Galway Model Car Club

I have worn out three servos now on the front of my fun factor 1/10 buggy. Today I installed a hevier duty, metal gear servo but I have a minor issue. When all the controls are centred, the servo is not. There is about 60% of the movement in one direction and only 40% in the other. The net result on the road is tighter turning to the left and larger arcs to the right. It is a Sanwa twin stick control. Any suggestions? Thanks in advance.

................. Maj7

Check you radio. It should have "stearing trim" knob or button. Make sure this trim knob is centered before you do any adjustments and before you attach steering linkage.

The procedure is as follows:

1. Disconnect servo horn from the servo

2. Set trim on the radio to 0 (middle)

3. Switch on the radio

4. Switch on the receiver

5. Set the wheels stright

6. Attach the servo horn.

7. Switch off radio and receiver

8. Secure teh horn with a screw.

9. Switch everything back and check if the wheels are turning properly

10. Drive your car and adjust the steering trim to make it drive stright.

Radio resetting procedures may be different depending on what kind of radio do you have. If above setup will not work you have to check all the componens. It is unlikely that the new servo is broken. The most probable resona are that it was not centered when you was installing the horn or the radio was not reset to the centre. It is hard to tell without seeing the radio or at least knowing the exact model. Some radios have servo travel adjusments for left ad right directions independently. Make sure everything is reset to factory setting before making any adjustments.

Thank you Piotr and Dirt Racer, this is the third servo to go into this car but the first to have this issue. The system I used to install the servo was, i believe as Piotr advised above, but I will go over it again later. I think the control is the cause. There is a limiter on the travel left and right but they are both set to 1, minimum, still the servo is definately straining when fully left as it starts "singing" at maximum. I also have a Futaba control si I wil also try that. Thanks again.

.................... Maj7

Servo Update!

I double checked everything again, still no joy. I swapped the throttle and steering connections on the receiver and got the same result. There is just more throw in one direction. I put a ruler on the car and I put the servo horn at 12 o clock, straight up. With the control all the way to the left the horn points to 10 o clock, 2 CM to the left. With the control all the way to the right the servo only goes to 1 o clock, 1 CM to the right. The only positive in this is I think I am actually getting more throw to the left on the new servo than on the old, and the same as the old on the right. I have read the control manual and there is a throw limiter on each side but they have no effect. The car is steering well, I just have a tighter left than right turn. Thanks for the help anyway.

.................. Maj7.

Maybe try the channel reverse switch so the controls are backwards and see if you still have the problem? if you do then check the mechanics or set up of the steering. if you take off the servo horn from the servo and push the steering rod forward and back to operate the steering is there any sticking or binding? are the steering tie rods from the steering plate to the wheel hubs the same length on both sides?

Bring it out to Mother Hubbards on Sunday at 10.30 if you want where help will be on hand

If you reverse controls on the radio repeat the test. Horn should move in opposite directions. If angles will be the same, problem is on the servo side. If larger angle will go to the other side, problem is with the radio. Disconnect the steering linkage from the horn to be sure that nothing from the steering system affects the angle servo moves.

If you have volt meter you can check control signal that goes from the receiver to servo. Dosconnect the servo and check voltage between mass (black) and control (white or yellow).  Note the voltage at the neutral position. It should be somewhere around 0.5 V. Now turn the steering wheel fully in one direction, note the voltage and repeat this for the opposit direction. The differences in voltage should be more or less the same in both directions. DO NOT SHORT ANY CABLES or you can fry the receiver.

Comming on Sunday to the track would be the best option as DirtRacer adviced.

Hi Guys, thanks for the advice, I will try this and let you know how I get on. I wont get to Ma Hubberds but thanks for the offer. Have a good weekend.

.................. Maj7

Whats with the EPA settings and the voltage readings ???

The CEN fun factor comes as standard with a sanwa saber dash twin stick handset ?

there is no EPA and voltage ?? 

to set up the steering first check your handset, on the saber dash there are two little trinagles one either side of the steering stick, on these little triangles there is three small marks they are avery basic control but they are steering limiters and they should both move the same otherwise you will get more movement one way than the other.

then follow these few simple steps,

remove the servo horn from the servo.

switch everything on.

set the trim on the handset to the mid point, this is the small slider under the steering stick.

finally refit the servo horn with the radio still switched on try to ensure that the steering wheels stay as straight as possible.

If you are unsure by all means call me (091)773861

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10 till 4 thur.

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Kyosho,Orion,AKA

Thanks for this Pete, I have tried this but I still seem to have more turn on one side, I think I need to try another transmitter. I will let you all know how I get on, thanks again.

..................... Maj7

Hi all, got it sorted, it was a faulty receiver. The problem got worse in  that the servo started jumping on its own and also completely reversing itself so I tried another old receiver I had and that sorted it.

Thanks everybody for the help.

.................. Maj7.