On 3/10/2012 11:39 PM, John Doe wrote:
The Daring wrote:

John Doe wrote:

Where to buy round rubber belting online? So far, I have one or
two possibilities, McMaster-Carr and Cadence Supply Company.

Also. How can you tell the minimum pulley outer diameter of a
rubber belt? McMaster-Carr says that their 3/16 inch rubber
belts have a minimum pulley diameter of 1 1/2 inches. Is there
some rule, like a belt that is twice as thick requires a pulley
that is twice as wide?

Any other information about rubber belting is appreciated. Like
resources for gluing the ends together. I will check YouTube.

Are you looking for something akin to conveyor belt material?

I might need round rubber belting that is non-reinforced. So that
the ends can be connected together to make the correct size belt.
Then again, the belt breaking could be very unpleasant since I am
planning to use it as an inline skate tank style tread. But I
would love to find out what it's like, so it can be tested
carefully at first.

The rubber that's used for skate wheels might do. I think it's
typical polyurethane. I think flexibility will affect rolling
resistance, like where the rubber goes around the end pulleys.
Flexibility varies with belt diameter. Apparently the polyurethane
belt diameter versus minimum pulley diameter looks something like
this.

3/32" 3/4"
1/8" 1"
3/16" 1 1/2"
1/4" 2"
5/16" 2 1/2"
3/8" 3"
1/2" 4"

Also, whether UHMW plastic pulleys will be good enough for the
wheels, or whether a bearing(s) is necessary. Apparently idler
pulleys include bearings. Or maybe something can be grooved and
pushed onto an ordinary skate bearing for the inner pulleys.
Gluing an o-ring or something similar onto each side of the
bearing might work for tracking the belt. The front wheel diameter
might be 5 or 6 inches. The rear wheel might need to be large just
so the belting has a larger pulley to wrap around.

Also possible is to use a tank style tread only for the trailing
wheels. That might require a more flexible rubber band/belt. That
would be less cumbersome than routing the belt from the rear wheel
forward to the front wheel. It might allow doing away with large
rear wheel too. And not using a tank tread for the front wheel
might be less dangerous (at some point). But... Using the front
and rear wheels as part of the tank tread provides a larger pulley
diameter on the ends.


Probably a large heavy duty O-ring would fit the bill. There would be no
joints to worry about and O-rings are produced in a wide variety of
materials. Possibly use a poly rope run around your pulleys to get a
measurement.

TDD