So this is my first blog entry which I will use to describe my first attempt at 3D printing in order to convert a HEA coal hopper into a MFA spoil wagon. From around 1989 redundant HEA coal hoppers were converted into box body MEA mineral wagons, during 1999 the MEAs began to be superseded by new MBA "Monster Box" wagons and the decision was taken by EWS to convert some of these wagons into MFA spoil wagons by cutting the body height down by 1m (depending on which works this was undertaken at depended on whether this reduction was undertaken top down or from bottom up).

Over the years I have amassed a collection of around 20 HEA coal hoppers, mostly the Bachmann model but some from the earlier Mainline(?) all of these are showing their age now having been stored in various garages for around a decade and having also been subject to various "over enthusiastic" weathering attempts in the past. HEAs do not fit my primary modelling era / location (South Devon 1999-2009) and so I have decided to convert them to MFA spoil wagons, retaining the HEA chassis but producing a new MFA body. Whilst I have scratch built 2 MTA spoil wagons in the past using plasticard in order to achieve a level of consistency I decided to try and use 3D printing techniques to produce the body. Probably at this stage I should mention that Bachmann did produce a MFA wagon in their range however it will hopefully be more economical (and fun) doing the conversion myself.

Using the MFA drawings in the book "Railway Wagon Plans - 1960s - Present (John L Fox)" I attempted to produce a 3D model using CAD software, whilst I have in the past used CAD extensively to produce 2D drawings for work purposes (when I was at a level where I could do fun things like draw and get paid for it!) I have never produced 3D models. Luckily I found producing 3D models fairly intuitive and after a few sessions of trial and error I had produced a 3D MFA body based on the drawings.

Once ready I uploaded the body to Shapeways for 3D printing, first shock was the price was higher than expected mainly due to postage. Hopefully if I do a bulk order for 20 wagons once the prototype body is tested then some economies of scale will be realised, as it stands it is only slightly less expensive than buying a new Bachmann MFA off ebay.

On arrival of the body from Shapeways it originally looked promising, the length and height appear to be spot on. The body is shown above with the demic HEA hopper which will donate its chassis (no laughing at the weathering please it was done about 15 years ago!).

Unfortunately on closer inspection all was not well, whilst the length and height were fine the width was well off. There should be an over hang on each side of the chassis but as shown above the body is currently sitting flush with the chassis frames, some quick checks showed that my body was 32mm wide whereas it should be nearer 36.5mm wide. So, some modifications have been made to the 3D model to increase its width, moral of the story here is to make sure that dimensions are checked thoroughly against more than one source - hopefully when the modified body arrives it will be a better fit!