0 Gauge Class 33 - Scratch Built

I tried to recall how I came to scratch build a Crompton Class 33 diesel locomotive. It is probably the most complex and time consuming modelling project I have undertaken to date.

Without doubt the styling proportions of the 33 make it a pleasing sight to my eye, compared to other Southern diesels. I was also attracted to the r.t.r. Lima 0 gauge offering, which is remarkably inexpensive to buy off eBay - around the £50 mark. But, the reviews I read revealed it to be woefully inaccurate dimensionally, so bad that some serious 'cut and shut' work would be necessary to bring it into line with the prototype.

With a 3D printer to hand I decided to design and make one. First point of reference are a drawing and photographs. There is a partially dimensioned drawing in a book that I own -  Diesel and  Electric locomotives of the Southern Region by N. Pallant & D. Bird. I copied this and enlarged it to 7mm scale and from this most dimensions could be measured. There are also drawings available from the web. Despite this some fine details are missing or obscure in the drawings so, recourse to the web for photographs was in order. Most are distant profile views like in the example above. It required much time to find suitable close up and side views to work from.

The bogie's were tackled first as I considered these to be the most difficult items to design and make, firstly because of the large number of details on them and secondly the precision fitting of motor and gears, particularly optimum gear meshing. Before starting the design I had to source wheels and motor & gears. All were eventually found on ebay. The wheel sets are Peartree Engineering 3' 7" finescale diesel wheels. These do not have locating spigots but use bushes mounted on the axles and fixed to the bogie frame. The motor and gear set are by an unknown manufacturer. There is a risk the motor would not be adequate and even having made the bogie and run successfully there is still uncertainty over whether it will pull the body weight and train.

The bogie is essentially two separate parts screwed together. An inner part is the motor frame containing motor, gears, wheels and pickups. If there are issues with the motor/gears performance needing change then only the motor frame would need to be redesigned for a different motor (in theory). The outer part of the bogie is the decorative part.

The parts were printed in black, which had an undesirable effect of hiding the details from sight. Weathering was applied with brown and beige pastel scrapes to highlight the details. Some mechanics of the bogie were omitted from the design either because they were too fine to be printed, could not be easily discerned from drawing or photo or, would not be seen from normal viewing angles.I think most details are included though.

In the above photo we can see the motor mechanics, noise suppression capacitor and electrical pickup, which rubs on the axles. One of the wheels on each axles is insulated. The metal can of the motor connects to the one side of the armature coil and the pickup for the power return. The power feed is collected from the other bogie.

The other bogie with its power pickup is shown above. The design and build is identical to the motorised bogie without motor/gears fitted.

And here are the two bogies alongside a scale drawing. Not yet obtained track so am using two lengths of Hornby 00 gauge Super 4 track for now

At the end of the day the cost will be about the same as a second hand Lima 0 gauge model. At least mine will be more accurate and making it from scratch fulfils my creative need.

To Part 2.

0 Gauge Vanwide Box Van

This box van was chosen because I have a dimensioned drawing from a magazine. It is an interesting wagon because it was probably the last 10' wheelbase box van to be made by British Railways (in 1962).

Given the name Vanwide because the open doors reveal a large access space 9 feet wide. The doors close flush with the body. When opening the doors pull outward and slide over the van sides being guided by top and bottom runners. The prototype is also noted for its flush plywood sides and lack of angle iron bracing. The end panels are corrugated from pressed steel.

Bizarrely, the two page article in the reference magazine (see below) only showed dimensions of the side panel. The chassis, end panel and roof had to be scaled from photographs.

For the model the doors are not operational, being embedded in  the side panels.

I was able to use some chassis components designed for previous models but this van still required much time over a two week period to design, 3D print and build.

Components were glued together using Super Glue, Added strength to joins was achieved by sprinkling sodium bicarbonate powder into the wet glue, a tip give by Monty's Matchbox Makeovers on YouTube.

This van is considered new for the modelled period so, it is finished in ex works condition. The red bauxite was mixed from Humbrol 100, 20 and 160. Two of these are matte. The gloss finish was applied from gloss cork tile sealer diluted with white spirit. All the above was chosen from what I had in stock The roof is Halford's grey primer and black pastel scrapes brushed over.the dry paint.

Compensated chassis uses the rocking yoke method previously explained and sprung buffers use an adaption of the Peco method, also previously explained.

References:

Another BR Box Van - Railway Modeller February 1968 (drawing)
Wagon Page BR Box Vans - Railway Modeller August 1971
Paul Bartlett's Photographs

Cost:

Plastic: £1.48
Wheelset: £8.75 (including postage) Peartree Engineering bought on Ebay.
Extras: pennies
Total: <£10.50

Also available from the trade: Kit £38 (Slaters Plastikard) or RTR £52.50 (Dapol).

0 Gauge Conflat Container Type A

The A container is half the size of the B container. I have 00 gauge models of the B container so, to model the smaller one for 0 gauge provided greater motivation. and it requires less plastic, thus cost.

I found a drawing and example on the web (see references below).

The box shape should be simple to make but I saw difficulties ahead due to the extensive detail of the panels. I tried to 3D print the panels with their narrow boarding twice but the print quality was very poor. On the verge of giving up and making it in paper and board I discovered that a small number of the prototypes had panels made from plywood with a pressed steel end. This was easy for the 3D printer to fabricate.

The livery is my own 'faded bauxite' mix of Humbrol 100 with a little 160 and then weathered with black and white pastel scrapes.

As with the wagon the chain securing hoops were made functional using phosphor bronze wire.

The decals were designed and printed onto sticky paper.

The large information panel required extensive research to identify data that could be read in a photograph.

I gave the container the same identification number (A3705B) as that in the reference below.

The shackles were very fiddly to make from 0.5mm galvanised wire and are rather crude compared to proprietary offerings. They can be applied and removed from container and wagon to operate the wagon with or without a container but they are delicate and I can see I may need to permanently fix the container and shackles to the wagon if they break due to handling.

References:

Container A3705B photos
Container A photos and drawing

Cost:

Plastic: £0.42
extras: pennies

Total: < £0.50

A variant of the container type A is available in kit form (Slaters Plastikard, about £13) and shackles (CPL Products, about £8.75)

Next up is a BR Box Van.