Would this steering mechanism work on a tadpole?

[Watt]

I'm making a tadpole bike for a school project and I'm wondering if anyone has come across a steering mechanism similar to the drawing I've attached.

I see that the "steering pole" can't be to close to the wheel, because then it would hit the tire when turning to the right.

Do you think it will be too much momentum to manage the turn?
Or that the construction will be to weak?

Any other thoughts?

 

[parajared]

Nope!
That's a bad way to go. I used to take off and land with an ultralight with a setup like that, except where you steer with your legs. It was mega unnerving. Little dips in the road and rocks would kick the bar around. Standard steering is the way do go with tadpoles.

 

[amberwolf]

The local ice cream and snack vendors on trikes around here have a steering that pivots both front wheels and their basket as an assembly like that, and even at walking speed it doesn't look easy to turn when I am watching them ride.

 

[ebent]

Study a few well made brands of trikes. There is a lot more to it than meets the eye.

 

[Chalo]

That approach is no good in a few different ways. Easy to tip, unstable at speed, terrible bump steer, etc.

Look up "Ackermann steering" for a lot of information you can use.

 

[Watt]

Thank for all the great input!

I've read about Ackermann, and I'll probably end up with that in the end, just want to consider some ideas first


Could it work if I used the single rear wheel for steering, and the two front wheels for pedaling?
And if this work, would it be possible to have the two front wheels on the same axle (so that they spin equally), or will that make them skid (right word?).


Thanks,
Harold

 

[parajared]

Yes, and it's a really neat way to go. Supposedly this style of trike corners even better than a rigid tadpole. The front wheel is rigid and does not steer, the rear wheels tilt and the geometry change steers the trike. I have highly considered building a trike like this. It looks even easier than Ackerman steering.

Can a quad steer like a forklift, sure. Firetrucks, boom lifts, and monster trucks can steer like this too. Would it suck to steer your trike steer rear wheels only, you bet: it would be like driving your car in reverse all the time.

The way you build a driveline where power goes to two wheels is you weld round disks with a bunch of holes drilled in them to a metal shaft. You run your spokes through the holes. You can buy pre-fabricated disks from atomiczombie. http://www.atomiczombie.com/DIY%20Parts.aspx You are basically building the hub: see bottom pic

 

[Dauntless]

That approach is no good in a few different ways. Easy to tip, unstable at speed, terrible bump steer, etc.

Look up "Ackermann steering" for a lot of information you can use.

What he's warning you about is the ORIGINAL Darwin Theory, by Charles grandfather Erasmus, who became disgusted with the ride of his buggy and make a steering mechanism that would turn a tighter circle on the inside than the outside, as the inside would make a smaller circle.

I've found the easiest to understand link to be at an RC site, of all things.

http://www.rctek.com/technical/handling/index.php

http://www.mech.uq.edu.au/courses/mech3100-old/steering/s1.htm