I've ordered also a book about "Offene Güterwagen" from MIBA Verlag (Band 3). This is a book that describes almost all open goods wagons that ran on the German railways. Lots of details, explanations in text about the construction, history and a reference to models (H0 scale).
At a modelshop I've even picked up a N scale version of such a wagon.
The brake cabin got a second coat of paint.
The spring steel cut to correct length. I had to adjust the length of the individual blades, so I was able to make 8 sets out of the 6 meter of material.
I'm not sure if the steel already has got any heat treatment; it is however quite tough and hard to drill. The burs had to be removed with a small grinding tool.
I tried to bend the lugs on the outer end of the top leaf, but even after softening the material (heating it up to red heat with a propane torch, and let it cool down slowly), it was still too brittle to bend. For bending it red hot, I didn't have enough hands to hold the torch to heat it, and bend (hammer) it around a small rod at the same time.
So I've opted for silver soldering lugs, made on the lathe.
Before cutting all the springs, the first one was assembled and tested on the scale. It takes about 37 kilograms to get a compression of about 6 mm. (just not fully horizontal)
Than the height was checked. With this curvature in the blades, the buffers are a bit higher than on the locomotive (136mm above rail head)
Shackles were used of a bicycle chain. These are almost the correct size (I had different sizes of chain to choose from, even from a motorcycle, only the holes had to be opened out to 4 mm.
With pins these shackles will connect the springs to the spring holders.
Taking the wagon to a model engineering exhibition with of Stoomgroep Zuid in Wijchen. The total weight of the wagon is already a bit too much to lift it alone by hand.
The spring holders (if that is the correct English name for it) are the connectors between the spring and the frame. With the shackles in between the spring blade and spring holder, there is still a bit of flexibility for the spring to expand during compression and move.
The spring holders on the real wagons are cast items.
I've made them from mild steel strip and a turned bush.
With this simple jig, the spring holders are silver soldered.
I started with making two spring holders, to test their dimensions and locate their position on the frame. The rest was made in a batch. A total of 16 all together: also a set for the beer wagon.
With measuring, testing the concept and making the jig, almost the same amount of time is used for the first two, than for the remaining 14 pieces.
Drilling the frames for taking up the spring holders. With M3 screws these are fixed to the frame.
Pins are used for assembly. These 4 mm pins are cross drilled, for taking up split pins. This drill jig is to make sure that the hole is going through the middle. A stop bolt is used to set the correct distance from the end.
In total 32 of this pins were made.
Springs connected to the frame.
A photo I've taken when the wagon was standing on a short piece of track, me sitting on the wagon. The compression is about 4 mm and the wagon is easy pushed around.
So I believe the calculation matched up and I can now finish the leaf springs. (a buckle in the middle is needed)