3D printed brake van

[tedp]

Some time ago, Tom Bell (Tebee) asked me how I felt about a 3D printed model loosely based on my 'legacy' brake van no. 15, a card-built six-wheeler made in 1976. This is shown on the left in the picture below, next to my two Airfix brake van bashes. The model is rather crude, but it still sees service on the branch. The C&DR is always short of brake vans, due to the number of complete trains stored in the fiddle yards.



Tom came up with a design within the constraints he has for much of his other rolling stock, which proved to have a slightly taller roof line similar to the Airfix conversions. In due course a printed body arrived, finished in his brown dye and looking as shown below, set up temporarily on an N gauge chassis. In the second photo it is set against the roof line of the Airfix brake van, which allows more space for a six-wheel chassis.





I sprayed the van grey at the same time I set to work on Tom's saddle tank. It was sanded down a little as well, but carefully so to avoid damaging the planking detail.



I expect the graininess will improve once I get down to painting, just like it did when I worked on the saddle tank. Today I set to work on the chassis. In view of the limited length of the vehicle, a rigid 6-wheel chassis with floating centre wheels was decided on. The fixed wheelbase is 43mm, which will pass round my hidden curves without trouble. The donor chassis is off a Minitrix German brake van. The floor was made up first, including the styrene strips it will rest on.



I cut out a little of the headstocks so the chassis ends would come through. Then the chassis was cut up and the N scale detail removed.



The centre axleguards were cut from another chassis. They proved to be one mm taller than the other chassis parts. After some head-scratching I had the solution, though.



I cut a slot in the floor for the base of the centre unit with about 3mm side play. Testing upside down with a 9" Setrack curve proved it would work.





Next, I fitted rectangular pieces of styrene top and bottom on the centre unit so it wouldn't fall out. The bottom one has a patch of 1mm styrene under it to ensure enough space for the centre unit to slide.





I test ran the chassis over the layout and it proved to work all right. The sideplay is enough to traverse the hidden curves. I added solebars with a notch cut out on the inside to clear the sliding unit, then I fitted the chassis in the body and checked it against the other brake vans.





As you can see, it is a little taller than its prototype, but it compares well with the newer brake vans.

To be continued!

[Hugh Norwood]

Hmmm, nice. What does the width of that door work out at?

[tedp]

8mm between the frames, i.e. 2ft. Only skinny guards allowed.

[DeadHorse]

You're gonna need a longer ladder. :-)

[tedp]

I would need a longer ladder - if I'd fit a ladder which in this one I won't!

Here is another shot of the chassis with the sliding centre wheels, showing the recessed solebars.



Yesterday night and today, since it rained most of the day, I made good progress with the brake van. I painted the roof and the sides, then had another look at the 3D printed frames. Something seemed to be lacking, and it was a few frame members that didn't come out very well in the printed model - at the top of the sides, and along the non-platform end. So I made them up using styrene strip. In addition, I fitted a roof profile board at the top of the non-platform end, similar to the prototype model.





Then I painted the frames black, similar to the old model. Only this time the frames are much finer and neater. Some touching up was needed - you tend to stray when painting such narrow ridges. Then I fitted a ventilator to the roof - an N scale buffer which I save and put to all kinds of useful ends. There is even a stovepipe for the tiny stove for the guard to keep warm when the winter snows come to Inverlochan Moor.



The brake stand was made from a piece of plastic tube, a handrail knob and a piece of wire.



A side view also shows the brake gear. I found the brake gear from left-over sprues of a number of Colin Ashby wagons did fit the bill. It is slightly too short for the distance between the outer wheels and the centre wheels, but that is very useful as the sliding centre wheels have to clear the brake blocks anyway.



Here is a close-up showing the brake gear, and the square of styrene that sits between them to keep them straight. There is a piece of styrene rod between each pair of brake units, to represent the central shaft. The pull rod (less cranks) is another piece of styrene rod. I didn't model the cranks - you won't see them anyway.



Here is a final view of the model in its present state. Still some final detailing, lettering and weathering needed.



To be continued!

[Krizzy]

Ted

This is a model where the texture of 3D printing actually scores!

Nice one, Ted, regards Roger

[tedp]

Thanks, Roger. The grainy surface indeed suits a goods vehicle.

Today I did only a little more on the brake van. I put on some lettering and fitted hinges and a door grip to the doors. It is numbered 15A, as its prototype is no. 15 and the roster doesn't allow any more numbers in the departmental series (11-19).

Then all was varnished. The semi-matt varnish proved to be far too glossy, but when I put on matt varnish, it proved to be semi-matt, so all came out right. Anyway the van is now in its newly painted state, still without handrails and safety chains. And it should take on a more scruffy look. Here it is on a trial working trailing an empty coal train out of Dunalistair.

[Brian Mosby]

like the look of the brake van Ted

[Krizzy]

Ted, how about a guard standing on the open veranda?

Roger

[tedp]

I'm out of guards, or appropriate figures, at the moment. I'll see what I can find, possibly at Winchester?

[tedp]

Final details!

Today I completed the detail on the brake van. I started by fitting safety chains to the headstocks. I drilled two holes approximately where the buffers on the N gauge chassis had been, then glued in two stubs of wire:





The chains were made up by cutting through every 5th link and fitting them to the wire stubs. No hooks provided - you'd be hard put to even see them in this scale, and in any case I don't have them.

Then I made up handrails next to the doors and the platform, using staples. Above each handrail I fitted a lamp iron, made of part of a staple. Then I fitted lamp irons to the ends of the vehicle, and finally I found a guard! I gave him my only remaining tail lamp in his hand, as if he is about to hang it on the outside. The lamp in hindsight seems a trifle large after I painted it white, but perhaps after weathering, it won't look too bad.

No weathering yet, but here is the final state of the model before weathering.

[tedp]

Right then. This morning I weathered the brake van, using matt brown and black acrylic dissolved in water. I just put a dab of each in a tin lid and diluted it. Then I found the varnished surface of the van tended to repel the watery solution, so I used a drop of soap to break the surface tension. The result was a dusty finish resembling track rust and dust on the paint.

The underframe and brake gear were done first. Here the wash is more prominent. It brings out the brake detail. The superstructure was carefully treated so as not to show blotches of the wash. You have to prevent the stuff from running into drops and settling there, which creates the wrong effect. So the vehicle sides are done first, then it is put on the radiator to dry, then you do the ends. The roof was done last of all.

Here the van is shown in service on the coal train:









Finally, the new van next to its 40-year-old predecessor, which is now withdrawn to the heritage roster.





This then winds up the tale of a new brake van for the C&DR!

[Richard Cockbill]

quite interesting i own my own 3D printer and have been experimenting with some of Tebees models that had designed, and so far not doing too bad. nice to see an easier way to scratch build the wheels and couplings.