DIY Geared Steering

[DCProductions]

Whenever I go off road in my kart (a rigid yard-kart), I'm constantly wrestling the handle bars I use for steering. I've looked at some rack and pinions, but new ones are expensive and it's hard to find one at pull-a-part. However, I have a couple of #35 sprockets laying around, one 12T one 36T, and I have an idea. While this isn't rack and pinion at all, the setup should allow for easier steering and much more control. What do you think?
I'm new to this forum, or really forums in general, so I'm not sure if this attachment worked.

[kibble]

Your attachment worked just fine.

It definitely seems like a good idea. I would do something like this, but would make sure the chain isn't too loose.

[DCProductions]

There would definitely be a lot of play in the steering if it wasn't tight. I was thinking of some sort of tensioner but that would be hard to fit in. What about a guide? Also are bearings really necessary?

[Doc Sprocket]

Yeah, I'd be concerned about the play.
Awhile back, I was fooling with a DIY rack and pinion arrangement that looked pretty doable. It basically amounted to having a sprocket on your steering column, and a length of chain welded to a piece of flat bar. Off each end of the bar is a tie rod going to each front wheel.

It does require a welder, though.

[DCProductions]

I never thought about just using the chain. That's a great idea, and I do own a welder. I've also been trying to figure out how to do Ackerman steering. Any good threads on that?

[r97]

only problems i can think of are:

excessive play, and your done if the chain breaks or falls of for some reason.

how much would it cost to get a rack and pinion from the junk yard? maybe you could rip the steering from a riding mower?

Originally Posted by toystory_4wd

Yeah, I'd be concerned about the play.
Awhile back, I was fooling with a DIY rack and pinion arrangement that looked pretty doable. It basically amounted to having a sprocket on your steering column, and a length of chain welded to a piece of flat bar. Off each end of the bar is a tie rod going to each front wheel.

It does require a welder, though.

i was thinking the same thing a while back, i ended finding out fowler had tried it, i think he said it just skipped teeth. how did yours turn out?



EDIT: if nor bearings some nylon bushings would be good.

http://www.nordstrom-karting.com/doc...%20Article.pdf

http://www.bcot1.com/karting/

http://blog.kartbuilding.net/2007/07...-for-go-karts/

[Doc Sprocket]

I didn't get far enough to test it on a kart- too many hobbies on the go. I think I had the tooth-skipping thing licked. A housing is made to keep the pinion in tight mesh with the rack.

Ackermann's easy. Locate the centre of your rear axle, and mark it. Now, run a string from the centre of your king pin to the mark on the rear axle. Now, make your steering arm so that the hole for the rod end would be intersected by that string.

EDIT- A lot of riding mowers use a sector shaft arrangement for steering, and it's bloody awful. Okay at 5mph. Deadly at kart speeds.

[theo]

I have done this on a buggy. just mount the top sprocket so you can shim it up.

[DCProductions]

Originally Posted by toystory_4wd

I didn't get far enough to test it on a kart- too many hobbies on the go. I think I had the tooth-skipping thing licked. A housing is made to keep the pinion in tight mesh with the rack.

I thought about pinning the piece of flat with the chain in between some bearings. Basically making a slot, 2 bearings on the bottom 1 on top.

Originally Posted by toystory_4wd

Ackermann's easy. Locate the centre of your rear axle, and mark it. Now, run a string from the centre of your king pin to the mark on the rear axle. Now, make your steering arm so that the hole for the rod end would be intersected by that string.

Thanks for that. I googled ackerman but all it gave me was a bunch of pictures of cars turning. My spindles are already custom (and bent) so it wouldn't be too hard to make some new ones. Right now the steering arms are pointed forward. Do I still line it up with the same line?

[DCProductions]

Originally Posted by r97

only problems i can think of are:

excessive play, and your done if the chain breaks or falls of for some reason.

how much would it cost to get a rack and pinion from the junk yard? maybe you could rip the steering from a riding mower?

That's probably the better way to go, but I have these parts just laying around. Thought it might be a fun project. As far as the chain breaking, I've been using a scooter's (like razor scooter) steering column which is made of some pretty thin metal. It's held up so far though so I think that 35 chain could hold.

Now, I've had the tie rod bolts fall out before so I could see the chain just falling out of the housing while I'm 4 miles out on a trail.

[Doc Sprocket]

Originally Posted by DCProductions

Thanks for that. I googled ackerman but all it gave me was a bunch of pictures of cars turning. My spindles are already custom (and bent) so it wouldn't be too hard to make some new ones. Right now the steering arms are pointed forward. Do I still line it up with the same line?

Yup- you just have to extend the line forward. It is a fair bit harder to achieve proper Ackermann geometry with arms that point forward, because of potential interference with the tire. But you've got the idea.