Being a treatise on VSF and Mars, and on 19th Century colonial warfare in general

(with a nod towards Messrs Gilbert and Sullivan, lest I take myself too seriously)

Sunday, 21 September 2014

Hullcutter II

I have managed only a little more progress today.

That's the bits of the hull in one piece, with a triangle of balsa at the front to prop it up.

As you can see, I've smoothed off the top of the bow with a hot wire.

I glued some balsa strips half a deck-height to the lower deck, and then hot-wired the remaining angle of polystyrene away. That gets the same look as in the Sky Galleons illustrations.

The bow probably needs some more bulk to be added before adding a ram, but it's taking shape nicely.

It will need only a little more work to imitate the window openings - I guess it gets hot in there turning that crank!

However I am very aware that several problems are building up, so it's time to pause and note the lessons so far from this learning experience.

The Lessons, or "What I'll do differently next time around"

In no particular order:

1) lining up the various decks was a nightmare and, with hindsight, not done accurately enough. Part of the problem was that, in trimming the expanded polystyrene, it is just too easy to have the hot wire at slightly the wrong angle and slice too much off. Then the deck thicknesses aren't quite square, so you're lining them up by eye to get the best-looking fit - and that's not a good idea with my eyesight. This will now require some significant (and messy) sanding and filling to get things square - I'll wait for decent weather for that and do it outside - it's going to be messy! The panelling will cover it, of course, but it's probably a long way round for a shortcut and the rest of my fleet should really be built more efficiently.

2) Next time I might well consider placing balsa on the top and bottom of the layer of polystyrene (or foam) for the lower decks. If I can get these properly aligned then I'll have a much better match deck-to-deck - AND the hot wire trimming would be nice and square. Pushing pins through the polystyrene to line up the balsa wood might help with this.

3) Care will be needed with the weight of the ram. The basic build of the craft is very light, so I'll have to avoid a heavy ram if at all possible or the whole thing is going to get very unstable. It's probably going to be a compromise between solidity and weight - too much weight will raise the centre of gravity and pull it well forward at the same time. Both are bad ideas. I might make the rear keel a bit larger to add a counterweight, but there are limits. In my mind this is the knottiest problem I have to solve. I may try laminating thin balsa wood - hopefully by crossing the grain and soaking the white glue through it will make it robust whilst still fairly light.

4) I really should have planned in the flying stand before I started, and build it in as I went along. Polystyrene doesn't take a drill very well. I mean, it REALLY doesn't.

5) The more I work with the polystyrene, the more I think that using a heavier foam makes better sense. This should compress a lot less than expanded polystyrene, and will be a better anchor for propeller housings and the flying stands. I'm toying with the idea of using bbq skewers thrust through the hull to act as anchors for the prop housings, but I'm not confident that the current construction will be sufficiently robust to hold them firmly in place. Time will tell.

So, bottom line, I need to pause for thought and solve some of these problems before going further - the ram, keel and flying stand in particular. I suspect the ship will be a bit scrappy in the end, but it's been a good test so far and it will be interesting to see how to firmly attach propellors.

nil desperandum!

Saturday, 20 September 2014

Hullcutter I

All I can say in my defence is that I blame DLI and his To Infinity and Beyond blog; he started making liftwood ships'n'things. And I'm nothing if not easily distracted.

It's been one of my long-term plans to make some sort of Martian liftwood galley. You know, one of those "OK, I'll do it right after I finish painting these, and base those, and then after I have added some of them, and ..." long-term plans.

Anyway, DLI's blog inspired me to drag it up my list of priorities. He's used balsa wood for the hull, which I probably wouldn't (I have neither the tools not the patience), but I find that seeing how someone else has done something always gives me ideas of how I might go about it. That's often because of a different set of skills or materials, and sometimes because I might want to achieve a different goal, but it's all good information. In fact that is why I often blog about how I build or convert stuff. It may be amateurish and you might not want to copy it, but it might just give you an idea about an alternative/related use for it, or trigger an idea for a better way to do something else, and good luck to you.

I decided I'd make a screw galley for my first attempt - I might manage to figure out cloudship masts and rigging in another lifetime - and I picked the Hullcutter from the "Cloudships & Gunboats" book as a fairly simple(?) one.

Next thing was to convert the deck plans. 18mm is about 6 feet in scale terms for my Peter Pig 15mm earthlings, so I fiddled with Word until I'd made a table with a 18mm grid. I then drew the Hullcutter decks onto copies of these grids.

I could have gone for a 20mm grid, but that's bigger by another 10%, and the length (14 squares-and-a-wee-bit) wouldn't fit onto printed A4 paper. Providence therefore dictated 18mm squares for my first attempt.

I also added some tabs towards of the rear of the lower deck to act as housings for the propellors. I know DLI had a few problems with getting these fitted, so forewarned  is forearmed!

I then cut the deck shapes out and glued them to 2.5mm balsa wood that I had lying around.

The next step was to carefully cut out the shapes on the balsa wood.

I glued the Lower, Bridge and Drag decks to some offcuts of 30mm expanded polystyrene sheet, cut out slightly oversize with a hot wire cutter. The main deck I left for gluing at a later stage.

I used white glue, which wasn't ideal due to the non-porous nature of polystyrene, but I scored it well (hopefully getting a better key for the glue), used lots of pressure and left it to dry well at each stage. Next time I might use a hot glue gun for a faster process!

Foamboard might turn out to be a better option that expanded polystyrene, but I used what I had lying around.

Once everything seemed to be dry, I used a hot wire cutter to trim some of the the polystyrene to the shape of the decks, especially where I needed straight lines to align the various decks. That was actually the entire thinking behind using the balsa wood in the first place - it would act as a guide for the hot wire cutter and make sure I didn't remove too much polystyrene by accident. (Yes, some thought really did go into this!)

Next step is to glue the layers together, and the main deck goes on top of the sandwich. Same glueing process.

I've left the drag deck off at this stage (this photo is with the glue only just on) so I can put some weight in top, but you can see it starting to take shape.

It's also quite obvious that I should also have added tabs to the main deck for the propellor housings! Ah well, next time ...

That is the result so far, but it's time to sign off soon, and the glue needs to dry.

The next stage might well be the trickiest as I will start to shape the hull and keep it as symmetrical as possible; angling or curving from the lower deck up to the main deck. Ultimately you won't see a lip of polystyrene round the edge of the main deck, and having the balsa wood decks will ensure I don't take too much off. Well ... it's good to have a plan anyway.

I still have to figure out a few more things before I'm done:
1) I'll have to cover the polystyrene for greater durability and a better look. I might use thin balsa strips for that, like planking. Or I might get a life and just coat the sides with some water-based filler.

2) Ram and keel. The ram in particular will have to be fairly sturdy as it will undoubtedly take some bashing as the model keels over (no pun intended ). I'll probably use thicker balsa wood, or a sandwich of balsa wood and/or mounting board to get the right thickness. A composite of the two materials might be the best solution for strength too.

3) Propellor housings. No idea how I'll do these yet - à voir.

4) Flying stand. For that I'm thinking of using a slow hand-drill to make a hole up into in each of the forward and the rear parts of the hull. The internal balsa wood layers should give the holes a shape and solidity that expanded polystyrene alone wouldn't. Or I might just embed the flying stand in the ram and keel if I make them solid enough.

5) Handrails. I've ordered some wooden stanchions from a model boat supplier in the UK, and I'll wait and see how they look. Alternatively I could use cocktail sticks or barbecue skewers for the uprights. It will probably be more balsa strips for the handrail bits (and I may add some heavier footings for the stanchions too).

6) Guns! (Two heavies, two rogues and one lob gun to be precise.) I'll probably bug Rodrick Campbell over at Highlander Studios, as he's been teasing us with pictures of 15mm Martian artillery that are in the pipeline.

But I'm happy with the start I've made. More to follow.