Not sure if motor, ESC or battery problem

sallokay

Member
Messages
5
Hi all,

I've got an ECX Circuit 1/10th electric truck that came with a Dynamite Tazer 15T ESC, Dynamite 20T Motor (DYN1171), and 1800mAh 7.2V 6 cell Ni-MH battery with Spektrum DX2E TX & Spektrum SR201 RX.

I upgraded the motor to a Tamiya Super Stock BZ motor (23T, 26,500rpm, 49mN.m torque).

The truck is now running VERY slow - & doesn't work at all until pressing the throttle a few times. I'm now wondering if the Tazer 15T ESC (continuous/peak 30A/300A) or if the 1800mAh battery is at fault for the slowness? Or something that I hadn't thought of..

Thank you in advance for any replies. I have very limited funds so don't want to make another mistake...

Cheers,
sallokay
 
The ESC may not be able to handle a 23T motor, or the motor is sucking up battery power quickly because of its size. I'm pretty sure the manual explains what motors the ESC is able handle.
 
I'd be surprised if a 23T brushed motor is drawing enough current to cause a problem. Is your throttle trim knob set properly? It almost sounds like the throttle end-point setting is off. Look in your manual for "Changing the travel adjust settings."

Turn your radio on in "programming" mode and then turn on your car. Hopefully this will help. Report back to us here and let us know what happens.
 
not knowing how new you are to the hobby, my first thought is possibly gear mesh? if you got it too tight, it might cause the problem you're describing.
If that checks out ok, try unplugging the motor leads, and plugging the stock motor back in.. and see if it acts the same. Don't install it, just try it in your hand.. that can help you pinpoint the issue.
 
The ESC is supposed to be able to handle up(down?) to a 15 turn motor (hence the 15T labelling). I have a mechanical engineering degree - and certainly understand revs/power/torque - but I must admit: I am out of my depth with electrical equipment generally - but, considering that 23T Tamiya motors range from 16,300rpm to 26,500rpm (for the BZ motor) http://tamiyabase.com/index.php?opti...log&Itemid=780 and also considering that the Dynamite 20T is 1/3 the price (yes I know Tamiya is overpriced, but still) of the BZ - I figured I should get AT LEAST as much performance out of the BZ compared to the Dynamite 20T.

Tested configurations include:
Tazer 15T ESC + Dynamite 20T motor + 1800mAh Ni-MH = fast
Tazer 15T ESC + stock silver can Tamiya motor + 1800mAh Ni-MH = fast
Tamiya TEU-105BK ESC + Dynamite 20T motor + 1800mAh Ni-MH = fast
Tamiya TEU-105BK ESC + stock silver can Tamiya motor + 1800mAh Ni-MH = fast
&
Tazer 15T ESC + Tamiya super stock BZ motor + 1800mAh Ni-MH = MUCH slower
Tamiya TEU-105BK ESC + Tamiya super stock BZ motor + 1800mAh Ni-MH = MUCH slower

This is why I'm guessing it must either be:-
- BOTH ESC's can't supply enough power to the BZ motor
- The 1800mAh 7.2V Ni-MH cannot produce enough "power" for the BZ motor (refer above don't know my electrical stuff well comment)
- the BZ motor is faulty if the above aren't likely..

I have read that the TEU-105BK isn't good enough to power a BZ motor - and indeed the specs for that ESC recommend a 25T motor maximum for it to run properly - but I thought that this would simply overheat the ESC, instead of the motor just going slow.

I have hooked up the battery directly to the BZ motor and it seems to spin SLIGHTLY faster than through either of my ESC's but I am unwilling to let it go on the ground because I obviously can't control it from there on... both the old Dynamite 20T and a stock silver can 27T run faster than the BZ..

Also - I have swapped the ESC/Steering servo receiver cables and it made no difference. Also - both ESC's are showing "full throttle/trigger" activation LED's when directed. I also have a spare battery and spare Tazer 15T ESC and have checked all the above combinations with the spares as well...

So - the ESC should be good enough for a 23T motor if # turns is the only factor worth noting.
- the throttle position is fine because both ESC's are showing full throttle on their LED's.
- backed off the gear mesh; no change.
- both other motors are running harder/faster than the BZ.

I have a multimeter - is there anything i can test? I wish I had a dynamometer to give some better specifics - but for now - I'm at a complete loss and not sure what to replace...

AAAAAND now... back to Mr Robot before I throw this damn motor in the dam! (yes, I really have a dam... don't ask!)
 
Seems like you've gone all the obvious and some not so obvious routes. I'm stumped too. It seems to me a more capable ESC would be the next logical thing to try. But it makes no sense. As a general rule ESC that can handle south of 15 turns start getting expensive. If spending that much, just go brushless. I suppose you could try a better battery.. but that makes no sense either. the initial Voltage is going to be the same no matter how much capacity the battery has. Unless you go to Lipo, and higher discharge rating
I would throw that motor in the dam, and try a differant one. It's cheaper than new batteries, or new esc's
 
Cheers @ChazOutlaw, I was hoping I'd missed something simple..

I think I'm going to ask for a refund as it seems the only logical answer is a faulty motor.

Thanks for everyone's help.
 
I think that is the battery problem. I had one myself and those batteries aren't good. A venom 3600mah 7.2v nimh battery is what you need for it
 
Cheers @ChazOutlaw, I was hoping I'd missed something simple..

I think I'm going to ask for a refund as it seems the only logical answer is a faulty motor.

Thanks for everyone's help.

The only common element among the problem configurations was the BZ motor. Did you get it returned?


What motor are you running now? :)
 

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