WIP: Helian Frigate 4

Posted by Mangozac on September 29, 2014

Made some more progress over the weekend. The prow banding has been done (which was actually far easier than I was expecting) and more work has been done on the stern. The really fine detailing has begun too.

I’m now deciding whether to chop the prow off off or not. It will make casting easier if the prow is separate to the rest of the model, but it makes casting faster and cheaper if it’s all one piece. The downside to having it single piece is that there will be a gate attaching on the bottom of the prow, so removal will leave a flat, featureless area…

Anyway it’s progressing nicely 😉



WIP: Helian Frigate 3

Posted by Mangozac on September 24, 2014

Just a quick update with a bit more progress to share. The prow and bridge areas have been puttied in and engines have been mounted. As you can see I’ve started detailing the engines, but there’s still a bit of work to do there. I need to hit the prow with some primer to check for smoothness and ensure there are no issues where the putty meets styrene. It’s hard to tell, as there was superglue involved in the construction and because of its relative translucency it will appear as a gap to the naked eye.


WIP: Helian Frigate 2

Posted by Mangozac on September 19, 2014

Not much progress to show compared with my last post, but I did discover something interesting I wanted to share.

So many of the CNC cut parts are mirror images, which means to make them I just drew one side and then mirrored a duplicate in Inkscape. But I discovered that with all of the mirrored parts one side was slightly smaller than the other. On larger parts this wasn’t an issue, but on smaller parts it’s really obvious. It was quite perplexing!

After giving it some thought I realised what the problem is.

Styrene is not a great material for machining. It has a tendency to melt very easily so you have to have your cutter and feed speeds very correct for the depth you’re machining at. It turns out that feeding with the cutter rotation direction will take off more (or maybe less, I’m a bit confused now) material than feeding against the cutter rotation direction. When the parts are mirrored in Inkscape, it also inherently reverses the direction of the paths, so that the two mirrored parts will end up with slightly different sizes. Fortunately it’s easily fixed: simply use the reverse paths command on the mirrored paths.

The curved “intake” looking sections adjacent to the bridge area are where this problem was really evident. What’s more the multiple passes used to cut the shapes from the 6mm thick styrene (4x 1.5mm sheets laminated together) had left very prominent marks on the sides of the parts.

So I created new toolpaths with a new machining strategy: first the little undercut areas are milled out. Then 5 passes are made through the styrene to cut out the shape, with a 0.3mm offset (so that the part is 0.6mm bigger in each direction). The cutter can then be run around the actual part size shape at full depth, since only a 0.3mm shave is being taken off. This creates a perfect part with perfect, smooth edges!

Here’s what it looks like post machining:


Next up: engines!

WIP: Helian Frigate

Posted by Mangozac on September 17, 2014

It will be pretty obvious to my followers that I’m a big fan of small scale, highly detailed space ship models. My good hobby friend and mega talented artist Aaron Dickey (known online as Vaaish) is also an aficionado of all things small scale (his Epic 40k models are arguably some of the best painted in existed). We were both bummed at the demise of the Battlefleet Gothic range over a year ago and set in motion plans to create our own line of highly detailed space ship models in the aesthetic that we love. Thus Battlegroup Helios was born.

Aaron has come up with a beautiful style for the first fleet (known as Helians) and created a stunning 3D model for the cruiser sized vessels (you can read about it here). Now that the 3D printing is under way (we had a couple of false starts) I have begun work on the Helian frigate design. I’m doing this as a traditional scratchbuild (although maybe I should call it a hybrid scratchbuild, considering the processes I’m using), since I prefer to work like that rather than 3D modelling.

Fortunately Aaron flexed his creative muscles again and drew me some awesome sketches to work from:

I then used Inkscape to draw vector artwork over the top of the sketches, working out all of the shapes required for the main forms of the design. Note how close Aaron’s freehand symmetry is!

From there I used my CNC router and a 1mm diameter cutter to cut out the shapes from various thickness styrene sheets. I forgot to take a photo by the result looks very similar to CNC cut terrain as it is supplied. It’s then a matter of trying to work out how all of these tiny bits are supposed to go together. And I do mean tiny: the parts look much larger on screen, but the overall length is approximately 55mm.

The base shape is starting to take form. Things are very rough at the moment and not many details are actually glued on (they’ve just been sat in place for this photo), but it gives a pretty good feel for the design. It’s now just a matter of slowly filling in details. My next step is to fill in the prow area with Milliput.

I’m trying to get a little bit done each night, so hopefully it shouldn’t take too long to complete. Once I have some resin copies I’ll then be cutting them up to make other weapon fitout variants.

Thanks for looking!