The selected axles (PE JR3 or JR5) have a 26 mm length between ends. In order to mount them, the bearings must be placed flush with the guard plates. For this, I pressed them hot, using a soldering iron (not too hot anyway!). Here are the dimensions of the bearings used (Fig 10).
But I did not think of the fact that there would not be enough backlash, and that the wagon would be very sensitive to the derailment, especially with very small flanges. If I had to do it again, I would change the axles as follows (Fig. 11).
To correct this blunder afterwards, I replaced the original 26 mm axles with 25.4 mm axles. The backlash is a bit too big, and the driving stability improvement is not obvious. The main derailment cause appears to be the combination of three factors: very small flanges, track not necessarily very well laid, and stiffness of the Roco drawbar springs. I was therefore led to increase the ballast by 25 g, which brings the wagon mass to 90 g. The overload is not too troublesome, thanks to the brass bearings, much less sensitive to wear than the plastic.
No particular problem. Possibly rear glue the buffers with super glue. But if the (ø 2) holes are well-made, the buffers should stand on their own. Also, glue the ramps through the inside of the body.
I have not mounted these parts yet.
As I said, the Carpena decals do not suit me, because the markings are black, whereas they should be white. So, for the moment I have printed labels with a laser printer, with the disadvantages of paper thickness and lack of sharpness.
Here is an example of a plate (I used the SNCF font provided gracefully on the Apocopa website). The only drawback is that lowercase letters are much smaller than uppercase letters. For example, to write “Is”, I am forced to change size between “I” and “s”. Why? I don’t know…
Attention: the original is vectorized; the image here is in bitmap (PNG), and therefore inevitably of lower quality.
After gluing the new ballast — which is actually the real chassis — on the chassis with super glue (because I have given up the double-sided adhesive), I fix the body with two 2.2 × 5 Parker screws. The drawbar bases are then secured to the chassis using M2 screws, interposing the 2 mm thick spacers (attention: modification, see below), without tightening too much. The drawbar must slide without any hard point.
This equipment, which partially covers the drawbars, can only be assembled at the end.
I bought brake equipment (rod assembly plus blocks) Makette ref. 2404. They are normally fixed under the chassis by four pins (see drawing opposite). However, the fixing screws of the elongated drawbars prevent the mounting of the pins on the coupling side. Too bad: I will content myself with the other two; in any case, the connecting rod passing over the axle almost touches it, which prevents it from falling.
Caution: the brake block horizontal rod bears on the Roco drawbar, which prevents the blocks from positioning correctly. So, I had to revisit the drawbar height adjustment spacers, replacing those 2 mm thick with 1.2 mm thick washers. The drawbar position is not too much affected.
Two ø 1.2 or better 1.3 holes must be drilled in the chassis to facilitate assembly, 8.3 mm behind the axles and 9.75 mm on either side of the centre line car. The unusable pin bars will be cut at about half their height. CA gluing.