I made the first set of crossing gates in early 2014, but didn’t get around to making them work at the time, partly because there were more urgent things to do to get the layout complete enough to exhibit, and partly because I hadn’t found a satisfactory way of making them work - not least because three of the four gates are on one baseboard, with the fourth on the adjacent board. The fact that the gates are severely skewed doesn’t make life any easier. However, with the completion of the creamery and the copse, the question of how to get the level crossing gates working arises again.
I’ve looked at various ways of purely mechanical operation, and also the use of Clearbox motor/gearbox combinations (used on the Brighton Road ground signals). None of these potential solutions seemed very practicable or robust, so no progress was made.
I’m familiar with servos in connection with my interest in flying radio controlled gliders, and subsequently came across their use in connection with rotating ground signals. After a considerable amount of experimentation I have arrived at a solution for the gates which seems to work well. Further detail is given here, and there is a short video here.
My initial attempt at making the gates proved not very robust. They were made entirely of Evergreen plastic section, but they warped a bit when glued together, and also proved to be a little fragile, especially the main post. My second attempt uses a brass frame (end-posts and top and bottom rails) with the internal timbers made of plastic, superglued in place. The photo shows the components - the top and bottom rails are brass square section, mortised into the square tube end posts. The main post has a section of 1/8”brass rod soldered to its bottom end, to provide the pivot, and to connect to the servo under the baseboards.
Whilst working on this end of the layout, we have also added the last few missing chairs and all the fishplates. More importantly (or at least with more visible effect) I have made and installed all the point rodding associated with the signal box - just the boardwalk in front of the signal box to add.
I have a few sheets of Colin Waites’ rodding supports and also Brassmasters. I had a trial run making some of each, and concluded that both designs are extraordinarily fiddly and difficult to make. Eventually I opted for the Brassmasters’ design, partly because they are smaller, and I think closer to scale size than Colin Waites’ effort, but more realistically because I don’t think I have enough Colin Waites to finish the point rodding on both the signal box and the ground frame, and they are no longer available The Waites etches have been posted on eBay for some other lucky modeller to wrestle with.
Finally, having got the electronics on the crossing gates working, I have turned my attention to the operation of the rotating ground signals. These have been through two versions so far: Fulgurex motors (too noisy) and Tortoise motors (difficult to adjust for 90 deg rotation). For the baseboard I’m working on, there are three ground signals, so a MERG Servo4 unit is ideal, easy to make and perfect for providing 90 deg rotation. The photo left shows the assembled kit in place under the base-board, with one of the adjacent relays used to close the switch which operates one of the servos. The photo right shows one of the servos fixed in place by a slightly modified MERG servo mount - a useful comparison between the size of a servo, and a Tortoise motor. There is more detail here.
If you’re interested in using electronics devices to operate a model railway, have a look at the MERG website.
March 2016 to August 2016
Not much activity on the layout for the past few months because I’ve been working hard on finishing a few locos and completing repairs to some of the older ones. However, in testing my engines I’ve been able to identify a few little niggles with the trackwork which I have been able to rectify.
I’ve done some more work on the crossing gates to get them working to my satisfaction - including replacing one of the electronics units which I managed to short-circuit. I’ve also continued with the replacement of Tortoise signal mechanisms with servos. The rotating ground signals are straightforward enough, but the semaphores have proved a little more difficult. A direct drive from the servo arm doesn’t work very well, because the required movement on the signal operating wire is so very small - less than a millimetre. This is only one or two steps of the servo, making the movement very difficult to control.
I’ve opted instead to use a lever mechanism to effectively gear down the servo movement, described in more detail here.
Whilst working on the electronics I’ve also fitted a smoke unit to the creamery chimney, controlled by a MERG timer. That’s prompted me to find and paint a couple of road wagons and some figures to add to the creamery scene.
Finally we have completed the D&S Sheldon & Cowan crane and its tender.
Next on my list of things to do is to improve the presentation of the layout - additions to the information displays.