Saturday, 16 July 2016

Wiring up the three boards

I originally made the baseboard in six parts using the standard length of the A1 foam board sheets but found that it was better to amalgamate the sheets so that there were only three boards. This kept the complication of switches over joins, etc. to a minimum.

Basic Wiring
I started work on the end nearest the window in the room as that had the simplest layout just the curve and two points. I am fitting the layout out with DCC Concepts Cobalt IP Digital point motors. These give a smooth change for the points and also have a built in feed for frog polarity and for point direction indicators.

First off, I lay out a power bus using copper tape (normally used to stop slugs climbing up plant pots!). I then run droppers down from all of the track positions that will need power and connect them to the appropriate bus.

Point Motors
Each point motor just gets mounted with a nice double side sticky pad (supplied with the motor). I then reinforce this with some foam board hot glued around to stop any twisting motion. Two wires are run from the motor to the power bus and the frog wire is run to the third position. That's each point wire!

The latest motors come with a sticky tab over one end of the motor connector board. This is to stop you putting the power leads into the switch positions. Evidently, this immediately kills the motor and markes it a dud.  This is NOT covered by DCC Concepts warranty. It is, however, carefully explained in the paperwork. I have 8 earlier motors from my previous layout and these do not have a sticker. Guess what? I did it to one of them. $23 later, I have a replacement and a new regime in place to ensure that I don't do it again.

2nd Caution
Make sure that all of your motors are wired up to the same polarity. This isn't as easy as you think. A motor can be mounted in both directions - just think of there being a front (with the point wire) and the back (clear). If you mount one so that it is in the opposite direction, the frog will get the wrong polarity and cause a short as you travel over it.

Thus, you have to ensure that the power feed is inserted in the correct orientation. 

Next, you have to ensure that you get the basic polarity right. Using my NCE controller, I have to enter 1 or 2 when changing the point. 1 and 2 are relative to the orientation so if you want 1 to be the straight route on all of your points, you have to get the feed wires the same for every point motor that faces one way and swap them for every point motor facing the other way. This becomes clearly evident when you read the next part of the blog.

Control Panel
Another nice thing about the Cobalt motors is that you can tap off them to drive LEDs. I have a full blog entry on how I did this. Check out HERE. If you read back from there, you will see all the trials and tribulations I had to get to where I am now with these point motors.

I have also connected a wire from the frog polarity connection through to my LED panel. Fortunately, when I made this, I did it on a breadboard so I can extend the LEDs - there were only 8 points on the last railroad and there are 13 on this one. As a test, I wired up point 8 to the old panel and found that it worked first time.

This is what the underside of the board looks like. As you can see, everything above the baseboard is connected to the two copper power busses and the frogs are connected to the panel with separate wires held down with clamps to the baseboard. Not as tidy as I would like but understandable, nonetheless.

To come back to the polarity of the power feed to the point, not only does it affect the 1 and 2 orientation from the NCE controller but it also affects the colours. Now I like to define a main on each point and like that to be Green on the panel. As the points are set up at the moment, I am getting a red on that so I have to swap over the feed to both points.

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