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Discussion Boards => General Discussion => Topic started by: Chesticus on January 07, 2008, 11:42:57 PM

Title: Need help on standards
Post by: Chesticus on January 07, 2008, 11:42:57 PM
Well this board helped on my last problem. I am dexigning a model RR. I am trying to find the proper/standard distance between track centers on a curve. You would think that would be easy to find, but I can't find it.

Help

Chesticus
Title: Re: Need help on standards
Post by: WoundedBear on January 08, 2008, 12:26:08 AM
http://www.nmra.com/ (http://www.nmra.com/)

Everything you need to know, all in one handy website.

Sid
Title: Re: Need help on standards
Post by: Chesticus on January 08, 2008, 01:55:16 AM
I went there and I do not see anything relating to how far apart the centerline of tracks on a curve should be.

Chesticus
Title: Re: Need help on standards
Post by: JerryB on January 08, 2008, 04:52:44 AM
Look here for center to center distances on various curves:

http://www.nmra.org/standards/s-8.html (http://www.nmra.org/standards/s-8.html)

and here for clearances on tangent track:

http://www.nmra.org/standards/s-7.html (http://www.nmra.org/standards/s-7.html)

Happy RRing,

Jerry
Title: Re: Need help on standards
Post by: Woody Elmore on January 08, 2008, 07:36:51 AM
You could use an NMRA standards gauge. You can get one from Micromark or join the NMRA.
Title: Re: Need help on standards
Post by: SteamGene on January 08, 2008, 09:07:44 AM
Woody,
I don't think they send a new member a Standards Gauge any longer.  I joined for the first time last year and didn't get one.
Gene
Title: Re: Need help on standards
Post by: JerryB on January 08, 2008, 03:59:20 PM
The NMRA hasn't provided new members with a 'free' gauge for quite a few years.

There is a significant price difference between sources for the gauges. For an H0 gauge:

NMRA Member price: $5.00
NMRA Non-member price: $12.00
Micro-Mark: $18.50

Other sizes / scales have similar prices.

I think these gauges are a required tool for model RRing. I even have one for 1:20.3 scale / 45mm gauge.

Happy RRing,

Jerry
Title: Re: Need help on standards
Post by: Chesticus on January 08, 2008, 09:35:43 PM
Thank you for all of the links you guys. I must have been pretty tired because I could not understand them at first. I was really frustrated. But I got it now. Thank you.

Chesticus
Title: Re: Need help on standards
Post by: Jim Banner on January 08, 2008, 11:59:04 PM
A couple of things to keep in mind:
- The NMRA wheel and track gauge gives clearance for tangent (straight) track only.  Because of overhang, you will need more width on curves to prevent trains from sideswiping.
- If the tracks are at different levels, you will need more horizontal space between them to allow for scenery.  An extra half inch for every inch of vertical separation is a good compromise between prototypical correctness and the realities of never having as much space as we would like to have.  The exception would be in cities where vertical retaining walls may be built at great expense because land values are so high.
Title: Re: Need help on standards
Post by: ddellacca on January 09, 2008, 12:34:54 AM
Jim,

I would never argue with you...., too much respect...
but NMRA RP S-8 does give the recommendations for
curvature separation, unless I'm mistaken.

Dick
Title: Re: Need help on standards
Post by: Woody Elmore on January 09, 2008, 08:30:53 AM
Sorry - didn't mean to imply that the NMRA supplies free gauges.

I can't see how anyone could do a layout without an NMRA gauge. I can't list all the times I've had new trucks with out of gauge wheels or switches that weren't in gauge.

Unfortunately, we are in the era of RTR right out of the box and people assume that everything they buy is perfect.
Title: Re: Need help on standards
Post by: SteamGene on January 09, 2008, 09:11:36 AM
I knew that NMRA USED to supply a "free" gauge with each new membership.   I just assumed you thought it still did.  If it did, I'd have three now.
Gene
Title: Re: Need help on standards
Post by: Jim Banner on January 10, 2008, 12:37:40 AM
Dick, I agree with you 100%.  I mentioned the standards gauge only because Woody recommended it without mentioning that the clearance it gives is only for straight track.  S-8 is the way to go for curved tracks but it applies only if the tracks are in the same  horizontal plane.  I find that using the separation recommended by S-8 and adding 1/2" horizontally for each 1" of vertical separation allows room for scenery.  I guess I caused confusion by forgetting to mention that the "more than" referred to the S-8 separation.  Incidentally, this adding 1/2" horizontally for every inch of vertical separation works in all scales.  For example, if I had a 48" radius curved track in 1:29 G-scale and wanted a parallel track, I would use 55" radius track if both tracks were on the same level.  But if one were a foot higher than the other, I would add at least 6 more inches to the radius of the outside curve, giving 61" radius. 
Title: Re: Need help on standards
Post by: ddellacca on January 10, 2008, 02:22:42 AM
Jim,

Just the way I took the NMRA information, also.
Good explanation.

Dick
Title: Re: Need help on standards
Post by: Loco Bill Canelos on January 10, 2008, 06:26:09 PM
Some one above mentioned a guage for 1:20.3, but I could not find the info on the NMRA pages above.   Anyone know the source for 1:20.3, 1:22.5 & 1:29 .

Thanks
Title: Re: Need help on standards
Post by: Jim Banner on January 10, 2008, 07:57:09 PM
There are details on cutting your own wheel and track gauge at the link below.  Scroll down almost to the bottom of the page.

http://members.shaw.ca/sask.rail/construction/lsbuild/lstrack.html (http://members.shaw.ca/sask.rail/construction/lsbuild/lstrack.html)
Title: Re: Need help on standards
Post by: JerryB on January 10, 2008, 10:19:26 PM
Bill:

The 1:20.3 clearance gauge I mentioned above is not from the NMRA. They don't have any LS ones available.

My gauge is laser cut from 1/4" smoke colored plastic and I believe is based on RGS standards. These gauges were manufactured by (or for) Jonathan Bliese who does business as Electric & Steam Model Works. He can be contacted through his website at:

http://www.rctrains.com/ (http://www.rctrains.com/)

I think the gauges are currently out of production, but Jonathan might know if one is available and / or might consider running a new batch if the demand is there. I think there are going to be quite a few clearance issues with the arrival of the K27 on RRs that were previously running only logging and other small equipment, so perhaps the time is right.

Happy RRing,

Jerry
Title: Re: Need help on standards
Post by: taz-of-boyds on January 12, 2008, 05:56:05 PM
Chesticus,

I fiddled with the NMRA standards a bit.  The ones that you may be most interested for track spacing are:
- S-8 Track Centers (mentioned before)
- S-6 Interurban Clearance and Track Centers

This one has some interesting discussions and reccomendations about what generally fits minimum radius from streetcars on up.
- RP-11 Curvature and Rolling Stock

I looked at the S-8 valuse and scaled them to the three scalles you listed:

First half of table:

Radius-Prototype   all ft   Tang.   1146   574
Prototype centers      13   13   13.25
               
G gauge Class II  - values in inches               
scale   radius   M(*)   Tang.   677   339
20.3   centers   8.9   7.7   7.7   7.8
               
scale   radius      Tang.   611   306
22.5   centers   8.0   6.9   6.9   7.1
               
scale   radius      Tang.   474   238
29   centers   6.2   5.4   5.4   5.5

second half of table:

383   288   231   193   166   146   131
13.5   14   14.5   15   15.25   15.5   16
                  
                  
226   170   137   114   98   86   77
8.0   8.3   8.6   8.9   9.0   9.2   9.5
                  
204   154   123   103   89   78   70
7.2   7.5   7.7   8.0   8.1   8.3   8.5
                  
158   119   96   80   69   60   54
5.6   5.8   6.0   6.2   6.3   6.4   6.6

Does this help any?
Charles
Title: Re: Need help on standards
Post by: Loco Bill Canelos on January 12, 2008, 06:53:20 PM
Thanks Jim. Jerry & TAZ,

Just what I need to make my own!!!

Many thanks to all!!
Title: Re: Need help on standards
Post by: glennk28 on January 13, 2008, 08:27:49 PM
Since these scales all use the same track and wheel standards, any gauge for #1 gauge track and wheels will do.  The larger scales--O and up--do not have clearances on the "Official" gauges.  Some independent manufacturers have done clearance gauges, but these do not reflect standards--more "Recommended Practices" 
Title: Re: Need help on standards
Post by: hobo on January 14, 2008, 10:34:00 AM
Before you attempt  to make your own track gauge for 45MM/#1/Large Scale track.   

Aristo-Craft makes one that includes a level to not only check the track and wheel gauge, but checks the track for level as you go.

The gauge can be found at most Aristo-Craft retailers, and is on their site.
The Aristo-Craft model number is 11906.

Russell