Polikarpov Po-2, Kartonowa Kolekcja 3-4/2008, 1:33 scale

[deckape]

Ahoy Chris
She looks superb my man eye candy for certain. Hardy Well Done.

Boats

[ccoyle]

Thanks, Boats!

I have tried several different means of creating the exhaust pipes. First I tried bending styrene rod. Since this is a skill I rarely have to perform, it is something I'm not very good at (i.e. I suck at it). So, after wasting some rod, I gave up. I searched the house and came up with several types of wire. I have steel wire of the proper gauge, but it does not form the necessary tight curve radii well. I also found some plastic-insulated copper wire. The copper wire by itself forms nicely, but the gauge is too small. The plastic insulation, when left on the wire, has too much memory, so when it is bent into a tight curve it tends to gradually revert back to a less-bent shape (aggravating!).

But - I think I found a workable compromise. I'm using the bare copper wire, but sheathing it with the paper parts after copying them onto 20# bond paper. I'm going to try to finish these today and will post a pic later. Ciao!

[Leif Ohlsson]

+ add thickness by covering the solid copper wire with thin paper strips, wound on like electric tape. Then even out the joins with white glue or, better, acrylic modeling pase. Paint matt black (and any additional rust effect you might come up with...). Could work? - L.

[ccoyle]

That's similar to what I did, Leif, except I added the paper as two halves instead of winding it. Here is the result.


The pipes aren't perfectly smooth, but better than flat, two-dimensional parts, I think. I chose to paint them light blue instead of black, as that's how the example in the Krakow museum is painted.

Cheers!

[jagolden01]

Came out very well!

[OSTOJA]

The engine is real. Chris, this is not the exhaust pipes, the pipes are sucking.

[Leif Ohlsson]

OK, to soften the blow, what Ostoja means, if someone missed it, is not that the pipes Chris has made "suck" in the derogatory sense. He's making a jocular remark, that those particular pipes literally do suck, i.e. they are the intake pipes (from the carburettor). Very intricate language play... (and I'm sorry if I'm destroying it; couldn't help myself since it took a while for me as well to get the point).

The pipes are very nice, as I'm sure Ostoja agrees. And I know that you know, Chris, they are not exhaust pipes, since you've colored them.

I'm eager to see how you manage the exhausts eventually. The stubs are easier than the intake pipes, but there is one particularly difficult piece, where two pipes merge into one common, wider, outlet.

Good work. - L.

[ccoyle]

Originally Posted by Leif Ohlsson

OK, to soften the blow, what Ostoja means, if someone missed it, is not that the pipes Chris has made "suck" in the derogatory sense.

I got a laugh out of that! I understood no slight was intended - I'm quite accustomed to the vagueries of English as a second language. As it so happens, my aptitude for all things mechanical might charitably be described as "challenged," so perhaps I should stick to generic terms like 'pipes' and/or 'thingies'.

The actual exhaust pipes (as opposed to the intake pipes shown earlier) on this aircraft are kind of odd. One of the cylinders vents only through a short pipe stub; that one was, of course, easy to do. The remaining four cylinders are all connected in pairs. The ventral pair are the ones Leif is referring to - more on those in a bit. A pair of upper cylinders are connected by a curved pipe that is not round, but tear-dropped in cross section. I achieved the proper shape by using the same technique I used for the intakes, namely sheathing a a wire frame with two copies of the pipe like an upper and lower shell. I think this pipe came out pretty good.


The lower pipes, OTOH, were a real pain. As Leif mentioned, there are two pipes coming from some 'junction box' (see? I used a generic term, 'cause I don't know what the thing is) that fair into the pipes coming directly from the cylinders. The model design omits the faired joint altogether; this, my friends, is unacceptable! I started by rolling and assembling all the kit's paper pipes. The paper main exhaust pipes turned out fine (except for being, according to my picture sources, a couple of millimeters too short), but the the elbow joint in the smaller, inner pipes proved to be far too sharp - the pipe ends came nowhere near the proper spot on the main pipes. So, I cut apart the smaller pipes and then just played around with the pieces, measuring and chopping, until I got something close to the desired shape, length, and joint angle. I glued these in place and filled in the gaps with PVA glue. This actually turned out far better than I expected it would, and I am satisfied with the result. In any event, that work is all on the underside of the aircraft and so will be invisible to the casual viewer anyway.


I will be very interested to see how Leif tackles this chore in his larger scale. Certainly, at 1/16 scale the engine in particular offers much scope for additional detailing - stuff that I decided to leave off after deciding I can only tempt fate so much.

Cheers!

[ccoyle]

Well, one last little challenge on this model. Two, actually. First, the kit propeller builds into a chunky, not-very-attractive, solid black prop. I did some image searching on the web and found that although there are many different colors of Po-2 props out there, there are in fact images of wartime examples with chunky, not-very-attractive, solid black props. So, I will leave that as it is.

The observer's machine gun is a different matter. The gun is supposed to be either a ShKAS or Degtyaryov example. Problem is, it looks like neither of these. In fact, it looks almost like a hybrid of the two guns. So, it looks like some more scratch building is in order.

More later!

[ccoyle]

Yes, another post already! Yes, I am trying to finish this thing up finally!

Here's a link to a good, succinct overview of the ShKAS machine gun, accompanied by some excellent photos. And here's my scratch-built version of the gun:

The kit gun, as designed, has a number of flaws, including wrong basic shape (the middle section of the ShKAS is round, not rectangular, in cross-section), wrong barrel length, and wrong feed type (the ShKAS was belt-fed, not drum-fed like the Degtyaryov).

And here's the finished gun:

I attempted to mimic the finish of blued steel by painting the gun Tamiya Dark Sea Blue with a shot of matte finish overcoat. I installed sight posts, but did not try to install sights; they appear to have been removable for stowage in any case.

On to the finish!