Wheels parallel or coned?

[ron]

Hi All
I'm about to turn the wheels and the original write up I have calls for the wheels to be turned with a parallel tread rather than coned, is this still the accepted method of finishing model loco wheels?
Ron

[Laurie_B]

Ron,
I think that nowadays a 2 - 3 degree taper on the tread is usually specified,along with a taper on the flange,and a root radius too.

Best have a look at back issues of M.E. and E.I.M.Details of tread profiles can be found in past articles by Doug Hewson (Class 4 tank)and Neville Evans (Penrhos Grange etc.).

There was also a series of comprehensive articles in M.E. a few years ago by Dave Hudson of the Bromsgrove Society,on the subject.I also seem to think the 5" Ground Level Main Line group has more info about profiles and wheel standards in general.

[Boadicea]

Ron, our good friend Alan Stepney's website gives wheel profiles here

www.alanstepney.info/page24.html

Regards Bo

[spurley]

Hi Ron

Take a look at Tubal Cain's Model Engineer's Handbook which has a very useful table on pages13.16 and 13.17.

Actually, see the attached scan:



Hopefully not transgressing any copyright? Maybe this 'gem' will encourage you to get a copy (if you don't already have one?). This seems to be the accepted standards for most clubs these days. If you need the figures clearer I can send an excel file.

Hope this helps?

Cheers

Brian

PS Sorry this seems to duplicate Alan Stepney's info but I didn't notice Bo's post until I'd gone through the scan and attach process

[baggo]

Hi Ron,

I think Martin's reasoning behind not coning the treads was that our rails are set vertically and not canted inwards as are full size ones. The advantage of a coned tread is that the axle tends to be self centreing on the rails and runs without the flanges contacting the sides of the rails which causes rapid wear of track and wheels. Having said that, the radius between the tread and the flange will have a similar effect on a parallel tread but probably not to the same extent. One problem with using parallel treads is that the wheels may tend to 'hunt' from side to side at speed instead of following a straight line.

John

[ron]

Thanks folks, coned they will be then.
Ron

[simonwass]

We did a test years ago by rolling wheelsets down the 1 in 50 left hand bend at Chesterfield. The parallel ground to a halt attempting to turn the corner, the 2 degree coned set 'steered' its way to the bottom of the hill.
Machine the all wheels parallel to basic finished diameter then set over and do the coning last as you will find it hard to measure a coned wheel!
Simon.