Saturday, August 15, 2009

How I made two cattle wagons

Disclaimer
As with all my postings, I am not holding myself up as any sort of expert - merely giving you a metaphorical opportunity to look over my shoulder and maybe learn from my mistakes.


Materials
Two thicknesses of plasticard were purchased - 2mm (80 thou) for the main body components and 1mm (40 thou) for detailing. Two A4 sheets of 2mm card are needed for each wagon. One A4 sheet of 1mm is sufficient for up to four wagons. I also purchased a pack of 3.2 mm wide half-round strip for the hinges and used this for one wagon, but on the second I used some insulated copper wire as I felt this this looked more realistic. I also purchased some 0.5mm blackened chain designed for model boats. For the roofs, I used a moulding for W&L Pickering coaches supplied by Garden Railway Specialists (GRS) as I had this to hand for an abandoned coach-making project.

From the 2mm sheet, I cut six 3mm strips, eight 5mm strips, 24 x 7.5mm strips and two 15mm wide strips. From the 1mm sheet I cut one strip 1mm wide, one 2mm wide strip, and four 3mm wide strips.

A bottle of styrene solvent and a brush were also purchased. You can buy a specific brush for styrene solvent as the solvent will probably dissolve the glue holding the bristles of an ordinary paintbrush. I bought a cheap No. 3 brush and crimped the ferule with a pair of pliers to stop the hairs from falling out.


Tools
The tools I used are fairly basic:
  • a cutting mat
  • a craft knife
  • a metal ruler
  • a metal tri-square
  • a razor saw
  • a small paint-brush (see above)
  • a sanding block and some sand paper)
  • a small flat file
  • a mini-drill
  • some pointed-nose pliers
Techniques
If you've modelled in plasticard before, this section is not necesary, otherwise a few techniques may come in handy:

Cutting plasticard
Plasticard can cut by scoring two or three times with a sharp knife and then snapping. Some of the narrow strips will need to be cut right through as they are too narrow to allow sufficient leverage for snapping.

Joining plasticard
Liquid solvent is the most effective way of joining plasticard. The two pieces are held together and a small paintbrush dipped into the solvent is run along the edge of the join. The solvent will flow into the gap through capillary action.

Simulating wood grain
Scratching the surface of plasticard with the point of a craft-knife with long stroking movements can give the impression of wood grain. From experience I've found that several light scratches look a lot more realistic than fewer or deeper scratches.
Fixing small details in place (eg rivets)
These can be lifted into place on the tip of the paintbrush after it has been dipped in solvent. While the solvent is still wet, the small detail can be adjusted into the correct position with the paintbrush or the point of a craft knife. Flooding the detail with more solvent will ensure it is firmly fixed and will also round off its edges (eg the cubes used for rivets will become more rounded in shape).

I also purchased a pack of plastic river heads from Cambrian models and used these for some of the finishing-off details:
The chassis
Over a period of around a year, I accumulated a series of LGB stake wagons on eBay. This seemed to be the cheapest way of getting hold of the basic wagon chassis.

The body was removed from the chassis by unscrewing the four screws, prising out the wheels and removing the swivelling axle box assemblies.

The vacuum brake gear was removed with a razor saw and all but one of the brake shoes removed from the axle boxes.

All details were removed from the bodywork with a razor saw and craft knife.

Then the edges were smoothed off with a sheet of emery paper:

Finally, the centre buffers were removed with a razor saw and the buffer beam cut in half (though I may deepen the wagon buffer beams on future wagons to match with LGB).
The dimensions of the resultant chassis was then compared with a drawing of a cattle wagon in Ralph Cartwright's 'Welshpool & Llanfair' book. A rough drawing was prepared to work out the dimensions of the various parts needed.

The body

I decided my model would not be an accurate scale model of the original, but would be 'inspired' by it.

The sides
For the outside frame of each side, two 5mm x 107.5mm x 2mm thick strips (ends) and two 5mm x 218mm x 2mm thick strips (top/bottom) were cut. On each of the 107.5mm strips, a mark was made 10mm from the end. These were joined as below:


Next, two 5mm x 87.5mm strips were cut and fixed 79mm from the inside of each end - leaving a 60mm gap for the doors in the middle:

Two 3mm x 102.5mm x 2mm thick strips were then fixed to the end pieces as shown:

A gap of 5mm was left at the top to provide an anchor for the end of the wagon.

Eight 7.5mm x 212mm x 3mm thick strips were cut. These were added as below to provide the slats for the side of the wagon. Note: I decided to fix these across the doorway at this time to ensure that the slats either side of the doorway aligned.

A gap of 1.5mm was left between each of the lower six slats. A simple gauge was cut from an offcut of plasticard to help keep the gaps consistent.

The uppermost slat was made only partially visible, with 3mm showing. The one below this was positioned midway between the sixth and the topmost slat. On the three wagons constructed, this measurement tended to vary slightly depending on how accurately the other slats had been fitted.

Two 3mm x 87.5mm x 2mm thick strips were then positioned midway between the end uprights and the middle uprights:

This assembly was left to set while the other side was constructed to this stage.

The middle section of each slat was then carefully cut away to provide the door opening. These planks, together with another 5mm wide one were then used to construct the doorway:

Three 60mm x 3mm x 1mm thick strips were cut and one end rounded off with sandpaper. These were fixed to the door planks as below. Note: a few mm were left overhanging the base of the door to facilitate fixing into the gap.

Next, two 5mm x 3mm x 1mm thick strips were cut and one end rounded (Note: I found it easier to round off one end before cutting them from the strip).

Two 2mm x 2mm x 1mm thick pieces were also cut for the latches.


These were fitted to the sides of the doors as below:

The door was then fitted back into the gap. The latches and the 'hinges' prevented the door from falling through the gap.

Despite these planks having been removed from the gap, some shaving was required on all the doors. Some were 'weathered' at the ends to show excessive wear.

Then some 1mm cubes were cut from the 1mm x 1mm strip and attached to the strapping (see techniques section above)

Four 27mm x 3mm x 2mm thick strips were cut, together with four 23mm x 3mm x 2mm thick strips to form the frames for the upper doors. (Note: The 27mm strips sometimes varied by half a mm depending on how much space was left above the main door).

These were joined to to make the frames. Note: I used the squares marked on the cutting board to ensure they were square and to counteract any slight inaccuracies in measuring. Any excess was trimmed off after the frames were stuck.

Four 23mm x 2mm x 1mm thick strips were cut and glued into the frames for cross-pieces.

Four 27mm x 2mm x 1mm thick strips were cut and one end rounded off each.


These were then attached to the horizontal frames and rivet detail added as below:

Note how 1mm of these hinge strappings overlaps the edges to support the frames when inserted into the side of the wagon.

Two 35mm x 3mm x 1mm thick strips were cut and one end rounded off. These were fixed eother side of the upper doors as shown and rivet detail added:

Two 102.5mm x 3mm x 2mm thick strips were then added to the rear of each end upright.

and two 92.5mm x 5mm x 2mm thick strips were positioned behind each of the uprights either side of the doors:


Constructing the ends

Two 91mm x 15mm x 2mm thick strips were cut and a line drawn 5mm from one edge:

A suitable saucepan lid was found to mark the curve of the roof on the upper portion:

This could no doubt have been done more scientifically, but I prefer a belt and braces approach (and besides, I had no pair of compasses to hand).

The curve was then cut out with a craft knife and smoothed off with sand paper. Then two curved strips of 1mm thick by approx 3mm wide were cut, using the above as a template. These were glued to the roof supports:

Two 85mm x 15mm x 2mm thick pieces were then cut for the buffer beams, together with two 80mm x 15mm x 1mm thick pieces. The 2mm and 1mm pieces were glued together as shown with a 2.5mm rebate at each end:

The top and bottom of one end were then carefully positioned 87.5mm apart on the grid lines of the cutting mat to allow for the measuring of the diagonal braces:

No doubt the exact measurements of these diagonals could have been determined on a scale drawing but 'belt and braces' came to the fore here.

Using the marks as guides, a 1mm rebate was cut and filed at the base,

and a 2mm and 3mm rebate created at the top of each diagonal.

On reflection, I wish I'd bought 5mm square tube rather than solid 5mm square section. It would have been a lot easier to rebate and would have looked no different.

The diagonals were carefully fixed in place, using the grid to keep everything square:

and then 85mm x 7.5mm x 2mm thick slats were glued in behind the diagonals, using the same method and spacing as for the sides:

Finally, rivet detail was added to the diagonals:

The roof
With the sides and ends completed,

these were assembled and filler used to tidy up some of my shoddy workmanship.

Eight 20mm x 2.5mm x 1mm thick straps were cut out, four with two ends rounded and four with one end rounded.

The double -rounded straps were added to the topmost corner of each side and bent round to each end - and rivet detail added:

The other straps were added to the bottom corner of each end, and rivet detail added:

Hinges were made from a short length of insulated copper cable, with the insulation cut through at suitable intervals. This was then attached below the doors:


The roof
I contemplated either having a removable roof or a fixed roof and a body which was removable from the chassis. In the end, I opted for a fixed roof as the body was a tight fit on to the chassis. This also meant the body could be spray painted without having to mask off the chassis.

A 235mm length of roof was cut from the domed roof supplied by GRS for their W&L Pickering coach kits. This glued in place and 200mm x 1.5 mm x 1mm rainstrips fixed in place on either side. Note: I had considered making the roof from 235mm x 7.5mm x 2mm thick strips, covered with a single 1mm thick sheet until I remembered having the spare coach roof.

Brake Gear
Once the body had been joined to the chassis, a brake handle and hangers were cut out and assembled into something which resembles brake gear - lined up with the one remaining brake shoe:


Door catches

20mm length of 0.5mm chain were cut to which were added eyelets made from bent wire:

Small holes were drilled into the door catches and door pillars and superglued in place:

A similar length of chain and eyelets was added to the brake gear.

Painting
The inside and outside were given two light coats of Plasti-kote grey primer. Once dry, the strapping, hinges and latches were picked out with black acrylic. The roof was also painted with black acrylic with a little silver and white added to tone it down.

So far, two wagons have been constructed. The plan is for another pair to be added to the fleet - but in the meantime, I need a few more open wagons.

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