1:3.4 FW 190 'Dora'

[Phil Clark]

Working in conjunction with renowned German Warbird builder Detlef Kunkel, I have recently started work on the fuselage/canopy/gun cover/cowling plugs for a 1:3.4 scale 190 'Dora'. The basic fuselage plugs have been produced by Detlef in Germany, but he has sent them to me for finishing & detailing before production of all of the tolling for a small production run of kits.

A strange choice of prototype some may say......so why this?

3-4 years ago, Detlef started development work on what he plans to be the 'ultimate' Warbird engine......a 1.7:1 geared 220cc 'V4' 4-stroke. Detlef's professional background is in engine and he's already produced a number of smaller geared inline twin engines based on commercially available cylinders (a 124cc inline twin based on a pair of ZG62 heads being one of the more recent). No stone has been left unturned during the development and following a decision 2-3 years ago to produce a limited run of just 20 engines to make the whole project 'just' cost effective.......perspective engine customers were asking for an airframe to put it in......hence the ultimate German WWII fighter.

Here's muggins with the fuselage plug as it arrived, alongside my own 'tiny' 1/5 Dora.

[Phil Clark]

As for the engine........

Early bench runs on a 34" x 18" SEP 3-blade prop are showing a peak rpm of 4,800.........this is 1,300rpm more than Detlef's Moki 250 on the same prop. Static thrust has already been measured at 110lb......and considering the estimated AUW of the Dora is around 80lb, performance should be exciting to say the least. Detlef is currently working on a new camshaft which he hopes will allow a larger prop still to be run........looking towards a scale 39" for the Dora.

More updates will follow once I have something worth showing.......could be a while as I have acres of rubbing down, filling, flatting etc....to do before any of the fun stuff starts.

Phil

[stewart clifford]

Nice

[Phil Clark]

Been pottering on over the last few weeks....................

The glassed foam surface had been roughly sanded to level most overlapping seams before I received it, but there were still a good number of major imperfections, small bubbles under the glass etc.......these were all filled and sanded before a sprayed coat of U-Pol 'Reface'. This is basically a thinner sprayable car body filler which can be built up into a thickness of several millimetres (so it says on the tin!!). It required a BIG gravity feed gun (I'm using a 1.8mm) and doesn't really flow but can be applied into a pretty even thick coat.

It's mixed as per body filler so has to be used once mixed. Cure time once sprayed is a couple of hours. It leaves a slightly orange feel finish, but block sands with 80 grit really well........all imperfections in the glassed surface were levelled in 1 application & 1 sand.

[Phil Clark]

Multiple applications of high build cellulose with a wet block sand at 120, 240, 400 then 600 have the surface at a stage where surface detail can start to be applied.

Cowling has had the same treatment & is now at the same stage.

[Phil Clark]

The canopy frame & the forward gun cover (the hinged panel ahead of the canopy) have obviously been formed as part of the fuselage, but these are required as separate moulded parts in the final kit, so these areas will be finished, detailed and moulded before the areas are removed from the fuselage, faces refinished then the fuselage finished, detailed & moulded minus canopy & gun hood.

Canopy 1st..........we've decided to fit the later blown canopy in place of the current early flat hood, basically because it looks better and the range of decent colour schemes is far greater for later models with the blown hood compared to the early flat hood models. The canopy frame is slightly different for the blown hood compared the flat, hence the need to change the entire canopy area, plus the mould taken to form the frame will also be used to pour the resin vac-form tool for the clear glazing.

The existing canopy area was cut off using a set of Arthur Bentley drawings we have plotted to the correct 1:3.4 scale for reference. All faces were levelled then faced with a balsa/Proskin laminate to take up the thickness of the cutter before the new foam canopy will be tacked in place. The idea here is that once the canopy is removed again, the flat faces will already be there......figured it was easier to complete these early in the work rather than later.