I have read alot of posts about min radius; My question is this. When someone says that a 22" min radius will work best for a specific engine or specific length passenger car are they talking about realistic appearances or are they saying the engine or car won't work at all?
It would be the car or locomotive will be able to negotiate the curve most of the time, because in order to look realistic you need 30"+ radius curves. For example a passenger car may have a minimum radius of 24", but look horrible due to the overhang, and probably would not look good on anything less than 30" or so. Often times, a manufacturer may state that it can make 18" radius curves or 22" radius curves, but half the time the loco or car will fail to negotiate the curve without derailing or becoming uncoupled. Not to mention it doesn't look realistic by any means.
yeah tru dat the over hang is considerable but I don't mind or should I say my engineer don't mind as long as the wheels keep rolling...he's happy
That's the real question; is it a question of realistic or is a question of trains wont run. i would think that if a 18" radius was to small for most trains to run on then why would most hobby stores carry more 18" stuff than other sizes and why would most train sets come with 18" radius track?
Quote from: tford on February 13, 2010, 10:04:36 PM
That's the real question; is it a question of realistic or is a question of trains wont run. i would think that if a 18" radius was to small for most trains to run on then why would most hobby stores carry more 18" stuff than other sizes and why would most train sets come with 18" radius track?
There is a simple answer-space- that is all most people have room for is 18" radius curves, although you can squeeze 22" radius curves on a 4'x8' it is a tight fit and most people just opt with the easy to use 18" sectional track over flex track. Most people are satisfied with a 36" circle of track (18" radius) and running it around the X-mas tree or on a table. Most kids that I know don't care about realism and wouldn't find anything wrong with a DD40 on 15" radius track followed by a 4-8-8-4 Big Boy, carrying an articulated auto carrier and an 89' box car. The only problem is that none of these can even rest on 15" radius curves let alone negotiate them. Heck they all require at least a 22" radius just to make the curves half of the time, and probably would need at least 24" radius for reliable running. And these would all require at least 30+ inch radius curves to look even reasonable let alone good.
I run 2 ovals 18 and 22 on my 4x10
No problem getting the 22 as long as you don't want outside sidings which I don't
My main pleasure is watching them run not seeing how much stock I can have on sidings etc
why 18" radius?
it has been a standard size for at least 50 years, abnd dates from an era of 40 foot freis\ght cars and smaller locomotives. most train sets sold use 18" radius, small steam or diesel locomotives, and 40 or 50 foot freight cars. all work well on 18" radius track.
modern railroading is dominated by massive 6 axle diesels, and freight cars up to 90 feet are common. passenger cars are also in hte 80-90 foot range. these are not going to perform well on 18" radius, but most will work on 22. they will look much better on wider radii such as 36" however.
my advice is to use 22 or 24 if possible, but if you can't use the 18. make your railroad represent a time and place where smaller cars and locomotives were the norm, say the 1950s, or ever a branch line winding through the mountains of west virginia in the 1990s, where larger cars and locomotives were prohibited from operating due to sharp curves.
I don't even run 50 fters on my 22
I think sticking with 40 is better and there are plenty of 40 fters or less out there including gondolas -ore cars and coal hoppers
Funny thing though I can run my Berk on the 22 and it looks ok and the -Northern even looks acceptable
The only passenger cars that don't look weird on the 22 are the early Overland types which can be run as a fan fare type set up
So I would say you are limited to freight on the 22 and 18
Here is a pic of my 22 and 18 with 2 sidings off the inside 18
You can see it fits the 48" wide plywood alright
A work in progress with no ballast or scenery yet
(http://bandb3536.com/overhead.jpg)
I like the plexi glass border as my 2-8-0 has hit the floor twice but only caused cosmetic damage, still runs great
Yeah I learned real quick about adding the plexiglass especially since klutzy me can knock them on the floor without a derailment ;D
How is a radius measured in terms of track (I know what radius is)?---From center of track to center of track? Essentially I am trying to plan how wide an area an 18" radius or 22" radius will consume.
thanks
Chris
center line distance
it is measured center to center as you have guessed. i'd add at least 4" to the diameter to ensure the track isn't right on the edge of the table.
thus:18" radius requires a minimum of 40", 22 requires 48".....
...thank you for the information. Excuse my ignorance, but if flex track is used, could I not build a curve with any size radius, such as 20", and not use an industry standard like 18 or 22"? Would there be any potential problem with doing this???
Chris
Yep, with flex track you can make any radius (but it gets tough once you try to bend it below 12" or so). No there's nothing wrong with 20" radius as long as you locos and rolling stock don't require a 22 or 24 inch radius or something like that.
here's mine 18" and 22" on 4X8 (http://i211.photobucket.com/albums/bb165/nitroburnr/IMG_8262.jpg)
Dear All,
Using flex track (or sectional curves, for that matter), you need to keep in mind the minimum center-line spacing between tracks to avoid overhang crashes.
http://www.nmra.org/standards/sandrp/s-8.html
(Scroll down to HO.)
One would not, for instance, put a 20" radius flex curve between 18"R and 22"R sectional curves, as it would need minimum 2-3/8" spacing, according to the NMRA.
Gomez Addams would be proud if you do, though.
Hope this helps.
Sincerely,
Joe Satnik
one thing you may find helpful if laying flex track are the radius guages made by ribbonrail. these thin pieces of metal curved to fit between the rails of track laid at a particular radius, and they are available in a variety of sizes from about 15" up to 48" radius. you simply set the guage between the rails of your flex track, it will force the track into the desired radius, then you fasten the track down. using these is an easy way to ensure a smooth curve and eliminate the kinks and sharper curves that sometimes result when laying flex track. these can also be used for handlaid track (like i do) and to elimiante kinks between sections of sectional track.
I have two of those.
jward or ABC were do you get these radius gauges?
The owner of my local hobby shop gave them to me about 5 or 6 years ago.
Here's the track gauge's that they make for HO scale:
5, 10, and 24 inch straight
and 5 and 10 inch gauges for 18 inch radius curves through 48 inch radius.
They are about $4 each.
Here's a pics
(http://www.walthers.com/prodimage/79899781/89703323021329.gif)
5 inch
Here'a link to walthers
http://www.walthers.com/exec/search?category=&scale=H&manu=ribbonrail&item=&keywords=gauge&words=restrict&instock=Y&split=30&Submit=Search (http://www.walthers.com/exec/search?category=&scale=H&manu=ribbonrail&item=&keywords=gauge&words=restrict&instock=Y&split=30&Submit=Search)
Here's what's in stock:
170-10 Track Alignment Gauges - Straight -- 10" HO
170-20 5" Track Alignment Gauges - Curved -- 20" Radius HO
170-25 5" Track Alignment Gauges - Curved -- 25" Radius HO
170-26 5" Track Alignment Gauges - Curved -- 26" Radius HO
170-27 5" Track Alignment Gauges - Curved -- 27" Radius HO
170-29 5" Track Alignment Gauges - Curved -- 29" Radius HO
170-31 5" Track Alignment Gauges - Curved -- 31" Radius HO
170-33 5" Track Alignment Gauges - Curved -- 33" Radius HO
170-1020 10" Track Alignment Gauges - Curved -- 20" Radius HO
170-1022 10" Track Alignment Gauges - Curved -- 22" Radius HO
170-1024 10" Track Alignment Gauges - Curved -- 24" Radius HO
170-1030 10" Track Alignment Gauges - Curved -- 30" Radius HO
170-1032 10" Track Alignment Gauges - Curved -- 32" Radius HO
170-1034 10" Track Alignment Gauges - Curved -- 34" Radius HO
Thanks, looks like they would be easy to use.
Dear All,
Track gauges:
Pros:
1.) The alignment gauges could come in handy where it is difficult to use a trammel, as in a corner of an around the wall layout.
Cons:
1.) Expense.
2.) Not the exact radius or spacing of radii you or the NMRA had hoped for.
You can easily make a trammel out of a cheap wooden yardstick, which will be good for radii up to about 34-1/2".
Just drill a small hole (e.g. 1/16") for the center of the circle at 1", then drill another at 1" beyond your target radius. Keep both holes at the same point on the width of the yardstick. (e.g. both holes 1/4" in from the left side...)
Use a marker to label the hole with the target radius, then draw a line through the nearby ruler "inch" numbers to avoid confusion. (Don't ask how I know this...)
Put a small nail through the trammel into the layout board at the center of the circle, then draw the circle with a pencil through the trammel hole at the target radius.
Longer radii, use longer thin strips of wood, marked and drilled at points measured with a tape measure.
This MR article (ask your librarian) shows the use of a trammel in an around the wall layout:
Let's build the Wildcat Central
Model Railroader, January 2001 page 74
A room-sized HO layout for today's big trains
Article also published in the book "Basic Model Railroad Track Plans", page 56
(FOAM, "KELLY, JIM", LAYOUT, TRACKPLAN, CONSTRUCTION, HO, MR )
Trackplan is 10x12
- Layout construction details
- Center-operating plan
- Standard gauge
- Continuous operation
- Double track main
Jim uses a camera tripod to float the center point for the trammel out in space.
I highly recommend this article, as it packs tons of tips on building layouts...
Hope this helps.
Sincerely,
Joe Satnik