tips for frame mounted servo setup?

[muddeprived]

I am going to attempt my first frame-mounted servo setup. I tend to run my clods with the servo on the axle but i wanna try something different this time, something more scale.

What should i keep an eye on when building this type of steering? Any particular setup better than the other? Should i put a bend or two in the draglink to lessen the rod end angles or leave it straight? The suspension will be a upper triangulated 4-link(no trackbar). It's not a dedicated crawler, but more of a trail basher.

Here's the build:
1:6 Gladiator

let me know what you know

Thanks

[ScalerLover]

Heres a couple of my trucks that ive frame mounted the servo just to give ya some good ref pictures.
My SCX-10


And my AX-10 Scaler w/ custom frame

[hitman46mod]

Try to get the servo low to reduce the angle of the steering rod, it will give you less bump steer and reduce the load on the servo.
Set your suspension up shocks and all and articulate the axle and find out where it stops. Try to get the end of the servo horn over the area your linkage is.

[muddeprived]

Thanks for the pictures and tips. The first picture is what mine will probably look like but with the steering box more to the driver's side for a longer draglink. I want to incorporate some bends in the draglink so the angle of the rod ends ain't so steep.

Set your suspension up shocks and all and articulate the axle and find out where it stops. Try to get the end of the servo horn over the area your linkage is.

I'm not 100% sure what you mean by this but i should figure it out once i start setting it up.

Thanks

edit: do you mean keep the drag link and tie rod on the same plane, (looking down on it, not front view)?

[muddeprived]

Which setup would work best: vertical servo horn (axle mounted method) or horizontal (like 1:1 rigs and pictures in above post)?

[dieselfuel]

try to get the draglink as flat as possible. just bending it to lessen the angles at the rod ends is not what i mean. mount the servo lower in the frame and if needed lower the ride height of the rig to accomidate. the steeper you steering angle the more bump/roll steer you're gonna get. also having the draglink as long as possible helps to lessen the angle.

[muddeprived]

Originally Posted by dieselfuel

try to get the draglink as flat as possible. just bending it to lessen the angles at the rod ends is not what i mean. mount the servo lower in the frame and if needed lower the ride height of the rig to accomidate. the steeper you steering angle the more bump/roll steer you're gonna get. also having the draglink as long as possible helps to lessen the angle.

I gotcha. I'm trying to get the servo as low as possible and as far over on the driver's side as it will go. I think I am going to use a 5 link setup cuz using a track bar would help with the bumpsteer. I'm just having a hard time fitting the servo above the axle plus have room for the track bar.

[shierkahn]

Originally Posted by muddeprived

I gotcha. I'm trying to get the servo as low as possible and as far over on the driver's side as it will go. I think I am going to use a 5 link setup cuz using a track bar would help with the bumpsteer. I'm just having a hard time fitting the servo above the axle plus have room for the track bar.

Running a trac-bar won't help with your bump steer... if anything it will make it worse. There's a lot of geometry that goes into the trac-bar, and if you don't get it right it will give you a crap load of grief.

Just do the drag link it will be alot less frustrating

[hitman46mod]

Originally Posted by muddeprived

Thanks for the pictures and tips. The first picture is what mine will probably look like but with the steering box more to the driver's side for a longer draglink. I want to incorporate some bends in the draglink so the angle of the rod ends ain't so steep.




I'm not 100% sure what you mean by this but i should figure it out once i start setting it up.

Thanks

edit: do you mean keep the drag link and tie rod on the same plane, (looking down on it, not front view)?

Originally Posted by dieselfuel

try to get the draglink as flat as possible. just bending it to lessen the angles at the rod ends is not what i mean. mount the servo lower in the frame and if needed lower the ride height of the rig to accomidate. the steeper you steering angle the more bump/roll steer you're gonna get. also having the draglink as long as possible helps to lessen the angle.

X2

This pic is what I was saying. this would be ideal. But not eveyone has room to put a servo in the center.

[Squadfer]

the ideal setup is to make your draglink as long as possible, this way it will be flatter. This is my setup in my scale rig.



I used to have a double bent draglink to lesson the angle of the rod ends but that ended with the draglink snapping in half at one of the bends.

You can see where it started to snap in this picture.

[trailduster79]

Only real suggestion I can give is to make sure your links have good triangulation.

I added a frame mounted steering servo to my K2-3L and the axle moved side to side too much, as there wasn't much triangulation in my front links.

The frame mounted steering on my high-lift based scaler works great and really adds to the scale apperance.

[muddeprived]

Originally Posted by shierkahn

Running a trac-bar won't help with your bump steer... if anything it will make it worse. There's a lot of geometry that goes into the trac-bar, and if you don't get it right it will give you a crap load of grief.

Just do the drag link it will be alot less frustrating

I was under the impression that the trackbar, when parallel with the draglink and mounting points on the same plane, would keep the axle on an arc that the drag link follows. This way the axle moves a bit to the side as you flex, decreasing the "pull" and reducing bumpsteer.