Blog Archives
Slip Ups – There is an Easier Way……………
My last post recounted the difficulties that I was encountering correctly wiring up a slip and the technique I had arrived at to overcome this, This precipitated various bits of advice including an alternative approach provided by Richard.
Richard’s solution is certainly a little easier than my approach to wire and does not need an additional point motor to run the extra switching required. It is, however, slightly less idiotproof in use than my version – this is because once the approach turnout is set for the branch in my version, the whole of the run was also set electrically. On Richard’s version, it is also necessary to decide whether the main line to yard is to be set for the yard.
This is what it looks like as a wiring diagram and it is important to note that the approach turnout (A) is also operating one of the slip’s switches too.
I need to fire up the soldering iron now and undertake the correction, so that we can play with trains!
A Bit of a Slip Up…….
I have been continuing with the wiring of Glenmutchkin, but have hit a snag; one that I should have been ready for – the wiring of the slip, I had been aware that a diamond crossing was a challenge to wire and I was suckered into thinking that the switches on a slip could over come the challenge, Well I go that wrong…….!!
The basic problem is that there are a choice of two routes through a diamond crossing and each route requires the polarity of the crossings to be different. The diagram below, which shows how a diamond crossing needs to be wired, should illustrate the problem. The only solution to this is to power the crossing polarity by way of an approach turnout – if you really don’t have one to set the polarity with, then you are going to have to resort to some switches – but at least it will give you a good excuse to interlock the diamond crossing with some signals to remind you on which direction it is set!
Hopefully this is clear that the crossings on the diamond crossing are activated by detecting the direction of the switch on the approach turnout. If it is set for straight ahead, then a train can’t travel over the crossing and therefore the parallel line can so the polarity of the crossings are set accordingly. Conversely, when the approach turnout is set to the branch, the line across the diamond can be used and the polarity is set to suit.
The principal with the diamond crossing needs to be heeded when the crossing is replaced with a single slip as I have, but it does get more complicated because the switch of the slip can also lead to a different route through the crossings. The crossing to the left of the slip is the more straight forward as it is only activated by the approach turnout. However the right hand crossing is more complicated as if the approach turnout is set for the branch then it always needs to be in the red polarity whereas if the approach turnout is set for the main, then it then needs to be controlled by the slips switch.
Hopefully the diagram above shows how this works.
The irritation I have, in addition to having wired it up wrong already (!) is that the approach turnout is on a different board to the slip. To reduce the number of wires crossing the boards, I have decided to simply use a duplicate point motor for the approach turnout located on the same board as the slip. It is expensive but rather more simple than the additional wires.
NB – please see also a follow up post on this wiring arrangement for an alternative approach.
Two Steps Forward and One Back
Having taken a few days off to make a long Easter break and absent the family for a few days, I have set about the wiring of the layout as it has laid untouched for too long!
First things first was to mount the control panel and rather smart it looks too……….
Control panel mounted in situ; a gap for the controller to the left and the aluminium strip to the right masks the power district switches.
Then onto the wiring itself, which takes a surprisingly long time…………….this is only about 50% finished!
The two key boards to the station throat
One of my slightly better ideas (you’re about to find out about a less good ones!) has been to make up mounting pieces for the DCC Concepts Cobalt point motors. These are inspired by those designed for the Tortoise units and work on the same principal; they have a uniform mounting arrangement so once set up the actual point motor can be swapped over if need be without disturbing the set up. This is what they look like:
Cobalt Point Motor Mount
Nothing too revolutional, but I hope it will make changing these at exhibitions a lot easier as this is the absolute devil on Portchullin.
And the less clever idea? Remember the multigang sockets I had used on the control panels (link here) well they are not rated at a sufficient capacity to operate the point motors. I think this is because Cobalts operate on a stall basis (the motor doesn’t turn off, it just stalls when it reaches the resistance of the physical stop). My guess is that this results in quite high ampage draw and has led to the following:
The multi-gang sockets with burnt out sections to the left.
Ooops! Back to the drawing board (or rather traditional tag strip) for the linkage of the control panel to the board.
There have been other problems too; the carefully recorded wiring lists proved to be wrong on occassions so I have had to prove each cable run (dooh!) and I found one of the power district switches was defective (but only after a couple of hours of trying to trace the fault!)
So things are getting there, but we are still not at the stage of the first wheel moving!
Control Freak
I have been back onto the layout of late, with a view to get the first wheel turning on it before too long. That means attacking the electrickery things, beginning with the control panel.
I made a start on this by drawing up a diagrammatic representation in MS Paint and then using this to get one of the online firms (Vistaprint) to print me up a poster board to form the basis of the control panel. I am not sure I chose the right material as it turned up on a light weight foam board and I had to mount a sheet of aluminium behind for it to be stiff enough to be useable. But it did look pretty smart I thought………….
The control panel deals with all of the signals and turnouts that the cabin will have controlled, with local ground frames (which will be located on the boards locally) to be used to control the goods yard and the MPD. The latter will be arranged such that it can be located either to the front or the rear, to allow some flexibility in operation.
I have got to the point where the full extent of switches have been wired in and I am just completing the jumper leads. I took a lot of care to plan the wiring prior to any construction – despite the locos being DCC controlled, there are an awful lot of wires. This is because I have stuck with traditional control for the turnouts and signals. There is further complication as a result of the desire to incorporate some bells and even a block instruments (well maybe, at the moment it is just the wires!). So in all, there are 90 odd wires doing something or another on the layout.
Somewhat in contrast to Portchullin, I have sought to keep the wiring as tidy as possible; everything is neatly collour coded and even labelled (to be fair it was labelled on Portchullin, but in a non colourfast ink………..!). I am hoping that this will make the wiring easier to debug at the start of the matter and repair if it does get damaged.
I am proposing to use a variety of connectors between boards and to the control panel, including this rather nifty varient of the D-sub range that is wired directly onot a cheeseblock wireless connector. Available to a variety of types from ebay including from this seller.
highland miscellany 