jcr

I have a cheap 60A brushless sensorless esc right now specs:
Specifications:
Continuous current: 60A
Burst current: 320A
Battery: 2-3S LiPo Battery / 4-9S NiMh Battery

Right now it is running a 3S lipo with a 3650 3000KV brushless motor and it is fine.

I was wondering if I can run a 3650 3900KV brushless motor with this ESC specs:
KV(RPM/Volt): 3900KV
Max RPM: 50000
Max current: 69A
Max watts: 900W
Max voltage: <13V
Rotor poles: 4
Resistance: 0.0081?

I'm trying to understand is the Max Current consider burst or continuous when reading these specs? ??

I have seen combos of these ESC with 3900KV motors but not sure what type of battery people run on it.

Riverbluff

My guess is you'd be right on the limit of the ESC with that motor. It would probably work fine, but given the right set of circumstances you could possibly over tax the ESC.

dan_vector

iTrader: (27)

As Riverbluff says you will be right on the limit of that ESC. If you are using in an offroad car then you will probably be exceeding the limits. However that said if the ESC is cheap then the worse thing that could happen is the ESC will either thermally cut out or fail completely. If it fails completely then it would be time to make the upgrade that it seems you may need!

HappyGene

iTrader: (135)

Hi jcr

If it's one of the foreign $15 cheapies , you'll be fine:



I run these with 3300-3950kv cheapie blue-finned motors on 2 & 3s every weekend. They get warm but gear the motor so it stays below 165f during the run and you shouldn't have any problems unless you crank up the timing. The brushed gear ratio suggestions in older AE & Losi manuals are good places to start with these motors. Be sure to get a temp gun.

It's a great combo but note that the latest batch of these have timing set at 28d from the factory so use the program card to move that down to 3d or none. Then as you become more acquainted with all this you can mix it up with different timing & gearing ratios.




I run with punch set lower too like level 1 or 2 pack after pack no worries.

Hope this helps
Gene

jcr

It is one of those ESC or similar to it. But I heard the blue fin motors are less powerful than the non-fin ones.

I got one of these motor:


It is going to be on offroad so I think I might be pushing its limit on the ESC.... probably better off with a 80A or 120A ESC.

HappyGene

iTrader: (135)

Yes the full can motors generally consume & deliver more watts so you would want to drop your pinion some on hot days or running in grass.

I agree with the previous posters to always get more capacity if you want to work that into your budget, just wanted to assure you that driving your existing combo softer than harder yields a long lasting and reliable system.

I've got an inexpensive full can 60a setup with a 2050kv motor driving 5 1/4" tires on a 4wd truck I use for grass play - geared for 155f with low-medium punch and doesn't quit until I hit something


That's a modified desertfox for which I desperately need arms & arm mounts...because I hit that immovable something!

jcr

Yeah I don't want to under gear it too much... so I might need another ESC. I got a Tsky 120A esc sitting around that would work with that motor on 2S lipo but reviews say running 3S on that ESC tends to fry it

So I still need another ESC if I want to run 3S on it or just stick with 2S....

HappyGene

iTrader: (135)

Oh, righto. Well in addition to the bigger speedo, I'd get a fan for the motor, too. Post pics here when it's done if you have the time

jcr

Right now I need to figure out where to use the TSky 120A and the 3900KV motor with 2S... maybe my drift car....