cable steering setup...

[RockRevolver]

Im building my rig so that I can run in light creeks, snow and mud. Im working on a cable setup so that I can keep the steering servo up as to not submerge it in the elements and fry it.

I have it so that when you turn it pulls on one of the cables that will pull on the knuckle and the steering rod will pull/push the other knuckle in the same direction. My question is how can I make it so that when the axel moves up and down how can I keep the slack outa the lines so that the wheels dont flop around?

here is a pic I made in paint...

 

[EeePee]

Bicycle cable housing.

 

[Double J]

Johnholmes did it. I can't remember exactly where the thread was but is has a decent pic of the set up.
If I find it I'll post it.

EDIT= here it is. http://www.rccrawler.com/forum/showthread.php?t=31990

 

[EeePee]

Here's another one.

http://www.rccrawler.com/forum/showthread.php?t=28389&highlight=cable+steering

 

[JohnRobHolmes]

Look at how a bike brake cable works. The handlebars can move without affecting the brake tension. This is what you want on your steering, and is accomplished with a housing and housing stops. The Single plate Clod EeePee posted has good pics of the setup.

These setups need a good bit of tweaking before they are dialed in. My servo mount is floppy as heck right now and it looses about 1/3 of its steering to slop.

 

[Cubman]

Or... you could just waterproof your servo :lol:

 

[ToTheMAXXcrawler]

thats one hell of an idea for cable steering.....almost makes me wanna try it.....nice touch

 

[RockRevolver]

thanks guys Im gunna look into this and draw out more pics before I start to put money into it Ill keep you updated as I go;-)

 

[Soya]

Or... you could just waterproof your servo :lol:

+1, whooole lot easier.

 

[EeePee]

These setups need a good bit of tweaking before they are dialed in. My servo mount is floppy as heck right now and it looses about 1/3 of its steering to slop.

Got barrel adjusters on there? You need them if not.

 

[RockRevolver]

Im looking into bike setups to see what I need.... now what is a barrel adjuster?

 

[EeePee]

Like a thumb screw, used to take the slack out of the cable.

Pictured on the right.

 

[JohnRobHolmes]

I dont have barrel adjusters, but I got the tension and centering done right the first time so they arent needed. I have set up quite a few pull-pull systems on my planes and there is no room for any adjusters. You HAVE to get it done right the first time or your control throws are off.

They would be very useful though. My problem is the servo mount, It flexes.

 

[rupps5]

I have not been here in a while and the first thing I see is a cable steering thread.....SWEET. It takes a bunch of tweaking and you definitely need barrel adjusters but the set up is fun and it works. Do you need it? no, but it is definitely different.

 

[RockRevolver]

thanks EePee for that! I got those on my handle bars I was looking at that today actually. now for the most part the pull, pull system shouldnt pull up on the axel should it? is my setup ok and how would you change it if you were in my shoes (besides water proofing and maken it a lay down setup) Are there any secrets I should know of? I wanna make it as simple and doable as possible! thanks guys this is pushing me in the rite dirrection!

 

[JasonInAugusta]

You know...hydraulics work under water.

Saw JRH's cable setup in person, needed a little tweaking and it'd work just fine.

RR, No...you shouldn't have the cable pulling up on the axle. The cable should connect to the knuckle, come across the axle to the other side then up. That way the motion is a pulling motion across the axle. Do the same for the other side. Your two cables will cross one another for about the center 1/3 of the axle. Use a large servo horn and set the system up in a pull-pull configuration.

Obviously...you need a solid link between the knuckles.

 

[EeePee]

I dont have barrel adjusters, but I got the tension and centering done right the first time so they arent needed.

It takes a bunch of tweaking and you definitely need barrel adjusters...

As I helped rupps5 figure his all out, I'll have to agree that the barrel adjusters really wake up the whole system. Even if you think you got the tension even between the two, and there's no slack, that all changes when you can dial in a touch of preload (pretension?) on each cable. The system becomes much more precise.

 

[rupps5]

I would dial in tension then dial out a bunch of it. If you don't you will end up with bent or broken parts. I am going to come up with a modded version soon as I start crawling again!

 

[RockRevolver]

looks good man! you mind if I pull off some aspects of your build into mine?;-)