FRIENDLY FROGS

There’s a common belief that you need to make points ‘DCC friendly’. This is a bit of a misnomer, as a more correct description is to make a point ‘electrically friendly’, regardless of whether you use digital or analogue control. What this refers to is the accidental contact that may be made between the back of the wheel flange and an open point blade, where the open point blade is of the opposite rail polarity. If your wheelsets are properly adjusted, then this shouldn’t be an issue. But if a wheelset does cause a short, this can be problematic. The result will be a micro-short. A 12V analogue system has a relatively slow-acting overload circuit, and trains will often continue to run. A DCC system, however, has a faster short circuit protection system and a micro-short will cause the layout to shut down. Shorts on both types of track power will also cause pitting of the wheelbacks over time. Making the point electrically friendly involves creating an insulating gap in the switch rail between the blade and crossing ‘vee’. The switched part of the blade is connected to its adjacent stock rail, whereas the frog end is electrically connected to the frog. Peco has made it easy to make its ‘OO’ gauge Electrofrog points ‘electrically friendly’. Here’s how to do it:

A Peco SL-E191 that’s been made ‘electrically friendly’.

You’ll see that there are insulating gaps in the closure rails of the Peco SL-E191 Electrofrog. If there are none in your point, you’ll have to cut the rails here.

Cut the wire and, holding the insulated end, bridge the closure and stock rails on one side. Apply the soldering iron and sweat the joints together.

Strip off a decent length of insulation from some thin, multi-strand wire. Apply flux and then solder, allowing the solder to flow along the exposed strands.

With both closure and stock rails linked, you now have to break the wire across the insulating gap. Break the joint with the tip of a scalpel.

Apply flux to the underside of the rail where there are gaps in the webbing. Then apply small amounts of solder to each exposed bit of rail.

Turning the point over, you’ll see the wires that cross the insulating gaps. Note also the gaps in the plastic webbing.

Use the scalpel blade to lift the wire upwards and then cut it back with a pair of fine-nosed cutters.

Repeat the process on the other closure and stock rails. When they’ve been soldered into place, cut back the excess wire.