Cambrian 4 Wheel Coaches Parts and Assembly

[Timber]

Hello

 

Over the past few years I have made a number of 4 wheel coaches using etches and 3D printed parts.  This is the latest model.  It includes a number of design changes to my standard build process, including 3D printed interiors.  The prototype is taken from a drawing in Mike Lloyd's beautiful book on the Tanat Vallry railway.  It is Cambrian Railway heritage.  This particular model is an all third, I have a partially complete composite and at some point will make a brake to complete the set.

 

As I upgrade my other coach designs to reflect the build process of this coach I will share some photos.  

 

This is the third set of etches for this model.  The previous set was close, hopefully this one will be right.  A fellow member has kindly offered to complete a test build.  After that the etches are available to members at cost should anyone be interested.  

 

As with all my models, I try and make them dimensionally correct but they are simple representations of the prototype....a more skilled modeller could potentially add more detail if required.

Edited July 1, 2021 by Timber

[Timber]

The etch is 0.5mm brass, it includes most parts with the exception of the usual wire buffers etc.  The roof can be replaced with a 3D plastic roof if required.   As with my locomotive etches I keep the build simple by folds.  But there is no reason why the parts cannot be seperated and constructed in a different way....

 

Etch 35240-1

 

Edited August 22, 2021 by Timber

[Timber]

First up is to make the body....it is cut from the etch, folded and then soldered.....

 

The end pieces fold inside the sides this is important for fitting the 3D printed roof correctly,

 

The sides are strengthed and held in alignment by the addition of the 3D printed interior......which is added later in the build

Edited July 1, 2021 by Timber

[Timber]

The chassis is made of two parts.  The inner chassis and the outer chassis.  Starting with the outer chassis.

[Timber]

This is folded in two directions into the etched creases to form the step.

 

First fold the outer part that will become the step.  All folders are into the etched crease.

Edited July 3, 2021 by Timber

[Timber]

Then through using some wooden blocks and holding the outer chassis in a vice fold the inner crease.  This will create the step section.   

[Timber]

Finally fold down the ends...

Edited July 2, 2021 by Timber

[Timber]

The inner chasis is equally easy.  This is folded.  The "H" Irons have a connecting rod that is reprsented by an etched strip.  After a few attempts at tring to make a rocking assembly, I have left this part of the chassis rigid and instead move the rocking assembly onto the axle rather than the bearings.

Edited July 2, 2021 by Timber

[Timber]

The inner chassis sits within the outer chassis. 

Edited July 2, 2021 by Timber

[ianb3174]

Awesome work again

[Timber]

The body should be fitted with handles, end steps etc.  There are a couple of sets of steps should any go missing.

[Timber]

The body plus inner and outter chassis then bolt together with 6BA screws and nuts.  At this stage just fit bolts in the four outer holes.  Leave the inside ones.  To ensure that the 3D interior is a snug fit I cut the screws short and fit with a half nut on the inside.

[Timber]

The body and chassis are now attached,

Edited July 4, 2021 by Timber

[Timber]

The internal bearings are etched from a single unit together with the brakes.  Both of these units fit into rocker assemblies in the chassis.  One can be left to rock the other can be soldered.  This provides the three point suspension.  It is easier to make two rocking assemblies then fix one in assembly.  It ensures that the spacing is identical and the carriage sits straight.

Edited July 5, 2021 by Timber

[Timber]

The bearing itself is a piece of 3mm OD 2.1mm ID tube that can be purchased on ebay.  This sits within the unit, simply soldered.  I cut a small grove for some light oil.  

[Timber]

The rest of the assembly folds together and the connecting V rods taken from the etch and added.  The brakes mountings are a simplification of the prototype, directionally correct but not super accurate.  They could easily be improved if required,

Edited July 5, 2021 by Timber

[Timber]

There are some outer brake shoe detail on the etches that can be added.

[Timber]

The assembly then drops into the chassis.  This is just a test fit later in the build these assemblies can be fitted and connecting rods added.

Edited July 5, 2021 by Timber

[Timber]

Removing the axle assembly for the time being, the next part of the build is to use two brass spacers at each end to thicken the headstocks to the right thickness.  These slot inside the fold down headstock and the steps.

Edited July 8, 2021 by Timber

[Timber]

These are simply soldered in place.  

[Timber]

Then the cosmetic headstock faces are added to the front and the two connecting rods to the H irons are soldered to the underside to complete the headstock build.

Edited July 8, 2021 by Timber

[Timber]

Vacume pipes (Markits), hook and buffers (Markits) are then added.

[Timber]

Next up is to fit the springs.   There are eight on the etch.  Double up and fit two to each H iron.

[Timber]

After fitting the springs the axle boxes can be added.  These are a 3D printed set of 6.  These follow the prototype being tulip shaped in design.

 

 

Edited July 9, 2021 by Timber

[Timber]

The lower step is a single etch that once again is folder.  This is a tricky fold as both sides are relatively thin.   I just hold the end with the legs in a vice and apply pressure to the top with a piece of wood.  But it is tricky to get square.

 

Once folded the recess where the axle box fit within the lower step are simply snipped out once the fold has been made.

Edited July 11, 2021 by Timber