Frog polarization for ROCO HO Ref 42451

I can only make guesses from using other Roco turnouts, so if anyone comes up with an answer based on experience, ignore this. ;-)

There are two "usual" methods of operation of double slip point blades:

- one motor, blades move alternately for crossings or for curve routes. This way, the frogs must be dead because either polarity may be required.

- two motors, driving all points of one end each. This way, there is only one route of the four available at any time. As there is only one route available at a time, the frogs can be polarized.

The Roco point motor has a single pole single throw switch built in. The Roco turnouts have three tiny electrical sockets at the sleeper ends beside the frog and the turnout motor has three wires connecting to the internal switch. (red/green/black?) Bare and twist the wire ends. From memory, the black is the single wire alternately connected to red and green. Insert that wire to the socket wired to the frog. The two remaining wires can be inserted by trial and error into the two remaining sockets. After that, do the same with the other point motor wires.

Regards, Greg.P.

All Roco Line double slips uses two drives.

The requested 10030 under-table turnout motor supports 4 switches. You have to connect with Roco 3-pole plug or to solder directly.

This is true for the over-table turnout motor 40295/6 and simple turnouts.

The problem with double slips turnouts is, that it is not that simple.

From other manufacturer double slips it is known, that you have to polarize the opposite frog according to the turnout motor.

To get an image of the problem consider the double slip as four simple turnouts pushed together. Two pair of points are moved together by one motor.

Or just make a sketch of all four possible ways with the rails colored according to their polarity.

Their is another simple solution to the problem: Buy the double slip with trackbed (42594). This one is already polarized on delivery. (Needs two 42620 trackbed turnout motors)

HTH Edbert

"Gregory Procter" wrote

Has the prototype *ever* used the first method? Not that frog polarity would be an issue.

What about track sectioning?

"Richard" wrote

I'd not thought of that. On thinking about it, it seems to me that if all frogs were earthed, this would work OK. as longitudinal earthing would signal occupancy just as well as lateral earthing when set for routes where the frog would be on the live side. The frog would need to be insulated from the contiguous live section. So there is no absolute requirement for switching polarity.

Track sectioning would work much the same way as it does on turnouts, only you have four of them ovrerlaid.

I assume each set of blades would have its own motor, but they could be under linked or computerised control.

Hello everybody. Thanks for your interest about my problem with all the post send this days.

I will read carefully all the replys and will extract the possible soluti>Hello Greg, Josep

We're on a _model railroad_ ng here. No, I don't know of any prototype using the first method, but then I'm not an expert on world wide DSP practices.

That would require 4 motors. I've definitely seen two pairs of points linked by equalized rodding.