Author Topic: 'El Sonora' in 1/72  (Read 2873 times)

Offline Old Man

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Re: 'El Sonora' in 1/72
« Reply #45 on: August 02, 2017, 08:37:21 AM »
A very convincing pair of wings there. I especially like your use of tape for the ribs rather than plastic strip which can take a good deal of sanding down. The spans of these early machines were large: as you write they were basically wings with an engine held together with lots of wire and a few sticks - which makes them a challenge to model.

Stephen.

Thanks, Steve.

The tape is useful stuff, if you can get ahold of it. I am still coasting on what I bought from my old local shop before it closed. Looking around, I am not seeing on the web for sale the plain masking tape strips, but there are color strips in 1/64 on offer. White and dark brown seem like they might be useful. The lengths are only 120' per roll, and I don't know what they are made of. Still, probably worth risking a few bucks to find out. The masking tape strip can be sanded, once under primer, and I have used the 'leveling up' technique with it (sanding down after primer till I see just the tape) on other projects.

Using Future before primer is new for me, and seems to help fix the stuff in place. Primer did not do that well, and in fact I suspect it may have attacked the adhesive. It it lifts off, a little CA gel will get it back down again.

I gave off using plastic strip because I often found it lifting off as I sanded it down thinner. This may owe to my not using solvent glues to fix it down, however.

I had thought of using decal film painted dark grey (I often use this for canopy framing), but ran into problems with flaking when I tried cutting very thin strips.

I find often you can get a decent 'tape' effect just scoring two parallel lines with an Exacto blade. The real thing is awfully thin.

Offline Old Man

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Re: 'El Sonora' in 1/72
« Reply #46 on: August 02, 2017, 08:42:31 AM »
The wings are looking great OM. I try to avoid sanding the aerofoil into plastic card and simply bend the plastic to get the curve, but that's simply to avoid the huge amount of dust (or plastic shavings in the case of oversized kit wings that need thinning!)

Ian

It does make for a lot of dust, Sir. I break out the vacuum afterwards, and I have thought of moving the business onto the porch, at least in summer-time. But I really do not like working with heat, I've not had much luck with it, so I stick with sandpaper....

Offline Old Man

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Re: 'El Sonora' in 1/72
« Reply #47 on: September 23, 2017, 06:02:27 AM »
Been working away on this, and it is at a point where some progress worth reporting has been made.

First, I painted the motor, and constructed the cradle on which it rests atop the lower wing, and contrived a radiator.



The motor was painted silver, then gone over with various rust-red and orange washes to give it a copper tone. The radiator is basically a rectangle of thick sheet, wit edges and top added from bits of rod and strip. It was painted as was the motor, but with yellow tining on the frame, for brass.

Here is the cradle and motor on the wing.



After painting the wood and metal tube elements of the cradle, I made the central girder portion of the undercarriage. I was guided by the scaled Putnam drawings of an early Curtiss, but angles and eye dictated final adjustments in length and such.

To give a sense of proportion, I tacked on a pilot figure for these next pictures, roughly where a pilot would sit, and I also slipped in the front spoke wheel (it is held in by the 'spring' of the converging structural members).





The central structural piece was over-long for handling, and trimmed back later.

Here things are painted, and the radiator is resting approximately where it will go.





After this came the tricky bit, which I will confess I put off a while, till last night things just seemed right --- putting on the rear wheels.



The difficulty should be obvious, getting those slanting bits with the fork ends to be the right angle and length so the the entire item would sit level when the wheels were on. All this had tobe done by eye, as I have no trust-worthy drawing. The little rod leading down on the starboard 'fork' is a visual aid -- it is cut to the length I decided was right (7.5mm down from the rear win spar) for the center of the wheels, and the 'forks' set by eye to match it. A lot of fiddling ensued, among other things I had to take these off to attach the wheels within the forks, and put them back on without benefit of the sighting rod. The forks are simply bent rod, and had to be pressed by tweezers onto the wheel axle ends. Then the various bracings where attached.



The vertical forks were assembled on the model, one length of rod with a bent end for each side, and the little cross-piece put once the verticals were assembled.

Here is a front view at this stage.



Next was putting in the final rear supports, and the 'fork' coming up to the nose wheel from the central element.



The sit strikes me as satisfactory. Now that it is up on its own three legs, the next step will be doing the engine plumbing, and the seating arrangements....
« Last Edit: September 23, 2017, 06:41:45 AM by Old Man »

Offline RLWP

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Re: 'El Sonora' in 1/72
« Reply #48 on: September 23, 2017, 06:24:50 AM »
Progress! Hurray, hurrah!!

I wondered what was happening with this build

Richard

Offline lone modeller

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Re: 'El Sonora' in 1/72
« Reply #49 on: September 24, 2017, 03:59:49 AM »
"The sit strikes me as satisfactory"!!!!

I thought that we Brits were supposed to be the masters of understatement! That is a mind blowing piece of scratch building. Wonderdful, just wonderful.

Stephen.

Offline boggie

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Re: 'El Sonora' in 1/72
« Reply #50 on: September 24, 2017, 09:31:08 AM »
Excellent undercarriage engineering Old Man!

Good to have another of your intriguing build to follow.  :)