the MRH Forum

Anybody test factor of adhesion on models? Dream and design
Reply
Prolific poster 3,069 posts DKRickman Prolific poster 3,069 posts
DKRickman

I've been wondering this for a while, and kind of thinking of setting up a test rig.  Before I do, has anybody already done it?

I know that the factor of adhesion for a steel wheel on steel rail (prototype) is roughly 4 - meaning that 4# on the rail will give 1# of tractive before before slipping.  What is it for our models?  We use sintered steel, brass, nickel silver, and rubber drivers, and nickel silver, brass, and steel rails.  I think I've seen aluminum rails as well, and there are even a few models with plastic drive wheels.  Does anybody know how much traction you can expect to get for a given weight on the drivers, using the various common wheel/rail combinations?

And if not, would anybody be interested in the results if I do such a test?  It might be something I'd write up for an article here, if there was sufficient interest.  Future dreaming and all that..  It's not like I have anything else to do.

Ken Rickman

Danville & Western HO modeler and web historian

http://southern-railway.railfan.net/dw/
Reply 0
Russ Bellinis Prolific poster 3,335 posts
Russ Bellinis

I think it might be "over thinking" the problem.

If I was designing a locomotive to build from scratch, the info might be essential for me to build a good working model.  Most of us buy r-t-r locomotives or in some cases build kits that we have either stock piled or find at a swap meet, train show, etc.  There is so many variables like weight, balance, as well as wheel material that I think a test that simply shows how many cars a model will pull is probably most useful.  I think the tests that magazines do telling us how many cars a model pulled on a straight and level track is ok as far as it goes, but it would be more valuable if they also tested on a straight 2% climb to see how much the pulling power fell off on a hill.
Reply 0
Jurgen Kleylein Prolific poster 1,119 posts
Jurgen Kleylein

Check old RMJ's

Railmodel Journal and Model Railroading magazines used to do loco reviews which included performance tests which also rated pulling power.  There was a breakdown of how it was done in one of the early RMJ issues which you may want to do a search on.  The ratings also included pulling power on grades, if I recall correctly.

Jurgen

HO Deutsche Bundesbahn circa 1970

Visit the HO Sudbury Division at http://sudburydivision.ca/

The preceding message may not conform to NMRA recommended practices.
Reply 0
Prof_Klyzlr Moderator 7,957 posts
Prof_Klyzlr

F-o-A measurements

Dear Ken,

FWIW, "O scale trains" magazine do IIRC, in their loco reviews. Someone also just recently did a bunch of testing on drawbar-pull (and thereby F-o-A) on various On30 locos, and published the results over on the "On30" YahooGroups list...

Happy Modelling,
Aim to Improve,
Prof Klyzlr
Reply 0
Reply