Quicrun 880 in vintage Bullhead - please help

[duggla]

Hi,
I recently bought and installed the quicrun 880 into my Bullhead from 1991. The operation was smooth and programming easy as usual...but one thing keeps giving me headache. The ESC is cutting out from time to time, for example when accelerating full throttle directly from reversing (I've turned off the "low voltage cut off"). I'm still running Nimh-battery packs and the orignal motors. Could it be the combination or what have I done wrong? Does anyone recognize this problem?

 

[Chubaka]

What turn motors do you have? It says 2-6s , a 6 cell nimh is slightly higher then a 6 cell at 7.4v. It states to run higher turns when using 2 motors together.

 

[duggla]

What turn motors do you have? It says 2-6s , a 6 cell nimh is slightly higher then a 6 cell at 7.4v. It states to run higher turns when using 2 motors together.

The original motors are 27 turns. I've seen quite a few Clodbusters and Bullheads with that motor setup, sold with the 880 installed, but maybe they weren't running nimh...? could it be some programming option that i've missed out on?

 

[The_RC_Dude]

Hi,
I recently bought and installed the quicrun 880 into my Bullhead from 1991. The operation was smooth and programming easy as usual...but one thing keeps giving me headache. The ESC is cutting out from time to time, for example when accelerating full throttle directly from reversing (I've turned off the "low voltage cut off"). I'm still running Nimh-battery packs and the orignal motors. Could it be the combination or what have I done wrong? Does anyone recognize this problem?

Not familiar with that ESC and that exact set up, but I can help with general trouble shooting. Make sure your NiMh pack is good and charged properly, make sure the motors are connected to the ESC fully, and make sure your radio batteries are good (when they are low, the radio might lose connection with the RX now and then, and everything will act weird). Also be sure that both motors are the same (if one is more worn out or bogged down than the other that could mess stuff up), no drivetrain binding (including the pinion/spur gear mesh!), ect.

Could it be that there's interference in the air? Very unlikely with the standard 2.4gz stuff, but possible. Last but not least, make sure that your punch/start setting on the ESC are correct!

 

[tntpoof]

id try a 2 cell lipo and see what happens could be that jump from rev to forward.. like other poster said use 2 nimh.. make a y cable to do so..

 

[The_RC_Dude]

Yes, try a 2s LiPo (but set the ESC to LiPo mode first, of course). Also don't change direction (forward and reverse) quickly like that, you'll strip the pinion and spur, and your diffs will not like it!

 

[tntpoof]

lipo mode is not necessary if you have a lipo buzzer... if not switch..

 

[The_RC_Dude]

lipo mode is not necessary if you have a lipo buzzer... if not switch..

Yes, but if you have the ability to change to LiPo mode on your ESC, then do it, as it's an LVC, and is another layer of protection against damaging your Lipo (s). I have a buzzer, and I use it mainly for seeing the voltage of my LiPos, and my ESC is always in LiPo mode.

 

[duggla]

Not familiar with that ESC and that exact set up, but I can help with general trouble shooting. Make sure your NiMh pack is good and charged properly, make sure the motors are connected to the ESC fully, and make sure your radio batteries are good (when they are low, the radio might lose connection with the RX now and then, and everything will act weird). Also be sure that both motors are the same (if one is more worn out or bogged down than the other that could mess stuff up), no drivetrain binding (including the pinion/spur gear mesh!), ect.

Could it be that there's interference in the air? Very unlikely with the standard 2.4gz stuff, but possible. Last but not least, make sure that your punch/start setting on the ESC are correct!

Since I haven't got any LiPo-packs lying around, I'll have to start with the ESC-programming.

You're mentioning the the punch/start setting...the default setting is "level 5", I don't really know what this option does to the car. Is there a correct setting or do I have to figure it out/tune it myself?
There's also the initial start force setting...nine different options here as well. Could it have anything to do with that?

 

[Greywolf74]

It could be something wrong with the 30 year old motor thats in it.

 

[The_RC_Dude]

Since I haven't got any LiPo-packs lying around, I'll have to start with the ESC-programming.

You're mentioning the the punch/start setting...the default setting is "level 5", I don't really know what this option does to the car. Is there a correct setting or do I have to figure it out/tune it myself?
There's also the initial start force setting...nine different options here as well. Could it have anything to do with that?

Ok, yeah, start with the programing and let's work from there.

I should clarify, there's not really a "correct" setting for the punch/start, it comes down to your car and driving style. First off, to clarify, the punch/start setting is essentially how hard your car can accelerate from a standstill. Your punch/start settings control how hard your car can do this. IIRC the higher the number your punch is set at, the harder your car can accelerate, which means you'll be able to do wheelies more easily, more "power slides", get up to top speed a tiny bit faster, ect. and vice versa with a lower punch/start setting. Now, there's more to this, there's a reason why everyone doesn't just set the punch/start on the highest setting. The higher the number, the more strain/wear/load you will put on your whole drivetrain (from the pinion/spur, to your driveshaft, diffs, CVDs/dogbones, and your wheel hexes, and so on), including your motor, ESC, and possibly your battery (which could be indirectly affected, but probably not by a massive amount).

In other words, higher punch/start equals more drivetrain wear and possible breakage, versus setting the punch on a lower setting. If you're heavy on the throttle and are accelerating all the time, you'll probably not want the punch too high. If you like tricks and stuff, you'll like a higher punch. Dislike maintaining/replacing drive train parts? A lower setting will do you well. And obviously, if your car is older/not built like a tank, you'll probably want to shy away from high punch. Hope this helps, try adjusting the punch/start! Also, are you getting the same issues with the ESC when going forward only?