Almost all the advances I had hoped for and wrote about in the last pasting have proved in one way or another a disappointment. Much of the reason for this lies with my growing understanding of the limitations of 3D printing and the present generation of materials used. So this summer has seen much wear on the path back to the drawing board.
Out of the fog of despondency some progress has bee made. I will be upgrading the main website in the next few weeks and add a number of coach etching that have existing production tools. To cut down confusion these will only be available with etched underframes. The long term intension is still to convert many of these to resin kits, and with so many available, and on my wish list, there is much development time to be spent refining my ideas and turning out patterns for models. As a basic principle I want to concentrate on those coaches that have a family affinity so that a single underframe moulding can be used for a number of different carriages.
The guinea-pig for this development work is the MET Dreadnought third. Some of you may have seen a body of this coach done as a one piece 3D print. However having spent a long time playing with it during the summer I reluctantly came to the conclusion that it was impossible to clean the stepping from the lower panels without compromising the beading. I have therefore decided to take a step back and make the patterns for the body by building up the thickness from brass etches. The design allows me to incorporate flanges at both the top and bottom of the sides. Etching drawings for the side and end components are finished and ready for printing.
I’ll be posting photos and graphic of this and other major components at various stages of their development to keep you informed of the progress.
There has been a discussion of 3d printed loco bodies in this thread with interesting contributions from Atso and Atlantic 3279. Experience with the O4/5 body has shown that, not only will a raw 3d print be expensive and need a lot of finishing, but that the machines which these prints are made on are not always consistent in what they produce. I have come to the realisation to the best way to produce loco bodies is to cast them in resin from 3d printed patterns. This will give major advantages e.g.
Lower prices and/or better margins.
‘Ready to paint’ finish.
However there are some disadvantages.
Longer lead times.
Batch sizes will be larger.
The holes for fixing handrails have to be drilled by the modeller.
Some parts e.g. backheads, cab fittings and possibly smokebox fronts will have to be made separately.
In view of the need to order resin castings in batches I am going to need some, maybe 12-15, pre-orders before they are put into production.
However this is all in the future, as most of my design time of the next few months will be directed towards producing drawings of frames for the loco and loco frame kits that have already been announced, together with some others that have been promised but not announced on the website. In all I am aiming to have about a dozen done by Christmas. Renderings of these drawings and forthcoming wagon and coach kits will be posted on my Newsletter as they are finished.
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I’ve had a prototype of one of the promised coach kits to work on over the last couple of weeks. It has taught me some interesting things about the sintered nylon I used. Basically while it will make acceptable underframes and roofs, getting the good finish needed for a coach side is all but impossible. So it’s one step back and one to the right and I’ll have to go off in a slightly different direction until the technology catchs up with me.
I had an enquiry this morning about some SECR coaches, and it may be worth posting much of my reply here to show everyone the way I’m thinking.
I’m working on a system to provide complete kits for most of the etched
coaches in the 4mm catalogue. This will consist of the body etch, more
or less as supplied at the moment, a roof, a floor/seat unit and one
piece underframes and bogies. Leaving the modeller only to supply
wheels, paint, glue etc. The price is likely to be in the region of
£70-80 depending on the prototype.
I’m also working on a alternative version of this system that uses cast
resin sides and ends instead of the brass ones. This has the potential
to be offered painted and ready to run, but is somewhat further away.
This latter item is the way I’m intending to produce the lits advertised in the coach kit section of the main website.