Originally Posted by
latentspeed
So the steering is more controlled as in less steering?
On my .3 I took out a defective mks 599 because it decides on its own if it when it wants to change its center, where I'm continuously needing to adjust the steering trim. Servo saver is tight and everything turns freely. Swapped it out with ko propo rsx which had no problems.
What happened was that I could drive the car harder. Much more predictable, stable, consistent and I was faster. Rotation was under greater control.
You are correct in that a slower servo can be easier to drive, but only to a point, then it becomes increasingly difficult to drive, more so than a servo that's too fast. One way we addressed that was by using our aluminum servo horn and running the link in the inner hole. This did two things, increased the resolution of the steering (more servo throw for the same wheel movement), and slightly increased the time it took to get max steering lock (again, greater servo travel for same amount of wheel movement). It also had the benefit of increased servo life as the wheels now have less leverage on the servo.
Bornhorst uses the mks 599 and for whatever reason the car was twitchy with it, at least for me. Lutz uses a super fast futaba that might be causing the same issue. Point is those two team drivers give their feedback to tekno and because of their super fast servos the cars are harder to control. Therefore the new steering on the new .4 might not have been needed. Maybe except on carpet, but I wouldn't know because there are no carpet tracks where I'm from. I may be wrong. It was a big shock to me that handling was so different from a servo change.
I have yet to meet a pro driver that doesn't want the fastest responding servo they can run. Those top guys have amazing reaction times and they need their equipment to respond immediately. If we simply turned down their servo's speed it would be worse for them. The change we did to the steering is not a speed thing, it's different geometry that alters the ackermann, specifically when/where it occurs in the turn. The best way to describe it is that it smooths out the transition of the ackermann effect. It transitions better on and off power as well as beginning, middle, and end of a turn. The old geometry was pretty aggressive and once you started the turn the car could really start to come around on you. So if you had an increasing radius turn you often time would be turning too much, then counter steering to correct, then turning more to get back in line, etc. The new geometry fixes that. You can still get a lot of steering out of the car, but it is so much more usable than before.
What I'm guessing is that because this buggy already has responsive steering, adding a responsive servo is too much. It needs balance between responsiveness and control.
Yes and no. You kind of have to separate the speed of the servo and how the steering works. Good example of this, especially in off-road, is whipping the car in the air. A slower servo is going to make correcting a car's in air attitude more difficult but might be easier to get around a turn whereas a high speed servo might feel a little twitchy in the turns but the ability to correct in the air is much better.
BTW I spoke with mks customer service and team manager Kenny. Still waiting to get an email or call if they will service this new defective servo. They are polite and their words sound promising. Will update this week if mks is a brand that stands behind their products and if they should or shouldn't be recommended.