I recently had the pleasure of spending a morning in the workshop of the talented and affable Jose Luis Lopez Ruiz.

Jose Luis is a well-known Spanish modeler who is perhaps best known for his pioneering use of the black and white technique. His work can be seen regularly in Panzer Aces magazine, among others, and on sites like Missing Lynx. If you spend any time on the Missing Lynx forum you will recognize his T-55 Enigma:

Over a nice Spanish coffee and a cupcake, Jose suggested that (among other things – stay tuned for a more in-depth post about our chat) I take up 1:48 scale armor. He explained that painting in 1:48 scale will change the “scale” that you see things in, driving you to refine your technique and control, with the idea being that once you move back to 1:35 scale, you will continue to work in 1:48 scale in your mind, thus producing finer detail in your painting.

It seemed to make sense and I was eager to try it, but I think Jose thought I needed a little more nudging. He asked me what subjects I like to build, and as soon as I replied “Modern Soviet stuff” he disappeared into another room. After a minute or so he returned with a small white cardboard box, which he held out to me with a boyish smile on his face.

“Here – now you build in 48!”

It was a T-62 by Gaso.Line Models!

Touched by his generosity, and with a genuine desire to see where this experiment would lead (I had become increasingly dissatisfied with the over-sized chipping and scratching on my SU-85 and thought that this seemed like a great way to refine my technique) I accepted his gift and committed to completing the project by May 20th – Jose’s birthday.

Gaso.Line’s 1:48 scale T-62 is molded in a pale green polyurethane resin. It comes with a turned aluminum barrel, a spring, and some brass wire for forming the headlight guards. Detail throughout is very nice, but a few areas of the upper hull showed signs that the mold was wearing a bit. The tracks were slightly warped, but nothing that hot water and clamping wouldn’t take care of.

The details on the glacis plate were a little distorted due, I believe, to mold wear, so I decided to sand it smooth and add a sheet styrene plate to re-face the area and serve as a basis for the addition of my own replacement details.

This required cutting through the fenders where they attached to the hull so that I could slide the new glacis plate under them.

The headlight mounts were cut off, holes were drilled in the bottoms of the headlights, and corresponding holes were drilled in the new glacis plate. A new splash guard was cut from styrene and wood texture was added by scraping the face with a razor saw.

I also decided that the engine deck mesh screens were due for replacement. I used a motor tool to cut away the molded screens while holding the upper hull over the end of a vacuum cleaner hose to catch the resin dust. I then replaced them with small pieces of brass screen that I roughed up a bit to simulate a well-worn vehicle.

At that point the upper and lower hulls were joined.

Next up: hull details and suspension.

Stay tuned!

There has been a lot of buzz lately surrounding Rapid Prototyping, or as it’s commonly called: “3D printing”, in the modeling community. While it’s true that it is an exciting technology, we’re still a very long technological journey away from practical and affordable applications for the average modeler. The day you can take your Iphone21 S into your local museum, scan that FW-190 and print out a model kit on your Mr. Make-a-Part 2000 is still a long way away. Oh well – what’s the harm in dreaming? It’s the dream that inspires…

There are, however, many practical applications for 3D printing technology today. One of these applications is the creation of masters for aftermarket resin accessories. Companies like Eduard (for their Brassin range) Aires, DEF Models, Live Resin, HAD Models, Falcons Bench and many more, are seeing the value in creating models in CAD software and using those models to have masters printed. But creating these models is not as simple as scanning the real item and punching the scale into a computer. There’s still no “make model” button. It takes experience and skill to design a scale model for printing, one which has value beyond just holding something “neat” in your hand.

As a daily CAD user, I’ve developed the “flow” and practices that allow me to quickly break down complex shapes and surfaces to create a plan for modelling them efficiently, and the skills to put that plan into action in various software packages. As a modeler and a product designer, I can look at a part and evaluate what a user is likely to want or expect in a product. As an industrial designer and former production machinist (who also happens to have done a lot of resin casting), I’ve developed the ability to look at a part and see it in terms of a production process. As someone with a full-time job and little time for my hobby, let alone a cottage industry aftermarket business, I know that efficiency is something that MUST be designed into the production process at every opportunity if the effort is to remain sustainable and enjoyable over the long run.

So when an aftermarket company approached me and expressed an interest in having some very small detail parts modeled in CAD and printed for the purpose of using those prints as masters for casting, I knew that I could leverage my skills and background against the new technology to help this company bring their product to market as efficiently as possible while creating a high quality product for the end user, the modeler.

The first step was to define the end goal – the deliverable:

Masters for resin casting 1:35 scale Leopard tank mantlet plugs for the Leopard 1 and 2 (2 types of plugs)
8 plugs per vehicle.

1:1 mantlet plug

Easy! But let’s look at it through the perspective of the company who would be offering these pieces.
They would need to select a casting vendor (or plan on casting them themselves) and have the parts cast. We’re talking about some pretty tiny parts: less than 2MM in diameter with details less than .25MM thick! The design of the parts should facilitate easy handling for the caster, packaging, and the modeler. It was an easy decision to design a “sprue” arrangement to hold the part and make casting and handling easier. I figured that it would be a negligible amount of added print time, material, and casting resin to extend the sprue enough to add 2 spares of these tiny parts to the sprue as one of these parts from each set was bound to be sacrificed to the “carpet monster”. OK, so now we had a sprue, or more accurately a casting block, that was about 30MM long and still only about 3MM wide. That’s hardly enough to mix a batch of resin, and mixing that small of a batch is likely to end up with an “off” mixing ratio, leading to uncured, wasted material and time. Casters typically overcome this problem with small molds by making “gang” molds. These are molds that produce multiple copies of an item with each casting cycle. This is done by making one mold of the original part, casting multiple copies, then making a mold of those parts that will create multiple copies of the item with each pour. Often detail is lost, shrinkage accumulates, and the product suffers. Overcoming the need for this multiple generation process is a perfect application for CAD and 3D printing! In CAD it’s a simple matter to pattern a feature or a body to create a “gang” master. I figured that if the caster could get 10 blocks of parts per pour, an economy of scale would be established immediately. After the main block is removed from the mold, the individual blocks could be snapped off of the “gang” block and dropped into packaging. All that was left was to add an additional bit of length so I could add a product number to each block, elevating the perceived level of quality, and we’d be ready to upload the file to the print bureau.

I uploaded the file and sent a link to the aftermarket producer letting him know how to order his prints. I also uploaded the STL file (necessary for printing) and another common type of CAD file (for his archiving in the event of future work CAD needs) to DROPBOX and sent him the link to the files. At that time, I ordered an archival print for my own use. My part showed up a week later and it looked fantastic! It’s really amazing what the new SLA and SLS machines can do. Be aware that some finishing is still usually required to get smooth surfaces on the masters. A little knowledge and a good working relationship with the print bureau can help minimize the amount of work required to prep the prints for casting.

While 3D printing might not yet have reached full maturity, where a modeler just has to hit the magical “make part” button (don’t forget, I’ve only addressed the CAD model side of the equation – I haven’t even touched on the skills required to successfully operate a 3D printer) there are still some great applications for the technology, and advances in affordability, fidelity and ease of use are constantly being made. Who knows – it may not be long before you’ll have to look at your stash shelf to see if you have room before you hit that button again!

The Leopard 1 and Leopard 2 Mantlet plugs will be available soon from LeopardClub http://www.leopardclub.info
They will include photoetched retainer chains.
http://www.facebook.com/leopardfibel

I can be contacted at Peterjhamann@gmail.com , or https://www.facebook.com/PeterHamannModelServices

One of the things that has always bugged me about my ASU-85 has been the total lack of detail on the interior of the crew hatches. Even though eventually I’ll add a seated Soviet tanker, which will help hide the smooth flat surface, I’ve decided to add some detail to help liven the area up a bit. I’ve also decided to try to attend the IPMS Madrid show in Mid-March (in a week and a half!) and since this is the only model I’ve completed in the 12 months since last years show, and thus, the only thing I’ll have to put on the tables, I’d better get cracking!

I looked for reference photos online and couldn’t find any. Sometimes this can be a good thing, as it (hopefully) means that no-one else can either, so the odds of someone pointing out an inaccuracy are minimal.

I started by planning the general layout of the detail and decided on a rim or gasket-like appearance, with a few fasteners and the suggestion of a handle and latching mechanism. Once I had the idea in mind it was time to get busy. My goal here was to try to complete the rework (minus paint and weathering) in one build session. I also wanted to leave the exterior of the hatch undisturbed since painting and weathering had been previously completed.

I started by tracing the hatch with a .5MM mechanical pencil.

Then I scanned the tracing and opened it in Adobe Illustrator.

I offset the scanned lines 2.5MM to the inside to account for the thickness of the pencil lead…

then measured the kit hatch to confirm that the Illustrator drawing was sized correctly compared to the kit part.

I then added the gasket width and a few other features…

copied the pattern a few times and printed it out onto plain paper. Here you can see the kit hatch laying on the print to confirm the size.

I attached the pattern to some .010 sheet styrene using double-sided tape.

I started by punching out the inside corners with my new RP TOOLZ round punch and die (2MM diameter).

And cut away the rest of the interior contours. Then it was just a matter of squaring everything up with a file and adding some details with styrene strip, punched bolt heads, stretched sprue and some thinly sliced styrene extrusions.

I think that the new hatch is a huge improvement over the original featureless kit part.

The whole process took a little bit over an hour and was well worth the time, in my opinion. Now to see if I can get it painted in time…

Stay tuned!