. Pulled the setup from the Castle setup page for a Q hydro- 1527 1.5D, Octura 1450, Hydra HV 240 instead of 180. On 6s it should run a calculated 33,300 rpm. I have other FE boats running about the same rpms and this just doesn't SOUND like that much. Tried an Octura 450 and a Prather 230 also- not a lot of difference. Boat is slow- probably only 40 mph. That's why I'm wondering if the motor was somehow mislabeled. Moved the strut up and down- down til it bogged, up til it didn't really push the boat. Temps are cool, not hitting low voltage cutoff with 1 6s 5000 mah 30c Polyquest . Oh yeah, the boat does have rear sponsons and the CG is right at the leading edge of the turn fin.

[m4a1usr]

There are several Kv checkers available. You really need to measure the new motor first - before damage - then compare. But it can give you an idea.

http://www.hobbyking.com/hobbyking/s...dProduct=10335

How are you propping the 1527/1.5D and in what hull?


.

I have that one Jay posted the link to and its pretty darn accurate. If you buy one make some bullet adapters to put in between which ever motor you want to test. Also make a battery adapter using a 9v battery. The wiring instructions that come with it are a bit weird but not to difficult to decipher. All around a good tool to have on the work bench. You can tell if your rotor has become demagnitized in just a few minutes. I highly recommend one for the guy who is wanting to know where his motors are at.

John

[MarkF]

I would send it back to Neu. If its the wrong KV then they will replace your motor with the right one. If not they will check to make sure there's nothing wrong with the one you got.

Mark