Modules Acquired & Wiring Updates
Back in October last year, I purchased the modules of somebody who since left our group, giving me another 90° and 9′ of track. These fitted into the car quite snuggly, as they were already crated for transport. Bear in mind that I already have 180° and 6′ of modules of my own!
As can be seen on the underside of the corners above, these boards have our original specification flying leads for connecting boards. These have been known to be ripped off in transit, so we’ve moved to brackets and sockets. Today’s project was to update the boards that we’re taking to Amberley in July.
The Grainge & Hodder boards only have reinforcement at the corners, where the legs bolt through, so a shim was required to prevent a meaty enough screw from poking through. The brackets also needed to be modified, as I’d failed to buy the same banana sockets as last time, these having a thicker barrel! A step drill in the pillar drill quickly enlarged these to the required ½”.
The Tim Horn boards have a thicker end plate, so only required a thin shim. This cruel close-up shows that I didn’t glue the shim on straight! Still, you can see the fully insulated connection below using blade connectors. I’ve used these as my soldering can be a bit hit and miss, which has partially melting a socket due to the metal insert getting too hot. Making the leads up separately, and soldering the cable to the blade connector to ensure continuity, I’ve acheived a much neater installation, at least in my opinion.
A Grab-n-Go Top Box Solution
Another recent addition to the toolbox was a grab-n-go Loconet wiring kit, comprising a reel of flat six-core cable, a set of crimps, a testing set and a bag of 6p6c connectors, all in a cake box.
Yes, they’re often called RJ11 but did you know that’s actually the jack once it’s wired? RJ stands for Registered Jack, a system of standardisation. RJ11, RJ12. RJ13, RJ14, RJ18 and RJ25 ALL use 6p connectors wired with differing configurations and numbers of connectors. RJ11 only uses two pins (6p2c) while Loconet uses all six cores of the cable (6p6c) so is closer t o RJ25!
None of that matters of course, so long as the jack fits into the panel socket and the wiring is Pin 1 to Pin 1.
Point Motor Wiring Looms
Currently under construction are wiring looms for Cobalt Digital IP turnout motors on now two of my modules. Cobalt point motors by DCC Concepts require a 10mm stripped bare wire for connectivity, and they recommend against tinning, even though fellow module owners have and it works. #
Coincidently, the spring connectors are the same pitch (2.54mm/0.1″) as PCB header pins but the standard size is 14mm LOA, 7mm accessible with the plastic collar in place. I’d like to keep the plastic collar as this effectively makes it a plug, so easier to service. I’m just waiting for my electronic component supplier (Dear Old Dad) to confirm whether he’s got longer header pins in his stock, as I don’t really want to buy a bag of 1,000!
As these wires only carry signals from the switch to the turnout motor, I’ve deliberately avoided any of my track bus colours. The first article in the latest MERG Journal has made for some very apposite and topical reading!
Another Useful Tool
We’re continuing to push the local knowledge boundaries, so I thought I’d throw this into the mix, a portable bench vise for the travelling modelling kit.
The component parts, deliberately printed in contrasting colours. Two body parts, the main body and the moving jaw. The desk clamp screw and foot, and the main screw, held in place by a printed circlip.
The assembled bench vise. The main screw was printed in two parts, the handle separate. This enabled the screw to be printed horizontally,so the striae don’t create a potential sheer point, as all the forces are tension. The handle is just a press fit on to the spigot, which is a triangulated hexagon for orientation. The desk screw was printed vertically, as there’s no tension on this part, only compression. The foot is a two-part print-in-place, with a floating (but not removable) inner threaded ring, enabling the screw to turn and the foot to stay still relative to the desk.
The assembled bench vise installed on my desk at work, the table of which is 25mm (1″) thick, to give some sense of scale.
No, it’s not a serious vice, certainly no substitute for a proper metal one, if you’re doing those sorts of jobs. However, if you’re after putting something in the suitcase or rucksack for holding parts while glue sets or files are filing …
A Very Useful Tool
As a complete aside, these gadgets are an absolute boon! No more multi-coloured finger-tips!
https://www.toolstation.com/plastikote-spray-gun/p55556
Just make sure that the can nozzle is aligned with the gap in the front before you pull the trigger. Don’t, just don’t, ask.
Adding A Bit Of Colour
In between mowing the lawns and pruning the wisteria at the weekend, I managed to get some base colours onto those 3D prints. As my Halford’s primers are running out, I’m replacing them with Plastikote from Toolstation. Halfords have apparently changed their paint supplier and gone is the range of manufacturer-specific colours for matching your restoration project, along with the quality. I can’t remember who told me to go to Toolstation instead but I’ll be forever grateful. Plastikote rattle cans are very good.
A tip I picked up many years ago was to warm them thoroughly in hand-hot water, then shake them for twice as long as reccommended in the instructions. This has the combined effect of reducing the viscosity of the paint and atomising the propellant, resulting in easier spraying and a finer finish. In addition, always spray the fiddly bits and edges first, then fill in the untouched flat panel area. Don’t be tempted to do it the other way around or you’ll be sanding out runs and worse.
The paint spraying is deliberately patchy, with red oxide as a base for rust and grime inside and sprayed upwards on the lower half and plain grey sprayed downwards on the outside for residual body colour. I have an enquiry in with Chivers Finelines for some bogie castings and I’ve already acquired bearings and wheelsets. I think some brake wheels and hopper wheels might also be in order. as I haven’t decided on a name for my railroad yet, I’ll just number the wagons individually, when I find the Railroad Roman decal sets I purchased and put in a safe place!
Improving Print Quality
Having been advised that a train of five hoppers plus caboose was going to be too long for most of the fiddle yards and passing loops in our modular group, I decided to print a sixth.
Irish logic? Maybe, but I’m entitled, second generation. No, that gives me two trains of three which, with removable loads allows for a little more interactivity.
Here is that sixth hopper, again before paint. This time, having noticed some reduced quality in the base due to lack of support, I printed it with additional support. You can see a couple that I’ve already removed, in front of the wagon and the discs visible are those that haven’t been snapped off yet. The support prints as a fractal tree, branching out to support the area as required, with a very thin layer at the interface with the actual model, making them easy to remove.
Scaling The Learning Curve
Flushed with that apparent success, I printed a pair of flat wagons, one with bulkheads, both in two parts. These will take some weighting before they’ll track well on the modular layout!
As I’m home alone this week, I’m going to see if I can get some base colours on these this evening and find the supply of Kadee trucks and couplers I’ve got stashed for the purpose. Stashed is a carefully chosen word as I know I’ve bought them, and I can narrow their location down to the 40m³ of my shed. Given their volume is somewhat closer to 10cm³ each, that’s not terribly accurate or helpful. Watch this space!
Access to a Bambu Labs P1S
Work recently acquired an FDM printer, a BambuLab P1S. Obviously, it’s for work stuff, obviously. I might have printed some model railway bits on it, purely as part of the learning process you understand. The learning process does not yet involve CAD as it’s enough for me to download and print the work of others. Thingiverse, Cults3D, Printables et al have seen a reasonable amount of traffic recently!
So far, I’ve printed a train of hoppers. In the spirit of US kits from the cast resin era, all I have to do is add trucks, couplers and paint.
An 0n30 hopper, which I printed five of, in its original print orientation, showing supports for the coupling bar. There’s some stringing in the hopper area but this will be rectified by the addition of load residue covering low down weight.
Unfortunately, Matte Black PLA isn’t the best choice of colour or material for photography. However, it does speed up painting and stop chips and dings being so obvious. Red oxide and grey primers have been acquired from Toolstation, as they’re apparently better quality rattle cans than Halfords these days.
Combining or Reducing Power Supplies
I have a Kitwood Hill Models Test Track Box into which I’ll be fitting the Digitrax Zephyr DCS50 it was designed for plus a Sprog II USB interface and I’d like to put one combined power supply into my Loco Testing Station, for use by both devices separately, not simultanseously.
The intention is to be able to switch between the two devices, so only one is live at a time – either one or other but never both. So I purchased from RS Components a 870-3271 C14 Panel Mount IEC Connector with 5 x 30mm Fuse Block and a 161-8280 RS PRO Switching Power Supply 15VDC 51W. I haven’t purchased switches yet as I haven’t decided on the aesthetic requirements – there’s no shortage of suitable options.
If you dig deep enough on the Digitrax website, you find:
Digitrax recommends the use of a dedicated PS315 power supply or equivalent for use with the DCS50. PS315 output is rated at 15VAC RMS 60Hz and allows up to 3Amps to enable correct operation of the unit. A DC supply of 18VDC and 3Amps will ensure correct track voltage.
Similarly, on the Sprog DCC website, you find:
Recommended Input Voltage 12-15V DC Regulated
As I’m a member of the Model Electronics Railway Group, I asked on their forum:
Will that RS PRO power supply comfortably and reliably but separately power both devices, do I need to do something a bit cleverer or am I attempting something that is impractical, inadvisable or impossible?
Without copying the entire thread, responses from various obviously knowledgeable people including Andrew Crosland of Sprog-DCC suggested that I was over-enginering the solution. I was focused on the desired outcome rather than examining my starting points. It would be better and safer to use the DC input capability of the DCS50 to see what the output at the track was if the input voltage was safe for the Sprog.
I found among my Stash of Oneday Useful Random Stuff (SOURS) a universal laptop power supply that is variable between 15 and 24 Volts DC which ticks two important boxes in the forum discussion; no mains voltage inside the test box and supply the voltage that best suits the Sprog or DCS50, as neither would be in use at the same time. Power into this supply is a standard IEC C13 “kettle” lead.
As suggested, I connected the power supply to the DCS50 and tested the track voltage with a multimeter at various input voltages, starting at 15VDC. Per the clear instructions on the transformer, I unplugged the mains supply before changing the voltage setting each time. What I found was:
| DC In | DCC* Out |
|---|---|
| 15.0V | 12.3V |
| 16.0V | 12.6V |
| 18.0V | 13.7V |
| 20.0V | 13.7V |
| 22.0V | 13.7V |
Above 18.0VDC input, which was confirmed to be within the capability of the Sprog but probably undesirable, the output from the DCS50 did not increase at the track.
Conclusion? There’s no need for more than 18VDC, which would not adversely affect the Sprog, though it’s preferable to turn it down to the recommended 15VDC. Or use 16VDC as a happy (and safe) medium!
The next step is to return the original power supply and C14 socket to RS Components, or try at least as I’ve had them some months, and purchase a suitable panel mount 12VDC socket to plug that variable power supply into, installed on the end of the test box.
Then, from that power socket to a centre off two-way rocker switch to choose between the Sprog and the DCS50. On the DCS50 side, a second such switch to choose between programming and controlling. All of that running at no more than 18VDC inside the box, so red and black cables.