The Flexiscale Co : News

I spent a bit of time over coffee this morning playing/making an Airfix kit. I haven't made an Airfix Spitfire for over 30 years. In this particular case I was making the Quick Build Spitfire. I'll test it on our panel of young makers later in the week. 

It's really fun, a very interesting experience. Is it a kit? Yes, absolutely. Not necessarily in the format we're all used to but definitely a kit. It's a bit more than that. This particular one also feels a bit like a combination of LEGO and a 3D jigsaw puzzle. 

The blocks are totally compatible with LEGO bricks. An exact fit and match. Some may fear that there may be consequences but the LEGO patent expired a few years ago and at a similar point in time they lost a trademark battle in which the judge ruled that a technical shape could not be a trademark.

What is fascinating to me about this kit is how Airfix is using a pattern present in the cultural psyche of children about how things fit together. The LEGO studs and sockets are almost a shorthand to children about making physical things and, increasingly through games such as LEGO Star Wars, making digital facsimiles of physical construction and deconstruction. The digital games are product marketing for the physical products which then extend the gameplay from screen. Ever increasingly LEGO kits are using specialist parts to create complex geometries making it a less mutable toy, the Airfix kits carry this on to logical extension with parts which are so specialised they can never be used for anything else but which together form a near accurate model.

One thing which saddened me was that the historical information about the item you're making has been replaced by an infographic panel about the statistics of the item which is probably in some ways less readable for the target audience of 5+. 

It's a lovely kit though and very fascinating, I hear they're selling very well and hopefully this will result in children progressing into being teenage and adult kit makers. 

Coincidentally this morning my attention was drawn to an article in Wired about LEGO's rise since it has been licensing existing characters and IP. Although the Airfix kits are not connected to LEGO the extension of the physical pattern of the studs into model kits just keeps on with the trend of LEGO-fication of content. 

Airfix Quick Build Spitfire kit.

A very interesting development. The Quick Build kits in case you haven't come across them are aimed at the 5+ age kit builders as an introductory range. The plastics have been carefully colour matched and the finish is very high. The use of a "LEGO style" stud system is really interesting. 

The Englands in real life are quite unusually built. Much of the structure of the locomotive is the boiler itself. The frames are bolted to the front of the firebox and the drawbar to the rear meaning that the firebox is taking much of the drawbar load. The saddle tank sits onto a subframe supported on a frame, with valances to either side hung off of the subframe. 

When modelling the Englands, since many of the different scale kits are without chassis to provide support during fabrication/transit, the majority of the structural integrity is taken up by these subframes with a small component being provided by the attachments between assemblies (smokebox/saddle tank/cab). 

The subframes need to appear delicate from the outside as they do on the real thing, yet have strong structural integrity.

Initial efforts surrounded strengthening the valances, thickening them inwards with additional supports and cross members. However in all attempts they were simply too fragile. 

A novel approach has now been taken which is to model them afresh and afix high resolution prints for the valances to them. This part of the development has been incredibly iterative through the use of 3D printing with over 20 iterations leading to the final result.

The saddle tank of the England is one of the most distinctive parts and one of the biggest challenges in making the kit. This is largely as we need to leave enough space inside for weight and the motor and gearbox and for the larger scale for DCC. Therefore it needs hollowing out.

Problems appear as soon as you start doing this. Firstly the saddle tank is actually wider than the frame it rests upon, therefore there either needs to be a greater wall thickness (reducing space inside and also using more material and machine time).  Alternatively some support structures need building into the base. Secondly make it too thin and it warps badly.

After many iterations we have a design which works, it has a cutout at the front of the saddle tank which allows the a continuous space with the smokebox for running cables for a smoke unit or for using the smokebox for the DCC chip. It has the rear surface removed so that there can, with the removal of a portion of the cab, be a continuous run from firebox to smokebox for cables/motors/electronics.

The largest challenge in designing this piece was machine time. In 16mm scale the print takes over 30 hours on the MakerBot to print.

For those of you who don't know what a Maker Faire is, the only real way to find out is to go to one. They're quite extraordinary. They're a place where craft meets technology and where preconceptions are there to be broken. 

We were lucky enough to go to three of them over the late summer/early Autumn: Brighton Mini Maker Faire, World Maker Faire in New York and Machynlleth Mini Maker Faire in Wales. Each of them was special in their own way and in part for what they represented in the history of the project.

Chris grew up in Shoreham-by-sea, near to Brighton. If Maker Faires had existed when he was at school, this would have been his local one. He did go on a pilgrimage to the model shop which consumed most of his pocket money on the way to Maker Faire.

We spent the day talking to people about the models and how we made the digital files and spent a huge amount of time enjoying watching children assembling the kits without instructions, just guessing which pieces fitted together.

One of the other exhibits was a people scanner which a group of Brighton makers had made for an art installation and which we hope to take to a model railway show next year in our quest for better, more representative, figures.

The first major piece of work was the assembly at the front of the locomotive. This is a fairly crucial piece being the face of the locomotive and several approaches were taken to create it. 

The initial plan was to print the chimney and it's base in one part, however it was clear that the base needed to be attached to the smokebox as there are some very fine edges which were at risk of warping/breaking in the resin print. 

Secondly the front platework was originally planned to be attached to the upper frames onto which the water tank is fitted on an England. On Palmerston in particular the prints for these frames are quite fragile at the point they meet the cab. This means that a stronger material will need to be picked for this part to be printed in and that has implications for minimum thickness of the thin platework. 

To thicken the platework would have compromised the quality and so an assembly was created which includes the balance weight, base of sandpots and the smokebox/chimney base assembly.

Having the smokebox door separate will allow for it to be printed with a different z-orientation so that it has the smoothest finish possible from the printer. 

The complete front end of the engine is beginning to look very England like, even in some of the rough MakerBot plastic. This whole iterative process including prints of each test part took nearly 2 weeks, however along with the upper frames this is probably the most important part of the locomotive both structurally and visually and it was worth the time getting it right. 

The length of time of some of the prints led to a new innovation, CCTV and a remote control kill switch for the printer as some of the prints were taking over 8 hours.

Peterborough 16mm Society Garden Railway Show