Wire in Tube

I have been asked about the method I used for 'wire in tube' point control. I'll desribe the three different ways that this is achievable. This is the low cost, no fuss, no electrics way of controlling points, especially useful on smaller layouts and planks/shelf layouts.

1. This first method I have used with electrofrog points on a DCC layout. Regardless of DC or DCC, the frog polarity needs switching every time the points are thrown. There are a few items needed for this to work properly.

You will need.

1. Good solid wire atleast 1mm in diameter. I have used some long welding rods a friend gave me some time ago. Brass rod is acceptable. K&S do 1mm dia. rod, product no. 3900 (1mm x 1m) Or you can use this Piano Wire (0.914mm) :
http://www.ebay.com.au/itm/Piano-Wire-Choose-Between-18swg-20swg-22swg-and-24swg-All-36-Long-Pack-of-2-/252093939564?var=&hash=item3ab1f83f6c:m:mHYSGPlppjGKVgntp764RYw

2. Slide switches.
In Australia use these : http://www.jaycar.com.au/Electromechanical-Components/Switches/Slide/Sub-miniature-DPDT-Panel-Mount-Switch--Slide-style/p/SS0852
In the UK : http://www.maplin.co.uk/p/double-pole-miniature-fh36p

3. Thin tube. I used R/C car aerial tubes

4. Electrical wire - for connecting to the switch and track/frog.

Here is a few pics of how it goes together on the layout.





I have used 3mm cork to raise the track so that the tube fits under to reach points further away. Each piece of wire needs to be cut to the correct length and the ends folded at a 90* angle, offsetting each end 90*. One end is bent 90* vertically to fit the throw sleeper and the other end bent 90* to fit the slide switch. The slid switch 'handle/knob has been drilled horizontally to take the wire 'hook'. Some 'No More Nails' or 'Liquid Nails' is used to glue the tube down to the base board.

Here is a wiring diagram of how it goes together with the slide switches.



Fairly straight forward !

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2. The next method I have used on Linden Ford. This involved the same diameter wire fed through drinking straws which had been joined together end to end. The same principle applies as the above.

Hornby lever switches were used in conjunction with this as it gives a good throw and lock. A little fettling inside the switch needs to happen to allow these to work. Basically, you are throwing away all the electrical contacts !



Above. Remove the green contact. Drill out the small hole circled red (left switch) to 1mm diameter to match the blue circle hole on the right. Leave the spring in place !

The wire rod needs bending up as shown below. Sorry, no measurements..



And this is fitted into the hole as shown, with the wire running through the redundant plug hole.



The wire rod is feed through 'drinking straws to the point throw bar. Note the position of the levers. They are lined up with the position of the point throw bars, hence the odd angle. The location of the levers depends on the length of the wire rod.



Now the important bit !

The Hornby levers have a 'lock in position' on the top of the slide, where the handle protrudes from. This needs to be set in the lock position and the points closed closest to the lever. Once this is done, the lever can be screwed down into position on the board. The reason for this positioning of the handle/lever, is that the spring will help 'push' the point blades across and hold them into position, hard up against the stock rail. You do not have to alter or remove the spring in the points.

A close up of the levers with the covers back on. these are screwed to the baseboard to stop them moving.



This method has been in operation on Linden Ford now for 2 1/2 years and nothing has failed !

I will add that the area between the straws was filled in with some polystyrene foam to bring everything up to a neutral height.

I have used this method with electrofrog poits and I had to mount a microswitch alongside the point.

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3. This is a relatively easy method if you have a circular saw ! This is preferable for Insulfrog points where no 'live frogs' are involved.

The items you need are :

1. Wire (same as above)
2. 3mm square brass tube. K&S have this. http://www.ksmetals.com/25.html Most good hobby shops stock this product.
3. Circular Saw.
4. Masking Tape
5. The wife's vacuum ! Make sure you ask SWMBO first !

So, this method involves cutting into the surface of the baseboard, before any track is fixed down permanently.
First up, lay out your track and points, (or just your points) to where they are to go as their final resting position. Now, take a rule and marking pen/oencil and draw a line (Straight) from the centre of the throw bar to the edge of the layout. Once you have done all the points, remove them from the layout.
Set up your circular saw to cut 3mm deep. Most circular saws cut a groove 3mm wide, but this does depend on your saw !

Cut a groove from the edge of the board to the other side of the points. You must go past the centre of the point as the circular saw will leave a tapered/curved up cut at the end. Vacumm up all the saw dust from the baseboard and the new grooves/slots.

Take the brass tube (3mm square) and cut into 10mm lengths. Depending on how far the point is away from the edge of the layout will determine how many sections of tube you will need. If the point is 50-100mm from the edge, two sections. For every 100mm after, add another section.

Bend the wire up at 90* at the point end and then feed on however many sections of tube you require. These can now be tapped into the groove/slot with a hammer. You may find them a little tight and the groove may need a little trimming with a Stanley knife.

Once all in place and your happy, cover the groove with masking tape or similar. Perhaps glue some heavy paper over the top with PVA. Do not allow any glue into the groove ! Lay your track down locating the wire and throw bar accordingly. Throw the points in the direction away from the baseboard edge. Now you can bend a handle into the end, either a loop or 90* bend downwards. This will make a nice handle.

Please not that you are relying on the spring within the points to hold the blades in position.

I trust this helps. Any questions, I'm happy to answer.

Cheers, Gary.

 

Cameron, you're welcome.

Andrew, the first pic shows the tubes prior to gluing into position. The dotted lines are where they are to be fixed. I had chosen to mount them 90* to the points for ease of installation and it will avoid any future issues. After all the most direct line between two points is straight !

As for running parallel point control wires, I would opt for something like this diagram.


This is what I would consider doing on parallel points. One wire would be straight from A to B, whereas the second would have a 90* horizontal bend in it followed by the 90* vertical bend, to fix into throw bar. 1mm (0.914mm : 290 swg) piano wire is quite rigid and if you were not totally satisfied with the 1mm diameter wire, I would suggest going up a gauge, 1.218 mm (18 swg).

I can't really see why the aerial tube with wire inside would not flex enough to get around gentle curves.

Paul, the bicycle brake cable is something that I would like to attempt as the wire/plastic sheath is quite durable, but also flexible. I'm sure this would be ideal for running under the baseboard to any position on the track.

Cheers, Gary.