Servo problems

[hansmoolman]

Can anyone help? I have included a video here http://hansmoolman.com/ (the video might take a few seconds to load). As you can see in the video, if I turn the steering all the way to the left or right and hold it there, its like the wheels turn all the way in that direction and then kinda “jumps back” a small bit from the full lock. It does this for both left and right, and sometimes the “jump back” is so severe that it almost jumps back to the steerings neutral position. Its like the servo has a hard time maintaining full lock to either left or right.
Does anyone have any solutions for this problem or have anyone encountered anything similar? The servo should be plenty strong to handle the steering as it is a high torque model. And sometimes the jump doesn’t happen on which occasion it keeps the steering lock no problem

[Trubble]

Are you running an external BEC, or is your ESC powering your receiver and servo?

[hansmoolman]

Originally Posted by Trubble

Are you running an external BEC, or is your ESC powering your receiver and servo?

No Im only running a Castle Creations Sidewinder V2 ESC. And the servo is a Hobbico CS170 Digital servo, 250oz torque.

Might the lack of a BEC be my problem? And what exactly does a BEC do?

[hansmoolman]

On a side note, I dont know if it was clear from the video but my servo makes a "crackling" sound as well when powered on. I was looking at BEC's on YouTube and I saw a guy with a rc heli that was testing ESC only vs. ESC and BEC combo and his servos made exactly the same noise with only the ESC connected as my servo is making. Here is a link to his video To BEC or Not to BEC - YouTube

When he hooks up his BEC the noise seems to go away so Im wondering could it be the case that the BEC will solve my problems?

[benoj]

The noise is normal from a hitec servo. But I don't see a bec really helping your problem since you aren't even straining the internal bec since there is almost no load on the servo, but if it did it with a slight load to it then I would say a external bec is needed. I think it's more likely something is wrong electrically inside the servo, like either the board or possibly the potentiometer.


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[Trubble]

Originally Posted by hansmoolman

Might the lack of a BEC be my problem?

I thought so, but went back and watched as best I could for binding, and I agree, it's happening way before full lock. Only thing I saw that I didn't really care for was the connection between the servo arm and the steering rod seemed loose. No telling how old that servo is or if it's been banging around like that for quite some time. Slop like that could possibly have knocked the pot out of whack.

Make sure you've got fresh batteries in the transmitter, if that doesn't fix it, borrow a known good servo, (preferably new, not sloppy), if that's smooth all the way to both sides, then install the new servo and hook it up to your truck's steering and see if that's it.

Originally Posted by hansmoolman

And what exactly does a BEC do?

A 'Battery Eliminator Circuit' draws power off the main battery pack, and powers the receiver and servo so you don't have to run with a separate battery onboard for just the radio. The BECs inside ESCs are usually the smallest and cheapest that the MFR can get away with so they can meet a price point. External BECs are usually better regulators that provide a lot 'cleaner' electrical power.

[hansmoolman]

Originally Posted by Trubble

I thought so, but went back and watched as best I could for binding, and I agree, it's happening way before full lock. Only thing I saw that I didn't really care for was the connection between the servo arm and the steering rod seemed loose. No telling how old that servo is or if it's been banging around like that for quite some time. Slop like that could possibly have knocked the pot out of whack.

Make sure you've got fresh batteries in the transmitter, if that doesn't fix it, borrow a known good servo, (preferably new, not sloppy), if that's smooth all the way to both sides, then install the new servo and hook it up to your truck's steering and see if that's it.

Both the servo and the batteries in the tx are brand new. Servo only ran once since I bought it and batteries were freshly charged. Also I was wondering about the loose connection that you mentioned and revisited my crawlers build manual to see if I maybe installed the wrong joint here but it seems not. The joint in the manual is a ball-type joint that allows some play when steering left or right. Might it be better to have a static connection here to try and illuminate the problem I'm having?

[Maxx_Savage]

Hi Hans where in Ireland are you?