Improvement of the Jouef
DEV Dd4s luggage car (2)

Original page created on 16/10/2017; updated on 8/03/2024.

Operations on the chassis

Sawing

The chassis is integral with the glazing, according to a common option at Jouef at the time (see UIC coaches). The first thing to do, since the windows will be replaced, is to remove them.

Note: I used a diamond disc, which is not ideal because it causes a heating that melts the plastic, even at low speed. A toothed saw disc would have been better.

I leave a height of about 6 mm to maintain a certain rigidity. The cut is not very regular. It must be equalized because the preserved height is important: it will determine the location of the chassis positioning wedges inside the body.

Steps

The only ones already present must be levelled off: they are very coarse and it will be necessary to make others for all the doors, the large ones and those of the conductor’s compartment.

Milling for future steps

The sides of the chassis are milled to receive the uprights of the future steps. The dimensions are given in the appendix (PDF).

The “conductor” steps will be fixed on the bogie.

Regarding the large steps on the bogie side, I design a mobile system that requires ⌀ 0.6 mm holes in the thickness of the sides (marks a).

1. Stop
2. Step
3. Pivot
4. Return spring

Moulding between the equipment boxes

This moulding, invisible in situation, is not a problem in itself, but I want to place a DIL switch to control future lights. To embed the latter, it is necessary to remove this moulding which is therefore milled. ⌀ 0.8 holes are drilled for the passage of the DIL switch pins.

Buffer beams

Notice the shims between the machining support and the chassis, with a total thickness of 12 mm, to prevent the underbody boxes from touching the support, which will be described later.

Buffers

Some buffer bodies were broken. On the other hand, replacement buffers are got back from Trix PBA coaches. Indeed, these coaches are delivered with buffers a little longer (as well as not compressed bellows) to equip an end coach. These buffers are fool-proofed: their tenon has a diameter of 1.5 mm on one side, and 2 mm on the other.

I drill the buffer bodies at 2.5 mm and I insert pieces of ⌀ 2,4 mm Evergreen tube. Once glued, I ream them to the desired diameter, either 1.5 mm or 2 mm depending on the side.

Fastening for elongating drawbars

The chosen drawbars are large Makette model (KKK1); the Roco are too thick and cannot be inserted between chassis and bogie. The front mounting holes are too close to the buffer beam, which, I recall, has been milled and therefore weakened. So I use the rear holes. I use miniature self-tapping 1.4 mm P-tite screws. The pilot holes are drilled at ⌀ 1.0 mm.

Bogie pivots

To give the chassis a three point suspension, we must first give a little more clearance to the pivots. This is achieved by shortening the pivot relief by the top, and flaring it with a 90° milling bit.

On one end, 2.2 mm thick shims (obtained by superimposing two plastic layers respectively 1.5 and 0.7 mm thick) are glued on both sides of the pivot axis, at 10 mm from it. See the picture below.

On the other end, the bogie will receive a 1 mm spacer around its pivot. So, the total height of the car, which was initially insufficient (44.3 instead of 45.3 — with wheels of suitable diameter), will be corrected.

Operations on bogies

As already said, I had refined the bogies a long time ago. It remains to cut the old loop coupling flush to the load beam, and to mill a semi-cylindrical housing to avoid interaction with the drawbar spring.