15" Sopwith Pup

The Tiger Moth is stalled (sic) at the moment due to my lack of mobility in the afternoon and evening so I rummaged through my stock and came up with this . An RC 2 channel laser cut model.

I've never attempted anything this small (except Airfix kits 60yrs ago) but at least I don't have to move around to work on it.

The quality of the cutting is absolutely exquisite. The instructions are only hieroglyphics so definitely not a beginners model.

We start with the servo mount.

Keeping things square proved to be a challenge.

Big fingers and old age shake don't help much!

Very nice but 15" span and RC sounds a bit too small for me!

That tank looks a tad big for that model Klippy.

You fly the model INSIDE the tank, O.F. So when a sparrow vents gas six miles away, the Pup doesn't blow away in the draught! [badass]

Because I'm interested in these things I weighed that first component The parts weighed 0.895gm or 13.1gn (Grains) after gluing together it weighed in at 0.97gm or 15gn, a weight increase of 14.5% on the unglued parts, ouch. And that's Cyano.

These are the parts that make up the forward fuselage, weighing 1.525gm or 23.4gn
Partly complete

And complete

Weighing in at 1.725gm or 26.6gn. Much better only 9.4% increase over the parts

The servo tray fits inside, there are small holes that all seem to line up, for the time being I've just used some wire to make sure everything lines up.

I find that thin Cyano doesn't work, it just disappears into the woodwork! A medium thickness seems to work fine but at the cost of extra weight because of the larger drop size.

Moving on to the fuselage proper

Those dotted lines are actually laser cuts, those parts are designed to be cut out after the sides are on.

Before I glued the formers on I checked to make sure they would key into the fuselage sides.

Now we can put the forward section on

So far everything's fitted perfectly without any need to open holes or file tabs.

Looking good Tony. Was it pricey?

one tenor wrote: Looking good Tony. Was it pricey?

Follow the link in post #1 John! [badass] Banggood, 16.58Gbp, free shipping.

Nice thread Tony, I'm looking forward to seeing this one in the air.

On the subject of cyano, I've always been of the belief that it's a heavy adhesive. A lot of it soaks into the wood and it doesn't evaporate which leads to weight increase. On a model of the size you're building here, I'd go for classic balsa cement. Most of the carrier evaporates leaving minimum weight of adhesive on the model. If you can't get hold of that, then PVA or white wood glue is similar, either watered down or not. The alternates take a lot longer than cyano to dry, but in my opinion, the weight reduction far outweighs the disadvantage.

Klippy
Looking at that fuselage I cannot imagine why the top rear is a 'solid' piece. The last thing you need on a Pup is unnecessary weight to the rear! or is it just a 'jig' for construction purposes?

Simon, post #9 the inner 'crutch' is mostly cut away, the top deck is very thin, soft balsa.

Here you can see where the inner former has been cut away prior to putting the top deck on.

The fuselage sides on, also very thin, very soft balsa.