CC BEC & Savox Servo ISSUES?

[Justingt5]

HI people,

I have been struggling for a few weeks with an issue with running the CC BEC in my slash 4x4 race truck??

THE RIG
SLASH 4x4
ESC: CC SIDEWINDER SCT
MOTOR: CC 3800kv (1410)
SERVO: SAVOX 1257tg
TX/RX: SPEKTRUM DX4S
CC BEC running @6.0v wired as per diagram

ISSUES:
I know the Savox servos are power hungry so before buying one i emailed castle to get their opinion on running the 1257 with the sidewinder and i was advised to bybass the sidewinders built in BEC and get the CC BEC to power the servo, so I did.

I get the CC BEC installed as per the diagram so red and black wire from CC BEC soldered onto a new deans connector on the end of the ESC power wires. I removed the red power wire from the ESC wire to disable the onboard BEC.

OK so my servo is now lightning fast (used castle link to set CC BEC output to 6v) and the fans on my castle kit (motor and esc fan installed) are now singing away.

I go to drive the car and it just glitches and stutters like hell at anything more than 2mm throttle trigger movement, also the tx inputs are delayed getting to the car (ie hit the brakes and nothing happens for like a second and then they come on).

I started off with the traxxas TX/RX but couldnt even drive it at all, I heard that stock radios dont like digital servos etc so got myself a Spektrum DX4S and the issue is still very much present.

I have trawled the web for days trying to find answers and still nothing hence this post. I have tried running it with the signal wire of the CC BEC removed and it makes no difference. I have tried wrapping the BEC in foil to reduce RF noise, shielded the RX wire and still nothing helps it at all.

From my reading online I soon saw that the CC BEC is a bugger for creating RF noise and the general consensus is the CC BEC needs to be as far away from the RX as possible. On my slash I have cable tied the BEC to the rear shock towers and positioned my RX on the bulkhead just behind the front shock towers.....on this model they cannot be physically further apart than they are.

The issue has to be related to the CC BEC itself surely as when I run it on the internal BEC on the ESC it all works perfectly with no glitching or stuttering to speak of at all, plug the CC BEC back in (removing the red esc wire from the connector again) and the glitching comes back.

I contacted Castle and had some email discussion with a rep there who told me I needed to buy the CC BEC PRO???? I wasnt having that the, CCBEC is rated to 10amps, i know the savox like to eat up the amps but surely never enough to smoke a 10amp BEC????? Anyway after another couple of emails of them saying it must be a faulty servo or faulty RX etc (how can it be when the car runs perfectly with ESC powering the rx/servo) they suddenly decided to send me a brand new CC BEC all the way from America free of charge. I fitted that to my car in the same way as the old one and it is EXACTLY the same as the first one and gltiches like hell to a point where its just not usable.

Its been driving me mental for 3wks now so until i find a solution i have cut the ba****d out of the car and taped up the wires on my ESC battery plug (so I can re-solder it in at a later date if a solution comes along) and will run the car with standard onboard BEC powering the RX and SERVO which works beautifully, only not at 6v so the servo is not only running slower than it can do, but now running with less torque than my standard Traxxas one has??

So Im £170 down and many many hours of my life that I wont get back and im barely any better off than I was before I started?

PLEASE HELP, any suggestions or past experiences/fixes are much appreciated.

[Justingt5]

I must be the only one to have had this issue then? The chap from Castle is still blaming the servo, and has suggested that I try it with the BEC wired up and powering the RX then unplug the servo and see if the throttle works normally?

Anyone heard of a servo being faulty in this way? Where it works no issues at 5v but then causes the throttle to glitch like a mad thing and make the car undriveable when being powered and its "preferred" 6v??

Thanks
JK

[Chalkie]

Can you not just run it off the speedo? I have Savox 1258 servos in all my cars and have never had any problems using them wired up as standard.

[Justingt5]

Thats what I have had to do in the end, but the speedo is only 5v so not getting the best from it. I am now looking to swap the speedo out for something that can output 6v so I get the max benefit from the servo and have the possibility to run 3S for kicks when I am not racing

Just really annoyed as it was castle that recommended the CC BEC and the damn wont work with their CASTLE speedo!! Frustrating aint the word

[imull]

There are a couple of things you could still try. If you're a bit handy with a soldering iron you could knock up an RX noise cap, rather than a power cap using a 100nF and 10nF cap across the power rail to see if that combats the noise from the BEC

http://www.maplin.co.uk/p/multilayer...apacitor-dt98g

If there isn't a ferrite in the output of the CC BEC you could try winding the output lead around one

http://www.maplin.co.uk/p/ferrite-ring-hem3016-qt26d

http://blog.oscarliang.net/wp-conten...ritering_2.jpg

These are fairly cheap solutions before you give up all hope

Ian