36C studios development thread: an A7 tank and other updates regarding J27, 20, etc.

[Atlantic 3279]

Whilst I emphasize that I'm NOT offering to get involved in any way because I already have a mountain of stalled projects on my list of intentions, I see it like this:

If you can handle CAD and you like CAD, if you can produce artwork in a suitable vector file format, and if making things by hand isn't necessarily your greatest strength or your preferred approach, then the most widely accepted "best way" to produce a chassis kit in a proven medium is to get the parts etched in metal by say PPD.

If you'd rather not confront your customers' perceived "fears" of etched chassis construction, if you fancy doing some cheap home manufacture of the kit parts, and if you are happy to either create an accurate master by hand or produce a suitable master by the 3D printing process, then you could supply cast resin copies of a suitable basic chassis block / frames, with or without cast-in metal strengthening. A 3D printed master would not have to be in a material strong enough to cope with long-term regular handling, mechanical stresses from use in a loco, exposure to adhesives and lubricants etc, it only has to serve as the master part and could therefore be printed in the material that gives sharpest definition of details.

[Nova]

If you'd rather not confront your customers' perceived "fears" of etched chassis construction, if you fancy doing some cheap home manufacture of the kit parts, and if you are happy to either create an accurate master by hand or produce a suitable master by the 3D printing process, then you could supply cast resin copies of a suitable basic chassis block / frames, with or without cast-in metal strengthening.

I will eventually be working with resin casting. however. as I'm currently living with my parents and waiting for the chance for the shed (in which my layout and my workbench will be located) to be completed, and it's looking to be a long while yet. I don't know if I will be able to have a resin version of the chassis available as an alternative when I do release the kits (and quite frankly I don't fancy my chances playing about with silicone and resin on my mother's kitchen countertop in the meantime).

as a matter of interest. what sort of thickness are the main plates for the frames on your J6 chassis? It's to give me a rough guide to work with when designing the first draft of the chassis so that the 3d printed chassis (which will still be available on Shapeways for those that feel comfortable using it) can simply have a casting made of it for producing resin copies with minimal modifications.

Likewise I am considering also making resin copies of the bodyshells for those that prefer that medium. I do have some ideas revolving around mixing brass powder into resin (in a process called cold casting) and experimenting with ratios to see what ratio best offers additional weight to the castings with minimal loss of structural integrity.

[Atlantic 3279]

The J6 main frames are 2mm thick, which leaves little room for a gearbox between them. In general, if users choose not to build up a train of individual gears using spindles set into the frames as I did, but fit a gearbox instead, they have to file out a bit more space in the relevant area. I don't (yet) have any idea of how thin the frames can be before they become too weak or unstable.

[Pebbles]

If you can't use casting resin on your mother's work surfaces what hope have you In using Hydrochloric Acid - providing you can get it. Whilst you may have many good ideas, from what you have indicated, you apparently currently lack the finance and facilities. Apparently you are still waiting for access to your parents' shed to use as a workshop. Atlantic's efforts have demonstrated that the application of new techniques require a learning curve; with always the possibility of initial failures. Perhaps in the short term a way forward would be to trial techniques you have cited on projects that can be carried out within the space and resources currently available to you.

[Nova]

Apparently you are still waiting for access to your parents' shed to use as a workshop.

I'm just going to point out that it is in fact my shed, it'll be used entirely to house my layout and workbench. it's just that currently there's another shed that needs to be gotten rid of that's plonked in front of the door (because it had to be moved to make way for yet another shed). I can just about get in but I've no chance of setting up a layout or even a temporary bench, especially when it's currently being used as a stores for other DIY projects my step-dad is doing, he's great at starting grand projects, less great at finishing. I'm only just looking at the possibility of a totally enclosed and furnished bedroom after 6 years of an ongoing loft conversion.

I'll be lucky to have my own place to run stock at home (baring a circle of set track on the floor) by the end of the year, and I don't fancy the prospect of having to explain why I have a 31 in LNER livery (see my main layout thread for context) every time I fancy running something other than an A2 or an N2 at the local club. it's also why both of my main threads essentially died for a long time. I still had every intention of doing both, but the situation wouldn't allow it

If you can't use casting resin on your mother's work surfaces what hope have you In using Hydrochloric Acid

the underlying assumption, which I perhaps should have mentioned, was that etching would be undertaken in the shed as well. the advantage of 3D printing through shapeways is that I can work on it anywhere and have the digital file designed and ready to go without taking up space (the design for an etched chassis as well to a certain extent, but that would require a learning curve all of its own with I'm still umming & ahing over), then it can simply sit waiting until I have the means to allow it for general sale with the option for a resin or etched chassis. my eventual aim is to also make a milled brass chassis for those that are interested

[Pebbles]

Nova

Detail! the essential point surely is that without facilities where do you go? Surely your priority should be a place of your own in which you can progress your aims without the frustrations you are experiencing. You are not alone in this. Individuals faced with similar issues tend to tailor their activities to fit whatever constraints are imposed on them. Peter Denny's writings of his early days are inspiring examples of what can be achieved.

[billbedford]

There are really really good reasons why no commercial kit manufacturers produce their own etchings, just are there are good reasons why very few people hand draw artwork. Quality of output is just one reason for both of these.

The best advice I can give is for you to work out the problems producing kits by building models for your own layout before even thinking about doing something commercially.

[Atso]

Having played around with home etching several years ago, I have to agree with Bill's comments. You'll struggle to get the quality (at least consistently) and speed of a professional etching firm and likely end up spending more money trying than it would cost you to use them in the first place.

Having been playing around with CAD in N gauge, I have to say I've learn a lot over the last twelve years or so (usually finding out what won't work! ) and there has been a fairly considerable cost attached in learning. However, I did start out with some white metal, etched (glued back then) and plastic kits first and saw how and why things were done the way they were and trying to decide if there was a better way. Had there been more quality locomotive body kits freely available back then, I would have probably stuck with these for a few years longer than I did - although I still build kits, these are mainly wagons and coaches (and I'm gutted I missed the boat with obtaining some of Bill's 2mm etched GNR coach range!).

I've recently been redesigning my L1 3D printed body from the ground up. The original L1 CAD was done c. 2009/10 and designed to take advantage of (the then new) FUD material from Shapeways. Looking at the original print now, it is very crude compared to my current efforts and looking at the CAD file, I can't believe just how much my design methods have changed over the last decade! To be fair, the original L1 was very conservative in terms of detail as I was experimenting with what FUD would and would not do. Any loco body I'm selling via Shapeways now is devoid of features such as buffers, handrails, safety valves, etc as they are fragile and far superior brass versions are freely available.

My thinking is to find the material that can best do the defined job. That is the designers job to decide what the criteria are, a Finney kit and Airfix are very different beasts. As others have said, some of the best kits make use of several different materials.

Just as another thing to think about, 3D printing, while making assembly easier (if well designed), does have the additional complication of needing a level of post finishing work to get the best out of the prints. I've written an article in this months BRM magazine that outlines some of the techniques I use when working with FUD prints prior to final detailing and painting that may be of interest to you.

[markindurham]

I'm a bit late coming to this thread, but getting back to a chassis for the J27 - and I haven't seen it mentioned, apologies if I missed it when perusing the thread - Alan Gibson have a set of etched frames for the J27 in their range. Couple those with a suitable motor/gearbox combination from High Level, and job done

Mark