Noob servo question

[kinggareth]

Sorry for the noob question, but I'm a noob so it's my job.

When mounting the servo horn on my servo i had the servo centred but the horn wouldn't go on pointing straight up it would sit either one way or the other. Now that everything is together I have to run the trim on the steering at 60% to the left to get everything straight.
The problem is that now the car steers significantly tighter to the right than the left which is really noticeable when driving it and is less than ideal.

Is there anyway of re-centring the servo or any other ways around this problem?

EDIT. if it makes any difference, the servo is an absima, the radio gear is Sanwa MT-s and the car is a B6

[danDanEFC]

I ain't the best on here but it sounds like it wasn't really centred.

[tonydevon]

Subtrim on the radio.

[markwilliamson2001]

Hi.

The easiest way to get this to work is to power the servo on with sub trim at 0.
This will properly centre the servo, so you can then fit it in the car. If it's one tooth off, move it to the right when viewing the spline when fitting into the car.

You can the re-correct using the sub trim on the radio, and then check the EPA/travel on the hand set so that the car steers right to left properly and the steering blocks just touch the caster blocks when at full load. There should just be a slight load "buzz" sound on the servo when full lock is achieved on the EPA.
Best to do this step when the car is off the ground on a car stand with wheels free.

You can run a little load, as there will be friction when the tyres are on the ground.

[mattr]

Originally Posted by danDanEFC

I ain't the best on here but it sounds like it wasn't really centred.

+1
60% is massively off centre. I'd expect single digits or low double.

Pop the servo horn off, set everything to zero on the transmitter, centre the steering in the car (make sure everything is equal left/right, turnbuckle lengths etc and the wheels are pointing forwards!) then power up and put the horn back on.
The spline will be 24/25/26 teeth, so at most you'll be about 15 degrees out. Correct with subtrim (as per Marks post).

Also, make sure the first turnbuckle from horn to whatever linkage you have is as near as possible to right angles to the direction of travel of the horn as well. Might need to tweak length to get this right. Then readjust subtrim. Might take a couple of loops.

Then use EPA to get the lock sorted out again, as per Marks post.

Think thats it.....

[kinggareth]

Thanks for the replies all of you, they've been a massive help.

I did wonder why I needed all of the settings on the transmitter, I thought it was all a waste of time, but the sub trim and EPA settings have been invaluable this time.

I think the 60% I mentioned was a little misleading, it was that I had to have the trim set to 60 on the transmitter and presumed it was out of 100.

I'm sure the rest of the transmitter settings are a waste of time though.....