Help determining kv

[crrcboatz]

Anyone help me determine the kv on a couple of motors? They were custom made by TP and only have build codes on them. The lady at TP said they do not keep records on those build numbers after shipping

[properchopper]

get one of these, use your voltmeter and do the math

https://www.ebay.com/itm/372693874872?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1lzRsZOvnQIKlL_tjd2XcpA65&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=372693874872&targetid=1644837436483&device=c&mktype=&googleloc=9031044&poi=&campaignid=16743749222&mkgroupid=138744546207&rlsatarget=pla-1644837436483&abcId=9300842&merchantid=424797374&gclid=Cj0KCQjwhqaVBhCxARIsAHK1tiNFqaf-9FmfoWYA9gqsqFcEtbI7RIbLpRIFYmeK6nnGntHURIQYDeQaAmSYEALw_wcB

[tbonemcniel]

https://www.skyrc.com/Accessory/SKYRC_BL_Motor_Analyzer

These actually work pretty well, as long as you know the pole count. You have to know number of poles or kv, to solve for the other.

[crrcboatz]

I like this BUT have no idea how to use it. I have never wired a FE in my life gentlemen! I would hesitate to buy something I have no experience with. I’m in a situation where the red, yellow and blue wires of the motor are not even marked! Great workmanship but the guy removed these markings on the wiring.

I need someone who can determine which wire is which as well as the process of determining the kv. This wiring thing is partly why I failed with the drill method. I’m a almost 50 yr nitro then gas guy.

[tbonemcniel]

Good news on that front, sensorless brushless motors don?t care which wire is plugged in where. If the motor happens to run in reverse, you simply swap any two to change the direction.

So with that analyzer I posted, you would connect a 2S LiPo battery to it, use the alligator clips to connect to the motor (nothing attached to the shaft). Within the box, you?ll set your pole count to 4 (I?ve never seen a TP that wasn?t a 4 pole). Then use the box to run the rpm?s up and it will readout the kv value on the screen.

It?s never as advertised, but very close. For instance, an advertised 2200kv motor may measure on the box as 2184kv. It?s reading is more accurate than the advertised value.

The pole count has to be correct though! If it?s a 4 pole motor and you leave the box on the default of 2 pole, that same 2100kv motor will read as a 4200kv motor!

[crrcboatz]

My understanding is the 56/80 series are all 6 pole. Ok thanks so much. If I understand you correctly the 2s battery will run the motor or the motor analyzer ?

Thanks for being patient with me sir!

[tbonemcniel]

You?re correct. The 56mm+ motors are 6 pole. I was primarily thinking of the 36/40mm motors.

Yes. The 2S LiPo connected to the motor analyzer will run it, as well as the motor you connect to it.