K track parallel geometry (2024)

Hi all,

Just wondering if anyone has some track 'plans' which show various tricks with the K track geometry?

In particular I am wondering the best way to build a parallel curve using the R4 and R5 radii but at the narrower spacing of the wide radius turnout instead of the standard 64.6mm spacing?

Also interested in anything else that is cool or clever, particularly with wide radius curves.

Thanks!

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There's a perfect solution IMHO: using 2205 flex track...😉😉

Needs a little work to be done nicely, but with a few specific tools, results are more than convincing.

Cheers

Jacques

Unfortunately flex track is not an option in this particular case.

I will play around with it in anyrail and come to a close enough solution.

Adjusting a parallel track (as apposed to strict curve) may be constructed from any set of existing sectional curves by adding a pair of short straights at each end , with the short tracks being of different length. using this as a base 30 degree building block you can then work up in multiples to ... 60, 90 ... degree.

A similar process could be used for 15 degree pairs, however these do not exist for R4,R5 (Which I take in context to be the 2241 and 2251 items)

using the standard available lengths a
... 2202/2293 pair with their 3.7mm difference would produce a 50.79 spacing of track (Outer effective radius for 90 degrees = 772.63)
... 2203/2208 pair with their 5.1mm difference would produce a 45.57 spacing of track (Outer effective radius for 90 degrees = 730.46)
... 2208/2293 pair with their 6.2mm difference would produce a 41.46 spacing of track (Outer effective radius for 90 degrees = 749.49)
... 2203/2204 pair with their 7.5mm difference would produce a 36.61 spacing of track (Outer effective radius for 90 degrees = 702.47 (or see below 681.98))
... 2202/2208 pair with their 9.9mm difference would produce a 27.65 spacing of track (NOTE: * track ties overlap)
... 2203/2293 pair with their 11.3mm

If you cut the straights yourself then the only thing to worry about is that the difference does not cause roadbed overlap
As is the case with the 9.9mm difference of 35.1(2208)/45(2202)

The 2203/2204 pair has a convenient 7.5 mm difference, so instead of butting 2 of these pairs together (which gives a 15mm difference) you could just use a single 2202/2203 pair
Note: the 2202/2293 delta (3.7) is very close to half the 2203/2204 (7.5) delta and will work using this technique

Edited by user01 April 2016 03:46:46(UTC)|Reason: Not specified

I could send you the trackplan of the layout I'm building now.

Do you use wintrack?

Rinus

Peter - thanks for the detailed response. Unfortunately the geometry for R4/5 does not work to allow a 57mm spacing between tracks that the wide radious turn outs use. I also confirmed this in anyRail today playing with short track spacing.

Rinus - I use anyRail

Eric, I have 2 locations of these tracks R4/5 and have to measure it what the distance is between them as I also use the sleeker K - track turnouts, I may have gone wider than 57mm because I use 1:87 passenger carriages.

I've just measured them and they have various distances between the R4/5 but one was 57mm, have you got a sketch and indicate what you've had in mind. I've thrown all my catalogues away so I don't know what the distance is between these wide turnouts

if you create a half circle you can set the inner circle (R4) back until it reaches 57mm and than counter extend the straight track so it is level with outer track and if the 2 tracks are at the end also 57mm extend the 2251 in the middle with a straight track to reach 64mm on both sides.

John

Hi John,

This is for my new layout I am in the planning stage for, you may recall the thread:
https://www.marklin-user.../t35023-Track-plan-ideas

I use only wide radius turnouts and R4/5 for my main line in tunnel areas, hence the need for a 57mm spacing solution.

I tried setting the spacing as per your suggestion but there is not a short enough straight length that will sit the spacing at 57mm.

I use a lot of flex tracks so it is not that big a deal though I do prefer it to be aligned perfectly in the situations required.

I was unable to upload my track plan today due to the website not allowing me to - I will try again tomorrow and you can see what I mean.

Thanks everyone

Opening comment on tollerence ...
for "so called" 57mm track spacing as prohuced by the 2272,2273,2274 items
Curveature : Using the provided specs of 902.4mm radius and an arc if 14dgrees26minutes the spacing is actually 56.96
Straight Length : The Marklin publications also imply a matching length for the straight (documented at 225mm) can be made up with a 2200(180mm) + 2293(41.3mm). These actually sum to 221.3 which is a whopping 3.7mm out.

Your mileage may vary ...

A 57mm track spacing would be made to work with approx 2.5mm(2.55) - while there is no single base set/pair to help with this for the lead-in to the curve, the x2 interim delta of 5.1mm can be achieved with a 2203/2208 pair.

The 2.55mm delta is almost lost in the rounding,
You may wish to simple shave this off the (Outer) lead-in track rails with a Dremel, or leave a gap (Inner track) and fill with solder if really needed

Edited by user02 April 2016 23:58:15(UTC)|Reason: Not specified

Actually TWO sets of individual deltas may be used to form a working delta of 2.5
Using 6.2(2208/2293) - 3.7(2202/2293) will produce an effective spacing (over 90 degrees) of 55.27

And TWO sets of individual deltas may be used to form a working delta of 2.4
Using 9.9(2202/2208) - 7.5(2203/2204) or 7.5(2203/2204) - 5.1(2203/2208) will produce an effective spacing (over 90 degrees) of 55.65

For 60 and 90 degree arcs, the use of 8 pieces of track (for a 5.0 or 4.8 delta) per intermediate delta is a bit excessive and unsightly.
Using a single pair for a 5.1 delta is manageable within acceptable tolerances

The complete solution of the nicer 5.1mm and a, compromising, 2.4mm lead-in/run-out will provide for 55.23 spacing (on paper) for a 90 degree arc.

finer granularity would require a base delta down to 2.0 mm but that would need an excessive amount of bits, using standard lengths. You are better off finding the cheapest single pair and trimming a bit. Keeping in mind the Base lead in metric and the x2 intermediate metric.

Showing a compromised but cleaner option

Showing the best "technical", but not aesthetic, solution (using 2.4)

Edited by user03 April 2016 00:02:14(UTC)|Reason: Not specified

When I was designing my K-track layout I wrote a little Windows program to help me know what bits of tracks would be needed, especially when one needs to adjust the spacing between tracks. Inserting small straight sections at an angle provides an excellent way to achieve rather fine adjustments. So, since we typically know the angles, we can easily have the program calculate the length needed to produce a certain spacing

http://layout.mixmox.com/1/calc

Enjoy

exactly: the best technically but not aesthetic and I've tried it once and looks shocking with long passenger carriages the way they move side to side

I think one has to realize there are ways of doing it and there are ways of avoiding certain perfections but theoretically still maintaining a 57mm distance between tracks
I couldn't see with the track plan where the problem was or is implementing some common and mathematical measurements to achieve the 57mm distance and there is always the perfect solution to use the flexi track on the inside or outside.

I've tried once by cutting a curved track (C-track sleek turnout) in half and created a slim s-curve to be able to connect tracks from opposite sides with a difference distance and it looked shocking aesthetically when a loco with its carriages went past it , in the end I could bare it any longer and cut away some of the cork bedding and just bent the track over a length of about 2 meters and now you wouldn't know it had a different distance in the beginning and there is no visual discrepancy you would notice.

Sometimes you just have to bend the rules

John

I made an alteration to my hidden station area and added a double slip point into the double reversing loops so trains can traverse from the outer to inner tracks.

Here is the geometry I came up with:

Eric, as I've mentioned before although it looks pretty good on paper the reality when carriages drive through this section you may change your mind, the train no longer presents an even flow

John