TP Motor Kv unknown

[CraigP]

Yeah, I think so. Start with a small prop and check temps. Or use a data logger... I only data log. But temps should be enough. Looking for motor temps around 140-150, ESC temps around 130-140.. if an ESC comes up for sale cheap in the 220-250a range, might want to shag it. So you race gas? Do you have a nitro boat? I started in nitro hydros, a long time ago... I'm loving FE, being an electrical engineer. LiPo batteries make a big difference, but miss the run times and noise of nitro sometimes!

[properchopper]

I received a TP 4060 V1 motor as part of a package deal, it was assumed to be a 2040kv but I don't see that as a listed kv. The numbers are not on the silver label like normal. Any way to tell the kv?

Here's a fairly simple/accurate way to find out KV on a motor already installed in boat. (Can rig a motor-only bench tester if need be):

Step One : Get your hands on one of these *
KIMG0624.jpg

Step Two ::
Plug everything in on boat and arm
On propshaft install a spare servo arm (or whatever) with supplied reflective tape stuck on for reading.
Install a volt reading device on the battery.

Step Three :

Aim tach at reflecto-thingie with one hand and push button
Pin xmitter WFO with other hand
Take picture for thread with third hand ()

KIMG0634.jpg

Battery V reading at WFO ; (battery started at storage V but doesn't matter for this test)
KIMG0625.jpg

RPM reading at WFO :
KIMG0627.jpg

Step Four :
Divide RPM 31,500 by WFO V 14.67 - you get a bench calculated KV of 2161.97 . Stated KV from TP Power is 2200. Pretty slick

*Tach won't break the Bank :

http://www.tmart.com/DT2234C-Digital-Laser-RPM-Tachometer-Non-Contact-Measurement-Tool_p341103.html

[CraigP]

Nice! Mikey likes it!

[Insanity Plea]

Thanks chopper, and everyone else for the info. After I get this busted hull figured out I'll revisit the kv issue. I know I can just run a couple different S batteries, but if it works good I'm going to want to know what I have.