rail joins

[ChristchurchLinda]

Hi ya,

I'm extending my layout using Hornby Flex track. I'm a perfectionist and I'm getting grumpy cause I just can't get a nice clean join. I'm using R910 Fishplates to join the track. My question is, without soldering (i don't have one) how much of

 

a gap can there be between the rails without affecting the electrics? I get one track to butt up nicely but i'm left with 1 to 1.5mm on the other track.

[Gregd99]

I am not an expert at this but.... I would say that you want to leave a gap of between 0.5 and 1 mm on both rails where you join to another piece of track.

 

the track will expand/contract with temperature. A small gap is needed.

[Fishmanoz]

I'm puzzled. Are you saying that it is necessary to cut flex rail lengths incorrectly to create room for expansion how does this compare with set track where rail length can be expected to be correct?

 

To answer the question as asked, good fishplate

 

electrical contact will be made as soon as rail insertion goes beyond the lead in area of the fishplate. However, fishplate contact can be a potential risk in the longer term and the shorter the insertion distance, the higher the risk. So given we are talking

 

DCC in the DCC forum, I would suggest using a bus and dropper wires if rail cutting accuracy can't be improved.

[walkingthedog]

I would advise you leave a small gap with set track as well Fishy. No need to push it together, track of all types and baseboards can move about a bit depending on where you keep your layout.

[2e0dtoeric]

Linda, don't forget that the rails in flexitrack can slide along in the sleepers, so you can butt one end up with no problem.

When it comes to curves, simple geometry will tell you that the length of a curve at different diameters varies. So with a

 

single curve in your flexi, the outside track will be 'correct', while the inside one will be 'too long', and you will have to cut a bit off to make it fit.

Small gaps of a millimeter or two won't matter, they'll just make the wheel noise a little louder.

Set-track

 

already has the lengths adjusted to suit.

 

So, you will need to use a good pair of cutters, (old scissors won't do!), and a small file for trimming off any burrs (rough edges) that happen after the rail has been cut.

 

As was said above, though,

 

for DCC, you really want to use a bus system, and dropper wires from each rail, to ensure a reliable connection. (This has been explained in length several times, so I won't repeat it all again). For that, you need a soldering iron, or someone who can do it

 

for you. A good soldering iron costs about as much as a decoder chip, so they aren't that pricey, really. You will also need a length of multi-core solder, (it comes in reels or tubes, and a bit of practice. Knock a few panel pins partly into a scrap of old

 

wood, and practice soldering wires to the pins. Once you get the hang of it, (and have burned your fingers a few times!!) it is easy.

[ChristchurchLinda]

thanks for all the tips guys. And yes it's because of creating the curves, inside or outside too short or to long!! I've been using good cutters etc. I guess i just needed to read 2e0dtoeric's comment "Small gaps of a millimeter or two won't matter, they'll

 

just make the wheel noise a little louder" I'll get around to the soldering thing........ So thanks again. As they say "Give your stress wings and let it fly away"

[walkingthedog]

I suppose that if you model modern railways you don't want to much clickety clack from the wheels, but if it's steam you want plenty.

[Fishmanoz]

To help get your cutting more accurate for curved flexi track, the difference in rail length is dependant only on the angle through which the track turns, and is independent of the shape of that turn. So if your track forms a 45 degree angle, the difference

 

is 13mm, for 22.5 degrees it's 6.5mm, and 11.25 degrees it's 3.25mm.

 

If you are starting with a nominal length, or centre line length, as you would have for example if you've designed using a programming such as anyrail, then add half the angular difference

 

above to the outer rail, and subtract it from the inner rail. For example, you have a 500mm length of track to lay, and it turns through 22.5 degrees, cut the outer rail to 503.25mm and the inner to 496.75mm.

 

So how useless is this bit of information

 

you ask? Take a simple example - you've used anyrail to design a curve which goes through 45 degrees, you use set track for the middle 22.5 degrees and design easements each going through 11.25 degrees at each end. Anyrail will tell you how long those easements

 

are and to cut correctly, add 1.6mm to that length for the outer rail, and subtract 1.6mm for the inner.

 

How do I know? I've done my design just that way.

[2e0dtoeric]

Prefer fit n cut, saves blowing my mental fuses on trigonometry!

[Fishmanoz]

I realise I'm the exception on this and most prefer the fit n cut. But I suspect Linda must be at least partly doing it my way or wouldn't have had the problem she had from cutting straight and trying to fit curved.

[walkingthedog]

That's what I do 2e0. I fit one end, curve the track fixing it temporarily with pins, mark where it needs to be cut and all is well. Gave up using geometry

[walkingthedog]

Didn't finish that post, flaming ipad. Meant to say gave up using geometry as soon as I could.

 

Maybe Linda is using your system Fishy because she hadn't thought of using ours. Maybe she will now. Try it Linda, less stress on the brain.

[Fishmanoz]

Maybe she will. I'm sticking with mine for now as I want to prove my theory that if you cut flex to the correct length and curve angle rail offsets, then you lay to fixed end points, the track will automatically assume the shape it was designed to. My

 

reason for thinking this works has something to do with the solutions to quadratic equations and definitely will cause my brain to explode this early on a crisp sunny autumn morning here.