I have posted photos of all of the gears meshing on my web page in the epicyclic hub project section to which there is a direct link below. There are also photos of the welded sun gear assembly and a shaft and planet cage with a full compliment of planets. I finished the lathe work on one pair of the aluminum hub halves and some photos of those are shown as well. All of the new photos are at the bottom of the page.
You didn’t think I’d do this, did you?
Very high cool factor.
Couple questions:
What do those small grooves on the axel do (you may have tried to help my addled mind with this before)?
What all comprises the individual planet assemblies?
This is like getting a susspence novel in monthly installments.
Christopher
The small grooves are for snap rings to retain the fork bearings in thrust. I couldn’t put stops in some places because I had other bearings to slide over before the fork bearings were pressed on.
The planet assemblies: each planet has a 440 stainless steel 8mm diameter shaft with snap ring groove pressed into the planet cage flange. First on the shaft is a 0.050" thick bronze washer. Second is the modified planet gear. Third is another bronze washer. Last is a snap ring to retain the gear in thrust.
…so the planets rotate on these pins- without a bairing?
I finaly ‘get’ the action of the fixed suncase bearing cage. Looking at the design, the idea of machining it within tolerance is daunting. Very impressive. It’s going to be neet to see how the cage holds up to the job of transfering all the force to the frame. I’m happy to see that the frame plate/link is screwed to the cage- allowing for custom plates or plate replacement- or custom frames to be afixed and removed.
Very tasty. Mmmmmmmmm. Has the same effect on me as the smell of fresh baked bread. Now to see those hub haves bolted together… 
Any weight guestimate, at this point? It’s cool how sleek the houseing is- belies the compexities hiden within. It’s almost too bad you ‘outed’ yourself as a Mad Scientist- I would love to have seen the reaction of fellow racing competitors at UNICON when, after a bit of a slow start, the 49’er tairs past 'em. As it is, the reaction will just be the ushual blawzay, “Ahh, 'nother Mad Scientist- what can a guy do?”
Christopher
Chris-
It weighs in at 3.5 to 4 pounds right now. I left the bearings in their boxes and the parts bagged up to weigh it. The bolts are in the axle and I have some material to romove from the hub halves (all of the holes to be drilled) but they will be refilled with bolts. My goal was for it to weigh less than me and so far I’m in.
What ever it is, it will be less than a Coker. By the way, Harper, How does it feel to know that you may have single handedly put Cokers out of the future of unicycling? This is a revolution people! Come forward and bow down to the new leader of the masses. There will no longer be “Coke Heads” but instead, lots of people growing their hair long to be like this modern day Leonardo Davinci of unicycling? Prepare for the giant 36" tire fire.
-David Kaplan
David-
Thanks, that’s flattering, but I think the Coker is not threatened at this point. Maybe if I can get the production costs of a hub down to $1000 per unit someone would think about buying one instead of three Cokers. Oh…there is another small issue concerning the fact the the hub is not yet tested. And the final, and perhaps most important matter, is that of esthetics. Those big wheels have a lot of visual appeal.
Woah! This thing cost you 1000? I’d rather buy a DM vortex, but what ever floats your boat.
-David Kaplan
David-
Time is money. I’ve got about 50 hours of machining time alone into this project to make two hubs. A real machinist could do it in much less time but not half the time. Shop time probably costs from $60 to $75 per hour. I have $350 outlayed in parts (gears, bearings, hardware) for the two hubs. All of the material I’ve used is surplus and so it cost me nothing. I’m using cheap, unhardenable steel and gears. The guy who did the welds for me did them for free. The time to research commercial parts and design the hub is not included here. So, when I get done, they would ring in at about $1000 each or so. If it works, I will try to sell the second one to recover the $350 out of pocket expenses and I will have a one-of-a-kind WAY cool unicycle. If it doesn’t, I’m out the $350 and I will have had a good time trying.
> How does it feel to know that you may have single handedly put Cokers
> out of the future of unicycling? This is a revolution people! Come
> forward and bow down to the new leader of the masses. There will no
> longer be “Coke Heads” but instead, lots of people growing their hair
> long to be like this modern day Leonardo Davinci of unicycling?
> Prepare for the giant 36" tire fire.
Not so fast…
The two cycles will ride very differently. Harper’s will have the speed
without the size. You’ll be able to fit it in a Mini boot! And with you on
the bus! But it will not carry the inertia of a big wheel like a Coker, that
makes it roll smoothly over bumps and keeps it a stable platform.
Each design has its merits. The Coker has a nice visual appeal, and rides
smooth. I think you will find the geared hub to be a little harder to ride,
and less forgiving on those same bumps. At least it won’t run you over when
you crash…
My impressions are based on the 20" Schwinn Tom Miller once converted to the
“gear ratio” of a 40" wheel. This was a higher gearing than Harper’s hub, so
it was more sluggish than I’d expect his to be. But it was definitely a
different ride from the equivalent size big wheel.
Stay on top,
John Foss, the Uni-Cyclone
jfoss@unicycling.com
www.unicycling.com
“You’re not supposed to wash your Roach armor” - Nathan Hoover, on safety
equipment cleaning methods
YOUR GOING TO SELL THE SECOND TO RECOVER COST? WHERE DO I SEND THE MONEY? Why am I shouting?
Uh… replace the Coker- no. Agment the Coker- yes! By god man- think of the SPEED!
Christopher
Sure. What do I need two for? And I do, afterall, have the original ACAD drawings, prints, bluelines, and parts orders. I also have a fair idea how to build or repair one.
I still plan to have one of them on a 24" unicycle to make a 36" wheel equivalent at the conventions this summer for people to ride. I’ll have a couple of seatposts of different lengths with saddles on them for different sized people. I plan to keep that unicycle. The other hub I was going to have partially assembled and have some drawing sets so folks could see how it works. Then I planned to sell it if I could find some total sucker (I mean engineering or unicycle buff) so I could recover costs. I would let anyone who wants prints have them for free (heck, they’re on the web anyway) but if too many people wanted blue lines the copying and mailing would become a hassle. E-mailing drawing sets is easy and free.
…no patent???
Harper,
Aren’t you going to patent this thing 
, or is that something you can’t/don’t choose to do?
Anyways, it looks like things are comming along VERY nicely.
Appears the new giraffe is a lot of fun too.
Keep up the FANTASTIC work.
Re: …no patent???
O-1-W-
A planetary gear system is old, old stuff and this is not a unique enough application to make it patentable.
The new giraffe is a TOTAL gas. I would recommend trying one at least once sometime to all. It’s so weird…it seems like you’re moving so slowly from up there. I wonder if that effect increases with height.
Ya, this is a great idea- if the funds are not tight (and if you don’t plan on a production run), you might consider retaining it permanantly for this perpose. Nothing like good hands on fun to enspire young engineers.
Greg and Steve’s efforts remind me of yester year and the synergy garnered by craftsmen in artist communities. Culture promotes culture.
If and when the hub goes on the block, you might consider an auction- I think it would generate interest and excitement in both the craft and riding aspect of Unicycling.
Christopher
Re: Re: …no patent???
Were you not even a weeeeeeeeeee bit frightened? Did your reactions to the balancing requirements seem like a natural outcroping of existing skill? Do you think it will become relegated to novalty status in short order?
Christopher
I sure hope I can find my way to the convention… I’d love to try the
thing out… just not sure I could afford to own one of my own 
I must say, kudos on the posting, following open source philosophy on the
thing. The more people who can can look at it, the greater the chance
someone will find it interesting enough to mass produce, or in general
improve upon.
That’s one of the great things about unicycling – the technology has yet
to get to the point where a single person could not change or improve it.
If you want to make a custom unicycle to your specifications, yes, it’ll
cost you, but it’ll still cost less than some top-of-the-line stock bicycle.
jl
> Sure. What do I need two for? And I do, afterall, have the
> original ACAD drawings, prints, bluelines, and parts orders. I also
> have a fair idea how to build or repair one.
>
> I still plan to have
> one of them on a 24" unicycle to make a 36" wheel equivalent at the
> conventions this summer for people to ride. I’ll have a couple of
>seatposts of different lengths with saddles on them for different
>sized people. I plan to keep that unicycle. The other hub I was going to
>have partially assembled and have some drawing sets so folks could see
>how it works. Then I planned to sell it if I could find some total
>sucker (I mean engineering or unicycle buff) so I could recover costs. I
>would let anyone who wants prints have them for free (heck, they’re on
>the web anyway) but if too many people wanted blue lines the
> copying and mailing would become a hassle. E-mailing drawing sets is
> easy and free.
>
>
> rhysling wrote:
> > YOUR GOING TO SELL THE SECOND TO RECOVER COST?
>
>
> –
> harper
> Posted via the Unicyclist Community - http://unicyclist.com/forums
>
> rec.sport.unicycling mailing list -
> www.unicycling.org/mailman/listinfo/rsu
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Re: Re: Re: …no patent???
Yes. Yes. Unfortunately, yes, unless I can learn how to freemount it or idle reliably. That means finish the hubs before July, 5-B-4-50 by August 28, and learn to freemount a giraffe. I should quit work…it gets in the way all the time.
I was thinking of getting a Coker, but hell I figure you’ll be done with the hub by the time I can get my hands on one.
How about building one on a Coker!?
I couldn’t resist…
-Mark
>
>
> David-
>
> Thanks, that’s flattering, but I think the Coker is not
> threatened at this point. Maybe if I can get the production costs of a
> hub down to $1000 per unit someone would think about buying one
> instead of three Cokers. Oh…there is another small issue concerning
> the fact the the hub is not yet tested. And the final, and perhaps most
> important matter, is that of esthetics. Those big wheels have a lot of
> visual appeal.
>
>
> UniDak wrote:
> > What ever it is, it will be less than a Coker. By the way, Harper,
> > How does it feel to know that you may have single handedly put
> > Cokers out of the future of unicycling?
>
>
> –
> harper
> Posted via the Unicyclist Community - http://unicyclist.com/forums
>
> rec.sport.unicycling mailing list -
> www.unicycling.org/mailman/listinfo/rsu
Sent via the Unicyclist Community - http://Unicyclist.com