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Salada
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Has anyone any opinions or knowledge of the value of wheel tyre coning in On30 (48:1 U.S. 'O' Gauge) ??. 

Does anyone know what the U.S. NMRA recommend regarding tyre profile ?

The following photos are of some wheels off a recently acquired wreck of Si's favourite Brand (Tri-orrible) that is currently going through the Salada Wagon Works shop as part of a recent crazy new scheme dreampt up by the Chavez Extension Directors.

The universal wheel/axle press :




The 'axle' diameter is rather weird - approx 0.0184 ", possibly because it is plastic ?.

This required a new mandrel turning to 0.0185 ". Tyre runout was variable but averaged about .0018 " but sometimes > .002 ". :








The tyre had almost zero coning, about .0005 - .001 ", probably due to wear rather than design.

So, should I cone the tyre or just true it up & reduce the flange thickness (way over even Mr Badmann's limits)  ??.   

Regards,    Michael


Warren G
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tire coning is noticeable in 0 gauge with HO track, with a new Porter, [Bachmann]] ,no others to check on

Helmut
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@Michael,
of course there are MNRA standards. Wheel/scale standards
For the cone/flange, there's a recommended practice RP 25.
In the small scales ( everything that runs indoors ) coning is just for optical appearance.

Si.
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" In the small scales ( everything that runs indoors ) coning is just for optical appearance."

Not according to the N.M.R.A.s legendary spec. 'RP25' it isn't ! :old dude:



- - - - - - -



Hi Michael :mex:



Way back when, in 1876, when Si.s favourite brand 'Tri-orrible' were simply just G & J Lines ...

... routing rocking-horses outta M.D.F. ...

... and the scurge of squirted-styrene, was just a 'Salada Wagon Works' NIGHTMARE ! :w:



Little did the Bros. know that Albert freakin' Einstein was gonna come along a century later, with his quantum dial-gauge ! ;)





If you'd mentioned RP25, DCC, 4G, WIFI, M25, LIPO etc. etc. ...

... they'd probably be tryin' to hoik out the b.din' sawdust from their lug'oles mate ! :dope:



Maybe you should go for the Bill Schopp 'Wonky'(TM) Patent elliptical drive !  :-



" Oh! I remember reading a 50s/60s, Model Railroader where he scratchbuilt a B&O 0-4-0T C-16 Docksider in the 1/43 flavor of O scale ...
...
and to give that rocking rolling ... because of very short wheelbase effect,
he drilled one driver with axle hole something like 1/64 or 1/32 off center."



BTW Sal. ... What the hell is that crappy cheapo plastic shaft & gear you've got there ? :shocked:

All my top quality vintage 'Tri-orrible' has Real-Metal(TM) drive components ! :P



:doh:



Si.

Helmut
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@Si
Go and read paragraph 5 of RP25 out loud. Then, if you understand just a bit of dynamics, give a reason why that small centering force can compensate the drag of a e.g. Standard H0 coupler 

Si.
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" Go and read paragraph 5 of RP25 out loud.
Then, if you understand just a bit of dynamics,
give a reason why that small centering force can compensate the drag of a e.g. Standard H0 coupler "


Oh well looks like the N.M.R.A. don't know their monkey-railroading from mechanics. :dope:

I've mailed them with your corrected spec. Helmut. ;)



- - - - - - -



Other than that ...

... it seems to ME that the RP25 coning in small-scales is actually VERY important indeed !

I haven't ever noticed any "drag" from a properly installed HO Kadee.






:brill:



Si.



There is of course somewhat of a "dynamic" difference ...

... between a speeding express train of 40' boxcars ...

... and a clunkin' funkin' On30 Porter with a few 4-wheelers ! :slow:

Salada
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My thanks to Warren, Si & especially Helmut for the NMRA & RP-25 links. I had no idea the darling NMRA put so much info into the public domain. None of the Brit 'Societies' publish anything so detailed - you have to pay your £$Yen to join first.

I see what Si meant, it seems the NMRA think coning is either unimportant OR useful, depending on which page you read.

I was rather puzzled by the NMRA "Wheel CODE" column (what code ?) until I noticed that the "wheel code" is simply the wheel thickness in Imperial. (good 'ole Yankee boys, still sticking to proper 0.001 " dimensions rather than this EuroNapoleon junk).

But, I don't understand why wheel (or tyre) width is so related to all the other spec figures. ????.

I took the NMRA at their word but upped the cone taper from 3 to 5 deg, close to prototype practice (depending on which country, some national systems vary a bit + - ).

I've more or less followed the RP-25 110 spec except I've upped flange depth to .0325 from .030 (for a reason). I greatly increased the root radius between tyre & flange to .025 " due to tooling difficulties ( my initial setting was .003 " but it didn't 'feel' right).
I've also reduced the flange thickness from .030 " to .0215 " ('cos it looks like a proper flange now). Hopefully that won't be a problem in splitting switch toes ?!.

All I have to do now is reduce the Tri-orrible wheels to a reasonable width (RP-25 again I suppose ?).

Photos to follow, forgot to upload before typing.

Regards,     Michael
 

 

Salada
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Si,

To answer you more fully I only THINK this junk that Fleabay sent me for a few pennies is Tri-orrible, it was invoiced as "Triang-Hornby" X-3170 (if that means 'owt ?). The motor & truck frame has no name anywhere.

The armature magnet is an enormous old horseshoe type, couldn't attract swarf from more than about 0.001 " distance. But turn the Volts up to about 16 on a 2A supply and the commutator bursts into a shower of sparks as the thing shoots off the end of the workbench. So there is life of sorts in there somewhere, but not necessarily as we know it Jim. I'm hoping a DCC motor chip & a good overhaul will improve it.

Currently (?!) it is a total fail through the Chavez track switches, hence it's early listing for an 'Intermediate Heavy' in the S.W.W. wheel shop.

There are also 2 much stronger magnets, 1 next to each axle. Probably too far from the commuwhatsit to contribute to any of Mr Faraday's torque ?. Some sort of magnetic track adhesion maybe ? - but surely only effective with steel track ?. Dunno.

Yep, the axle is squirted styrosh*te of some sort, but it does have a lovely helical cut worm gear moulded into it. If I wasn't a lazy sod I'd bore out the placky gear & stick it onto a proper Real-Metal (TM) shaft. Maybe I will if it plays up.

I've "invested" in it purely as a test bed for 'Project X', the Chavez Director's crazy new traction/gauge/business idea (still secret until the poor old Sal.Wag.Works staff try to turn their craziness into some viable form of traction power). Too much said already !.

The puzzled postman (more used to delivering my tax demands) has also delivered a few other "investments" in the last few days. All mostly semi-functioning junk but from a sow's ear may emerge a ......?

Regards,     Michael

 

jtrain
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The NMRA, despite of all its drawbacks, has done a great service to the hobby by helping to standardize HO and N scale trains so that everything runs, more or less, the same.

Tell me Michael, are you able to get Kadee wheels in the UK?  It would be much easier in the long run to replace the wheels rather than re-profile them to RP25 standards.

--James

Helmut
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The problem is that Michael needs 0n3 Code110 ( or thereabouts ) wheelsets. H0/00 Code 110 can be obtained from here

Si.
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Problem SOLVED !  ( or sol-ved, as Clouseau would say )


;)


" 0n3 Code110 ( or thereabouts ) wheelsets " ...


... can be obtained from here





Very fishy indeed Francois ...

... X-3170 if I'm not mistaken !



:moose:



Si.

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Probably the only full spec RP-25 ex Tri-Orrible wheels in the world.........? :





No running test yet (later) - but we'll now see if tyre coning makes any difference. My hunch is it can't make things can't worse.

The reason I left the flange depth slightly oversize was to leave 'some meat' on the flanges when it came to machining the flange edge radii, R2 & R3 in above RP-25 diagram. Turning 0.018" radii is not really tooled up for 'out the drawer' in the SWW machine shop.

Thanks again to Helmut & Si. (any idea if them thar KD wheels are available in the Y.U.K. ?).

Thanks James, but as Helmut explained, I am working in 48:1 but using HO track standards (poor man's option but I have plenty else to waste my dosh £ on. I also have my local barman & his family to support). So pure HO stuff is way too small for U.S. 'O' Gauge.

Regards,  Michael







Si.
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" any idea if them thar KD wheels are available in the Y.U.K. ? "



Hi Michael :mex:



The Kadee On30 wheelsets ARE available in Blighty ! :old dude:

I buy mine from 'Gaugemaster' in the link Clouseau found ^^ above. ;)



High-tech Placky(TM) axles, with metal cast wheels.

A straight swop out for Bachmann, Hornby, etc. etc. HO wheelsets.








Here they are, with NEW axle-bearings on some  M.M.M.M.M.& M.Co.  'Tri-orrible' diecast passenger trucks.

A favorite with Wolfy & the  M.M.M.M.M.& M.Co.  carshop ! :cool:



More info & photos etc. HERE



:moose:



Si.

Si.
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:brill:



Si.

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If you don't use coning every time your wheelset is running round a curve one wheel on each axle is slipping.

This will cause loss of traction on driven wheels and excess drag on non driven ones.

Tom

Helmut
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Which is all true for the prototype, but not for the "tramway" radii used on model layouts. As even the NMRA state in their RP25, tread taper is not necessary for models, whereas proper fillet and flange rounding are. The 'guiding' effect seen on a single truck or car rolling down a straight length of track is due to the fillet, not the taper. Once it is part of a group of cars being drawn along, all guiding work relies on the flanges, especially in curves.


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