Delichon's designs

[Delichon]

Having read about 3d printing, I decided to have a go at producing some Mark 1 coaches in HO – chopping up Playcraft coaches is fun, but I thought that there might be an easier way. Armed with Keith Parkin’s book and Sketchup, I set to work to create a TSO / SO / SK as a trial. I had the design printed in Shapeways’ FUD and I-materialise’s Prime Grey. The FUD print was somewhat disappointing – not only because of the surface finish, but also the fact that the material seemed to have sagged during printing. Perhaps this was because of the comparatively great mass of material at the ends of the vehicle.

 

 

The Prime Grey print seemed to be better (no sagging) although the slightly stepped finish on the roof did detract a little from the appearance. Note that I got the door windows in the wrong position (too low), so the design had to be revised slightly. I also took the opportunity to reduce the thickness of the sides a little (except for the windows, since the quarter light framing depth is already below the recommended thickness so for strength the original bodyside width was retained). A few bits will have to be added separately (eg end handrails / tank filler pipes) as these are better represented with wire. Curiously, I-materialise seem to have changed the orientation of later prints (although I did not request it) so the stepped finish occurs on one end where it is less visible and easier to deal with in any event.

 

 

An underframe was also required, so this was again printed in Prime Grey. Originally I drew up the basic underframe only, intending to detail it later, but realised that I might as well include the battery boxes etc.

There was also the question of glazing – cutting this out by hand would be tedious, so I tried printing it. The transparent resin available from I-materialise (on the left of the photo) is colourless but extremely expensive, so I plumped for Shapeways’ Transparent Detail (right of photo) which is much cheaper but has a slight yellow tint. Originally I tried hollowing out the windows to save on material costs, but this gave rise to a visible edge inside the window, so I changed to a solid design.

 

 

 

 

A BFK and BG have also been designed – the latter of course requiring a shorter underframe. I suppose I should design some bogies – probably B4s (BR1s can be made from stretched Playcraft bogies and I gather that Commonwealth examples can be had from US-outline manufacturers).

 

 

[backofanenvelope]

Nice work Delichon,

 

Doesn't look to rough from here and looks a good use of Sketchup.

 

Regards

Tom

[Dazzler Fan]

What sort of prices did Shapeways charge?

 

It is generally by cubic centemetre, and you look

like a lot of CC's.

 

Regards

 

Noel

[Delichon]

IIRC, the FUD test print was a little over 100 euros, but I am unlikely to use the material for further coaches. Prime Grey is a bit cheaper and I-materialise do not charge for postage on orders over 100 euros. Ironically, the BG was more expensive than the other coaches - even though it is shorter, it has fewer windows so uses more material.

[ben racey]

Really nice work, great stuff!

 

Regards

 

Richard.

[HSB]

They look very good but a bit too expensive to buy for most people. Any chance of you using these as masters for some cheaper resin castings? You have a lot of potential customers in the British 1:87 Society.

Howard

[Allegheny1600]

I agree with Howard!

I would be interested in resin cast versions but €100 per coach is too much for me. Very nice work though btw.

Cheers,

John E.

[Delichon]

Seeing as Wild Boar Fell's excellent Warflats / Rectanks were printed in Polyamide which apparently has a smooth finish, I have ordered a test print in that material - if it gives a satisfactory result, it should be possible to make the coaches at significantly lower cost. A B4 design has also gone for test printing, which should hopefully be an improvement on chopping up the short Lima bogies into various pieces and trying to get the tough plastic to stick together using three types of adhesive plus Milliput and metal strip .

[DART_8124]

Regarding the B4 bogie could this accommodate EM gauge axles? This is because I model Irish railways in 1:87 scale using EM gauge track to represent 1600mm (5s 3d) gauge. I reckon that these would be 26mm long axles.

[Delichon]

The B4 test prints have not arrived yet so I have not been able to test for fit, but as they were designed for 16.5mm gauge it is unlikely that EM axles can be accommodated. However, the design is in the form of a simple kit with sideframes attaching to a stretcher, so by fabricating new stretchers (or using etched subframes) modellers working in other gauges could adapt the bogies to suit.

[PhilH]

Great thread, well done. It's really interesting to see how the hobby is evolving, and I can see that this technology, although in its infancy, is going to be part of the way forward.

 

Thanks for posting.

[Atso]

I like those MK1's! Interesting to see you've used Prime Grey for these. I've done a couple of prints in this material and I've now got some 51' suburban bodies on order with iMaterialize in Prime Grey based on your results!

[Delichon]

A case of one step forward, two steps back The initial print of B4s (in FUD) arrived broken - I am not sure whether this was a manufacturing or design fault, but I have revised the design a bit (the stretcher also proved to be a bit short, so I have lengthened it slightly). The new print was sadly a bit warped, which explains the use of wheelsets with different axle lengths in the photo.

 

 

One other problem is that the slightly spidery nature of the B4 means that the journal area is small, which prevents a pinpoint bearing from being used, and the (thin) FUD breaks with use in this part of the print. It will either be necessary to bulk up the design considerably or use a different material (I-materialise now offer brass - cast from a printed wax master - so I may try that). Although the FUD design will be made available, I would only recommend it for use as a cosmetic sideframe.

 

Some Polyamide prints of Mk.1 types also arrived - these are much cheaper than Prime Grey, but the finish is rougher and some of the detail has not reproduced properly (eg cantrail gutters). You get what you pay for, I suppose.

 

 

Prime Grey for comparison :

 

 

Suburban coaches unfortunately require glazing, hence this gargantuan sprue :

 

[Delichon]

The B4 has been revised to an inside bearing design. The photo also shows the streaked finish of Prime Grey in the painted coach body :

 

 

I have also designed a Class 73 (both JA and JB variants) in Prime Grey :

 

 

The grilles have been cast in brass by I-materialise; the irregularities in the castings give a handmade look, although they proved to be slightly larger than the holes that had been left in the bodyside for them, necessitating some additional filing . The cantrail grilles have only two divisions instead of three – owing to minimum wall thickness in brass it would have been awkward to do otherwise. I am not certain that brass cast in this fashion would be suitable for precision work though.

 

 

 

The stepping characteristic of Prime Grey means that the roof domes need considerable filling and sanding to get a good finish. Additionally, the model appeared to have suffered minor distortion resulting in slight sagging in the centre (consequently the cab windows were not in line) . Happily, this fault could be corrected by making a saw cut in the centre of the body, bending to shape and applying epoxy. The jumper cables are from MJT and the scrapbox.

 

 

 

The chassis is also in Prime Grey, although extensive modification is necessary in order to fit a mechanism. Prime Grey is of quite low strength, so reinforcement with brass angle is necessary to allow cutouts for motor bogies to be opened out. The bogie sideframes will be in FUD.

 

[2A-Rail]

Liking the look of this, the class 73 model captures the prototype well.

 

Not trying to stray off topic, I take it Prime Grey is (currently) the best 3D Printing finish? Looks far nicer than FUD prints I have done.

 

Johnny

[Delichon]

It's mainly a matter of horses for courses - one has little choice but to use FUD for thinner / more detailed items but Prime Grey is adequate for most of my needs. Usually a few coats of Halfords filler primer and rubbing down can improve the streaked surface finish, but where the stepping is evident rectification can be awkward if there are details in the vicinity. With PG, one has to be careful regarding storage on account of its limited strength - I have had occasions where underframes have been left resting on their trussing and the ends have begun to droop after a little while, so I now store them flat on their backs until needed (the interiors will then provide the necessary bracing). With the coach bodies one again has to ensure that they are adequately supported until required - although I think that the wall thickness has some effect as designs with thicker walls (at least a scale 9inches in HO) survive better than when I have reduced thickness to 6in. Having said this, in the case of the Mk.1 bodies the gangway rubbing plates project below the rest of the body so if rested on these, the centre of the body is unsupported. However, I have not had any cases as serious as the early FUD Mk.1 shown in the OP, which had presumably distorted during manufacture.

[Delichon]

It has been some time since I last posted here, but there has been some progress. The JA has been painted and awaits some underframe detailing :

 

 

 

The JB is also underway - bearing in mind the era, it should be possible to deduce the intended identity of the loco :

 

 

I have also designed a 2 Hap unit (again in Prime Grey). The motorcoach underframe is in fact in FUD and was about 2mm shorter than the PG item despite using the same file. This was resolved when modifying the underframe to fit the motor bogie (the metal sideframes were already attached to the second-hand bogie). The trailer bogies use stretched Playcraft mouldings. It will be seen that the FUD has discoloured somewhat - to a pale green.

I shudder to think how long it would have taken to hand-cut glazing - with printed windows the whole unit took about 10 minutes

 

 

The seating (a mix of Hornby and Playcraft) has had to be reduced in width owing to the thickness of the body.

 

 

Having a spare EPB driving trailer to hand, I decided to try some 6S cars. Some modifications to the print were necessary as I did not get the front windows quite right. Also, the side windows on the unit are a non-standard type. These are likely to be my last coaches in PG, as I-materialise have become more strict with regard to minimum wall thickness, which would make design of the window vents more awkward.

 

 

 

In fact, I have tried a test print in FUD again (an SR design 2 Hap) :

 

 

 

Another unit that could otherwise be hard to make in HO :

 

 

A VAB would be fab, but my wallet might not survive  .

 

 

 

[Bluebell Model Railway]

Great work, been trying a bit with the 3D stuff myself on Google sketchup... although not having much success... although coaches for now are a bit beyond me... but yours look great, its certainly interesting the different printing materials and different results.. certainly I will bare that in mind if I ever get to the printing point of my coaches.