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Testing my "Chew Toy Mk 2", I've run into an issue where the car would seem to run away for a moment, full throttle and no steering. It's the same motor and ESC from the "MK1", which did the same thing, once.

I'm curious to know if this is an issue with using NiMH cells when the voltage drops off a bit and there's high demand, a problem with Turnigy ESC's, or some other kind of interference. Seemed to happen when I throttled it aggressively, and after a few minutes of running.

Motor is an Orion VST2 Pro 10.5
ESC is a Turnigy Trackstar 80A
Receiver Spektrum SR215
Transmitter Spektrum DX3C
Servo Hexfly HX-3CP (Standard Redcat)
Battery ECO Power 4200mAh NiMH 7.2V

I did get the Turnigy programmer after the MK1 had a few issues. I turned off the low voltage protection since I'm not using LiPo, and that helped with and issue I had in the MK1 with the car freezing. You can see me having issues with this and the runaway in the MK1 video in the "Chewtoy" thread.

It kinda sounds like the high current draw is causing bec issues. Several esc's even warn that similar situations are possible if the battery can't meet the current demand.

I don't know how reliable the internal bec is, but an inexpensive external one might fix the problem by drawing power upstream of the esc.

Or, a external receiver pack. If you don't already have one laying around, the 4-AA holders are cheap.

Could be the fail safe momentarily hitting throttle instead of brake until the signal is restored. What happens when you turn the radio off?

Is it Spektrum, they are notorious for "brown outs" with high draw servo's...

10.5t is the limit with Tracker 80amp and with NiMH cells it may well be brown out .

juicedcoupe wrote: ↑Sun Apr 25, 2021 12:41 am It kinda sounds like the high current draw is causing bec issues. Several esc's even warn that similar situations are possible if the battery can't meet the current demand.

I don't know how reliable the internal bec is, but an inexpensive external one might fix the problem by drawing power upstream of the esc.

Or, a external receiver pack. If you don't already have one laying around, the 4-AA holders are cheap.

While shopping A-main for tires I saw there are a few capacitors that seem to be for this purpose, so I ordered one. We'll see how it goes.

RC10th wrote: ↑Sun Apr 25, 2021 9:24 pm Could be the fail safe momentarily hitting throttle instead of brake until the signal is restored. What happens when you turn the radio off?

Is it Spektrum, they are notorious for "brown outs" with high draw servo's...

It IS a Spektrum transmitter and receiver. The receiver was bought recently, though the transmitter is more than a few years old.

Are you asking what happens when I turn the radio off while it's running away? Or just when I'm putting the car up? If the latter, nothing, really. Are you thinking the car would take off? Pretty sure it doesn't do this, though I think I still have my 90's habits of turning the car on last/shutting the car off first. I have switched between two cars before, though, running one and leaving the other on, but idle, without an issue.

Dadio wrote: ↑Mon Apr 26, 2021 2:48 am 10.5t is the limit with Tracker 80amp and with NiMH cells it may well be brown out .

I was thinking it could be the combo. I got a capacitor on order to see what that'll do. Any other brown out strategies other than more battery/less motor?

Also, went back and added my full system, for reference, since it sounds like it could be the combo of cheap stuff I got. Heh!

The Trackstar ESC's I have are already fitted with capacitor's , mine are the earlier ones and have the caps on a jumper lead , I think the later ones have them as a part of the ESC , adding more caps is a cheap experiment but unlikely to work I'm afraid .

Dadio wrote: ↑Mon Apr 26, 2021 1:33 pm The Trackstar ESC's I have are already fitted with capacitor's , mine are the earlier ones and have the caps on a jumper lead , I think the later ones have them as a part of the ESC , adding more caps is a cheap experiment but unlikely to work I'm afraid .

I wasn't sure if he was talking about the esc capacitor packs or a glitch buster.

Yeah, I ordered a *checks page* "Glitch buster".

I'll try that before I make other changes, but saw someone else talking about turning down the "Punch". Is that worth keeping in my back pocket?

This "Chew Toy" is turning into quite the development program. Started with rearranging the redcat's steering links for full range, re-bleeding shocks for better consistency, shimming links to reduce bump steer, and now ironing out electrical issues.

Also new to me are "gyros". Found a cheap one on ebay to play around with.

The "Glitch Buster" definitely did not work; ran away right on the first stab of the throttle! lOL! Either the cap needs to be way bigger, or I need another option.

Don't have time to play around with the "Punch" setting right now. But I may fully charge the battery, again, so I can play around with the Gyro.

What you probably need is lipo battery power to cure the brown out and turn the wick down on punch .

Dadio wrote: ↑Fri Apr 30, 2021 2:04 pm What you probably need is lipo battery power to cure the brown out and turn the wick down on punch .

Rats. I was hoping I could keep squeaking by with trickle charging on my old Pro-Tech 706.

HS-YZ250 wrote: ↑Mon May 17, 2021 9:59 am

Dadio wrote: ↑Fri Apr 30, 2021 2:04 pm What you probably need is lipo battery power to cure the brown out and turn the wick down on punch .

Rats. I was hoping I could keep squeaking by with trickle charging on my old Pro-Tech 706.

The glitch buster will help momentarily its not a cure but it will help bigtime......................

KidAgain wrote: ↑Thu May 20, 2021 9:24 am

HS-YZ250 wrote: ↑Mon May 17, 2021 9:59 am

Dadio wrote: ↑Fri Apr 30, 2021 2:04 pm What you probably need is lipo battery power to cure the brown out and turn the wick down on punch .

Rats. I was hoping I could keep squeaking by with trickle charging on my old Pro-Tech 706.

The glitch buster will help momentarily its not a cure but it will help bigtime......................

My vision's starting to get bad: dusted the car off this past weekend and found I put the glitch buster in backwards, so it wasn't doing anything. Heh!


Question: I'm replacing the Redcat's stock servo because it doesn't fully return to center. I bought a Futaba S3305 as an affordable replacement, but then saw its note about having a high current draw and wondered if that was a contributing factor to brown-outs. I chose Futababa because it was affordable and an established brand I recognized from back in the early 90's. Are there standard servos that are better about current draw? Or is that pretty typical across the board?

HS-YZ250 wrote: ↑Thu Jun 17, 2021 11:03 am

KidAgain wrote: ↑Thu May 20, 2021 9:24 am

HS-YZ250 wrote: ↑Mon May 17, 2021 9:59 am

Dadio wrote: ↑Fri Apr 30, 2021 2:04 pm What you probably need is lipo battery power to cure the brown out and turn the wick down on punch .

Rats. I was hoping I could keep squeaking by with trickle charging on my old Pro-Tech 706.

The glitch buster will help momentarily its not a cure but it will help bigtime......................

My vision's starting to get bad: dusted the car off this past weekend and found I put the glitch buster in backwards, so it wasn't doing anything. Heh!


Question: I'm replacing the Redcat's stock servo because it doesn't fully return to center. I bought a Futaba S3305 as an affordable replacement, but then saw its note about having a high current draw and wondered if that was a contributing factor to brown-outs. I chose Futababa because it was affordable and an established brand I recognized from back in the early 90's. Are there standard servos that are better about current draw? Or is that pretty typical across the board?

On a buggy with a glitch buster cap properly installed servos should not be drawing much during normal operation. Set the yend point in your radio so the servo is never trying to push past the physical limit of the steering rack. That would be a big drain as it would use all of the power it could in that situation. Current drain is listed on most servo spec sheets, though it’s reported only the reputable brands list the spec’s correctly.

I have a savox servo and a spektrum receiver and I have yet to have the widely reported glitches due to brown out. Though I am running a Novak esc and lipo.