Narrow Wheels

[kciocia]

I'm looking for some wheels for my 40+ lbs flying wing. The gear is fixed so I'm trying to find the narrowest possible.

My ideal wheels would be:
< 5 ounces
Foam Filled (or solid foam, though if it were durable enough I'd try pnuematics)
Aluminum hubs
3.5" - 4" diameter
<1" wide

Any suggestions? I've looked at Dubro semi-pneumatic and found them to be too flimsy. I need something with sturdy sidewalls, and of course low bounce, shock absorbtion etc. I'm flexible on material (hubs and tires) and on weight, but the size is a must.

Thanks,
Kevin

[kd7ost]

I don't know of any wheels that fit the description and will still support a 40 pound plane. What about wheel pants? They help reduce drag.

What about some baby carriage wheels? They won't absorb shock well though. What diameter are you looking for?

Dan

Oop's re-read your post and don't know why I didn't hit on the diameter the first time.

[flyingwingfan]

Just something off the top of my head. How about making a sandwich wheel from a pair of say, 3 inch dia. discs of .125 aluminum sandwiching a rubber disc .500 inch thick by whatever diameter you want.If you bolt the assy. together, you could vary the stiffness by how tight and by the number of bolts-screws you use to assemble the wheel. I bought some rubber discs like what I suggest at a surplus store some years ago. Would it work for you? Frank

[Tuner]

Id use a sandwitch of Carbon/Kevlar Disks rotated so the fibers are at different 45 deg. angles from each other. I would consider making a groove for a rubber O Ring.
http://dragonplate.com/ecart/categories.asp?cID=3
Or Just use Kevlar.
http://www.cstsales.com
Kevlar handles shock better than brittle carbon fiber.

Problem with aluminum is it can be bent easily I suspect your design could bend on a heavy landing not to mention all the little bolts would create more drag than a smooth surface.

[kciocia]

I like the idea of baby carriage wheels, though I'm not sure how much shock they can take. I am going to have wheel pants but I'm still trying to get the cross-section down.

I like the sandwich idea but I feel it's more trouble than it's worth. I'm trying to get off the shelf components where I can to keep cost/production time down.

I just ordered some rubber wheels from McMaster (part no. 2829T68) to see how they look. They can take the load and should be able to take the shock (Durometer 65A) but I'm a little scared of the hubs breaking on a hard impact, but I'm mostly just afraid of a hard impact.

I'll let you know how they work out.

-Kevin

[Tophinater]

You mean something like this? 2 wheels on each hub, being a total of 4, I would think would work pretty well.

http://www.lynxmotion.com/Product.aspx?productID=239&CategoryID=39

[kd7ost]

I'm thinking a 40 pound plus plane will explode those plastic hubs on the slightest of hard landings. I've broken them with a 4 pound electric plane.

Dan

[kciocia]

Those little foam ones just tear if they get any side load.
The ones from McMaster look good. They weigh in at ~127g and have nice sturdy hubs. The rubber is only about the outside 3/8". It's fairly soft, but won't buckle and shouldn't tear. I don't think they are going to absorb much shock, but I'll just have to build that into the struts.

-Kevin

[kd7ost]

I would think you'll have some good ground effect lift off a wing that large. You should be able to set it down pretty gently.

Dan

[Glennis_Aircraft]

We do a lot of RPV wheels - custom stuff like you are looking for - but not with foam tires. Foam won't last on 40lbs.

http://www.glennis.com

e-mail me with your specs and questions.

Dennis

[Ralph Walton]

Cut some discs of plywood maybee 1/2" thick wth a holesaw. If you need a thicker hub glue a smaller disc to the center. Drill to suit your axle size.