1/144 Hamp update

After a couple weeks of hardly any workbench time, I found some opportunities over the weekend to get back to this build.  Got the cockpit base-coated with an oil wash, and started trying to figure out what to do with the engine.


Scratchbuilding radial engine cylinders in 1/144 turns out to be no Hawaiian vacation, and after several attempts I still haven’t gotten it quite right.  There’s a brief mention of how to approach this on page 63 of Brian Criner’s excellent “Modelling the Mitsubishi A6M Zero”, though he does it in 1/72.  He describes using a punch and die to create “over 500” (hey, no problem!) tiny discs, which he then stacks with smaller diameter spacers to create the impression of cooling fins.  Should work just the same at half the size, right?  Well, not quite.

First of all, for an even remotely to-scale appearance I decided it had to be .005 styrene sheet.  This is paper-thin, and the biggest problem is just physically dealing with the discs once they’re punched.  Sized at .038, they’re semi-microscopic and display a stubborn static-cling tendency with tweezers, cocktail stick, fingertips, etc.  Even more than most incredibly tiny parts they love to fly off into space at the slightest provocation.  Keeping them aligned while gluing becomes a very fine balancing act involving intuition, trial and error, and luck. 

Between having a couple dozen of these lying around plus dozens of other minuscule bits, one sneeze at the workbench these days would do as much damage as a Kansas tornado.

At least I don’t need 500 discs, as I quickly found out that even such small bits rapidly fill the available space.  .038 is the smallest punch size I have so smaller spacers were out of the question, but there’s no room anyhow.  First thing was to mark out the seven axes of the front row, spaced about 51.5 degrees apart, on some styrene sheet.  Then using a compass for a circle cutter I marked out a 3/8” circle to use for a backing plate.  Once I got a piece that fit OK inside the cowling I drilled the center hole for the propeller shaft and started gluing.  My first effort went awry when I discovered fit problems after about the 3^rd cylinder, and they didn’t look right anyhow. 

I was slicing a sliver off the discs to make a straighter gluing surface, but this combined with less-than-perfect alignment to give a distinctly uneven appearance.  After some thought I decided it would be better to make the cylinders as standalone pieces that could be sanded flat on the back and maybe narrowed at the bottom for fit.  Starting with the bottom disc stuck in some Blu-TacTM on a flat toothpick clamped in the jaws of Mr. Helping Hands, I tried stacking using superglue applied with a short, slender piece of wire in an Xacto knife handle. 

This was fine til the superglue started to tack up, making first placement the final placement.  After ruining a couple this way, I tried using white glue and found the opposite problem, not enough adhesion even when dried.  Guess I’ll try liquid cement next, if it doesn’t melt these tiny styrene flakes.  Luckily by now I’ve got kind of a production method down so it’s becoming less time consuming, and no doubt at some point I’ll actually figure this out and end up with fourteen (or at least the front seven) passable cylinders glued to the backing plate.  Then I need to get back to crash molding a decent canopy…