Mamba 5700 brushless gearing help

[HixX]

Hi all,
I've fitted a 5700 Mamba to my Worlds and are struggling to find the right gearing, has anyone any experience with this motor and the BJ4?

[BenG]

This is the equivelant of a 9 turn motor, so follow the gearing in the BJ4 manual for a 9turn

[jimmy]

I've not seen the Mamba nor have I any idea what the 5700 motor is compared to the LRP motors I have used. But from what I know the brushless systems rev more and dont like to be over geared. I'd suggest 15t pinion on the kit spur like I use with the LRP 3* and go from there.

[footey]

ive got a gtb 6.5 in with a 18 pinion on kit spure is that to big

[Rob Fitzgerald]

Just this minute been playing with one in my XXX CR try 2 of 3 pinions smaller than you would normally use with a 12 or 11 as a starting point.

[Richard Lowe]

I'm guessing the Mamba 5700 relates to 5700kV (which towards the slower end of brushless motors)? Jason suggests a 17t for a 2* Reedy/LRP motor which I believe are 6500kV rating, so I'd start on a 17 or 18t with the Mamba.

OT:- I've just noticed on the Novak site they have/are releasing a 3.5 (10500kV!) brushless motor

[jimmy]

Wonder if the current speed controllers will actually handle that motor ?

What KV is the 3* richard, any ideas ? I was told 13:00 ratio for that motor in 4wd, which is 15t. I thought it might be undergeared but but it was great.

[Chris Doughty]

Jimmy,

http://www.lrp-electronic.com/e/lis/

the 3-star is 7,700 KV, their 4-star is something like 8,600 Kv

[Richard Lowe]

I'm not that sure actually Jimmy to be honest, I got the kV rating from the Tower website, but I've just spotted now that they have the 1, 2, 3 and 4*'s all rated at 6500kV in their descriptions

Novak give kV ratings on their motors, assuming the Reedy/Novak motors are similar speeds...

Novak Reedy kV
3.5 - N/A - 10500
4.5 - 4* - 9000
5.5 - 3* - 7400
6.5 - 2* - 6400

I have NO IDEA if those are correct, just an (un?!)educated guess.


:::edit::: Mr Doughty to the rescue

My guesses were'nt too far off