Welcome

Live steam model on 7¼" gauge of the Württembergische T3 no 924

Welcome to this blog. It will inform you about the progress of designing and building miniature live steam, coal fired locomotives for passenger hauling. Currently I'm working on a 7¼" gauge, scale 1:8, German T3 steam locomotive.

In 2006 I started this new project. This is a small 0-6-0 branch line locomotive of the German KWStE (Königlich Württembergischen Staatseisenbahnen) origin with outside cylinders and Walschaerts valve gear. The loco is about 1.10 metre long and will weigh approx. 100 kg.

On the left you'll find the index where you can browse through the different articles and on the right you'll find all the extra's. On the top tabs you'll find a brief description of my other locos.

Enjoy this site. Erik-Jan Stroetinga. The Netherlands. Europe.

Thursday, 6 February 2020

Güterwagen Omk (part 8) finishing the leaf springs

For finishing the leaf springs a so called spring buckle had to be made. 
This is a strap around the individual leaves and keeps them together as one set. 



I've used 12 x 2 mm mild steel. To make a sharp bend possible, a grove was cut in the milling machine.


Bending it to a U shape was than done on the sheet folding machine.



To make the buckle fully closed, a plate is silvered soldered on the top.
To keep it positioned during soldering, a weighted pin was placed on the assembly. It is holding the parts in position; but still allows them to expand when heated to red hot. A clamp would probably deform the parts. 

 

A M3 hole was taped on the top of the buckle, a recess for the bolt drilled on the underside. 


On top of the spring, a small wedged plate is inserted, so that the buckle is fully enclosing the leaves.  A bolt from the underside is pushed through the assembly and screwed in the top plate.  A capped nut is locking the bolt. 
This is not original as on the full sized wagons, but was done to act as an sturdy end stop. This way there is a limit to the compression of the spring. The capped nut will touch the underside of the frame when the maximum load is overstressed. 


A high strength Allan screw tightens the leaves together to the top plate. The buckle only has transfer the pushing force from the hornblock to the top plate.





The space between the leaves is protected with Dinitrol anti rust compound. 



The bearing housing, seen from the backside



It is glued into the hornblock.  The close fit of the parts (only 0.03 mm play) makes the glue to set very fast. 


The assembled bearing block


A recess on top of the bearing block; for positioning the spring buckle. 


The buckle in position on the bearing block. 


Fully compressed; the capped nut acting as end stop.
Tested on scales before; each spring takes up about 400 N  (~ 40 kilograms) 



The wagon unloaded on the floor and....


loaded with the me sitting on it. About two third of the compression is reached.