forum.ww1aircraftmodels.com

WW1 Aircraft Modeling => Under Construction => Scratch builds => Topic started by: Old Man on May 08, 2017, 02:03:14 AM

Title: 'El Sonora' in 1/72
Post by: Old Man on May 08, 2017, 02:03:14 AM
I will be doing a scratch-build of 'El Sonora', the aeroplane which constituted the 'Flota Aérea del Noroeste' operated in 1913 and 1914 by the faction of the Constitutionalistas led by Alvero Obregon during the Mexican Revolution.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/El_Sonora_zpsztkllkxa.png)

The aeroplane is an early product of Glenn Martin, and in fact I only learned of its existence when looking for background information on development of the B-10. I was instantly hooked; everything needed for a 'ripping yarn' of the most classic sort can be found in the tale this machine --- just how it reached Mexico in the first place is only the beginning....

Since it was operated by the force led by the man who emerged from the revolutionary decade as President of Mexico, and one of the men who piloted it went on to a commanding, if checkered, career in the Mexican Air Force, the machine is fairly well known in Mexico, and there is a fair body of photographs to be found. But I have not been able to find any scale drawings, and so will be putting this together rather as the thing was flown, by the seat of my pants, guided by what the photographs of this and other early Glenn Martin products make clear, namely that he cribbed shamelessly from Curtiss.

The trickiest bit of this is the un-cowled motor, so that is where I have started.  In assembling an early Curtiss V-8, I have had to do something resembling precision work on the cylinders, which I don't like to do and try to avoid. My instinct is to employ the old sculptor's maxim, suitably altered for plastic modeling --- take up a piece of plastic and remove everything which is not the part you want. But with the varying rings and steps, this was not going to be a good method for the cylinders of this motor. It took several tries before I got a useable result.

 

I used 'flying jigs' to get the cylinder pieces uniform. The bits to be assembled were measured against, and in some instances attached to, stock strip pieces of known thickness, and sanded down to match these standard pieces.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_8925_zpsuqfqzrok.jpg)

 This shows the principle, though it is from an earlier run. From left to right: finished cylinder, dressed cylinder piece on the 'flying jig', raw cylinder piece on the 'flying jig', and raw cylinder assemblies. On this run, the upper step was 2.5 mm, and the lower 0.75 mm. This did not allow for the irreducible thickness of the base ring, and so on the finished item I reduced the lower step to 0.5 mm. This necessitated boring all the way through the lower piece, and fixing the wire pin in the upper piece.

 

On my first run at this, I made the block too thin. On my second I spaced the cylinders too wide. Further, in both of these, the block was patterned on the OX-5 motor's block. The commercial success of the Curtiss OX-5 motor drowns the earlier V-8 models Curtiss produced, and while the various permutations from the model O on are basically similar, there are a lot of detail differences. OX-5 material can be used as a guide, but by the end-stage, period photographs have to be employed, and given the vagaries of such things, I have had to employ a certain amount of creative gizmology in here.

 

When I began the final run, I started by making the cylinder mount. It is hollow, with a base piece of 15 thou card, 11mm long and 5mm wide, a spine piece 2.5mm high down the center, and side pieces tented in. Shaved discs of 2 mm rod are attached.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_8942_zpsch5my1st.jpg)


Here are the new cylinders with the some of the receiving holes bored in the cylinder base.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_8950_zpsviwjnuag.jpg)

Here are the cylinders attached.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_8953_zpsjdelmw26.jpg)

Here is the cylinder assembly mounted to the second OX-5 pattern block. The block is 3 mm wide, made of three pieces of 1 mm sheet laminated together.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_8956_zpspxinofhg.jpg)

Here is the start of detailing. A further disc of shaved 2 mm rod tops each cylinder, with a head piece of slightly thinned 2 mm rod atop this. Curtiss cylinders were held down by four long bolts and an 'X' fitting over the cap. The block has been re-shaped to the earlier pattern.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_9002_zpswvgli2mc.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_9005_zpsq5rnqqk0.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_9007_zpsomlmljam.jpg)

Here are the fuel feeds and rocker arms in.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_9010_zps3333a20u.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_9012_zpstttxlrmq.jpg)

Here is the current state, with water lines and exhaust ports in, as well as sundry other 'works' shown in photographs....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_9020_zpsnlnod7hc.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_9022_zpsg76eb86t.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/Curtiss_Motor/IMG_9025_zpsewqdbhoj.jpg)

Further work on this motor must await mounting on its trestle above the lower wing, so it can tie in with the radiator and fuel tanks and carburetor and wing assembly.

In keeping with the policy of getting all the trickiest bits out o the way first, however, the next step in this will be producing three bar-spoke wheels....
Title: Re: 'El Sonora' in 1/72
Post by: Juan on May 08, 2017, 02:12:00 AM
Wow, your scratch building at this scale is amazing.  Really looking forward to your progress.
Title: Re: 'El Sonora' in 1/72
Post by: ondra on May 08, 2017, 02:22:02 AM
My hat is off to your scratch building skills, sir, this is pure pleasure to look at!

Cheers

Ondra
Title: Re: 'El Sonora' in 1/72
Post by: IanB on May 08, 2017, 04:42:08 AM
This should be fun!
 That is beautiful work on the engine. Having just completed 4 scratchbuilt engines for my Muromets I can fully appreciate what went into this!

Ian
Title: Re: 'El Sonora' in 1/72
Post by: RAGIII on May 08, 2017, 05:48:34 AM
That is an amazing piece of scratch building and the results are one beautiful engine!
RAGIII
Title: Re: 'El Sonora' in 1/72
Post by: lcarroll on May 08, 2017, 06:27:48 AM
Fascinating subject and amazing work, this is going to be a great one to follow!
Cheers,
Lance
Title: Re: 'El Sonora' in 1/72
Post by: dr 1 ace on May 08, 2017, 07:08:26 AM
Fascinating subject and amazing work, this is going to be a great one to follow!
Cheers,
Lance


Big Ditto to all the above

Ed
Title: Re: 'El Sonora' in 1/72
Post by: Des on May 08, 2017, 08:20:01 AM
Amazing work on the engine, your scratch building skills in 1:72 scale are amazing, I had difficulties scratching the same engine in 1:32 scale for my Curtis Hydroaeroplane. I will be following your build closely as I love this early type of aeroplane, excellent work so far.

Des.
Title: Re: 'El Sonora' in 1/72
Post by: lone modeller on May 08, 2017, 08:35:05 AM
First class scratch building of a quality we have come to expect from you. Just incredible how you manage not only to get in all that detail, but to be consistent with it. Having had considerable experience scratch building engines in this scale I can only write that I truly admire your skill….and just wish I had more of it!

Stephen.
Title: Re: 'El Sonora' in 1/72
Post by: GAJouette on May 08, 2017, 12:06:27 PM
 Old Man,
Scratch building is a challenge to itself my old friend. But doing so in 1/72 scale requires a large dose of talent along with equal portions of skilled wizardry. I have no doubts that you have an endless supply of both. Well Done my old friend,keep up the excellence!
Highest Regards,
Gregory Jouette
Title: Re: 'El Sonora' in 1/72
Post by: Manni on May 08, 2017, 02:42:24 PM
Unbelievable! This is great. I will watch carefully and try to learn from your skills
Manni
Title: Re: 'El Sonora' in 1/72
Post by: rhallinger on May 08, 2017, 11:02:32 PM
Another great build, OM.  The back story is interesting and that engine looks fantastic!  Very well done.

Regards,

Bob
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on May 10, 2017, 02:34:22 AM
Thank you, Gentlemen.

I appreciate the kind words.

I will be getting back to the bench this evening. I expect to take a solid run at the spoke wheels before the weekend.
Title: Re: 'El Sonora' in 1/72
Post by: coyotemagic on May 10, 2017, 03:39:20 AM
Spectacular engine, OM!  Can't wait to see what else you have in store for us!
Cheers,
Bud
Title: Re: 'El Sonora' in 1/72
Post by: ALBATROS1234 on May 17, 2017, 12:46:15 AM
great start on the engine old man looking forward to seeing the rest of this curtiss machine come together.
Title: Re: 'El Sonora' in 1/72
Post by: sobrien on May 17, 2017, 08:49:11 PM
Senora was a Glenn Martin built Curtiss copy.
Title: Re: 'El Sonora' in 1/72
Post by: KiwiZac on May 18, 2017, 01:55:06 PM
It's one thing to scratch these early birds at all, let alone the bravery/madness needed to do it in 1/72! My hat's off to you, sir. Beautiful work so far!
Title: Re: 'El Sonora' in 1/72
Post by: stevehed on May 20, 2017, 09:55:14 AM
Well done, Sir. Will be watching with great interest as always.

Regards, Steve
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on June 19, 2017, 09:34:12 AM
We have wheels, amigos!

I don't mind confessing this step nearly bounced me off the project, and even now I am still considering improvements that might make the contriving of spoke wheels a more regular process with a smaller ratio of failures to acceptable outcomes. But I have got enough of the bugs out to present a method which can produce acceptable results.

The method is derived from routines presented by the late Harry Woodman, master scratch-builder, whose book is available on-line, and highly recommended....

http://rclibrary.co.uk/files_titles/1216/ScaleModelAircraft_Woodman.pdf

But his method was meant for 1/48 scale work, and probably (though this is not clearly stated) employed waxed sewing thread for spokes. Adjustments have to be made for work at a smaller scale, and employing monofilament ('invisible thread') for the spokes.

The basics remain the same: two circles pressed together to make a wheel, sandwiching between them a spacer representing the axle, and a pattern of spokes attached separately to each circle and, in their centers, to each end of the spacer/axle. This crowns the spokes out as the unit is assembled.

Alignments of various sorts are essential, and have to be got at least more or less right.

Alignment of the spokes with one another I refer to as internal alignment: Half the spokes are attached to one end of the spacer/axle, and to the mating surface of one of the wheel halves, and the other half of the spokes to the other end of the spacer/axle and other wheel half's mating surface. When the mating surfaces of the wheel halves are brought together, the spoke patterns must be offset from one another, as this provides an optical illusion of more spokes than there actually are which is essential.

Alignment of the wheel halve's mating surfaces with one another I refer to as external alignment. Ideally the things should go together precisely --- a small off-set can be made good, but too great a mis-alignment here will show, particularly at the inside where the spokes sprout, a place where the eye will be drawn.

Alignment of the spacer/axle also has to be right, or at least to look right. If it is very crooked, and this can happen even if the external alignment is acceptable, the wheel will not look right.

Three factors complicate the matter further. First, there is not a lot of 'give' in the monofilament. It must be very strongly attached, both at the rims and the center, and will only stretch a little. Second, the wheel halves are pretty insubstantial. In 1/72 scale they ought not be more than a half millimeter thick, and there should not be more than two millimeters difference between outer and inner diameters, in fact it really ought to be a bit less. This makes bringing them together against the strain of the monofilament crowning out at the ends of the spacer/axle difficult. Third, when cleaning up, after the wheel halves have been attached, care must be taken to keep sanding sticks and knife edges away from the spokes, and the assembly should be held only by the rims, never by the center. Nothing really can be done on the inside seam at all.

It is made no easier by the fact that the wheels for 'El Sonora' are much smaller than standard. Wheels of Great War types generally run about 10mm outside diameter in 1/72 scale (or 15mm in 1/48), but the wheels on 'El Sonora' were only 20" in diameter, scaling out to an outside diameter of 7mm.

After a good deal of trial and error, which exposed various problems in succession, I finally reached a point where I have been able to produce this weekend a five reasonably usable wheels for 'El Sonora' (which needs three).

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9226_zpsmhpdpknj.jpg)

Here is what is needed for a wheel:

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9221_zpsrjvstzjl.jpg)

The two wheel halves are obvious, the bits beside them are two thin discs made of small slices of 1mm rod flattened down hard in a smooth-jaw pliers, two thin slices of 1mm rod left as is, and a half millimeter disc of of 1.3mm rod ---these make up the spacer/axle and anchors for the centers of the spokes. The octagonal piece is the weaving jig for the spokes, it is 1mm thick. The square pieces, one of white and one of clear plastic, also 1mm thick, with holes in the center, are assembly tools. The tape is used to tack down the ends of the monofilament line at start and finish. The larger sheet of plastic is one means of providing a background against which the spokes can be seen clearly during several steps (they don't call this stuff 'invisible thread' for nothing...)...

The wheel halves are cut off the end of a length of tube with a 7mm outer diameter.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9194_zps8b4dzj4s.jpg)

The suggestion of 'roundness' can be given to the end of the tube before cutting off the ring, and once cut off, the excess can be sanded down to a proper thinness. The ring on the left is finished, the one on the right is straight off the tube.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9195_zpshyvd5r5a.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9197_zpsj6mvuvmr.jpg)

Here a wheel half is on the weaving jig, with the spokes in place. The pencil marks are measured to provide a placement guide for centering, double-face tape sticks the piece in place, the projecting piece of 1mm rod at the center spreads the spokes out. Both ends of th length of monofilament are taped down on the back of the jig. A dab of CA gel is placed between the paired spokes on the rim, and spread to cover them. Care must be taken to keep glue off the inside rim, and it s best to do this twice. Let the glue set ('liquid patience' can be used to ave time, but doing so will make it necessary to replace the double-face tape for each use of the jig). Test by a little nudge with a toothpick to see each spoke is firmly attached.

Then clip the lines outside the rim, and lift the half-wheel with spokes off the jig....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9200_zpsyiansgnh.jpg)

Trim the excess monofilament off at the rim, closely (the stuff is very resistant to sanding, so get it right at the edge with the scissors or knife). Place it mating surface up on the opaque assembly tool, prepared with double-face tape, and glue one of the thin flattened discs in the center. Hold over a white surface while you do this, so you can see the center....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9202_zpsm4sgufcm.jpg)

Place the wheel half mating surface down on a flat white surface, and glue one of the un-flattened discs of 1mm rod in the center....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9204_zpskkvmqymb.jpg)

Return one of the two wheel halves to the assembly tool, mating surface up, and fasten the half millimeter length of 1.3mm rod to the center disc...

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9207_zpsba4cl3wh.jpg)

Leaving that piece in place, attach the other wheel half to the bit of 1.3mm rod, taking care to off-set its spokes from those of the other wheel half. This is where the magic begins to happen....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9210_zpsp76jmwhe.jpg)

The wheel halves are still separated by a bit under a millimeter's distance, however....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9213_zpssyccyzom.jpg)

Apply glue all around the mating surface of the bottom wheel half, taking care to keep it off the inside rim. Place the clear assembly tool over the upper wheel half....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9215_zpsed4zxsv5.jpg)

Squeeze the assembly tool together, doing your best to see the wheel halves come together with their otter diameters closely aligned. You won't always succeed, but about two out of three times the result will be acceptable. Holding the sandwich firmly together for a minute of so will be enough for the CA gel to set. If it looks useable, douse wit accelerator and tend to the seam, thinning down the outsides of the 'tire' a bit as well.

I am still mulling over ways to improve the final external alignment. I am thinking that a 'collar' of the tubing, with several lengths of stout rod, perhaps 1.5mm thickness, affixed to the outside of the 'collar', would provide a good resting point for the bottom wheel half, and a good guide for fastening the upper wheel half to the spacer/axle piece, and for pressing it down to mate with the bottom wheel half. Another length of the tubing could be used as a tool to press down the upper wheel half in this step. I expect I will give that a try before I actually put wheels on 'El Sonora', but as I have usable wheels in hand, and know I can do this at the rate of about forty minuted a wheel complete, I consider the problem solved, and now, with wheels and motor in order, I can move to making the airframe. Next step will be the wings and engine mounting....


Title: Re: 'El Sonora' in 1/72
Post by: lcarroll on June 19, 2017, 11:46:25 AM
   Hat's off to you OM, that's real Model Building you've described here, and outstanding work at that! I marvel at the Scratch Builds that you, Des, and Stephen (Lone Modeller) turn out. It takes, IMHO, a very special love of the hobby and considerable skill to work in your chosen genre. Great Build logs, wonderful subjects, and always so much learned. Keep those posts coming!
Cheers,
Lance
Title: Re: 'El Sonora' in 1/72
Post by: RLWP on June 19, 2017, 07:18:35 PM
I knew you would crack this problem in the end, they look great!

I think this is one of things that will bug you, and no-one else will notice. There is so much going on with El Sonora to do with the unusual configuration, exposed engine, flimsiness, pilot position, rigging and so on. A slightly off-centre 7mm wheel is going to disappear in the impressiveness of the complete model

Your wheels are brilliant, I still can't understand why anyone would scratchbuild in such a tiny scale - you must be mad!

Richard
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on June 19, 2017, 10:26:23 PM
   Hat's off to you OM, that's real Model Building you've described here, and outstanding work at that! I marvel at the Scratch Builds that you, Des, and Stephen (Lone Modeller) turn out. It takes, IMHO, a very special love of the hobby and considerable skill to work in your chosen genre. Great Build logs, wonderful subjects, and always so much learned. Keep those posts coming!
Cheers,
Lance

Don't under-estimate innate perversity as a motivating factor....

But seriously, thank you for the kind words. I will always maintain scratch-building is more a question of nerve than skill, and am firmly of the view that many modellers have the craft skills necessary for it, even though they think they don't.
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on June 19, 2017, 10:42:36 PM
I knew you would crack this problem in the end, they look great!

I think this is one of things that will bug you, and no-one else will notice. There is so much going on with El Sonora to do with the unusual configuration, exposed engine, flimsiness, pilot position, rigging and so on. A slightly off-centre 7mm wheel is going to disappear in the impressiveness of the complete model

Your wheels are brilliant, I still can't understand why anyone would scratchbuild in such a tiny scale - you must be mad!

Richard

Thank you, Sir.

I expect you are right, though with two caveats. First, a crooked or off-center axle can effect the 'sit' of the model. Second, the interior rims really out to be at least dull silver, which catches the eye and heightens imperfections. Some of the first could be finessed in fastening, though (this will have to be attached to a base, there is nowhere to conceal lead in front to keep its tail up), and I could go with a light grey on the rims, I suppose.

I am going to give the 'tube tool' a try, and I am also thinking of ways to sort of 'box in' the wheel halves on the existing assembly tool (lengths of thin strip fitted around a sample wheel on on both elements, which would hold the wheel pieces in place, and give a positive visual mark for alignment as the things are pressed together) to avoid slippage on the surfaces, whih dos seem to present a problem with the current method.

1/72 is just 'my scale', and has been, back when I was young, and again now. I was a jeweler for some years while a young man, and so my craftsmanship is attuned to quite small things.
Title: Re: 'El Sonora' in 1/72
Post by: RLWP on June 19, 2017, 10:50:43 PM
Three or four pins would be enough to guide and locate the rims. I would probably put them inside and slide the haves over the pins

And a grassy base with a slip of styrene under a tyre would be practically invisible and true up the wings

Richard

Title: Re: 'El Sonora' in 1/72
Post by: Old Man on June 19, 2017, 11:23:53 PM
Three or four pins would be enough to guide and locate the rims. I would probably put them inside and slide the haves over the pins

And a grassy base with a slip of styrene under a tyre would be practically invisible and true up the wings

Richard

Thanks for the placement suggestion. Inside could be tricky because of the risk of interfering with the spokes. The pins would need to be no more than 0.75mm thick. The circle in the pressing plate would have to be cut precisely, if it were done with the existing flat pieces. Pins could be both inside and outside on the projected 'tube tool'. One advantage of 'inside pins' is less chance of involvement with the final glue application.

Sonora State, unfortunately is pretty much desert --- they've thought of everything to make a modeler's life difficult, the cabrones...
Title: Re: 'El Sonora' in 1/72
Post by: RAGIII on June 19, 2017, 11:31:10 PM
   Hat's off to you OM, that's real Model Building you've described here, and outstanding work at that! I marvel at the Scratch Builds that you, Des, and Stephen (Lone Modeller) turn out. It takes, IMHO, a very special love of the hobby and considerable skill to work in your chosen genre. Great Build logs, wonderful subjects, and always so much learned. Keep those posts coming!
Cheers,
Lance

I can't say it any better!!!!
RAGIII
Title: Re: 'El Sonora' in 1/72
Post by: RLWP on June 20, 2017, 01:52:07 AM


Sonora State, unfortunately is pretty much desert --- they've thought of everything to make a modeler's life difficult, the cabrones...

Are you sure?

(http://www.geo.arizona.edu/Antevs/biomes/grslnmx.gif)

http://www.geo.arizona.edu/Antevs/biomes/azlifzon.html

 ;D

Richard
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on June 20, 2017, 02:20:57 AM
Maybe it could hve landed on that srub in a pinch, Sir, but take-off would be problematic, I expect. Pictures I'm sure are of the machine show flat, pretty bare earth, and I doubt anyone mowed it....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/El_Sonora_zpsztkllkxa.png)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/02_jefes_constitucionalistas_junto_al_biplano_sonora_zpsw1uhpgwj.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/Martin%20Pusher_lrg_zpsqujjzlkm.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/304_zpsfkbguqwj.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/massonsonorasky_zpshdy4q7ny.jpg)
Title: Re: 'El Sonora' in 1/72
Post by: RLWP on June 20, 2017, 03:01:32 AM
Yes, that seems unlikely to me too. She seems to be standing on some kind of prepared surface

Richard
Title: Re: 'El Sonora' in 1/72
Post by: lone modeller on June 20, 2017, 03:29:02 AM
This is a tutorial that I have been waiting for. Spoked wheels in God's Own Scale is something which I have wanted to do but did not really know where to start. You have blazed a trail which one day I must follow. I have just used Eduard PE spoked wheels for my Voisin (will post the last bit later) and they are nowhere near as realistic as yours.

All of your models are mini-masterpieces but I am especially attracted to these early machines - all wood, wire and faith to get them into the air. This is proving to be another super build log to follow - very many thanks.

Stephen.
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on June 20, 2017, 07:18:30 AM
   Hat's off to you OM, that's real Model Building you've described here, and outstanding work at that! I marvel at the Scratch Builds that you, Des, and Stephen (Lone Modeller) turn out. It takes, IMHO, a very special love of the hobby and considerable skill to work in your chosen genre. Great Build logs, wonderful subjects, and always so much learned. Keep those posts coming!
Cheers,
Lance

I can't say it any better!!!!
RAGIII

Thank you, Sir. I appreciate your interest and support.
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on June 20, 2017, 07:31:22 AM
This is a tutorial that I have been waiting for. Spoked wheels in God's Own Scale is something which I have wanted to do but did not really know where to start. You have blazed a trail which one day I must follow. I have just used Eduard PE spoked wheels for my Voisin (will post the last bit later) and they are nowhere near as realistic as yours.

All of your models are mini-masterpieces but I am especially attracted to these early machines - all wood, wire and faith to get them into the air. This is proving to be another super build log to follow - very many thanks.

Stephen.

It is a kind of 'Holy Grail'; leaving the covers off was so common.

As you can see from discussion above in the thread, I am still thinking to refine the process --- alignment in the final stage of assembly remains a bit more dicey than it really ought to be, especially since if it does fail, a good deal of work and time is rendered worthless.

For wheels of more standard size than these, the weaving jig should also be larger, as the length of the line affects its taper, and this in turn affects where the lines 'cross' (in optical illusion) in relation to the rim. Also for larger wheels, I would like to at least try a dodecagon rather than an octagon shape for a weaving jig. It might pile things up a bit thick in the center as the lines cross over one another there, but 'more space = more spokes' makes sense on its face.

I have tried a photo-etch set once for this and botched it badly. Good on you for making it work.
Title: Re: 'El Sonora' in 1/72
Post by: steveb on June 20, 2017, 01:20:30 PM
Wow, those wheels! Not to downplay any of the other work, but the spokes are really great!

Steve
Title: Re: 'El Sonora' in 1/72
Post by: Borsos on June 20, 2017, 10:34:12 PM
Great work all around, but yes, the wheels are incredible!
Borsos
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on July 12, 2017, 01:42:08 PM
This spoke-wheel business is getting out of hand. When I posted up last, ways to improve the making of these were occurring to me. I have gone ahead and implemented these, with some success. I made seven of these this past weekend, at the rate of about one and a half hours per wheel. I think I have gotten this to a true 'production' state. The completed wheels are much improved, easier to handle in the finishing stages, and 'finer' in the size of their components.

Here are the jigs and tools now used in making and assembling the wheels.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9294_zpstqdi3ede.jpg)

The jig at the left is for weaving the spokes onto a wheel half. It finally occurred to me to have wife print out something with eight points. However, the eight points, probably owing to distortion in being blown-up from a small original, do not quite align correctly. On this, the notches at the points were adjusted till all the lines crossed precisely over the center dot before the central spacer, of 0.75mm rod, was placed.

The jig in the center is to hold the wheel halves aligned when they are attached to the axle/spacer. It began as a weaving jig, but failed in that because I had assumed the points were aligned truly, so that it produced off-center spokes. The four rods of 1mm rod around what was originally a centralizing collar hold the alignment. The center was cut out to give a good view of how the spokes were lining up.

The item at the right is the tool for fastening the wheel halves together. Its base is an earlier weaving jig ready to hand for the purpose. A ring off the tubing stock is in the center. Four long pieces of 1.5mm rod are attached and form a guide. The wheel halves, joined already to the axle/spacer, are placed inside. A length of tube then presses down, guided by the rods, and applies uniform pressure to both wheel halves, while the rods preserve external alignment. This item also has the secondary function of holding the wheel halves while their mating surfaces are marked for notching.

Here are the pieces employed....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9264_zps0zaanbtk.jpg)

At the top are two raw wheel halves freshly cut from the tube. Beneath these, at the left is a wheel half tinned down and marked for notching, and at the right is a notched wheel half ready to receive spokes. I had tried notching in earlier experiments, but discarded it as it weakened the wheel halves and they bent in assembly, but that was in the early going, and the assembly tool now removes that difficulty.

On the near right is a finished axle/spacer, and on the far right is the 'raw' item. A hole is put in a square of 0.75mm sheet, a length of 0.75 rod is put through and fastened. The square is clipped and sanded down till round, and while of greater diameter than the rod, not greatly so. The rod is then trimmed down. It is important one end be longer. Both must be sanded to a bit of a point.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9269_zpsvsaeseu6.jpg)

On the left is a notched wheel with its spokes. The spokes, pressed into the notches, work to center the wheel half. These are glued in, being sure the spokes are deep in the notch, and the notch filled above them with CA gel. The notches are put in with a knife-edge needle file. Once the wheel half is cut off the weaving jig, an the excess trimmed, the mating surface can be sanded flat with a fine grit sanding stick. The notches fix the spokes firmly enough in place to allow this it very little risk of disturbance. On the right is a wheel half with spokes trimmed, and the wheel's axle/spacer affixed. The short end goes into the lower wheel half.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9272_zps4wsr0xxe.jpg)

Here is the second wheel half also attached to the axle/spacer, correctly aligned.


(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9275_zpsq52quzis.jpg)

The longer end of the axle/spacer allows glue to be applied after the second wheel half s aligned.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9276_zps55vgyrrs.jpg)

Here are the joined wheel halves in the assembly tool. Glue (CA gel) is applied in a manner which avoids the rods. The length of tube is pressed down; it can be held in place between thumb and middle finger, or placed on the bench and pressed down. After a ten count I apply liquid patience, and continue to hold for a slow sixty-count. A Once the 'plunger' is removed, a knife-point will lift the wheel off the base, and it can be lifted out readily.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9301_zpshhkeexro.jpg)

One the left is a wheel fresh out of the assembly tool; on the right is a finished wheel.

Finishing consists of clipping the excess off the axle/spacer, and dressing it down with a 'swizzle-stick' sanding stick. Examine the outer rim for un-glued seam, and apply a bit of CA gel smoothed down with a tooth-pick. Sand the outer rim down smooth. Then You can sand down the sides of the tire with a heavy grit sanding stick, keeping it tilted slightly away from the center and the spokes. Though you should not hold the wheel in a death grip, you can hold the center while you do this with reasonable safety. Sand down close to the 'points' of the notches (the dark color of the set CA gel will be visible). Finally, knock down the edges of the outer rim to give the thing a bit of rounding, and end with some smoothing from a fine-grit sanding stick.

Here are the weekend's production....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9305_zps40aatbtl.jpg)

The penny is for scale, and the wheel from an Eduard N.17 kit shows how how undersized these 20" wheels are to the more usual items. It would not be difficult to scale this up to produce wheels of the diameter of that kit piece. At that size, a dodecagon rather than an octagon might be employed, though an octagon would certainly do.

At any rate three wheels will be selected from those pictred here for incorporation into 'El Somora'.

I will leave you with the contents of the 'swear jar', all the various earlier wheels and attempted wheels which have gone before....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/spoke_wheels/IMG_9307_zpswjbf3ao2.jpg)

Title: Re: 'El Sonora' in 1/72
Post by: RLWP on July 12, 2017, 05:32:26 PM
Fantastic work!

If you get stuck on octagons in the future, it's a very easy construction using a rule and a pair of compasses. A dodecagon is easy too

Richard
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on July 13, 2017, 02:09:17 AM
Thank you.

When I got out of plane geometry in high school I pretty much swore to never look back....
Title: Re: 'El Sonora' in 1/72
Post by: Borsos on July 13, 2017, 03:05:12 AM
Wooow. This plate with all the countless failed tries! You show clearly how much work and sweat you invested into this solution. Chapeau! That's really great modelling.
Borsos
Title: Re: 'El Sonora' in 1/72
Post by: RLWP on July 13, 2017, 03:09:09 AM
Thank you.

When I got out of plane geometry in high school I pretty much swore to never look back....

Oooh, no. No mathematics involved, just sensible drawing practice as you would have found in any drawing office

Richard
Title: Re: 'El Sonora' in 1/72
Post by: lone modeller on July 28, 2017, 02:28:17 AM
Wow OM that is a really useful tutorial. I have bookmarked this for future reference - and I bet that I will still have as many failed attempts as you!

Stephen.
Title: Re: 'El Sonora' in 1/72
Post by: ondra on July 28, 2017, 03:15:38 AM
Many thanks for sharing the tutorial, you have solved the issue with a solid portion of ingenuity!

Thank you for the inspiration and my hat is off to you!

Cheers

Ondra
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on July 29, 2017, 03:43:27 AM
Thank you very much, Gentlemen.

I am finally getting onto the wings for this today; should have something solid on it quite soon.
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on August 02, 2017, 03:39:56 AM
On to the wings....

I freely acknowledge that a good deal of what I am doing in this build is conjectural, as there are no drawings available, nor have I even seen stated dimensions for this particular aeroplane. There is a decent photographic record of the machine, though, and Mr. Martin's designs at this time were largely copies of Curtiss aeroplanes, albeit tweaked somewhat. I am operating on the courteous assumption that basic elements, such as aspect ratio, were not significantly altered by Mr. Martin and his workmen.

That said, after some study of photographs, and period drawings of various contemporary Curtiss machines, I settled on dimensions and pattern for the wings. In these old 'flyers' produced by early designers in the U.S., the wings are the main structural element. Aside from motor and associated plumbing, there is not much besides sticks and strings (though there are a lot of those, the strings particularly). A rib spacing of 4.5mm provided a wing-span of 180mm, with a little fudge at the tips, scaling up to about 12.9 meters, or about 42' 6", measuring flying surface tip to tip, which is within the range of long-span Curtiss 'flyers' Mr. Martin would have been copying (spans given for Curtiss machines, by the way, often give the distance from aileron tip to aileron tip, not the span of the actual flying surfaces). I used the five foot basic chord usually employed by Curtiss. The 'ear' wingtips are Mr. Martin's; Cutiss wingtips generally were squared and ended at the outer bay of interplane struts.

 

The wings started out as blanks of .030" styrene sheet, cut to measure and bent by hand. After bending, they were sanded to a smooth curve surface. On the concave undersurfaces, this was done with heavy grit sandpaper fastened to a large bottle (about 4" in diameter), with a such paper on a smaller bottle (about 1" in diameter) used for final shaping. The upper surfaces were done with heavy grit sanding sticks. Once the shape was in hand, I began laying out the ribs.

 
(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9392_zpsjbtbhypa.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9394_zpsonepevcx.jpg)

 I managed to cut myself a little cutting these out, but am of the school that blood sacrifice to the modelling deities secures some favor in a build....

 

Once the ribs were laid out, I 'broke the plane' between them with a narrow 'swizzle-stick' sanding stick, and the curved edge of a #10 blade used as a scraper perpendicular to the plastic. You don't need to go very deep, just enough to leave a 'ridge' readily apparent to your finger-tip brushed along the surface.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9395_zps7zu0ufox.jpg)

Once this had got a couple of coats of white primer, and a couple of coats of Future, the next step was applying rib tapes, quite literally in this instance: I used 1/64" pin-stripe cut masking tape. Fiendishly useful stuff, and I am beginning to look for resupply (the company is 'Line o' Tape') as I am now down to about half of my last 240' roll of it.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9400_zpsbbdldjbk.jpg)

 As will be seen in the photographs, Martin used a dark tape (possibly even blackened strips of wood or cane) to secure fabric to the ribs. I darkened the tapes with an ordinary #2 pencil. This then received two more coats of Future, which helps fix the tape down firmly, and seals the pencil marking. On the undersurface, it is only necessary to draw in the tapes, there is no need to 'break the plane'....

 

After this, I have begun to paint the fabric....

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9404_zpstr5xfogj.jpg)

 Again, it will be clear from the photographs Martin used a pale fabric indeed. I have used a mix a light grey and tan, quite thinned, and brushed on between the ribs. It will get a couple more coats of this, but I will say the coverage looks more uniform to the eye than it does under flash and a macro lens.

 

Next step will be picking out which wing will be which, and beginning to assemble the motor and undercarriage to the piece chosen as the lower wing....
Title: Re: 'El Sonora' in 1/72
Post by: lone modeller on August 02, 2017, 03:46:42 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.
Title: Re: 'El Sonora' in 1/72
Post by: IanB on August 02, 2017, 04:11:15 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
Title: Re: 'El Sonora' in 1/72
Post by: Old Man 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.
Title: Re: 'El Sonora' in 1/72
Post by: Old Man 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....
Title: Re: 'El Sonora' in 1/72
Post by: Old Man 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.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9590_zpsw4gnl31g.jpg)

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.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9591_zpsh0lxp6tk.jpg)

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).

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9594_zpskezbpwye.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9597_zps0y3x9tbq.jpg)

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.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9629_zpspoiup678.jpg)

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9630_zpsmvmsoy4l.jpg)

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.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9702_zpsc3rhe13u.jpg)

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.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9709_zpskozt6oy6.jpg)

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.

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9706_zps2hlrkd06.jpg)

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

(http://i1220.photobucket.com/albums/dd447/vieuxhomme/book_scratchbuld_proj/el_sonora/construction/IMG_9717_zpsduhw74ga.jpg)

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....
Title: Re: 'El Sonora' in 1/72
Post by: RLWP on September 23, 2017, 06:24:50 AM
Progress! Hurray, hurrah!!

I wondered what was happening with this build

Richard
Title: Re: 'El Sonora' in 1/72
Post by: lone modeller 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.
Title: Re: 'El Sonora' in 1/72
Post by: boggie on September 24, 2017, 09:31:08 AM
Excellent undercarriage engineering Old Man!

Good to have another of your intriguing build to follow.  :) 
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on July 19, 2020, 08:33:02 AM
This build is being continued in the 'corona virus lock-down' group build for stalled projects):

https://forum.ww1aircraftmodels.com/index.php?topic=11033.0

I will update this thread with major advances, but detail progress will be found there.
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on September 02, 2020, 05:16:56 AM
All right, my friends.

The upper wing is on!

(https://i.imgur.com/rGL1vK8.jpg)

(https://i.imgur.com/cNK6mSn.jpg)

(https://i.imgur.com/lc4YqnJ.jpg)


Everything is not quite all Sir Garnet,  but it is acceptable, and most adjustments will be minor.

I dropped the booger twice, just in my lap, mind, but that was enough to spring things, as miniscule amounts of glue are all that is employed. The second drop came as I was trying to adjust position on the last strut (of course), and that one was bad enough I popped the wing off, and made new struts, which went on without further incident. As you can see I did not rig as I went, the thing was much too wobbly with four, or even eight struts in place, to hold while doing things like incidence wires. With sixteen struts in, it can be handled with care. Painting struts, and rigging, are the next step, and this will include some minor strut adjustments, as things stiffen up with the pull of the elastic.

Once that is done something quite delicate will be needed. You may notice the radiator is off. This is because its position, relative to the forward tube supports of the motor's cradle, is too far back, and interferes with the proper forward 'cabane' structure (which two parallel tubes, with a cross-piece and triangle at the top. The lower tube supports will have to be removed and placed a bit further back, and the cradle extended a trifle where the radiator goes. I feel reasonably confident I can manage this without undue difficulty. A new, thinner radiator piece may be needed.

I may also have to redo the rear outermost interplane struts, as these support (and go through) the mid-gap ailerons. It is just behind the leading edge, mind, and a notch with white-glue filler might suffice, but a hole may prove necessary. I confess I had not considered this when assembling the wing cell, but better to have plowed ahead and got the thing into one piece when the fit was on me and my blood was up.

Hope to have more progress in a week or so, as I am back on the bench now.
Title: Re: 'El Sonora' in 1/72
Post by: lone modeller on September 03, 2020, 01:50:38 AM
Some extremely delicate work going on there OM but with your skill and experience I am sure that you will get things right eventually. This must be one of your most complex and delicate scratch builds - only a master would even contemplate attempting this one.

Stephen.
Title: Re: 'El Sonora' in 1/72
Post by: IanB on September 03, 2020, 11:47:30 PM
Wow, that is going to be a LOT of rigging.
Coming on nicely though, despite setbacks.

Ian
Title: Re: 'El Sonora' in 1/72
Post by: Alexis on September 04, 2020, 11:55:32 PM
That is going to be a lot of rigging , for it's scale it is a good size ! Coming along really nice so far and beautiful detail work on the engine !


Terri
Title: Re: 'El Sonora' in 1/72
Post by: RAGIII on September 06, 2020, 04:29:20 AM
The Model looks awesome with the upper wing mounted. The engine also looks Fantastic! Looking forward to the next update!
RAGIII
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on September 09, 2020, 09:19:18 AM
Some extremely delicate work going on there OM but with your skill and experience I am sure that you will get things right eventually. This must be one of your most complex and delicate scratch builds - only a master would even contemplate attempting this one.

Stephen.
Wow, that is going to be a LOT of rigging.
Coming on nicely though, despite setbacks.

Ian
That is going to be a lot of rigging , for it's scale it is a good size ! Coming along really nice so far and beautiful detail work on the engine !


Terri
The Model looks awesome with the upper wing mounted. The engine also looks Fantastic! Looking forward to the next update!
RAGIII

Thank you all for your kind words.

A strategic retreat has proved necessary here, but with reinforcement most of that has been retrieved. I expect much of the difficulty was that I am out of practice. My attempt at rigging this was a fiasco. I botched most attempts to attach the end of a line, and between cleaning up after failures and over handling of a quite fragile assembly, I was beginning to do harm. I stopped, and took off the wing.

I made stouter struts, and using the traces of previous attachments, put in some real locator holes, to receive a pointed end put on the struts. I took advantage of the monoplane interlude to re-position the front supports for the engine bearers

I have put in the first eight struts. The outer ones on the port wing have proved a tad longer than the rest, but this has been fixed subsequent to the pictures. Doing so benefited greatly from the greater solidity. The rigging towards the center is the most tricky, because the places you naturally want to hold to keep things steady you can't, because the fragile undercarriage is in the way. While I have not completely got the knack back, things did go easier once the inner incidence wires were in place.

At any rate, here it is as of a few hours ago...

(https://i.imgur.com/8HtXrW2.jpg)

(https://i.imgur.com/1hIWMXv.jpg)

Once the struts in place are fully rigged I will add the next bay, and then tend to the tubular bracings in the center. I think I should leave off the outermost pairs till I have the mid-gap ailerons sorted out.
Title: Re: 'El Sonora' in 1/72
Post by: Alexis on September 09, 2020, 10:20:10 AM
I guess after this build you will be known as Lord of the Struts !

Are you using steel wire for the rigging ?


Terri
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on September 10, 2020, 12:13:31 AM
I guess after this build you will be known as Lord of the Struts !

Are you using steel wire for the rigging ?


Terri

One might hope they will be more obedient then, with such a title.....

They look a little larger than they really are in the pictures because they're still white. I do expect I can thin them down a bit once everything is in place and rigged. The plastic strip I used scales out to something a bit over a 2 x 4, which really might not be much overscale. But is about half again bigger than the first set.

I am using EZ-Line, as I have been for years. I put a teensie bit of CA gel where the end should go, wet the line with accelerator, hold its end to the glue for a slow ten count. I was used to a failure rate of about one in fifteen, on this I was getting one success for three or four tries. Since the technique and materials are the same, the difference must be me, with some reference to the delicacy of the assembly, which was difficult to hold still.

If I had stiff straight steel wire thin enough (0.005" or less) it would be an excellent option. cut to length it could be secured by white glue --- sure and invisible once dried. That wouldn't lend any strength, though, which the elastic does in some degree. Would have made this a lot easier, though --- a lot of the damage I was doing came when removing glue build-up from failed attempts.
Title: Re: 'El Sonora' in 1/72
Post by: RAGIII on September 10, 2020, 11:55:19 PM
Looking good on the second attempt! I am sure you will sort it all out!
RAGIII
Title: Re: 'El Sonora' in 1/72
Post by: lone modeller on September 11, 2020, 02:28:54 AM
Being out of practice can be a real problem. However it looks to me from where I am sitting that your old skills are returning and I see no decrease in the very high quality of the modelling that you are doing. This really is a very delicate but large structure and I can well understand the nightmare of handling it. However it is looking excellent now - it will look even better later!

Stephen.
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on September 11, 2020, 12:24:10 PM
Looking good on the second attempt! I am sure you will sort it all out!
RAGIII

Being out of practice can be a real problem. However it looks to me from where I am sitting that your old skills are returning and I see no decrease in the very high quality of the modelling that you are doing. This really is a very delicate but large structure and I can well understand the nightmare of handling it. However it is looking excellent now - it will look even better later!

Stephen.

Thanks, guys, I appreciate your confidence. If I were advising someone starting on one of these 'flyers' I would strongly recommend doing the wings and motor first, and only then putting the undercarriage in place. That would have saved me some difficulty.
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on September 18, 2020, 12:40:25 AM
Lost ground has been recouped and more now.

(https://i.imgur.com/V6fRny4.jpg)

Strut length has been adjusted here and there, after rigging was in place. The outer bay landing wires are functional. They are deliberately short, and pull the wing structure up and level. This will be repeated with the final bay. I have left this off for now, because I need to dope out the aileron arrangement. A fellow over on Britmodeller, one Matti64, was kind enough to send some good Curtiss drawings that are a godsend for that.

Once the rigging was done, I could do the tubular arrangements in the center section.

(https://i.imgur.com/q0Q3iX6.jpg)

(https://i.imgur.com/dZsvMfl.jpg)
 
This is 0.6mm rod, and matches up with existing pieces. The triangle is got by bending ends of two lengths of rod. I had previously cut a little length of rod that matched the width separating the verticals. I placed this 'gauge' on some two-sided tape, and then stuck bent rod stuck down on the tape till I had the triangle right in relation to this standard width. Then a crosspiece could be trimmed to fit. A dab of CA gel on joints, and then douse things in accelerator. This, I found by happy accident long ago (I swear I've spilt more of this stuff than I've actually used), obliterates the tack of any tape quickly. So the assembled piece can just be lifted up and rinsed for use.

The lower portion of one of the rear supports is a bit askew. I will leave it for now, but will think again when assembling the tail. That's a bit down the road --- 'cockpit' arrangements, controls and such, ailerons, radiators, and forward stabilizer arrangements are the order of the day.

(https://i.imgur.com/puj3LQH.jpg)

Rigging is slowly coming back to me. Got my failure rate down to about one in four from four in five. Once all the lines were in, I trimmed down the struts a bit by scraping with a blade's edge. With color on they look all right to me.
Title: Re: 'El Sonora' in 1/72
Post by: kensar on September 18, 2020, 03:48:33 AM
Good to see progress on this, OM.  The rigging must seem to take forever.  It will be interesting to see the ailerons sorted out.
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on September 18, 2020, 10:02:37 AM
Good to see progress on this, OM.  The rigging must seem to take forever.  It will be interesting to see the ailerons sorted out.

Thanks, Ken. When I had it down, it wasn't that time-consuming, The method is pretty simple. When things don't work it is very tedious.

I'm reviewing close ups of Curtiss reproductions and museum pieces, as well as the new drawings for the aileron details (can't rightly skip what ya don't know's there). Am not sure yet how it pivots at the inboard end. There are not a lot of pictures of these 'flyers' taken from the rear.
Title: Re: 'El Sonora' in 1/72
Post by: lcarroll on September 18, 2020, 12:02:27 PM
    Great progress O.M. I'm in awe of your patience, it's resulted in a very impressive and totally unique model. Keep up the great work and you'll have it complete in no time! This project is a fine example of the talent of our Members, you've really done some great Real modeling" here,  my sincere compliments!
Cheers,
Lance
Title: Re: 'El Sonora' in 1/72
Post by: lone modeller on September 19, 2020, 03:09:27 AM
Every time you post something on this project it looks even more impressive. This is a truly fine example of a bird cage model - and of first class modelling.

Stephen.
Title: Re: 'El Sonora' in 1/72
Post by: Alexis on September 19, 2020, 10:14:12 AM
Really starting the to have a fawniess for this bird , but i still wouldn't want to sitting in the any of those seats ....my god I would be scared shitless . The Men and Woman back then were very brave pioneers in aviation .


Terri
Title: Re: 'El Sonora' in 1/72
Post by: dr 1 ace on September 20, 2020, 07:53:45 AM
Ditto all the above compliments !

Ed
Title: Re: 'El Sonora' in 1/72
Post by: RAGIII on September 21, 2020, 01:47:10 AM
Ditto all the above compliments !

Ed

Ditto to My Amigo's Ditto  8)
RAGIII
Title: Re: 'El Sonora' in 1/72
Post by: Old Man on September 24, 2020, 10:57:20 AM
Thank you all for your kind comments and interest.

Terri, you couldn't get me up in one of those either. Here is a view to confirm the worst imaginings:

(https://i.imgur.com/9WmaYlt.jpg)

Lance, a couple of people have done some image modeling, a CAD and a 3d render of some sort.

(https://i.imgur.com/Ws1JVer.png)

(https://i.imgur.com/GJ7gHMs.jpg)

These are consistent with the photographs (there are others out there more fanciful). I don't know if the CAD was not quite completed and abandoned, for the mid-gap ailerons are missing, and enough else is right the modeller must have known of them.

I have found among the photographs one which settles the fitting of the ailerons. While I make them, I might as well do the tail surfaces and front stabilizer too.I will have to match paint, but expect I can.

Hope to get time in on this and the Roland this weekend.