a pair of circular pipes exists, running in parallel.

I wish to use them as tracks for a small railcar.

where to buy wheels, whose "tread" surface is a semi-circle of the
right size to fit over the pipes? very low speeds in this cargo
application, friction-caused efficiencies should not be an issue.

Or must they be made up by a shop on a custom order?

wrote:
a pair of circular pipes exists, running in parallel.

I wish to use them as tracks for a small railcar.

where to buy wheels, whose "tread" surface is a semi-circle of the
right size to fit over the pipes? very low speeds in this cargo
application, friction-caused efficiencies should not be an issue.

Or must they be made up by a shop on a custom order?


Try doing a Google search for "concave rollers".

Here's one example:

http://www.intechpower.com/Power-Cor...er_Specs2.html

--
Jack Novak
Buffalo, NY - USA

(Remove -SPAM- to send email)

go to a fence supply store. they sell all sized rollers for gates that are
shaped to run on pipe rails.

Don

"Ed Ruf (REPLY to E-MAIL IN SIG!)" wrote in message
...
On 4 Jan 2006 16:12:31 -0800, in sci.engr.mech
wrote:

a pair of circular pipes exists, running in parallel.

I wish to use them as tracks for a small railcar.

where to buy wheels, whose "tread" surface is a semi-circle of the
right size to fit over the pipes? very low speeds in this cargo
application, friction-caused efficiencies should not be an issue.

Or must they be made up by a shop on a custom order?

Can you use a standard v-groove wheel instead or do you need the full
contact area between the two?

http://www.mcmaster.com/ctlg/DisplCt...MMainWidth=915
--
Ed Ruf Lifetime AMA# 344007 )
http://EdwardGRuf.com

On 4 Jan 2006 16:12:31 -0800, wrote:

a pair of circular pipes exists, running in parallel.

I wish to use them as tracks for a small railcar.

where to buy wheels, whose "tread" surface is a semi-circle of the
right size to fit over the pipes? very low speeds in this cargo
application, friction-caused efficiencies should not be an issue.

Or must they be made up by a shop on a custom order?


Always amazes me that I can think up at least three simple things that
I would have included right off to assist in an answer ,rather than a
huge long thread, when asking for help in any "original post" asking
for aid or information.

Where are you located, roughly?

What size is the existing "rail", and is it straight and level, or
curved, or ?????, and what span between centres?

What load capacity?

Used Indoor or out, or both or combined or ????

If it's not a trade secret, why not tell us a bit about the proposed
use?

Take care.

Brian Lawson, (former user of numerous different applications)
Bothwell, Ontario.

wrote:

a pair of circular pipes exists, running in parallel.

I wish to use them as tracks for a small railcar.

where to buy wheels, whose "tread" surface is a semi-circle of the
right size to fit over the pipes? very low speeds in this cargo
application, friction-caused efficiencies should not be an issue.

Or must they be made up by a shop on a custom order?

Got a fun park with a roller coaster ride near you? You might ask where
they get their wheels from.

Or try asking at a casters store (yellow pages, "casters".

Cheers
Trevor Jones

According to Brian Lawson :
On 4 Jan 2006 16:12:31 -0800, wrote:

a pair of circular pipes exists, running in parallel.

I wish to use them as tracks for a small railcar.

where to buy wheels, whose "tread" surface is a semi-circle of the
right size to fit over the pipes? very low speeds in this cargo
application, friction-caused efficiencies should not be an issue.

Or must they be made up by a shop on a custom order?


Always amazes me that I can think up at least three simple things that
I would have included right off to assist in an answer ,rather than a
huge long thread, when asking for help in any "original post" asking
for aid or information.

Where are you located, roughly?

What size is the existing "rail", and is it straight and level, or
curved, or ?????, and what span between centres?

What load capacity?

Used Indoor or out, or both or combined or ????

And -- does the wheel need to drive the carriage along the rail,
or just roll freely?

My first suggestion in the latter case would be to find pulleys
for rope or cable of the same diameter, and use those as wheels.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

wrote in message
ups.com...
a pair of circular pipes exists, running in parallel.

I wish to use them as tracks for a small railcar.

where to buy wheels, whose "tread" surface is a semi-circle of the
right size to fit over the pipes? very low speeds in this cargo
application, friction-caused efficiencies should not be an issue.

Or must they be made up by a shop on a custom order?

I don't recall your saying what size the pipes were. As was mentioned by
another poster here, wire rope pulleys are available in that cross-section.
Lighter construction of the same type is available in fibrous rope pulleys.
Some have integral bearings, others are just bushed.

McMaster-Carr carries them in sizes to accommodate up to 1-1/4" rope.

LLoyd

"Lloyd E. Sponenburgh" wrote in message
...

wrote in message
ups.com...
a pair of circular pipes exists, running in parallel.

I wish to use them as tracks for a small railcar.

where to buy wheels, whose "tread" surface is a semi-circle of the
right size to fit over the pipes? very low speeds in this cargo
application, friction-caused efficiencies should not be an issue.

Or must they be made up by a shop on a custom order?

I don't recall your saying what size the pipes were. As was mentioned by
another poster here, wire rope pulleys are available in that
cross-section. Lighter construction of the same type is available in
fibrous rope pulleys. Some have integral bearings, others are just bushed.

McMaster-Carr carries them in sizes to accommodate up to 1-1/4" rope.

LLoyd

I used to have a horizontal photographic copy bench, and the carriage on it
that held the camera ran on a pair of 2" diameter tubular rails. The
carriage did NOT have wheels in the ordinary sense, but four sets of triple
balls races, each set had its three races at 120 degrees to each other, so
the contacting surfaces were the outer surface of the tubes and the flat
surface of each outer race, thus they made line contact.

The use of sets of three races surrounding the rails may not be suitable for
your purpose, but you could use four PAIRS with the members of a pair set at
120 degrees to each, running on the upper part of the rails . This would
give a very low friction running system, better than trying to use wheels
with semicircular circumferences, which would have quite high wiping
friction where the outer edges of each wheel wipe past the rails. Wheels
with outer surfaces like vee pulleys would be better, but still have higher
wiping friction than the pure line contacts of the outer surface of standard
ball races.

Dave.(uk)