Cars T-maxx 3.3 Diy Electric Conversion. Burnt Esc

[Simon Sørensen]

Hi Peeps!

I am currently converting my old T-maxx 3.3 to electric. Today I got it running but burnt my ESC after 10 minutes. I wonder why. Maybe someone here can shed some light on it since i am a newb in RC building...

I am running a 3900KV 4pole motor with a 60A ESC (Now deciesed.)
I had a Spankin new 3S lipo 6000mAh 65C batteri for power.

When i got the power disconnected i noticed one of the motor wires was disconnected from the ESC. -I think the curcuitboard got so hot the soldering melted and let go of the wire, but the motor was only luke warm, so that doesnt make any sence...

Could it have been a bad soldering that just broke off? And would disconnecting one motorwire make the ESC shortcurcuit?

I have been reading the manuals for the motor and ESC. It seems the motor is rated as max 69A the ESC at 60A/320A burst.
The motor is not that big compared to ex the T-Maxx stock engine and it only has a 3,17 axle. So I guess it will be pulling some current to push the weight. but it ran like shot out of a canon until it burned the ESC...
Could I have overloaded the 60 amp ESC with the 69A motor? -But again, the motor didnt seem hot?

anyway Ill stop rambling. I plan on buying a new 80A ESC for the motor, but also on buying a bigger 2050KV motor with a 120A ESC and put that in the car. As I said this is new turf to me, but as far as I have figured out I prolly need a bigger motor with more torque so I dont strain a smaller system too much...

 

[RandyDSok]

Typically when an ESC is burned out... it is from being over loaded with too high of an amp load. The only real way to know for certain is to put an amp meter inline in the circuit.

Most cheap ESC's that list their burst amperage... are way over exaggerated and the amp load they mention last for such a short period, it simply isn't a real number you can count on.

The rated KV a motor has is unrelated to it's amp rating... so only look for their voltage range, amp and/or wattage numbers... the KV is just how fast it spins for a given voltage.

 

[Simon Sørensen]

[

Typically when an ESC is burned out... it is from being over loaded with too high of an amp load. The only real way to know for certain is to put an amp meter inline in the circuit.

Most cheap ESC's that list their burst amperage... are way over exaggerated and the amp load they mention last for such a short period, it simply isn't a real number you can count on.

The rated KV a motor has is unrelated to it's amp rating... so only look for their voltage range, amp and/or wattage numbers... the KV is just how fast it spins for a given voltage.

Thanx Rdsok.

The motor was listed as 69Amp and the esc as 60Amp. I think I overloaded it by using a too small engine for the car. The motor prolly mostly drew max current wich overheated the underpowered esc...

I am an electrician by trade so I have some understabding of how electricity works. -I just don't have much experience with RC. So thanx for the pointers.
QUOTE="rdsok, post: 171238, member: 201"]Typically when an ESC is burned out... it is from being over loaded with too high of an amp load. The only real way to know for certain is to put an amp meter inline in the circuit.

Most cheap ESC's that list their burst amperage... are way over exaggerated and the amp load they mention last for such a short period, it simply isn't a real number you can count on.

The rated KV a motor has is unrelated to it's amp rating... so only look for their voltage range, amp and/or wattage numbers... the KV is just how fast it spins for a given voltage.[/QUOTE]

 

[RandyDSok]

A lot of mods on RC models are done by the community... conversions from an IC engine to electric motor is probably the least done simply because it includes the cost and time of a lot of trial and error to get a good working combination. This type of mod on a popular model ( such as the T-Maxx ) is probably easier to find examples of but still takes a lot of time and effort in the research. I've never seen a if using this engine, use this motor as a replacement guide or chart because of the differences in power, torque and other factors makes those comparisons difficult at best.

When I modded airplane motors ( usually looking for more torque or speed )... I always used an ESC that was overrated for the job and as I mentioned, I ignored the "burst" values since they are mostly useless. I didn't ever venture into cars or trucks... but the concepts are the same none the less.

Good luck finding a good combination... and have fun with it. After all, that is what it's about, often the challenge a mod or build brings is half of the fun.

 

[Simon Sørensen]

Yeah. It is trial and error... and thats why I wanted to do it myself... I like throwing challenges at myself... I am allso building an 1/10 scale aluminum drifter from scratch atm... I hope to learn some things with the traxxas as my testbed before i get to the drivetrain on the drifter...

A lot of mods on RC models are done by the community... conversions from an IC engine to electric motor is probably the least done simply because it includes the cost and time of a lot of trial and error to get a good working combination. This type of mod on a popular model ( such as the T-Maxx ) is probably easier to find examples of but still takes a lot of time and effort in the research. I've never seen a if using this engine, use this motor as a replacement guide or chart because of the differences in power, torque and other factors makes those comparisons difficult at best.

When I modded airplane motors ( usually looking for more torque or speed )... I always used an ESC that was overrated for the job and as I mentioned, I ignored the "burst" values since they are mostly useless. I didn't ever venture into cars or trucks... but the concepts are the same none the less.

Good luck finding a good combination... and have fun with it. After all, that is what it's about, often the challenge a mod or build brings is half of the fun.