Post summer status
Entry posted by Vistisen
838 views
Here is an update. In the last six months there has not been a lot of time for modelling, and to be honest there seems to have been a lot of wasted time, as the learning curve for motorising and laying of hand-built points has been steep. There has been far too much ‘two steps forwards and 1.9 steps back’. This has made it hard for me to keep up interest. But I hope I have reached a tipping point. I have decided that this post will focus on the things I have learned in that hope that others can avoid some of the pitfalls I have jumped into.
The current status is that a lot of the point work in the main station area is now down and fixed in place and wired up. This means that I have now reached an area where I can lay several meters og track without having to worry about points. I’m also pleased with the control panel, but this is where the problems start. One of my major focus points was to try and keep the wiring tidy. I am using the DCCConcepts Alpha system which certainly looks good. It is also very easy to use with easy to fit wires that plug into sockets. I plugged it all in and it all worked.
But then whilst doing the second half of the board I discovered that I could make the wiring even neater and self-contained by fixing the two digital switch panel boards to one side of a strip of plywood and the corresponding alpha unit to the other side. So I unplugged all the wires, moved the boards and then re-attached all the plugs, To my horror only half of the switches worked. By fiddling about with the plugs, I could see that there seems to be a problem with the wires sitting too loosely in the sockets. I could get most of the lights working by moving the wires about, but the connections are too unstable to trust. I have a few extra wires and have tried replacing the most troublesome wires and that seems to do the trick. My advice is to avoid moving cables about. The plugs are easy to connect but that does not mean that they should be moved repeatedly. Also make sure that you buy wires that are long enough to avoid putting strain on the connections. My current plan is to buy new cables and make sure that they will not be moved after being plugged in the first time. This really ought not to be necessary and I feel that DCC Concepts should perhaps look again at using slightly more robust connections. Whilst they are rethinking that, I have another small wish. In the instructions they make it very plain that you must take great care with polarity when connecting the power supply to these switch circuit boards. Why not just put a couple of diodes on the board to make it impossible to connect them the wrong way around?
My next issue was with insulating joiners which are very necessary for my hand-built points.
Peco have introduced excellent metal joiners for their bullhead rail and these work well with the SMP flex track and C&L rail I am using. But when it comes to insulated joiners for bullhead rail there seems to be only extreme options ranging from The Peco ‘Gumboot’ which looks horrible and is far too long to be used in the middle of points to separate the frog from the switchblades, to the ExcatoScale cosmetic ‘Stilettos’ I rapidly gave up trying to use them as they normally broke before I got them on to the rails. I ended up using the Tillig insulated joiners that are designed for flat bottomed rail. But they can be ‘persuaded’ to fit bullhead with a bit of finely applied violence. Until a better option arrives this is for me the best compromise.
As those who follow this blog will know (I salute your patience), I have built very light baseboards that use 5cm of extruded foam for strength. This excludes using under board point motors. I am using the relatively new DCC slightly strangely named SS point motors. I assume ‘SS’ stand for Small Surface, and not a refence to a historical German military unit! They are small and powerful. Again, my experiences are mixed. But this I think stems more from my limitations. One of the good things about them is that you can wire two points to a control panel so that a crossover can be controlled from one unit. They also have an adjustable throw, but that is where my problems start. My hand build points are not the most uniform, which means that sometimes the throw of the two points in a crossover is not precisely the same. This gives me an issue as the throw is only adjustable per output and I am running two points of it with different requriements. Normally the difference is small enough for the flexibility of the rail to soak up the difference. But I have experienced that the stepper motor can end in a situation where the midpoint of its throw can drift off-centre, and this gets progressively worse until it is actually stuck at one end of its travel. DCC Concepts have obviously encountered this as they have included a ‘recenter’ button on the control unit, which does NOT function as it says in the instructions. In that it does not recenter the switch but actually moves it to one endpoint of the travel and then when the point Is next changed this will move it back to the middle. NO, that does not make any sense to me either! Especially if it is stuck at the ‘wrong’ end of its travel what happens then?
How to handle what happens when you are running two points off the connection and then reset is not easy either. I end up unplugging the ‘OK’ point and here again I am worried about how robust the supplied connecters as they are the same design used in the control panel switches.
What the reset button does to the adjustable throw is unknown to me. It must be involved as it is the change after a reset which ACTUALLY recenters the throw ( not the button that claims to do it) this change must surely be the maximum thrown or it will not be re-centred?
Not to mention how it affects the polarity of the Frog switching which is not directly connected to the direction of the motor, this I know because as there is a switch to change the direction of throw compared to the DCC command which does NOT change the polarity of the frog power as well.
I fear that there are lots of things with which I am going to have to experiment. The simple but expensive solution for me would be to only run one point off of a connection and use two circuit boards with the same DCC Address to control a crossover. But there must be a better way.
In my station area I have a lot of points relatively close together, and since the whole area has only wide radius curves I have chose to set the track centres at 50mm. This means that I can not fit even the small SS motors between tracks. My solution is to use rods in tubes under the track bed to the outer edge of the track sections. This seems to work fine but it means you have to lay points in the right order… which I didn’t. I managed though to force the rod and wire through the foam track bed without damaging the point that I had glued down. Given that the point motors are wider than they are long, a little right-angle crank would surely make things easier as they could then be fitted parallel to the trackwork.
As you can see form the first photo I lay and ballast plain track at the same time. I use a thinned Copydex mixture that I paint thinly onto the foam track bed. I then lay the track, cover it with ballast. Then I lay a strip of 9mm plywood on the rails and weight it down at 20cm distances with 1 kg weights. Once dry, I hoover the extra ballast up using a bagless handheld vacuum so that the ballast can be reused. Point work that is still attached to the paper templates printed from Templot. These are also glued and weighted using the same Copydex mixture, but I have not painted or ballasted them yet. I learnt from laying the very first point that something that seems to work fine on the building bench might not work as well when it gets the test train which in my case comprises a Bachman Prairie pushing three Dapol 6 wheeled milk tanks. These trucks are terrible runners that can suddenly derail at the slightest provocation. It is much easier to re-solder check rails or switch blades in situ if the points are not painted or packed In plastic ballast!
One of the big issues for me has been wiring dropper wires and getting frogs wired correctly. It can be difficult to check polarity when using AC DCC power to the track. So I have found a new use for my Power TEST panel that I originally built to test the four pin XLR connections (two for DCC power to the track, and two for a separate DCC accessory bus) between each baseboard. By plugging the relevant baseboard’s XLR plug into this panel I can check polarity in the rails by using a 9volt DC transformer and a multi meter instead of the DCC power. The powercab runs on the accessory bus so that I can test point motors as well.
-
2
5 Comments
Recommended Comments
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now