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Please advise on this design

Old 05-11-03, 07:24 PM
  #1  
groggory
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Please advise on this design

Right now I am working on the next generation racer for my school's Electrathon Race team. If you're interested you can see the Irwindale Electrathon Race pics or visit my thread on it here . But on to my question.

My next design is going to be a tricycle, 1 wheel in the front, 2 in the back, front wheel drive (hub motor)/ front wheel steering. I've made a few sketches so far on how I think the front wheel steering should work. Very rough mind you, but I'm just getting a feel for where I want to go with this whole design.

I want to have a little suspension on the front wheel to keep it firmly planted on the track and I plan on doing this just as my road bike does, slightly flexible tubing on the front fork. I've ridden many times on my road bike and noticed the fork flexing and taking up the tiny bumps, I think that this would be a good design for this bike.

The question I have is how to properly design the bearings and surfaces for the pivot point. I was looking at making the pivot point behind and below the center of the front tire. The front tire will most likely be of 16" diameter.

Here are my sketches to illustrate what I'm talking about. A slightly modified heavy duty headset should work I would think??? I'm just not sure how to impliment it, I've never taken apart a headset before and seen exactly what surfaces rotate about the other surfaces. So to anyone familar with the inner workings of a headset, please advise...

Thank you very much


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Old 05-12-03, 01:32 PM
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D*Alex
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Man, do you need a course in GD&T!!!!!
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Old 05-12-03, 02:21 PM
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The Toninator
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i like shiny things
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Old 05-12-03, 02:23 PM
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groggory
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just some sketches coming straight out of my head. I am capable of proper blueprinting, but for this case I didn't see a reason. I'm also learning Solidworks so I can accurately model everything.
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Old 05-13-03, 03:35 AM
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MichaelW
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Which way is up on your diag.?
The steering of a bike is very sensitive to changes in headtube angle and fork rake. Make sure you get them to work together.
Putting the steering and drive through one wheel is not a good idea. You have limited traction, and will quickly run out. Why not share the load amonst your 3 wheels.
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Old 05-13-03, 07:24 AM
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With the pivot for the front wheel below and behind, your machine will be uncontrollable. The steering axis needs to touch the ground in front of the contact point of the wheel to provide the caster effect.
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Old 05-13-03, 08:54 AM
  #7  
groggory
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Originally posted by AndrewP
With the pivot for the front wheel below and behind, your machine will be uncontrollable. The steering axis needs to touch the ground in front of the contact point of the wheel to provide the caster effect.
DOH! You're right. I'll work on some new drawings to reflect the change...

I just thought of a shopping cart at the market.....

Thanks :-)

Oh, and the next ones will be very pretty (solidworks 2001 drawn)
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Old 05-13-03, 01:35 PM
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Well, those painfully ambiguous drawings now seem to be unavailable, so I can't really look at them (now that I have the time....), but if the steering is as was described, yeah, it's not only going to be dynamically unstable, but also a ***** to steer!
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