Madaves servo position

[Luke123]

Getting myself a madave in the new year, keep looking at picture on the net and noticed that the servo doesn't sit centre? Does this not have an effect on steering? Maybe at the higher level of racing?

[tisher]

nope but you do need a kimborugh servo saver and update your turnbuckles. I have to turn the epa down on my steering overwise I can lock out the wheels

[westie]

The cheaper servos tend to be ok, but the higher level ones seem to offset the steering, I've raced ok with it like this but tends to give more steering to the left?! on my next new chassis I'm going to slot the one hole (similar to the rc12r5.1 chassis) to get the servo in the middle.

Luke

[terry.sc]

Mounting the servo in the middle means the servo output is off centre, the servo is where it is so you have equal length steering linkages which is much more important.

If you think it should be centred for weight balance, the heavy end of the servo is the end opposite the output so ideally when mounted on the centreline it still isn't perfectly balanced. It's simpler to position the receiver and ESC to one side to get the weight balance right, although you can also just compensate for any chassis tweak by adjusting the rear springs.

[terry.sc]

Originally Posted by westie

The cheaper servos tend to be ok, but the higher level ones seem to offset the steering, I've raced ok with it like this but tends to give more steering to the left?!

Strange as that would indicate more weight on the left side wheel than the right. Compensate by tightening up the right side rear pod spring a fraction of a turn to get the front corner weights balanced. The way to do it ideally is to use a tweak board, or you can do it with the coin test.

Put the car on a flat surface, and press down on the chassis to settle the car. Put a pound coin on the top of each front wheel, and then lift the front end putting a small screwdriver under the exact centre of the front of the chassis. Very slowly lever this up until the front wheels lift off the ground. The aim is for both front wheels to lift at the same time, shown by both coins dropping off the wheels simultaneously. If the tweak is incorrect, as it almost certainly will be, one front wheel will lift before the other and that coin will drop off the front wheel first. If this happens, loosen the rear spring on the side of the car the coin dropped off first by 1/8th of a turn, tighten the other spring by 1/8th of a turn, settle the car and retest. Keep doing this until both coins drop off the wheels at the same time. The car will now be balanced and should steer the same.

[Karl Dransfield]

I believe Luke is referring to the servo spline not the servo itself. Especially with the Savox 1251, if standard servo mounts are used, the servo spline is not in the middle of the chassis. This forces you to have to use odd track rod lengths, which results in more steering to one side than the other and different ackerman angles from left to right.

[Luke123]

Originally Posted by Karl Dransfield

I believe Luke is referring to the servo spline not the servo itself. Especially with the Savox 1251, if standard servo mounts are used, the servo spline is not in the middle of the chassis. This forces you to have to use odd track rod lengths, which results in more steering to one side than the other and different ackerman angles from left to right.

This is what i ment, is it just savox servos that are out? It would really bug me if the car was running different length track rods

[Karl Dransfield]

The savox ones are the worst for it. But they are not the only ones. I've found the best fitting servos for mardaves to be the futaba low profile ones. The spline is bang on centre without any fiddling about.

[tisher]

I am running a savox low profile and had absolutely no problems at all with steering I think your tyre set up would make much more of a difference

[Luke123]

Originally Posted by tisher

I am running a savox low profile and had absolutely no problems at all with steering I think your tyre set up would make much more of a difference

Do you mean you don't get problems on the track or it's perfect in the car?

I'm not sure what tyre set up would have to do with steering angles/lenghts

[Luke123]

Originally Posted by Karl Dransfield

The savox ones are the worst for it. But they are not the only ones. I've found the best fitting servos for mardaves to be the futaba low profile ones. The spline is bang on centre without any fiddling about.

Which model futaba do you use as there are 2 available from what I can see

[Karl Dransfield]

Originally Posted by Luke123

Which model futaba do you use as there are 2 available from what I can see

Futaba BLS551

[tisher]

Originally Posted by Luke123

Do you mean you don't get problems on the track or it's perfect in the car?

I'm not sure what tyre set up would have to do with steering angles/lenghts

I mean its perfect on the track and tyres are the most important thing to get the car round a corner

[coleman758]

Originally Posted by Luke123

Getting myself a madave in the new year, keep looking at picture on the net and noticed that the servo doesn't sit centre? Does this not have an effect on steering? Maybe at the higher level of racing?

I think the answer to your question is, not the servo if of centre. But they are mounted like this so the spindle that holds the servo saver is in the centre.

[Luke123]

Originally Posted by tisher

I mean its perfect on the track and tyres are the most important thing to get the car round a corner

Totally agree tyres are one of the most important things, but from what I've learnt racing touring cars, every little bit helps. So if the steering angles are correct then that will all add up.

[Luke123]

Originally Posted by coleman758

I think the answer to your question is, not the servo if of centre. But they are mounted like this so the spindle that holds the servo saver is in the centre.

Sorry I didn't write the op very specific to what I ment. I did mean that some servos the splin isn't centre. The position of the servo isn't that much of a big deal as it can be compensated for with the esc. But the steering linkages aren't centre with some servos.