Building the chassis

Chassis itself

The notice says :

Detach the floor from the plate. Bend at 90° the different elements as indicated on the right, fold line inside (buffer beam, underbody flanks, air tank and brake cylinder holder, NEM couplings fixing brackets).

I did as indicated, but I regretted, because these details become very exposed: for example I damaged a shunter handle. But, on the other hand, the bends help to position the side beams. So…

Strengthen with solder (straps and ends in particular).

I did not do that, afraid of not being able to insert beams or drawbar bases correctly. Moreover, I keep at the level of the buffer beams a flexibility that would allow me to correct a lack of perpendicularity more visible when the end walls are mounted.

Then detach the beams (red), beam decorations (blue) and lower beam parts (orange). Solder the beam decorations on the beams…

The overlay of the beam and beam decor parts is facilitated by passing a steel wire rod through each of the footboard holes. Solder on the opposite side to the decor to avoid damaging it (the guard plate fixing rivets are already very little visible…)

… then solder them on the floor and finish with the lower beam plate.

I think it’s better to mount the “lower beam plates” (orange) on the beams (blue and red) first. Indeed, putting solder into the corner of the two parts will be easy, while, in situation under the chassis, it becomes almost impossible. Illustration (background: solution of the notice, in front of: mine).

Mounting the chassis beams

To this, the creator of the kit replied:

Nothing complicated for the lower beam plates, simply let the solder seep by the mortises, that’s more than enough, if there is too much solder, put flux again and get the solder back from the bottom of the chassis to the soldering iron.

I take good note of that for next time.

Attention: the length of the side beams must be corrected: it is 77,2 mm whereas the inside space between buffer beams is only 76,8 mm: it’s thus necessary to shorten the side beams of 0,4 or 0,5 mm so that they fit. Note that mounting with “tenons and mortises” is very easy. The adjustments are surprisingly accurate. I almost never needed to adjust them.

Brake set

Under the chassis, solder the 4 brake pairs, then the control rods (triangles) after having twisted at 90° the central part then the brake shoes.

Personally, I preferred to mount the assembly on template before soldering it on the chassis. I chose to use a round nickel silver control bar. Not only is it more realistic, but it makes it easier to connect the brake shoes (the original flat part doesn’t fit into the small holes provided), and to position the decoration of the shoes.

Here’s the process:

Into a wood or, better, epoxy board (shown in blue), drill two holes 0.5 mm diam., 2 mm deep, distant of 17.6 mm. Prepare a first “pair of brakes”, enlarge the shoe holes a little if necessary with a drill. Prepare two 0.5 mm diam., 22 mm long nickel silver bars, plant them into the board holes. Tin the parts. Put successively on the bars: the brake shoes (half-etched side underneath — pay attention to the position of the etching representing the shoe articulation axle: I made one mistake); then the “pair of brakes”. Hold the parts down and solder them. If a shoe has turned, it’s easy enough to correct by melting the solder again.

Get the obtained assembly out of the board, turn it over, put the second pair of brakes then the shoes (shown in red), etched face towards the base again. Replant the bars into the board.

Mounting the brakes, first side

Mounting the brakes, turning them over

Lay a 17.7 mm thick template (green). Hold the parts down well on it and solder the red pieces.

When the assembly is finished, shorten the ends of the nickel silver bars (cutting pliers then file) to obtain a length of about 19 mm (almost flush with the shoes). Note that with this way of proceeding, the soldering is always done on the inside of the shoes and doesn’t risk impeding the etching.

Mounting the brakes, second side

The original control rods are shortened to keep only the triangles.

Once the assemblies ready, mounting and soldering them under the chassis poses no particular problem. It remains to solder the rods on the new bars, then the safety brackets on the chassis.

Here is a view of the brakes a little later in the mounting process, when the axle boxes and the wheels were mounted.

View of brakes under chassis

Mounting the cylinder and the brake valve

For the air tank and the cylinder, after tinning, the soldering is done through the openings left by the folding of the straps.

Previously, I soldered the transmission levers on the cylinder, replacing the flat fake spring with a guitar string spinning on a diam. 0.3 mm silver nickel rod.

Small problem: either the piece representing the transmission between empty / loaded rod and cylinder is too long, or the distance between rod and cylinder is too short. In the photo below, the original length of this part is shown in red.

Detail of the brake cylinder

It turns out that the cylinder is misplaced, as shown in the photo, but I can’t help it: the location is imposed by the chassis straps (not visible here); small design mistake, confirmed when mounting the brackets: it can be seen that the brake levers (blue lines) are not centred on these brackets (red lines). The cylinder should be 0.5 to 1 mm further to the left (red arrow).

I got the confirmation on the forum by Gérard Huet himself, who is at the origin of this kit (see full post):

In fact, the good trick so that the brake cylinder is in the right place is to first position the triple valve rods on the control rod. The cylinder is then placed so that the rod falls right onto the small end of the shaft protruding from the triple valve.

Personally, I got out of it by shortening the transmission piece, by soldering one on the other, shifting them, the two copies provided and cutting the surplus.

For the brake control rods, levers and transmission, the drawing of the manual is hardly readable, especially with very small parts printed in yellow on a white background. It may be convenient to consult the corresponding PDF file.

Mounting the “stops” of the guard plates

Positioning these stops is delicate; I did it by positioning and holding them with tape, then soldering them with soldering water.

I just realized that the wheel hub is cracked…

Guard plate stop

Mounting the axle boxes

After extracting these parts from the foundry cluster, they must be de-burred and flattened over the spring supports (be careful: file with delicacy, because the nickel silver is twisted quite easily). Then tin them, as well as the chassis beams at the corresponding locations. The parts are held by the finger (the faster it is, the less it burns!). To facilitate a possible correction, only solder one side; check the position in relation to the guard plate before soldering the other side.

Suspension tie rods

Building the steps

The internal distance between supports being 10 mm, they are positioned taped on either side of a 10 mm thick piece of plywood. The step is inserted above; its centring is facilitated by the notches etched under the step.

Step

Elongation drawbars

I don’t intend to mount these drawbars, but I must still point out that there is also a small design mistake here that makes their operation impossible.

Design mistake

To correct it, just turn the reinforcement (green part) up and down. Disadvantage: the hook will have its opening directed towards the frame, making the attachment of the return spring more difficult.

Couplings

For mounting screw couplings, dummies of course, I used the same method as for the brakes, namely to plant the nickel silver rods which will serve as a hinge, in a board, to the exact spacing of parts provided in the kit. For the shackle, I preferred to use ø 0.5 mm silver nickel rod, flattened at the joints.

Of the eight parts representing the clamping cranks, which must be soldered in pairs to obtain the desired thickness, only two (highlighted in green) are correctly etched. Two others (in orange) have no half etching but are still usable at the cost of a small adjustment with a file.

Bad etching of the couplings

To prevent the solder from seeping into the joints and blocking them, it is recommended to insert a sheet of oiled cigarette paper between the parts. Since it is difficult enough to put the pieces on the rods, I didn’t do it; I simply oiled. Only one of six joints was blocked. The ball of the crank was figured by a drop of solder.

Screw coupling

Note that the hooks are equipped with a long tail with a small hole: they are designed to receive a traction spring held by a pin passed through this hole, as shown on the coupling on right. This will be for the sake of it, because I don’t plan to actually use this coupling. By the way, the spring I used would probably be too stiff for proper operation. But the coupling remains removable if I fancy installing a NEM box one day.

Here is a photo of a real coupling (on 150 X steam loco) to get a better idea on ​​how it must appear. The crank is different: it is folding here.

Actual screw coupling

I used a piece of transmission spiral
Ref. BB-5213, 2017 price: 3.50 €
at micro-modele
stretched to make the turns non-joined.
This is actually more of an helix than a spiral…