Strange glitchiness with sidewinder and MM with ccbec

[Sammus]

Howdy, here are my two setups I'm having problems with:

Jammin CRT.5: Mamba Max, Feigao 9L, 4s1p A123, ccBEC, 12/46 gearing (~33mph)

Rustler: Sidewinder, Ammo 36-56-3300, 3s1p A123, ccBEC, 12/40 gearing (~40mph)

Both of the cars are running Futaba R603FF 2.4Ghz receivers and I use a 3PM transmitter, on both the cars I have removed the +ve wire from the esc to rx lead.

Both the cars have acquired a strange glitchy behaviour since switching to A123 cells (both of them used to run 3s lipo). It seems like sometimes if I gas it, the throttle locks on for a second, and often causes the car to go somewhere I dont want it to :(

I've never had any glitching before, does that sound like radio interference glitching? I though 2.4Ghz was near immune to glitching?

At any rate, I removed the ccBEC from the rustler, which let me tidy up the wiring a little better, and in the extremely short (ie a few minutes) run I gave it doing circles in my garage (it's been raining heavily for a while now..) - where I've recently noticed the glitching during my test runs of both vehicles - I wasn't able to replicate the glitching again.

Redoing the wiring on the CRT.5 will required me to redo my chassis layout, so I thought id ask if the kind of glitch I described (momentary throttle lock on) sounds like radio interference?

My bro had the same issues running a sidewinder in his evader when using a 6 cell nimh stick pack. It disappeared when he put his lipos in. Naturally this suggests it's a battery issue, but my new A123 packs are much more capable than my old fried no-name underrated lipo's! surely it's not a battery thing?

Any input would be greaty appreciated :)

Thanks!

Sam

[crazyjr]

I have no experience with the A123's, but it sounds like you are losing power to the reciever for a split second. I am not sure, but its possible that 1p on the a123's might be a bit short of proper power for your application

[Sammus]

I had considered that, but according to the specs on the a123 website, I should be able to pulse up to 140A, and have a constant 70A before the voltage drops below 2vpc, which would still be 6V (plenty for the reciever...)

My old fried lipo packs rated to 100A pulse when they were new and I never saw the problem either...

As an update I am starting to think it is interference. I had a quick read of the faq on CC's website, and after twisting the batteries wires and braiding the motor wires, I've been unable to replicate the glitching (didn't move anything on the chassis!). Hopefully it will stay like that :)

I was able to experience that same problem the other night. I have in a rustler, stock AM rx, MM 6900, CC BEC, but a cheapo 8 cell tenergy nimh pack that had been charged 2-3 weeks prior. 2s or 3s lipo there is no problem. So a deadish 8 cell would cause it. Also, my lvc was set to auto lipo and it recognized the 8 cell as a 3s. So I don't know if perhaps it was bouncin off the lipo cut off or not. I was geared pretty high too. Perhaps it is a battery thing with you.

Just read the rest of your post. Maybe it is just wires interfering. Direct soldering the motor wires and twisting them has done wonders for me.

[Arct1k]

Could be interference - I always twist motor wires etc grab a glitch buster

http://www.horizonhobby.com/Products...ProdID=NOV5626

[Sammus]

Those things look cool... I've got several large super low esr caps hangin round, I might just make my own :) Any idea on the capacitance and V rating?

[Sammus]

Any other ideas what this could be? I thought I'd cured it but apparently I havent. My setup:

Pic.

I recently moved the BEC from the alu plate at the front to over behind the motor, but it didnt make any difference.

The glitching is still there, and my only options are to have the throttle cable running past the motor (how it is now) Or along the battery. I can't decide which would be worse - I'm thinking the motor would generate more interference.

Could it possibly be from the Rx sitting on the Servo?

This is driving me nuts There's so many variables. I do suspect it is the BEC though because I was having the same problems in the rustler that disappeared after removing the BEC. I even get glitching without the wheels on, just sitting there blipping the throttle, very occasionally the throttle just locks on for a couple seconds. This has already caused my poor car a bunch of damage :(

Does anyone else run those glitch buster caps? I'm considering it, but it seems like a bit of a bandaid solution, I want it to run properly without one...not many people seem to use them...

[BrianG]

Motor wires carry high current AC signals, which can produce a lot of noise. The throttle cable being in close proximity to those motor wires could be causing issues. Or, it could be noise coming from the CCBEC. During testing, the BEC had some noise, but a capacitor ("glitch buster") helped a lot. I would suggest somehow routing the throttle cable away from the motor wires and installing a 1000uF 10v capacitor onto an unused slot on the Rx.

You could also get one of those small ferrite "donuts" similar to the ones Quark ESCs use. You just wrap the throttle cable through it for one turn fairly close to the Rx.

[lutach]

Originally Posted by BrianG

Motor wires carry high current AC signals, which can produce a lot of noise. The throttle cable being in close proximity to those motor wires could be causing issues. Or, it could be noise coming from the CCBEC. During testing, the BEC had some noise, but a capacitor ("glitch buster") helped a lot. I would suggest somehow routing the throttle cable away from the motor wires and installing a 1000uF 10v capacitor onto an unused slot on the Rx.

You could also get one of those small ferrite "donuts" similar to the ones Quark ESCs use. You just wrap the throttle cable through it for one turn fairly close to the Rx.

Hi Brian,

It might be something else causing the glitchs. I have my ESC wires going where the motor wires come out and I don't see any glitching at all. I use an Rx pack and before that I used on external BEC that went in the garbage after it caused some serious glitching at high speed and a few broken parts on my Stampede. Here are some pictures:

[Sammus]

Hmm placement is getting difficult. One side is all battery and esc, the other is motor. I've redone the layout again: Link. I flipped the BEC around so the output isnt so close to the motor wires... The other option is on that centre top plate but thats getting pretty close to the Rx and I was recommended to keep the BEC away from the Rx.

It's a shocking layout already, all battery and esc on one side, little motor and servo on the other. Horribly unbalanced. I can fix that later once I figure out the problem with this glitchiness.

With the new setup I think it glitched a lot less. It's dark now and I'm scared to drive it even in daylight after last time... But in a medium sized two story brick house, me in one corner upstairs, the car in the furthest corner downstairs, it was responding fine (a little delayed.. but still OK). There was one spot before where it would seem to glitch more often. Stab throttle and brake a few times and it was fine. It wasnt until I walked downstairs right up to the car still blipping it and it locked on again for about 2 seconds. Damn.

When it does it it always does it after a slight cog (cant understand how its even cogging with next to no load on the motor).

I haven't done a lot since then, I just reflashed with the latest firmware and changed the start power from high to low. I'm not really 100% on what start power does, but it only seems to glitch when you apply throttle from zero (not zero speed or rpm, zero throttle input), so I figured reducing the amount of power running through the system at that moment could help.

I'm pretty keen to get my hands on more of those panasonic FM series caps - only place in oz that sells them have a minumum order though, and want $12 for shipping for some strange reason, so I'll have to buy a lot of them to make it worth it.

Do you know where one could buy a suitable ferrite bead thing? I've noticed a lot of the air guys use them. I've tried searching many things in tower and amain but havent come up with anything, and looking in electronics stores I only just thought of lol.

[BrianG]

A couple places to try, but some might be too large/cumbersome:

RadioShack

Parts Express

All Electronics

[Sammus]

Yeah I've been browsing the aussie stores and found a bunch. They want $15 instead of $1.50 though heh. I think I might just get some solid rings instead of those snap things. If I even need to get any. Could all the electronics being mounted directly to all that alloy influence it much? I'm assuming no since so many people have all alloy trucks and none of these problems.

[RBMike]

I had this problem and for me it was the CCBEC. I got a Novak BEC & the problem is gone. I had glitches & 2 runaways when using the CCBEC on 3 different Spektrum RX's.

My set-up:
Medusa 36-60-2K
Moded MM(2fans& case holes)
A123 5S
Spectrum RX's
Hitech 985MG
Was CCBEC, now Novak BEC

[Sammus]

I've been looking at different ferrite rings etc, but they have a lot of ratings I don't know how to read so I'm not sure of their suitability. I was thinking perhaps a few wraps of the throttle signal cable around something like http://australia.rs-online.com/web/s...duct&R=4674188.

I also have a Revo 3.3 converted to electric, and it runs the same Rx and ccbec, but with a cheapo chinese air esc that came with a ferrite ring at the end of the esc signal cable. In the revo all the wires and signal cables etc are right next to the batteries all ziptied together in a big bundle, and I've never had a glitching problem with it, so I'm hoping that a single ring on the esc might do the trick. That website has a minimum 10 unit order anyway so I can always add another if need be.

The castle BEC has issues, get a Koolflight Ultimate BEC and you will have no problems. It is noise free.