Large 10" Wheels in the UK?

[Daniel Vernall]

Hi all,

I'm beginning to piece together a shopping list for a heavy weight I have a design for. The design requires large diameter wheels at the rear of the bot. I was looking at something like these.

http://www.robotmarketplace.com/prod...ree_tires.html

But I'm trying to find a uk supplier for this sort of thing. I seem to have found a similar sort of thing here at a very reasonable price:

http://www.rosscastors.co.uk/260mm-p...-bearings.html

But I'm not sure how easy it would be to fit an axle to them for use as drive wheels. I'm thinking of connecting both rear wheels to 1 powerful motor via an axle and chain/gear setup.
Does this seem feasible? and if so any advice on ways to mount these wheels to a drive system? (My design uses seperate forward wheel turning, as oppposed to "tank" turning)

Thanks in advance!

Daniel

[maddox10]

You can buy those full foam wheels at any decent DIY or agricultural shop, with hubs.

[typhoon_driver]

You can get puncture proof tyres cheaper on ebay.

Your plan is entirely feasible. Just remember that the vast majority of these types of wheels have bearings in the center as they are meant for wheelbarrows and sack trucks.

[Daniel Vernall]

You can buy those full foam wheels at any decent DIY or agricultural shop, with hubs.

Ah thanks for the reply. I was under the impression these were a lighter and more durable alternative to foam tires. These are polyurethane molded tires. Is this true, or have I fallen prey to sales talk?

Thanks Gary for the heads up about the bearings I'd forgotten about the that, I'll have to look into replacing the hubs

[maddox10]

Yes, you fell for marketing. The catch is in :" a heavy foam-filled rubber tire".
Those tires they show are not that uncommon anymore.

There were people who tried filling normal air tires with PUR or simular foams, with most of the time horrible results.

[epicentre]

There were people who tried filling normal air tires with PUR or simular foams, with most of the time horrible results.

May I ask why this didn't work as expected? It was something I was considering investigating.

I've been looking at wheels as well, and one of the options I've been considering are the 10" go-kart wheels that seem to be very popular. However, unless I'm misunderstanding something, wouldn't these wheels be prone to being punctured, or easily damaged in such a way that makes them useless? I don't recall seeing them damaged that often, however all the ones I've found are pneumatic, and not solid/foam-filled in any way, which is why I'm confused. What am I missing?

Thanks in advance.

[maddox10]

10" kartwheels are used by quite a few machines, with succes, foam filled or not.

Punctures do happen, but not a lot. Wheel falure is most of the time due broken hubs.

On filling a tire with PUR from a can and the failure of that. PUR doesn't expand evenly, and that deforms the tyre. Resulting in a very wobbly wheel, if it doesn't squeeze off the tyre from the hub. But even if you would use the exat amount of PUR and have the tyre in a mold to avoid deformation, you end up with a kind of brittle mess that will pulverise with each hit.

Using a stronger 2K PU foam give heavy results.

Foam filled kart wheels are know. Using a split hub and a upholstery-foam donut is one way to do it.

And currently, we're using a set of tyres like Sewer Snake uses on Bullfrog. We're very happy with the result.