[Engine Lane Junction]

Hi

What type of micro switch should I buy if I am using the wire in the tube method for point activation and how should it be wired up to the point?

Regards

 

[alastairq]

small DPDTor SPDT slide swiches can be had from most electronics stores....however, attaching them to the point operating mechanism will depend on what method you are using.

I suspect currently you are using what us auldfahrts remember as the ''Mercontrol' system?

I have used wire from bike spokes as well...whatever.....

the switch is best linked to the system you actually handle...ie the lever itself, the bit YOU actually operate...sorry, description isn't my forte.

I drill a small hole through the plastic slider on the D/SPDT switch, bending the point operating wire through 90 degrees to pass through the hole.

Then I use the plastic slider to operate the point.

this overcomes the 'mechancal' resistance in the switch.

If you are using 'posh' levers, then you would need to link the lever to the plastic slider somehow?

An alternative to the DPDT slide switch..which is very robust.....maybe the Peco slide switches?

These are the ones that Peco want you to clip underneath their point motors.

they differ from the slide switches in that there is little resistance to the movement of the switch over its contacts.

These can be placed underneath the point tie bar, or alongside to engage in the control wire, or even at the lever end....as long as you arrange some method for the point,or control wire,or lever, to move the slider switch via its central hole....bit of stiff wire, for example?

The peco switches are less robust though, so be warned.

Wiring is simple..there ought to be 3 contacts [or 6 contacts.....3 each side.]

locate the ''always in touch' contact....usually the middle one, but not always.

The other two contacts will be ''either/or'...in other words, one will be connected to the first contact only, at any one time.

Take a wire from each rail at the entrance to the point, and connect each to one of the second pair of contacts mentioned.

then connect a wire from the crossing of the point, to the first contact mentioned.

Thus, the point crossing 'polarity' will be to which ever running rail the switch is thrown for.

SO, MAKE SURE THE SLIDE SWITCH IS ORIENTATED, SO THAT WHEN THE POINTBLADES ARE SET FOR ONE DIRECTION..IE THE CURVE, THEN THE CROSSING VEE IS CONNECTED ELECTRICALLY TO THE CURVED RAIL.....AND VICE VERSA FOR THE STRAIGHT??

if you happen to use a DPDT switch, then wire just the row of contacts on one side for the point.....I used the other to work signals, etc......or even to activate the drunken switchman?

I'd draw a diagram......but I struggle with dyslexic fingers.

don't forget to insulate the crossing vee from the rest of the world.

 

[poliss]

I thought that the whole point of using the Wire in Tube, or Bowden Cable method, was that it is purely mechanical and doesn't need anything electrical.

 

[alastairq]

I am ASSUMING...[dangerous word, that]...the OP is referring to changing the polarity of the crossing?

which is all my diatribe was referring to??

 

[Mike Bellamy]

QUOTE (Engine Lane Junction @ 23 Dec 2007, 09:40) <{POST_SNAPBACK}>Hi

What type of micro switch should I buy if I am using the wire in the tube method for point activation and how should it be wired up to the point?

Regards

Have a look at the Blue Point Turnout Controller stocked by EDM Models (amongst others). This is operated by a lever, rod or wire in tube and includes all the electrical switching you need. It also has an over centre spring to hold the blades over on hand built points or if the spring breaks on a Peco point. It is a bit like the Tortoise motor without the motor!

For details see http://www.ngtrains.com/Pages/Track/track.htm#Blue%20Point

Hope this helps

Mike

 

[upnick]

I have used what are known by the radio control aircraft modellers "snakes" better known as golden rods which link servos to moving surfaces, two types are available ..... they are a plastic rod within an outer tube the centre of the plastic inner rod hollow to accept piano wire bent at a right angle & epoxied in place to connect the tiebar of the point. run under the board they can be bent/angled to your desired position at the front of your layout.
The red and yellow ones are probably enough for most applications ...... and can be extended to any length with threaded rods usually in the shop where stocked.
Although they come 3ft in length already and can be cut to suit ..... when glueing to the underside of the board roughen the outer tube with sandpaper well as the outer tubes dont key glue well otherwise .... i use epoxy glue for them.

Another use is to keep wires tidy with a piece of the very useful piano wire again cut overlong solder on the end of the wire temporally
and thread through.

upnick.