Any suggestions for HO gradient?

On Tue, 24 Feb 2009 12:09:27 +1300, Steve Caple


That's neither 3.5mm:1' nor 1:87.
Greg.P.
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On Thu, 26 Feb 2009 10:20:01 +1300, Greg.Procter wrote:

No, 1:87.1 or 3.5mm/ft is what NMRA defines for H0. And these two are not exactly the same, but so for all practical purposes. Incidentally, I am building French prototype to NMRA standards. But, European standards association MOROP defines in their NEM standards H0 scale to be 1:87 ... The difference is futile.
In practice the most annoying is that MOROP did not accept the NMRA wheelset dimensions in relation to switch points. NEM adheres to a back-to- back distance for wheelsets of 14.3 mm, while NMRA defines a 'check gauge G' from inside one flange to the outside of the other of 15.3 mm. That cannot easily be measured by means of a caliper, so NMRA sells a Gage for that. Although all dimensions of rail and switches, turnouts, are virtually the same, the misunderstanding about the required wheelset dimensions remain. Fortunately the RP25 is more widely used here too. Some makes, like ROCO, only give problems with Shinohara code 70. Not with handlaid code 70 or PECO code 83.
--
Groet, salut, Wim.

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The check gage is indeed one of the sort of silly things to meaure as it is more valid towards what track is to be measured by. It ends up being directly the number that is needed to clear a point or other obstruction in the trackwork so it is indeed a viable number to meet. If you have a thin flange, and you do the back to back dimension, you can fail that critical check gage value in reality but still meet the specs of the standard. Thus with the NEMA standard, I'd have to pull the point back further from the stock rail to insure that I don't pick at the points while the NMRA standard tells me exactly where I can go with the spacing of the points as the wheel will never get under that 15.3mm spec. Maybe only a mm but the spacing between a point and the stock rail is already way too large compared to the relationships of the prototype.
-- Bob May
rmay at nethere.com http: slash /nav.to slash bobmay http: slash /bobmay dot astronomy.net
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It's a design that's very difficult to alter dimensionally on proprietry turnouts. I've often shimmed the check rail(s) of proprietry turnouts to pull wheelsets away from the frog nose, but that leaves narrow tyred wheels in danger of dropping between frog and guard rails. The wide spacing also causes wheel drop, particularly on European 4 wheel wagons. I've concluded I eather build my own turnouts or accept the wheel drop.
Regards, Greg.P.
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You could always put a shim in the bottom of the vee crossing (frog) if you run uniform wheels. i.e., all wheels to RP25 for example. This will stop the wheels from dropping.
-- Cheers.
Roger T. See the GER at: - http://www.islandnet.com/~rogertra /
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wrote:

True, but my HO modelling started in 1959 which results in a wide variety of wheel types in my collection. I convert the worst operating and worst appearing wheels, but I never catch up. I prefer spending my time building new models and I continue to buy those new models that fit my modelling theme. (it's a compromise)
Greg.P.
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"Greg.Procter"

I have a small, by North America standards, collection of rolling stock. Something like 150 freight cars, around 20 vans (cabooses) and about 15 passenger cars. A few of these came with metal wheels, usually those purchased in the past couple of years which, in my case would be the passenger cars. However, almost all the freight cars and vans came with plastic wheels. It took me about two years of buying a package or two or three per month of 33" metal freight car wheels to convert the lot over to all metal wheels.
Have you considered doing something similar to standardise your wheel sets?
I found it made a noticeable different by running all cars with the same brand of wheels. My switches could be fine tuned to the one brand and my locos could pull a couple more cars thanks to the freer running steel wheels.
-- Cheers.
Roger T. See the GER at: - http://www.islandnet.com/~rogertra /
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I've started to purchase bulk packs of KD couplers and metal wheels. I seem to run out of both fairly quickly, and the bulk packs are usually cheaper per unit.
Availability not guaranteed. Products available in my location in the US may not be available in other countries, or even the next hobby shop.
Puckdropper
--
On Usenet, no one can hear you laugh. That's a good thing, though, as
some writers are incorrigible.
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wrote:

I got a thousand odd wheels and axles made in various sizes by a local engineering firm. Problem #1 is that there are a variety of sizes and axle lengths. The "standard" size wheel (1m diameter = 11.5mm scale)is loosely adhered to by different manufacturers, so I found I needed three different diameters to be physically able to fit in the underframes. I needed three different axle lengths (24, 25, 26mm) and both spoked and disk. That's more than a dozen variations. (26mm axles aren't common so I just got a bag of loose axles) Problem #2 is that I have to buy a large batch which requires money. Problem #3 is I've currently run out and there are other calls on my cash just now.

I long ago discarded all plastic wheels - same result as you have found. I occassionally set up a production sequence and do a large batch of wheels. Nowdays several European manufacturers have switched to NMRA profile, but I have about 50 locos to do before I can fill the frog gaps.
Greg.P.
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wrote:

So you're not actually into scale modelling - fair enough, it's your hobby!

Umm, the NMRA thought that extra .1 was worth mentioning! Tell them your theory.

The distance between flange back and opposing flange face is the important dimension for wheelsets. Everything else, other than fl.depth and tread width stems from that dimension.
It's very annoying that NEM did not go straight to NMRA compatibility, but manufacturers generally wish to maintain compatibility with their past products in that customers may well have layouts using turnouts that were designed for original wheelsets. I upgrade older rolling stock wheels and operate them over a variety of modern turnouts and self laid code 70-75 turnouts. I've used code 100 track and turnouts in hidden staging areas.
Greg.P.
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Greg.Procter wrote:

No, Greg, you tell us YOUR theory as to how the difference is detectable in any real model, let alone significant in any practical sense.
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When did _I_ become the NMRA? (I was on the NMRA DCC working group for about 3 years, but not the scale committee) THEY considered the difference between the internationally accepted 1:87, the British 3.5mm:1' and 1:87.1 to be significant enough to set it into their standards. If they hadn't felt the distinction to be significant then they wouldn't have made the distinction.
Regards, Greg.P.
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Greg.Procter wrote:

Stop avoiding the issue. Do YOU, as fount of all wisdom, deem the difference significant, and if so, why?
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Of course it's significant! For a start it requires two extra key presses on the calculator to convert any dimension from full size to scale size.
Now it's time for _you_ to stop avoiding the issue: - why add two extra keystrokes and an extra .15% to an already existing (and somewhat irrational) scale? Those extra keystrokes increase the likelyhood of errors. What intrinsic advantage is gained by that addition? - US arrogance? - a significant improvement in accuracy? - something I've overlooked?
Rergards, Greg.P.
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Greg.Procter wrote:

Wow.
So you are agreeing that it doesn't really matter in any practical sense whether it is 87 or 87.1? Good, that's what everyone else has been saying. So at last you have caught up. Congratulations.
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On 2/27/2009 3:17 PM a_a_a spake thus:

Yes. Let me reinforce that in hopes of drilling the idea into Greg's horrendously thick skull: IT DOESN'T MATTER WHETHER YOU USE 1:87 or 1:87.1. NOBODY'S EVER GOING TO NOTICE THE DIFFERENCE!
So it *doesn't matter* that certain organizations, publications, standards, etc., use one or the other. For all practical purposes, they're completely interchangeable.
Got it? End of discussion.
Sheesh.
--
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David Nebenzahl wrote:

David, why hope to achieve the impossible?
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On Sat, 28 Feb 2009 18:23:30 +1300, David Nebenzahl

So long as you never do any modelling it doesn't matter if you use 1:240, 1:87 or 1:32, so I can see where you're coming from. Your US standards setters have made the statement that the .1 does make a difference, in that they added it over the existing international standard.
Regards, Greg.P.
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I'm saying that better minds than yours have said that .1 is important and that you have followed meekly along with it without a single thought crossing your mind.
Regards, Greg.P.
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Greg.Procter wrote:

nobody except you has said it is important

thought? not a concept relevant to your existence.
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