I have posted the dimensioned drawings and a nice color cartoon drawing of the revised geared hub with new (proper) planet cage, planet bushings, and shafts. The assembly and parts drawings are accessible from this link.
I have done the modification to both axles and have done the lathe work on the two planet cages. I hope to finish all of the parts this weekend and then post photos and lace the wheel again. Then sheepishly ride it.
I machined almost two planet cages today. Scott Bridgman and Roger Davies I know will appreciate this. The cage in the cager3 pic is done correctly. The one in the cagew3 pic was doomed from the beginning. The other shot is of the turned down axles with bosses and ridges left to press on the planet cages. The photos are about 200K each.
While I was parting the doomed one off of the stock on the lathe, the parting tool broke, the stock tilted, and the part was thrown from the lathe. I faced it up the best I could and the gouges weren’t in critcal positions so I thought I would continue. I wasn’t sure if everything remained true when I fixed it up. The dowel pin holes went in fine on the turntable. When I moved to the other end mill to cut the slots for the planet gears, I cut the first two 180 degree opposed slots perfectly. The third, when I moved the part, I cut on the wrong side. Irrepairable…three hours of work shot. I could have been riding instead. Needless to say, I didn’t cut the fourth slot.
The other planet cage turned out perfectly … everything within 0.001". Go figure. So that’s why you make two hubs … just in case something like this happens. I think I will build the first hub entirely and ride it for 50 miles or so before I even make the other planet cage.
And, Roger, I took your advice and opened up the planet cage flanges another 0.030" (0.75mm) on each side to accommodate bronze thrust washers on both ends of the gears.
Remeber: you do this for your country. Only by ignoring buetyfull days like this will we beat the Canadians in the race of Unicycling Technological Superiourity. If the hub is not ready to demonstrate by the Mega Con, the Canadians will see this as a sign of weekness and stream over the boarder. The fate of the free world rests in your hands, Greg: don’t blow it.
I trust you were not in the path of the flying part! Ouch! After 12 hours+ in the Metals lab, I was working on a part at the buffing machine, lost my hold on it and had it thrown by the wheel. It didn’t take me long to find it- after shooting off the guard, it had lodged in my left hand. 
Thanks for the ‘Thrill of victory’ and ‘Agony of Defeat’ pictures- I enjoyed playing ‘one of these things doesn’t go togeter’ with 'em. I’m still amazed- .001"- Wow!
Christopher
So I machined all of the bushings and thrust washers for two hubs today. I set the four gears and their associated parts on 0.001" undersized pins so I didn’t have to press them into the cage. They turned freely with no slop. They engaged the ring gear perfectly. But the sun gear wouldn’t engage. I took the cage out of the ring gear. It engaged the sun gear perfectly. Ha, ha, ha, ha.
Guess what. The ring gear has 90 teeth (divisible by 2, 3, 5, 6, 10, 15, 30, 45 but not by 4) the sun gear has 60 teeth (divisible by 2, 3, 4, 5, 6, 10, 12, 15, 20, 30). Funny, huh? SO it’s going to be an offset four gear (VERY unappealing) or machine three gear cages.
Well…at least I got to put in 5 miles each way on the Coker. Gorgeous day again.
Re: Geared hub modification
It’s too late Christopher, we Canadians have been infiltrating your
countries most intimate systems, nothing in your country is secure now! We
Canadians have a secure foothold now.
Dustin
Zupancic
“harper” <harper.yn8a@timelimit.unicyclist.com> wrote in message
news:harper.yn8a@timelimit.unicyclist.com…
>
> So I machined all of the bushings and thrust washers for two hubs today.
> I set the four gears and their associated parts on 0.001" undersized
> pins so I didn’t have to press them into the cage. They turned freely
> with no slop. They engaged the ring gear perfectly. But the sun gear
> wouldn’t engage. I took the cage out of the ring gear. It engaged the
> sun gear perfectly. Ha, ha, ha, ha.
> Guess what. The ring gear has 90 teeth (divisible by 2, 3, 5, 6, 10, 15,
> 30, 45 but not by 4) the sun gear has 60 teeth (divisible by 2, 3, 4, 5,
> 6, 10, 12, 15, 20, 30). Funny, huh? SO it’s going to be an offset four
> gear (VERY unappealing) or machine three gear cages.
>
> Well…at least I got to put in 5 miles each way on the Coker. Gorgeous
> day again.
>
>
> –
> harper - Greg Harper: Frequent Faller (oops)
>
> -Greg Harper
>
> (now able to meet the pavement at 1.5 times normal speed)
> “It takes twice the man to ride half the bike.”
>
> ------------------------------------------------------------------------
> harper’s Profile: http://www.unicyclist.com/profile/426
> View this thread: http://www.unicyclist.com/thread/16701
>
Harper -
If I understand the problem, four planet gears won’t work with your ring and sun gear combination of 90 and 60 teeth when the planet gears are positioned 90 degrees apart. But I think that four gears will work if they are positioned at 120 and 60 degrees apart. That wouldn’t be too bad would it? Have you considered using just two gears so the cage you’ve made would still work?
Steve Howard
Steve-
Four gears placed 60 degrees apart puts a gear at 0, 60, 120, 180 degrees, or all on one side. Placed 120 degrees apart puts a gear at 0, 120, 240, 360 (back to zero) which is just three gears anyway. I have room to move the 90 and 270 degree holes to 108 and 288 degrees respectively where they would work and not interfere with the original holes. This is the same as selecting 4 of a group of 30 gears each placed 12 degrees apart but skipping 26 of them. This places the gears at 0, 108, 180, and 288 degrees. This requires thinning out the bracing between the two planet cage flanges on two of the four corners more than I would like to make room for the gears to be shifted. The pattern also places non uniform forces on the sun and ring gears.
Two gears would allow the sun gear to shift laterally within the ring gear. I think I will just make a couple of three gear planet cages. I would like the thing to work this time so I’m willing to spend the 8 or 10 hours required to make two of them.
Is this a change from the first incarnation- or a just relized artifact? If it is a change, how did re-engenearing the planet cage effect the change? My poor addled brain…
Christopher
Just a realized artifact…realized too late. I have picked up some stock to make the two, new, and hopefully true, planet cages. I will make them with a three gear pattern with 120 degree spacing.
On a more positive note I rode the Coker 10 miles yesterday and successfully climbed both big (VERY steep) hills on my commuting route. I can usually only make it up one of them. I rode my 20" Torker on a walk with my wife and dog and can still one-foot with either foot over rough terrain. I practiced freemounting the giraffe and nailed four in a row at one time and was consistently getting up every other try after warming up. So, I feel alot better about remachining planet gears…the whole weekend was not a loss. And I did get all of the bushings and thrust washers done.
This is markedly more impressive to me than your mad-scientist antics. Ok, now I have to go out and bust my ass (again)… thanks.
Christopher
Re: Geared hub modification
In article <rhysling.zuqz@timelimit.unicyclist.com>,
rhysling <rhysling.zuqz@timelimit.unicyclist.com> writes:
>
> harper wrote:
>> *
>> Guess what. The ring gear has 90 teeth (divisible by 2, 3, 5, 6, 10,
>> 15, 30, 45 but not by 4) the sun gear has 60 teeth (divisible by 2, 3,
>> 4, 5, 6, 10, 12, 15, 20, 30). Funny, huh? SO it’s going to be an
>> offset four gear (VERY unappealing) or machine three gear cages.
>> *
>
> Is this a change from the first incarnation- or a just relized artifact?
> If it is a change, how did re-engenearing the planet cage effect the
> change? My poor addled brain…
>
I got 9/10ths of the way through asking the same question, before
going back to Greg’s pictures. The old design had SIX planets.
The new cage affair was only going to use four. While six is a
common factor to 90 and 60, four is not.
I’d recommend just doing one cage with 3 and the other with the
4-of-30 pattern, then decide later which is “best”. 'Course
I don’t have to do all the designing and machining…
There’s also a 5-gear option.
Is it clear that the planets have to be caged? The plate-with-
pins part of the old design was okay. What happens if you make a
new press-on plate then use hard steel pins and bronze bushings?
I must say, this is all very exciting! Thanks for not merely doing
this, but taking the time to show us and talk about what you’re up
to. It really is quite wonderful!
============================================================
Gardner Buchanan <gbuchana@rogers.com>
Ottawa, ON FreeBSD: Where you want to go. Today.
Re: Re: Geared hub modification
Gardner-
I’m going with the 5 planet gear option. There will be 5 support posts between the two cage flanges each with area equivalent to a 1/4" stud. The posts have a buttress like profile due to the radius of the mill used to cut the slots so, over most of the 0.455" gap the posts will be substantially stouter.
To clarify rather than propogate any more errors, I checked the sun and ring gears for tooth count. The sun has 30, not 60 teeth, the ring has 60, not 90 teeth. It’s pretty much the same problem where here 30 is not divisible by four. But they are both divisible by five.
I have done the lathe work for the two new cages and will put them on the turntable tomorrow.