servo centering problem?

[Snelo]

Just build my Mardave v12 VRX this weekend.

All is good apart from the servo will not centre. I've uploaded a video to show the problem below.

http://www.youtube.com/watch?v=mq4Dj6KwGYY

The Servo is a Hitec.

After reading round; is the problem due to having the wrong servo saver? As i think hitec servos have 24t and therefore require the red servo saver.

If this is the case what size is the servo saver? Small, Medium or Large?

Is there anything else that could be causing the problem?

Thanks

[Chequered Flag Racing]

1. Put the car on a car stand and try it. Carpet maybe causing drag.
2. Which Hitec servo is it?
3. Which make SS have you fitted?
4. Which radio do you have? It may have a secondary steering centre sub trim in a menu.
5. Hitec are 24t on the spline so you need a SS to suit. A 25t one will be to big. Colour doesn't matter just has to be 24t.
6. Hitec are not the best at being consistent when returning to centre

[4_cell_racer]

You have the wrong colour serve saver on your servo....as you said in your post you need the red kimborough servo saver for hi-tec servos

Could also be the servo it self....some hi-etc servos are known not to centre to well :-/

I would also check the steering hubs are not binding and check the steering cups are not tight on the ball studs on both the steering arms and servo save......if you can change them to schumacher ball grippas (ball studs and cups)

[Yellow4]

I have seen this with both of my mardave cars. The problem both times was the bullstuds and cups. They should be loose enough to drop when you lay them horizontal, most just stay in the position you stand them in.

Also you tend to find the servo will centre when the car is moving as is rightly pointed out grip dont help.

Mardave do a a good adjustable set, in black.

[Chequered Flag Racing]

I have seen pictures of the Mardave 'Red' steering cups with the tops cut off to free them up but can't find a picture at the moment

[coleman758]

Is it a new servo saver? I was having problems with mine. The spirng must have lost its tension over time and would not take the weight of the servo movement.

[SlowOne]

Sorry to be the bearer of bad news... Hitec servos are notorious for not centring accurately, and are not used by anyone in pan cars. Yes, you need to have all the steering mechanisms sorted as people are suggesting, and the right servo saver. Nonetheless, even if all this is perfect, the Hitec is likely to let you down.

If you are using most 40Mhz systems, then a Futaba 9602 analogue servo is the best buy. If you are using most 2.4GHz systems, and any with high response functions, then you will use the Futaba 9650 digital servo. These are by far the most popular, and the most reliable. I've used four 9602s in various cars, and currently have three 9650s. They have never failed, and they are valuable second-hand because of that.

If you can re-drill the mounting holes, then a Savox might do, but they are involved in a lot of interference problems with 2.4Ghz systems. There's a good Sanwa equivalent but I can't remember the number. As a straw poll of any pit will tell you, Futaba has the greatest number of drivers, and for good reason! HTH

[Chequered Flag Racing]

Originally Posted by SlowOne

If you can re-drill the mounting holes, then a Savox might do, but they are involved in a lot of interference problems with 2.4Ghz systems.

No issues with my Savox & Spektrum when running 1s & booster in a Mardave

[LongRat]

Your servo gears are making noise suggesting that they are under quite a load. I would check what has already been said and free up those ball joints. I did mine by bending them off the balls almost to the point they pop off, holding them there and then putting them back. Not had a problem since.

If you are looking for a servo, MKS servos are probably the best there are. Very few people use them in cars however.
I have one in one of my aircraft and although half the size of what you would run in a Mardave, has a lot of speed and an insane amount of torque considering its size. The only way the case can take the loading is because it is machined from solid billet - the whole thing.
In my Mardave I run a Sanwa ERG RZ. I firmly believe that the fastest servo you can get is the one you want in a pan car. High torque isn't required. I've looked around for fast servos and the fastest I have found - http://www.mks-servo.com.tw/goods.php?goods_id=hbl980

I must say that although the Hitec analogue servos do not centre brilliantly, the digital ones I have have all been great and still work very well. I am not sure it is fair to tar all of the range with the same brush, the analogue ones are cheap and good for applications that don't require the precision of a direct-link pan car steering.

[CrashBangWallop]

If you are using the supplied red Mardave ball cups they are probably very stiff the only way of getting them to work properly is to crush them slightly with some pliers this either makes them work perfectly or completely knackers them. Best thing to do is get rid and use Schumacher ball studs, cups and 35mm gold turnbuckles. Perfect every time.

HiTec servo as per previous posts are not the best at re-centering therefore your you car will drift left then right - a real nightmare.

I run a Savox 1351MG in my mini stock and has had some real abuse and has not failed me yet. Only disadvantage is you have to run a 4700uf power cap to cope with the demands of the servo or it will get the jitters if you run 4cell NiMh.

Failing that just use the good old Futaba S3003, they are reliable, cheap and you wont have to run a power cap.

Hope this helps.

[Chequered Flag Racing]

Originally Posted by Chequered Flag Racing

I have seen pictures of the Mardave 'Red' steering cups with the tops cut off to free them up but can't find a picture at the moment

Found some black ones with tops ground down