Finally finished my buggy conversion!!!

[Mozzy]

Well, I was at RC Garage (LHS) tonight after getting the buggy completed & running.

We went out the front for some quick runs on the road & OMFG (!!!) it was like a rocket on just 60% EPA.

Turned a brand new front set of crimefighters into pizza cutters & they have the centre of the tread removed.

Then Nick (the shop owner) had a burn & burn it did when the Quark ESC caught fire!!! A massive cloud of smoke came out as it burned away.
It was quite funny to watch actually.

I'll be having a little chat with Aiden from Ark Innovations on Monday after yet another unsuitable recommendation.

Receiver, motor, battery & servo are ok.

Here's some pics.











Suffice to say, I WILL NOT be putting another Quark in any of my 1/8 machines, they just can't cope.

[pullinteef]

What gearing did you run? That 2779 KV on 5S is a ton of RPM (51411) and amp draw. Too bad, but I wouldn't be so quick to judge Quark on that. They make some very good products overall, and anything will fail if it's pushed too hard. I bet it was fun while it was working though!

[lincpimp]

A 6xl on 5s lipo!!! That setup can most likely pull 150 amps, if not more... No wonder the quark died. Try a 9 or 10xl next time. Conversion looks nice though, good job.

[DRIFT_BUGGY]

How long did it run for before going up in smoke?

[Mozzy]

I was using a 15t pinion & stock 46t spur.

The motor has a max draw of just 110A, & the ESC can cope with 120A, I thought I was doing ok with my choices. Also, had the throttle EPA at 60%.

Especially considering the Aust distributor recommended the ESC & had checked my motor (I sent it last time I toasted one of these) & said it should be good.

Bummer, guess not.

Well, I'll ask him what he'll do now after this.

I have a 2084kv sitting here will that be any better?

& oh yes, it was fun alright for about 10-15mins.

I guess, I still have a lot to learn about these things.

Just looked at these, http://www.impaktrc.com/product_info...oducts_id=2461 http://www.impaktrc.com/product_info...oducts_id=2681 would they be better suited?

[pullinteef]

I think you are overgeared also, especially for that setup. (I get 67.8mph theoretical / 62mph drag adjusted on the gearing calculator)

Just as a note, and I'm not saying you did this, but make sure to set the EPA after doing the ESC neutral/max calibration. If you set the EPA to 60% and then calibrate I think that 60% throttle will register as the 100% point as far as the ESC is concerned. Someone please correct me if I'm wrong. Also, how does reducing EPA affect temps? I remember reading that brushless motors don't like partial throttle so much, is this true?

[lincpimp]

Originally Posted by Mozzy

I was using a 15t pinion & stock 46t spur.

The motor has a max draw of just 110A, & the ESC can cope with 120A, I thought I was doing ok with my choices. Also, had the throttle EPA at 60%.

Especially considering the Aust distributor recommended the ESC & had checked my motor (I sent it last time I toasted one of these) & said it should be good.

Bummer, guess not.

Well, I'll ask him what he'll do now after this.

I have a 2084kv sitting here will that be any better?

& oh yes, it was fun alright for about 10-15mins.

I guess, I still have a lot to learn about these things.

Just looked at these, http://www.impaktrc.com/product_info...oducts_id=2461 http://www.impaktrc.com/product_info...oducts_id=2681 would they be better suited?

The 2084kv motor would be a much better choice with the gearing you have... The amp ratings of motors are not really viable with car use. They are based on some sort of prop testing.

[tc3_racer_001]

yep, i can confirm that. also, i run 4s with a 2550kv, and a 12t pinion, its stupid fast (for me) but i would definately be wary of that motor, its a 4s motor at max. (really i dont think its suitable for any application, its too hot to use and on 3s eficciency is out the window.)

try a neu :P

1512 2.5d seems popular on 4s and a bullet on 5s.

[BL_RV0]

The 2.5d is a 5s motor, and a rocket on 6s.

[Mozzy]

I always calibrate as per ESC manuals, which for this was everything at 100%. I remember having to readjust everything due to running nitro motors on the same model.

It was 60% of the maximum available power at WOT....I think that's how it works.


I might try the 2084kv on a 14t pinion to see what it's like & if temps are very low try the 15t pinion again.

I'm now wanting to shy away from high kv motors as I want long runtimes for racing.

Also, I'll be working at my mates LHS ( I called him today & he was trying to convince me to come down as they were busy. hehehe) & we're going to be making up complete BL conversion kits comprising of mount, motor, ESC, pinion, battery & tray for a lowish price.
So, I'm guinea pigging alot of things to see where I'm going wrong in order to be assured that if I/we convert a car or sell the kit with explicit instructions on what to do, that it won't come back fried.

Basically, make a dikhead proof conversion kit that can whip a nitro without the reliability issues.

Thanks for the help fellas.

[tc3_racer_001]

fool proof until you let them adjust the pinion mesh!!! lol. some people have such trouble with this i just dont get it

2084 (8xl right?) sounds better. im running a 12t and its pretty quick so according to brianG's calc, it should be close (11t on 2550 is the same as 14t on 2084) but yours may run hotter due to the build quality - going to try the MMM?

[Sammus]

running at 60% epa is no good either, esc's dont like running at constant part-throttle. I've blown several traxxas escs, every one of them was fine for high speed stuff with a lot of full throttle. use it on a tight track where your only around 1/2 most of the time and they melt. Something to do with how they control the power output (pwm), im not sure why it makes it heat up more.

[Mozzy]

Yeah, exactly! Meshing's not rocket science, but, some people just can't do it. I just don't get it.

Of course we'd offer the option of it being converted in house & handed back after a full pack of testing to make sure.


Tomorrow, I'll be trying the buggy again with a MM V1, 2084kv & the 5S. With a change to the 14t. Fingers crossed!!

So, Sammus, it's not good to cut down the EPA to restrict WOT? I need some clarification on this that is 100% certain.
No offence Sammus.

Thanks again.

Might have some pics of another toasted MM V1 after tomorrow!

[Sammus]

Yeah I'm not 100% on the tech behind it. I know castle tell you not to do it, but in response to a slightly different question. That and I've noticed that my ESC's run hotter at partial throttle than at wot.

[Mozzy]

I had a quick read & it's saying that the ESC is 25A & the motor can draw 45A, that's not comparative though.

My ESC's can all cope with more amps than the motors can draw, so, where does that leave CC's theory/explanation?