Page created on 02/07/2024; updated on 16/07/2024
Electrification of A2Dx generator vans
With regard to lighting and conductive couplings, the vans are equipped in the same way as the other coaches, except that:
- the strip is shortened (this is by design: a cutting line and connection pads are placed in the appropriate locations);
- only the “passenger” end is fitted with a conductive coupling.
In addition, these vehicles are fitted with lamps (as is another coach likely to appear at the end of the train), and a function decoder.
Tail lights
The printed circuit boards designed for other coaches are not suitable here: the lights are too far apart. So I used a circuit designed for the VSE coaches, cutting it in half and tinkering with the connection points by scraping off the solder mask. For ease of installation, the two half-circuits are joined by a ⌀ 0.5 nickel silver bridge, which also acts as an electrical conductor.
To fit the circuits to the back of the coach, the width of the end piece of glazing must be reduced. To remove it, you first have to remove the side glazing. This is very easy, as only two small pieces of thin double-sided adhesive hold them in place.
Next, cut along the lines shown in the following photo, then glue with a little Kristal Klear.
You also need to slightly machine the top of the chassis. The photo shows this on an A5rtu coach, which has a slightly different end shape. But the principle is the same: you need to remove the part that protrudes above the line shown.
Remember that, in the case of the van, there is no electric coupling at this end.
The circuits fitted with CMS 0603 LEDs are stuck to the wall with thin double-sided tape.
Current pickup
My first van had been fitted with bronze strips rubbing against the inside of the flanges, but there was a lot of drag and squeaking.
For the one that arrived recently, I decided to fit it with brass bearings. To do this, I hollowed out the axle boxes to a depth of 1.5 mm using a ⌀ 2 spherical milling bit mounted on a mini drill inclined at 15°.
Close-up:
The tricky points are:
- Keep the bogie side horizontal to obtain the same depth on both axle boxes. This is achieved by placing a small wooden wedge underneath;
- centring the milling bit in relation to the axle box. Good to know: the bogie wheelbase is 26.4 mm.
Once the depth stop has been set, proceed slowly at low speed to avoid jamming and melting the plastic.
The flanged bearings have a 25/100 wire soldered to the edge with Bergeon flux.
They are then glued into their housing using CA glue, and held flat using spring clips.
To ensure that the wires stay flat against the side of the bogie, I thought the best solution would be to drill 0.5 diameter holes in the inner brake blocks. These brake blocks shouldn’t be stuck to the side members, of course…
In the foreground, you can see three holes, only one of which will be used. It’s not easy to guide the (HSS) drill to drill where you want…
The wires are slid into these holes, then joined and soldered to a small piece of self-adhesive copper tape. Flexible wires are also soldered there.
Close-up view.
Axle preparation
Non-insulated wheels are mounted on insulated half-axles. If Trix wheels are used, at least the width of the hub must be reduced, as it would otherwise rub on the bearing flange. To achieve this, the wheel is held in an epoxy flange drilled to 10.5 mm. The milling cutter has a diameter of 6 mm, which is sometimes insufficient for certain hubs.
Click on the image for a closer view.
Personally, I reduce — by lathing with a file! — the width of the wheels to 2.8 mm and the height of the flanges to 0.8 (instead of 1.2). Here are the ground wheels, mounted on a half-axle, and their sleeve made from a piece of Bic pen cartridge.
With a 14.4 mm sleeve, the distance between centres varies from 22.8 to 23.0 mm. I take this opportunity to adjust these differences to the slightly different spacings of the brass bearings.
Once the correct values have been obtained, the axles are mounted on the bogies and the position of the sleeve fixed with a little CA glue.
Decoder and power reserve circuit
I used two 2,200 µF / 25 V capacitors in parallel, mounted on a pelletized circuit, with a 100 Ω resistor and a 1N4148 diode.
For the decoder, I had to choose between a too long Lenz Standard+ V2 and a fairly damaged ESU Lokpilot FX V3.0, which I chose anyway. But I can’t get the power reserve to work with this decoder, whereas it works fine with the Lenz. I’ll have to have another look.
Here’s the decoder programming:
- F1: tail lights on the coach at the opposite end of the train;
- F2: van lights;
- F3: compartment lighting;
- F4: dimming of lighting for night traffic.
Wired van:
The decoder is stuck vertically to a partition. On the right you can see the location for a loudspeaker, which to my knowledge has never been offered, nor the sound decoder adapted to the noise of the generator.