Point electrical switches

[009 micro modeller]

I’m currently laying some track on a layout, including a point. Previously I’ve relied on the blades for electrical contact, which has worked fine except on the last layout I built, and since this one will also be handling loose-loaded

wagons of gravel (with obvious minor electric issues should any spill and get stuck in the points) I’m tempted to have some sort of electrical switching as well. It’s a relatively simple insulated frog point and I understand how it works and (mostly) which bits change polarity, but I’m struggling to work out the simplest way to wire it. Mainly to improve the way the point looks in scenic terms, I’m trying to minimise the number of wires and soldered connections. I’ve seen an article before where the author had integrated the electrical switching into the wire-in-tube switch, although I can’t remember how they did this. If it relies on sliding contacts it might replicate some of the issues that come from relying on the point blades themselves. This is the point (N gauge; the one I actually use will be 009 but apart from the sleepers the design is the same), with the positive and negative (non-moving) sides marked:

[Nigelcliffe]

One, of many, ways of including a switch in a wire-in-tube setup is like this, using a roller arm microswitch. The green thing is fixed to the wire (the striped item) so it moves with the wire. 

 

If the two fixing screws go into slotted holes, the position of the switch can be fine-tuned. 

Typically, microswitches come as single pole change over (three contacts).   Microswitches can be stacked, and their operating arms fixed together with a bit of scrap etch, so a double pole one can be assembled. 

 

 

 

If concerned about the electrical contact of the blades, then you'll need four wires, somewhere along the rails indicated below with the circle.

 

 

You'll need two poles, so that's either two switches, or a double pole switch.  The switch should connect the wire beyond the frog to the respective colour of fixed rail when the blades are in the correct orientation for travel along that route, and should disconnect the other rail. 

 

There is a three-wire version, which treats the point as a live-frog (electrically), but its as many solder contacts onto the rail, so doesn't really save you any issues of fixing wires to rails.    

 

 

 

[Pete the Elaner]

1 hour ago, 009 micro modeller said:

I’m currently laying some track on a layout, including a point. Previously I’ve relied on the blades for electrical contact, which has worked fine except on the last layout I built, and since this one will also be handling loose-loaded

wagons of gravel (with obvious minor electric issues should any spill and get stuck in the points) I’m tempted to have some sort of electrical switching as well. It’s a relatively simple insulated frog point and I understand how it works and (mostly) which bits change polarity, but I’m struggling to work out the simplest way to wire it. Mainly to improve the way the point looks in scenic terms, I’m trying to minimise the number of wires and soldered connections. I’ve seen an article before where the author had integrated the electrical switching into the wire-in-tube switch, although I can’t remember how they did this. If it relies on sliding contacts it might replicate some of the issues that come from relying on the point blades themselves.

 

Points are hard to replace because they are locked in place by surrounding track & ballasting. A remote switch does not have to suffer from this limitation, so can be changed more easily if required....

...but you'll be less likely to need to replace it anyway.

Assuming you ballast & weather your points, this can cause a lot of the reliability issues.

The switch will be exactly that...a switch. Its only function will be to make a reliable electrical connection, not something which has a different primary function (ie to look like a rail).

A proper switch should therefore be more reliable & you will be less likely to need replacing.

[cliff park]

Microswitches in particular are very robust and free from dirt problems as they are virtually sealed, and cheap

[DCB]

It is much easier with live frog points, I just put a 10p Chinese micro switch so the point tie bar pushes it to make contact when the point is thrown and feed the frog from either left hand or right hand rail.  The switch is no higher than the rail surface and I secure them with small screws or large track pins.  With dead frogs you need two switches as there are two electrically isolated rails at the frog.  Operating points by wire in tube can be really ugly and connecting the wire to a peco point is "Challenging"  Ideally the wire will come up from underneath from a groove in the baseboard like the way a peco point motor drives.  Using wire in tube to operate the switches using the little pip on the end of the peco tie bar allows you to hide the switches under line-side clutter is maybe an easier option

For points exposed outside in the garden a reed switch or two operated by a magnet pushed by wire in tube could be the answer I am planning on fitting one to  an outside siding this evening or tomorrow.

[Ron Ron Ron]

Sorry to be a bit OT, but there are such a thing as ready made manual point motors, that are operated by wire-in-tube or push/pull rods.

These have switches built-in, for switching frog polarity or operating signals or control panel LED's, ..... just like electric point motors.

For example, the Blue Point manual switch machine looks very much like a smaller version of the Tortoise point motor, except it's operated manually.

 

 

 

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[009 micro modeller]

1 hour ago, Ron Ron Ron said:

Sorry to be a bit OT, but there are such a thing as ready made manual point motors, that are operated by wire-in-tube or push/pull rods.

These have switches built-in, for switching frog polarity or operating signals or control panel LED's, ..... just like electric point motors.

For example, the Blue Point manual switch machine looks very much like a smaller version of the Tortoise point motor, except it's operated manually.

 

 

 

.

 

Mare they suitable for 9mm gauge?

[Ron Ron Ron]

1 hour ago, 009 micro modeller said:

Are they suitable for 9mm gauge?

 

Yes. Designed for use with N through to 0 gauge layouts.

The electrical contacts are double pole, double throw (DPDT) rated at 5 amps, so they have plenty of capacity to power a frog or just about anything else you’ll want to drive.

 

 

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[melmerby]

4 hours ago, Ron Ron Ron said:

Sorry to be a bit OT, but there are such a thing as ready made manual point motors, that are operated by wire-in-tube or push/pull rods.

These have switches built-in, for switching frog polarity or operating signals or control panel LED's, ..... just like electric point motors.

For example, the Blue Point manual switch machine looks very much like a smaller version of the Tortoise point motor, except it's operated manually.

 

 

 

.

What's inside the little housing?

Do I assume a through linkage in the form of a  pivotted, inverted T operating the changeover switch?

 

Just found the link:

https://www.micromark.com/Blue-Point-Switch-MachineTurnout-Controller

 

 

A useful bit of kit.

Could even be used so that one Tortoise could operate a second turnout (e.g. crossover)

Edited July 11, 2020 by melmerby

[Ron Ron Ron]

9 minutes ago, melmerby said:

.....A useful bit of kit.

 

Certainly is.

No faffing around fabricating bits of metal and making cranks etc.

They used to be sold in the UK by a few stockists, but I don't think anyone has sold them here for a while.

 

Another similar bit of kit is the Bullfrog Manual Turnout machine.

Made from laser cut plywood. Used to be available both ready assembled and in kit form.

 

https://www.handlaidtrack.com/bf-0002

 

 

 

 

Note the built-in switch.

 

 

 

 

 

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Edited July 11, 2020 by Ron Ron Ron

[009 micro modeller]

1 hour ago, Ron Ron Ron said:

 

Yes. Designed for use with N through to 0 gauge layouts.

The electrical contacts are double pole, double throw (DPDT) rated at 5 amps, so they have plenty of capacity to power a frog or just about anything else you’ll want to drive.

 

 

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Although presumably they work with insulated frogs as well?

[Ron Ron Ron]

2 hours ago, 009 micro modeller said:

 

Although presumably they work with insulated frogs as well?

 

Why wouldn't they?

They move the point blades and hold them against the stock rail.

The frog is not affected by the point motors, unless using a built-in switch to change frog polarity on live frog points (e.g. electro frog).

They should work just fine with insulated frog points.

 

 

 

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[009 micro modeller]

1 hour ago, Ron Ron Ron said:

 

Why wouldn't they?

They move the point blades and hold them against the stock rail.

The frog is not affected by the point motors, unless using a built-in switch to change frog polarity on live frog points (e.g. electro frog).

They should work just fine with insulated frog points.

 

 

 

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Yes that’s what I thought, it’s just that powering the frog had been mentioned.