sorry about that....i was logged off!
ok...took notes so I can respond to the rest of your letter.
what does 559 mean?
I love how you
split the problem up. Awesome. I need to do that more in my life, at least in my mind. I am not sure if my wife would apprecaite, "Now Honey, lets split this discussion into parts so we can better handle it". That attitude might work with some people, but not for others
In addition to splitting up problems, another good problem solving approach is to break the solution into versions. My friend suggested that as he is getting tired of waiting for a fixed wheel chair. So my first version is to just get a set of good bearings into his existing wheel. The second version I will create (oh I feel like a roman God) a wheel out of parts.
Yes....Eventually I got on the binge of checking out every bicycle wheel component. Rims, spokes, hubs, bearings,axles, and wheel chair components that
the mfr used to connect wheel to chair. (nut or bushing...the two predominant choices).
I started with the bearings as I wanted my friend to try out the design and come back to me with a jaw dropped in awe. That is my hoped for payback. I know, I know, no strings attached when giving.
the price range is from 6.00 to 100 plus per bearing. I chose ceramic hybrid technology. I chose Boca as the manufacture only because their site gave me the opportunity to sort out types of bearings more readily. They do have a decent reputation, which helps. I chose a bearing which would fit into his existing chair as nearly as possible. Only the outside dimensions were important for that as I am designing the axle (which defines the inside dimension)
I chose the Ultra Seal Ceramic. 32 mm OD, 15 mm ID and 9mm thick. because I am designing the axle, I can avoid having to purchase ea bearing with a flange (original manufacture design required one). I chose that bearing over the Yellow Seal Ceramic as the Ultra Seal Ceramic has a non contact seal. The Yellow had a more robust seal but it is a "contact" seal and I wanted my friend's jaw to D-R-O-P.
The hub is another animal. I am beginning to realize I had better write about my findings in another note. You guys might already be sleeping.
Oh (looking at my notes of your reply)....my friends dirt cheap wheel chair has dirt cheap plastic wheels (no spokes) with plastic hubs with poor design.