In this week’s post I will show you how I modify Peco points or turnouts to use with DCC, and explain why I make the changes.
Peco make a variety of points in all the common scales and I have used them for many years. Personally, having used them for American and British trains in both N and OO scales, I think they are the best ready-to-run points available. However I always make modifications to them rather than use them directly out of the packet. You can use them directly from the packet and they will work just fine, but I find for lasting reliability a few improvements are needed. For my example I am using some brand new OO/HO large radius points as shown bellow.
This point, as it states on the packet, is an Electrofrog. This means that the area where the rails cross, commonly called the frog, is metal, allowing the maximum amount of electrical connection with the pickup wheels of your trains. Peco’s other points are called Insulfrog and these have a plastic frog. Insulfrogs are the easiest to install because the plastic frog isolates all the rails so you don’t have to make any electrical brakes in the track or do any special electrics. But the downside is the large electrically ‘dead’ section over the plastic frog which can cause stalls with slow-moving or small trains. So I always use Electrofrog points.
To use the point shown below all you need to do is connect the two inner rails using a plastic rail joiner.
Below is an extract from the back of the Peco packet showing how to wire this up for DC or DCC power. With DC power if you don’t include the isolating rail joiner the point will also switch the power on and off in the two sidings. It does this by making the polarity of the rail connected to the frog the same as the stock rail (outside rail) for the route that is not selected.
As I said before, using this point directly out of the packet and connecting it as shown above should work just fine but the drawback is how the power is delivered to the frog.
As supplied, the frog relies on electricity travelling from the stock rail into the point blade via the contact of the two surfaces. Then it travels up the blade rail to the frog. When the point is changed the other point blade makes contact with the other stock rail and the power is fed from that side, also reversing the polarity of the frog. The point throw bar has a built-in spring which keeps pressure on the point blade, holding it against the stock rail. When the track is new and shiny this is fine, but over time dust and grime will get inbetween the two and the electrical connection will become weaker. And if you weather and ballast your track this connection will probably stop working altogether. It can be cleaned by using a piece of fine sand paper or a file but this is not an ideal solution or a permanent fix. Plus the point blade can easily be bent and it’s next to impossible to get it back to straight again.
There is also another problem that can occur. Electricity will always follow the path of least resistance. For example if you had a bit of track with two power connections and one was badly soldered, although you can’t tell, the electricity would flow through the good connection.
So imagine you had a point connected as described above with dirt or dust inbetween the point blade and the stock rail; it’s just about working and the locos will travel over it. But the train you are pulling has a coach with a light in it powered from the track and there are pick-ups on all wheels of the coach. As the coach spans the point blade, i.e with one truck or bogie on the stock rails and one on the frog the electricity will elect to travel through the coach and not through the points. If the lighting circuit in the coach is only a 1.3v LED with a tiny current draw it will not be designed for a lot of power and there is a chance that it will blow. This could happen as the full voltage being pulled by the loco is now passing thought the coach circuit. With a DCC powered layout it may also have the current from several locos running through the coach and I have seen a coach that was parked across such a point that got so hot that the truck actually melted.
So now you know why I modify the points, but what do I actually do?
The first step is to decide how else you can power the frog because it needs to be fed from one stock rail or the other, depending on the direction it’s set in. This can be done in a variety of ways. Peco make an accessory switch that can be fitted to their point motors to power the frog. Seep point motors and Tortoise slow motion point motors both have a built-in switche that can be connect directly to the frog. Peco also make an electronic switch called a smart frog, this will only work with DCC. The smart frog is connected to the power bus and the frog. As a train wheel makes contact with the frog, if the polarity is wrong, it will detect a short faster than the DCC control system and reverse the polarity, allowing the train to continue as if nothing was wrong. Other companies like Tam Valley make the Frog Juicer which works in a similar way to the Peco smart frog.
Simply feeding the frog will greatly improve the performance of the point because the power will run up into the frog and back down the point blades but there’s still an issue. The point blade that’s not touching a stock rail will be a different polarity, as both point blades and the frog are all the same, and there’s the possibility with wide flanged rolling stock that a short could happen as a train passes by. To overcome this Peco have given access to the connecting wires on the underside of the point. In the picture below you can see two small slots in the plastic, each with a connecting wire in. These wires join the frog to the point blades. I remove these wires; as they have been spot welded in the factory you can simply put a small flat ended screwdriver into the slot next to the wire joint and twist. The spot weld will break, repeat for the other end and the wire will fall out.
The problem now is the point blades are again reliant on the contact with the stock rail, however Peco have made this easy to fix. As you can see in the image below, next to the slots where we removed the connecting wire, they have omitted some of the plastic allowing access to the underside of the stock rails and the top of the point blades. On older points this access is not there but can easily be made with a sharp knife.
Using a soldering iron I tinned the underside of the rails with solder.
I then stripped the insulation off some solid core wire and cut it into strips, the same length as the distance between the stock rail and nearest point blade.
Then I placed the wire over the gaps and used the soldering iron to attach each end to the tinned area.
Repeating this on both sides means that the point blades are permanently connected to the stock rails.
And there you go; the point is ready to be installed on the layout. There’s no danger of a bad connection to the point blades, or a short between the free point blade and the stock rail and the frog is powered via a switch. This point will be electrically reliable even when weathered and ballasted .
So although Peco points work straight from the packet, in my experience making these improvements up front will make your layout more reliable and keep your trains running well for years.