My new (virtual) unicycle

Inspired by Steve Howard’s ability to build amazing stuff I took some time today to build me a new uni.

Now, I don’t have access to the same sort of tools and equipment that he has, nor do I have the skills necessary to build an actual unicycle so I had to settle for the virtual sort.

I’ve only got just the basic parts but it’s coming together nicely. I need to add cranks, pedals, and a seat. Those are the most difficult since they aren’t simple geometric objects.

Anyway, if you want to see a picture of my progress you can at:

http://www.unicyclist.com/gallery/Michael_Grant/aaq

Please forgive me for the obligatory checkered floor. It just doesn’t seem right to do a computer rendered scene without it.

In case anyone is interested in how the image was made, it was created using PovRay for windows. If anyone else uses PovRay and would like a copy of the source I’d be happy to share it.

I think this could be a good way to verify frame design and parts sizes before committing to actually making it for real. Or at the very least an interesting alternative to spending the evening staring at the television since it’s too cold/dark to go riding.

-mg

Re: My new (virtual) unicycle

Nice model.

When will the Fireball tread be on the tire?

Doug

Re: Re: My new (virtual) unicycle

Tread has been something that so far has eluded me. I just added some really basic tread but I’m not happy with it. I’ll have to think about the Fireball tread. That would be cool.

Tonight I also added bearing holders and a seat. The seat turned out to be easier than I though. It’s this:

//Seat
intersection{
sphere_sweep {b_spline 4,<-5, 5, 0>,2 <-2,0,0>,.5 <2,0,0>,.25 < 5, 5, 0>, 1.5 scale z2 rotate z5}
cylinder{-3z,3z,3.5 translate <-.3,3.5,0>}
scale 2
translate y*((Wheelradius+(TireWidth3))+10)
translate z
.5
pigment{Gray05}
normal {
wrinkles 1
scale 0.05
}
finish{Shiny}
}

The latest incarnation of my virtual uni is at:

http://www.unicyclist.com/gallery/Michael_Grant/aar

I wonder who’ll finish their custom uni first? Me or andrew_carter? Of course I’ve got an advantage in that I have an infinite availability of “virtual” parts.

-mg

that’s awsome.

Re: Re: Re: My new (virtual) unicycle

I will. I put together the uni.5 hub with a hardened stainless steel axle on Saturday. I get the 700c wheel built around the hub tomorrow. Nice Nanoraptor tire from David Maxfield. Amy Drummond sent me some low “Q” 140mm aluminum cranks but she made me pay for them. Then it all goes back on the SH 29er frame. Zoom.

Re: Re: Re: Re: My new (virtual) unicycle

“Whoooo Hoooo! Hurray for our side! America has the best unicycle engineers. No squirrel is safe before our might!”

-Christopher LeFay, as he thumps his chest and marches around the office, much to the consternation of his co-workers.

Re: Re: Re: Re: My new (virtual) unicycle

Harper,

You’re my hero! Someday (when I grow up) I hope to be able to graduate from the virtual world to the real one.

I’ve been wondering about stainless steel. Is it better than CrMo? Cheaper? Lighter? Stronger? Easier to obtain? Can it rust? Why (not)?

-mg

Stainless and cromo come in a wide range of grades which will effect cost, strength and obtainability. Generally cromo will be better for a uni (or b*ke) frame.

Stainless can rust under certain conditions but not much. You might get a bit of rust around the welds as some of the chrome (the element in stainless steel that makes it stainless) will leech out when it is welded.

Re: My new (virtual) unicycle

“mgrant” wrote…

> Anyway, if you want to see a picture of my progress you can at:
>
> http://www.unicyclist.com/gallery/Michael_Grant/aaq
>
Very cool.

> Please forgive me for the obligatory checkered floor. It just doesn’t
> seem right to do a computer rendered scene without it.

Couldn’t agree more. :smiley: (Though shouldn’t there be a teapot nearby?)

Here’s my effort at the same:

Also created in POV-Ray, I’ve been “working” on it (I keep procrastinating)
for some time now.
Here’s a version with the latest addition - a white Primo “The Wall” Tyre:

I’m interested in what people think of this so far.

As you can see, the webpage needs updating with a new video and the jpg of
the unicycle complete with tyre. The tyre will be black but white shows the
tread better.

I’m currently “working” on the seatpost. The seat is going to be the
trickiest bit.

I am astounded by your tiny code which produces a very realistic looking
seat, mg! I was thinking of using blobs or a mesh or something along those
lines when I get around to it.

I know of at least one other rec.sport.unicycling dweller who’s designing
one of these in POVRay. I expect he’ll show himself in this thread but if
he’s keeping his work under wraps maybe he won’t so I’ll not name him.

Andrew
0xADF

Re: My new (virtual) unicycle

> Here’s my effort at the same:
>
> http://feldhaus.co.uk/unicycle.jpg
>
> Also created in POV-Ray, I’ve been “working” on it (I keep
procrastinating)
> for some time now.
> Here’s a version with the latest addition - a white Primo “The Wall” Tyre:

Very nice! I’m especially impressed by the level of detail. I’ve been lazy
with mine so if you look close you’ll notice the spokes just sort of
“magically” attach to the hub (and a lot of other anomalies). But the code
is compact. My total source (excluding standard include files) is only
about 200 lines.

> I am astounded by your tiny code which produces a very realistic looking
> seat, mg! I was thinking of using blobs or a mesh or something along those
> lines when I get around to it.

I was a little surprised myself. I didn’t think I’d be able to achieve a
semi-realistic looking seat using POV-Ray primitives. Then I discovered the
sphere_sweep object. I had tried using blobs but couldn’t get it even close
(I don’t really understand blobs very well). Meshes are out of the question
since I have no way to build them (except by hand which would take forever).

I’m glad to know there are others who enjoy doing the same sort of thing.

-mg

You guys should put saddles on those virtual unicycles. They look really uncomfortable.

I’m using an alloy called 17-4PH that Steve Howard told me about. It’s WAY easy to harden. I doubt if it’s any where near as hard as quenched CrMo. The SH MUni that I have has an axle made of this stuff that I’ve taken awkwardly off some 3 foot drops. Max Dingemans rode it on one of the MUni rides at UNICON so that should tell you something about how tough it is.

I bought a 1.375" dia, 12" long bar from McMaster Carr for something like $36. It was enough to make 2 axles.

Steel is steel. It all has about the same density.

As someone mentioned, some stainless alloys can rust somewhat and, at a weld, especially to something like mild steel, it WILL rust.

Your wish is my command.

http://www.unicyclist.com/gallery/Michael_Grant/aas

-mg

Aaaahhhh…that’s SO much better.

I didn’t want to say anything, but… those checkers make you look fat.

-C