RC10Talk - The Net's Largest Vintage R/C Community

I use a Futaba 3pk radio with a Spektrum module. The problem is all my Futaba digital servos have this problem where they move erratically. I changed to normal servos and the problem goes away.

Erratic how, at what points in the travel? Sounds like a receiver issue-

The servo move to the righ or left ok,the problem is when it move move trembling,my apologives for the english I speak spanish and need the google translate to talk.

What servo?

s9551-s9351

The 9551 is a little twitchy in it's resolution steps anyway IMO, the other one I have not used but I know is the same servo as the 551 with more torque and case size. Have you tried adjusting the servo sensitivity and speed in the 3rd menu in your 3PK? Do you have any exponential?

In only use the 1menu,If you explain I do what you say.

When using the Futaba Digital Servos, a small "shaking" ( or you called it "trembling") is normal. Because the Digital servo is very sensitive.

Make sure your 3pk is on level 3 adjustabiliy Then go back to menu 1 and select servo speed Then slow down the speed and see if you have any change- Some is common, especially with the metal gears

Digital servos?

I have this problem, but I use a KO-radio with spektrum recievers.

The problem is most likely a combination of the high draw servos and the spektrum recievers.

Spektrum recievers "brown out" at a pretty high voltage, wich can drop with the digital/high draw servos. This also happens with Savox servos, as they draw a lot of juice. You'll get a lot of erratic movement, or no movement at all until the esc reboots.

The best thing to fix this is a "glitch buster" capacitor. I've had the best luck with the racer's edge one, as it's the biggest.

http://www.racers-edge.com/Glitch_Buster_Power_Capacitor_p/rce2474.htm

*edit - I re-read your post, don't know if it's the same issue I'm talking about*

How do I adjust that on my transmitter

RC10resto wrote:How do I adjust that on my transmitter

One other thing to try is a "glitch buster" from Novak. Something similar might be found at a local hobby shop or even made by you. This helps the speed control if the servo and/or motor are using a lot of the voltage and the esc is having a hard time keeping it at a constant output. This fluctuating voltage can sometimes cause the servo to "twitch" like you are having. i might not be doing the best job explaining this but I hope this helps. You could find one here: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNRE0&P=ML that might help.

yeah, you can save yourself a ton of money if you can solder, and find yourself an electronics store, pick up an electrolytic capacitor, at least 1000uF or more, rated at 10-12V, and wire it up to the pigtail made from the receiver battery box that you never used. Your whole radio system will quiet down.

sheesh....Novak wants 10 BUCKS for a friggin' 16 cent part. I used to use an ultra-cap which is the old novak 'stutter-stopper' that I had from old samples which we'd get from vendors at my work. perks of working in the electronic industry.

Thanks, I couldn't remember the specs on the cap so I didn't want to post the wrong info.