forum.ww1aircraftmodels.com

WW1 Aircraft Modeling => Under Construction => Scratch builds => Topic started by: lone modeller on April 04, 2021, 08:45:30 AM

Title: 1/72 SIA SP 2
Post by: lone modeller on April 04, 2021, 08:45:30 AM
Evening All,

I have had a loss of mojo recently, in addition to which I have not been able to decide what to make next until a couple of days ago. I am hoping that this new project will give me a bit more motivation to tackle something in plastic and offer a subject which has rarely been modeled and then usually as a vacuform. The subject of my choice is the Societa Italiana Aviazione (SIA) Savoja Pomilio (SP) 2, a pusher design derived from the Maurice Farman MF 11. It looked like this (scroll down the page to the second photograph):

http://www.ww1-planes.com/Italy/Savoia.php

or nearly like this:

(https://live.staticflickr.com/65535/51093271273_698e078e24_c.jpg) (https://flic.kr/p/2kQWnue)

because the cover illustrates an SP 3 which had a different shaped nacelle and reduced wingspan. This is also the subject of vacuform models. The SP 2 has been on my list of possible models for some time now, so I thought that perhaps it was time to give it a try, the more so as I only have one other Italian model in my collection: this one will help to keep it company.

I have not made much for the reasons given above, but making wings and tail surfaces means that with a little effort and in a relatively short time there is something to show. I cut and shaped the wing blanks from 30 thou plastic card which had been inserted into  in a length of drainpipe and hot water poured in. The tail surfaces were also cut and shaped from 30 thou card:

(https://live.staticflickr.com/65535/51092729566_539dc67e37_c.jpg) (https://flic.kr/p/2kQTAss)

I marked off the ribs on the wings and horizontal tail surfaces and added 10x20 thou strip:

(https://live.staticflickr.com/65535/51093271298_bd7bc61ba6_c.jpg) (https://flic.kr/p/2kQWnuE)

These are awaiting being sanded down. I also decided to make the two prominent radiators which will be attached to the sides of the fuselage nacelle. I glued together some scrap card and filed it to shape and after scoring the sides added pieces of 10x20 thou strip to represent the metal straps around the cooling pipes:

(https://live.staticflickr.com/65535/51092820757_41cec5ec72_c.jpg) (https://flic.kr/p/2kQU4yH)

I will start to make a nacelle next to alleviate the tedium of sanding down the ribs on the flying surfaces and to give me something to show for my efforts.

Thanks for looking.

Stephen.
Title: Re: 1/72 SIA SP 2
Post by: lcarroll on April 04, 2021, 11:41:25 AM
Stephen,
      There's some pretty complex construction features apparent in that photo but nothing you haven't tackled successfully in the past. I'm looking forward as always to following your progress on this one, and expect it will be a real adventure!
Cheers,
Lance
Title: Re: 1/72 SIA SP 2
Post by: Alexis on April 05, 2021, 01:35:26 AM
Love your adventures so will tagging along on this as well ! And you are off to a great start already  :)


Alexis
Title: Re: 1/72 SIA SP 2
Post by: RAGIII on April 05, 2021, 01:40:54 AM
Another impressive start to what I am sure will be an awesome build!
RAGIII
Title: Re: 1/72 SIA SP 2
Post by: DaveB on April 05, 2021, 02:30:40 AM
Off to another great start there, Stephen -

Be an interesting one to see once finally completed

Regards

Dave
Title: Re: 1/72 SIA SP 2
Post by: Rookie on April 05, 2021, 03:54:10 PM
Nice to see you back here with this beautiful project Stephen.

It's refreshing to see an Italian bird. I have the datafile too, and it looks pretty complicated to build. Nothing I would take on for a while.

The wings and tail surfaces already look great! Any idea what you are going to do with the Fiat engine? It will be clearly visible despite the 1/72 scale.

I'll be on row one following you building this!

Willem
Title: Re: 1/72 SIA SP 2
Post by: gbrivio on April 05, 2021, 05:28:12 PM
Interesting project, yor approach to wings creation is brilliant. Looking forward to next steps.
Ciao
Giuseppe
Title: Re: 1/72 SIA SP 2
Post by: ermeio on April 06, 2021, 04:25:59 AM
Awesome subject and great start!
It will be a showstopper
er me
Title: Re: 1/72 SIA SP 2
Post by: Bughunter on April 06, 2021, 06:44:25 AM
That is a great start. Maybe there are some not so easy steps ahead of you, but it looks like you are going step by step. When the time comes, you will come up with the right solution.
I will follow with interest!

Cheers,
Frank
Title: Re: 1/72 SIA SP 2
Post by: RichieW on April 11, 2021, 07:33:32 AM
Hi Stephen, this looks like another fascinating project. I shall watch and hopefully learn.

Richie
Title: Re: 1/72 SIA SP 2
Post by: lone modeller on April 15, 2021, 07:00:21 AM
Evening All, 

Many thanks Lance, Alexis, Rick, Dave, Guiseppe, Ermio, Frank and Richie for your kind and encouraging comments. I have been in sore need of those recently as this update will show!

Well I nearly lost my mojo again. I finished sanding down the ribs on the horizontal surfaces and then turned to constructing the nacelle. My original intention was to push mould it in two halves, so I dutifully carved the male mould from basswood and after a couple of attempts I had two halves. Then I saw the problems which I had not given sufficient thought to, namely that I had a seam down the nose and the leading edge on the nose was rather blunt. I then did what I should have done at the start - look at a similar nacelle which I had made for a previous build. I refer to a Voisin III model which I made some years ago which has similarities in shape with this one:

(https://live.staticflickr.com/4288/35244785132_87dffa6a9a_c.jpg) (https://flic.kr/p/VGsJHb)

The leading edge of the nacelle is sharp and the sides are flat so that the angles are quite sharp. The front of the nacelle is slightly curved and very prominent - any joint there is going to be a b.... to fill and hide. When I looked up how I had made the nacelle the answer was a blinding flash of the b.....obvious:

(https://live.staticflickr.com/2845/34122274576_7b22bb6e85_c.jpg) (https://flic.kr/p/TZgzqU)

Make the sides and bottom from flat card and mould the top surface! This method means that the sharp edges of the lower part of the nacelle are easily reproduced, (no rounded corners resulting form the push mould which have to be sharpened), and the top surface has no seams! Easy when a little thought is given to the problem, or even simpler if I look up how I did something in the past....!

So back to square one and start again... by making the sides and bottom from 30 and 20 thou card respectively. This also made the cutting of the two rectangular and one round window in the bottom of the nacelle easy - no trying to match holes on each half of a nacelle moulding. I could curve the rear of the underside by repeatedly bending it with a pair of tweezers. I put some supports along the fuselage sides to hold the floor in the correct place, added some simple framing, painted the insides, made a blanking piece which represents the fuel tank behind the observer and a throttle quadrant, and it was ready to be assembled:

(https://live.staticflickr.com/65535/51115807889_4e09530d43_c.jpg) (https://flic.kr/p/2kSVSQz)

The seat in the image is a spare resin from Barracuda - I am not sure if it is accurate but as nobody is likely to see it I am not too concerned. Similarly I have left the interior details to a minimum - I will add an IP and control wheel but nothing else will be visible. The fuel tank blank helps to support the fuselage sides until I can fix the top in place. The rear of the fuselage was blanked off with 60 thou card to allow for the necessary filing and shaping. Filler will be needed here later too.

I moulded the top using the male fuselage mould and a new hole cut in plywood sheet. At this point I again ran into problems. Generally I can get a decent mould after two or three tries - not this time. Male moulds made from balsa wood seems to need a smaller gap than those made from basswood so I had to keep sanding down the male mould. Then I could not get the front of the nacelle to mould properly: I was close to putting this project on hold and starting something else. I decided that I would give it one more try and slightly change the angle when I pushed the male mould into the plastic sheet - and it worked immediately! I think that I am beginning to lose my touch with this moulding process as I have never had quite so many failures before.

Quite a lot of plastic had to be removed but that was straightforward so that I am at last at this stage:

(https://live.staticflickr.com/65535/51115490062_e16fd6a2e1_c.jpg) (https://flic.kr/p/2kSUfmN)

(https://live.staticflickr.com/65535/51116058001_de4f299dfe_c.jpg) (https://flic.kr/p/2kSXabR)

The engine will consist of a row of rod pieces glued together with the top of the engine detail: I do not intend to make the lower parts as they will be completely concealed on the finished model. This was dropped into the fuselage so that I could measure the size of the hole which I need to cut into the moulding later.

I am hoping that I can now complete the nacelle and engine details and proceed with painting.

Thanks for looking.

Stephen.
Title: Re: 1/72 SIA SP 2
Post by: Edo on April 15, 2021, 03:29:00 PM
wow!
brilliant work!
very interesting to follow

ciao
edo
Title: Re: 1/72 SIA SP 2
Post by: RichieW on April 15, 2021, 05:01:07 PM
A valuable lesson in perseverance for us all Stephen. Well done for not throwing in the towel. Looking forward to seeing the next step.

Richie
Title: Re: 1/72 SIA SP 2
Post by: Dave Brewer on April 15, 2021, 06:02:03 PM
A fascinating project Stephen, coming along very nicely.Beautiful Voisin by the way!
Cheers,
Dave.
Title: Re: 1/72 SIA SP 2
Post by: Gisbod on April 15, 2021, 07:31:06 PM
That’s beyond amazing Stephen...

You do know you can buy ready made kits don’t you?  ;D

I’m in awe...

Guy
Title: Re: 1/72 SIA SP 2
Post by: kensar on April 15, 2021, 10:53:20 PM
I'm glad to see you worked that out.  Great progress, Stephen.
Title: Re: 1/72 SIA SP 2
Post by: Alexis on April 15, 2021, 11:16:02 PM
Excellent Stephen on working out the issue with the seam , very neat solution indeed !


Alexis
Title: Re: 1/72 SIA SP 2
Post by: Bughunter on April 16, 2021, 05:51:26 AM
Plastic fantastic!

Cheers,
Frank
Title: Re: 1/72 SIA SP 2
Post by: RAGIII on April 17, 2021, 11:49:56 PM
In spite of multiple pulls it is the end result that counts! Looking great and as always I look forward to the next update!
RAGIII
Title: Re: 1/72 SIA SP 2
Post by: IanB on April 17, 2021, 11:59:23 PM
I have the same memory problem sometimes. These posts serve more than one purpose! Nicely done once the memory had been jogged!

Ian
Title: Re: 1/72 SIA SP 2
Post by: Monty on April 19, 2021, 02:42:48 AM
Some amazing problem solving Stephen, and great progress! Not an easy subject, but certainly coming along beautifully! And some great techniques described... Thanks! Marc.
Title: Re: 1/72 SIA SP 2
Post by: DaveB on April 19, 2021, 02:59:02 AM
Great progress, Stephen!

Your nacelle looks good despite your problems.

Regards

Dave
Title: Re: 1/72 SIA SP 2
Post by: gbrivio on April 19, 2021, 04:17:14 PM
The nacelle looks good, glad you didn't give up and made it. The Voisin model is a little gem and gives a preview of the SIA in the near future. Thumbs up.
Ciao
Giuseppe
Title: Re: 1/72 SIA SP 2
Post by: lone modeller on April 22, 2021, 08:29:21 AM
Evening All,

Many thanks indeed to all of you who have dropped by and been kind enough to leave positive and encouraging comments. I really appreciate them, the more so after I had had such difficulties with the moulding process.

Gary: I do know that kits are available on the market, but I have a masochistic streak which means that I enjoy making problems for myself trying to make my own parts.

Ian: I just wish my memory was better - it seems to be deteriorating rather too quickly for my liking! If it was better I might find solving some construction problems a little easier...!

Evening All,

I glued the new nacelle top to the  sides while the rear of the nacelle was blocked off with thick card and filed to shape. A liberal amount of filler was applied to the joint between the moulding on the top of the nacelle and the sides and rear where the fit was not perfect. The obligatory sanding and filling followed...

(https://live.staticflickr.com/65535/51131250050_bbd3f80f73_c.jpg) (https://flic.kr/p/2kUi2fJ)

(https://live.staticflickr.com/65535/51130137346_ea90c731a7_c.jpg) (https://flic.kr/p/2kUcjub)

(https://live.staticflickr.com/65535/51130137366_fb2a9f5437_c.jpg) (https://flic.kr/p/2kUcjuw)

The nose now has the sharp edge and corners similar to those I managed to achieve on the Voisin. I have opened up the apertures for the cockpit and engine compartment in the nacelle. I cut around the outline of the openings with a new scalpel and finished the edges by carefully scarping and filing. The latter was a bit delicate as I did not want to damage the interior of the cockpit, although the pilot's seat was not in place at the time:

(https://live.staticflickr.com/65535/51130137316_184e22c717_c.jpg) (https://flic.kr/p/2kUcjtE)

(https://live.staticflickr.com/65535/51130389644_f887916300_c.jpg) (https://flic.kr/p/2kUdBu9)

(https://live.staticflickr.com/65535/51130348718_b555bde0c7_c.jpg) (https://flic.kr/p/2kUdpjw)

After fitting the pilot's seat I added some detail to the top of the engine: ie the part that will be just visible on the completed model. Basically I added the cam shaft from small pieces of rod between small cubes of card, the latter representing the housing for the valves on the top of the cylinders. Some thin pieces of rod on the side of the cylinders represent the carburretor intakes and I have drilled holes on the opposite side to take rod for the exhausts later. The engine was fixed into the rear of the nacelle so that I can now start painting.

(https://live.staticflickr.com/65535/51130389569_530719c8a1_c.jpg) (https://flic.kr/p/2kUdBsR)

(https://live.staticflickr.com/65535/51130137236_b816623ee9_c.jpg) (https://flic.kr/p/2kUcjsh)

Thanks for looking.

Stephen.
Title: Re: 1/72 SIA SP 2
Post by: Alexis on April 22, 2021, 11:11:28 AM
Really nice work on the fuselage Stephen . Engine details are very convincing , just the right amount of detail  :)


Alexis
Title: Re: 1/72 SIA SP 2
Post by: RAGIII on April 23, 2021, 08:03:54 AM
Your usual outstanding results Stephen!
RAGIII
Title: Re: 1/72 SIA SP 2
Post by: RichieW on April 23, 2021, 08:04:12 AM
Excellent job on the filling and sanding, you've completely covered your tracks there Stephen.

I totally agree with your point about making your own parts being fun, I can't thank you enough for nudging me towards having a bash at scratch building. I'm already planning my next project and I'm nowhere near finished my current build.

Richie
Title: Re: 1/72 SIA SP 2
Post by: DaveB on April 24, 2021, 02:15:49 AM
That fuselage has come out really well, Stephen.

I also agree with Alexis on the engine - great details that will really pop out once painted.

Regards

Dave
Title: Re: 1/72 SIA SP 2
Post by: lone modeller on April 24, 2021, 03:49:15 AM
Thanks Alexis, Rick, Richie and Dave for dropping by and leaving those kind comments.

Richie - scratch building is addictive, as any scratch builder will tell you. IMHO it is more rewarding that building a kit, but the builder does have to overcome the feeling that it is too difficult to do. In reality it is just a small extension to adding extra details to a build. The big advantage is that if you make a part and it is not quite right, make another one until it is! Best of luck with your current project (which is going extremely well BTW), and good luck with the one being planned: I am looking forward to seeing both completed!

Stephen. 
Title: Re: 1/72 SIA SP 2
Post by: Bughunter on April 24, 2021, 04:33:29 AM
Even it is (partly) hot formed, this is cool stuff! :D :D

Cheers,
Frank
Title: Re: 1/72 SIA SP 2
Post by: RichieW on April 24, 2021, 05:47:45 AM
Scratch building is so addictive Stephen that I am contemplating selling my stash of Wingnut Wings kits. Hhhmmmmm.....decisions, decisions. In a way I miss building kits but at the moment I am learning so many new skills and so much about the history of aviation that I may only build WW2 kits from now on.

Richie
Title: Re: 1/72 SIA SP 2
Post by: Alexis on April 24, 2021, 11:52:20 AM
Yup , you have the bug big time ...GOOD !


Alexis
Title: Re: 1/72 SIA SP 2
Post by: kensar on April 25, 2021, 02:35:52 AM
Your nacelle came together very well.  The lines on it are well blended.  It will look great with some paint on it.

After doing some scratchbuilding, kits just don't have the same appeal.  However, I will be keeping the ones I have!

Title: Re: 1/72 SIA SP 2
Post by: lone modeller on April 29, 2021, 04:47:29 AM
Evening All,

Thank you Frank and Ken for your kind comments. Richie I know how you feel about scratch building: I disposed of my kit collection several years ago and have no regrets, but I am aware that scratch building is not for everyone. Looking at some of the models on this site and the superb details that modellers add, I sometimes wonder whether I would be better taking up origami or knitting, but the very generous comments made here help to keep me going.

I had to make a new top wing as the old one suffered badly from banana syndrome and I was quite unable to straighten it out: the one in the photo has been discarded and the new wing is still being painted. A coaming was added around the cockpit from 20 thou rod and I have carved a propellor from wood.

I have been coating plastic with acrylic paints over the past week - mainly mixed colours (Revell white and beige 314) for the CDL on the wings and flying surfaces and white and Mittlegrau (46) for the struts and nacelle. The wood sides of the nacelle are Revell brown (381). I applied many coats of the CDL and grey (probably 10 on the flying surfaces and nearly as many for the grey on the nacelle), to build up a solid layer of colour which has a smooth semi-matt finish. The national colours were Humbrol enamel red (60) which also needed several coats as the paint is rather thin, and Humbrol enamel Dragoon Green (MC 7) which I have had since the mid-1970's! The national colours may not be an exact match but given the variations in pigments and fading which took place, I am claiming that these are probably close enough to be acceptable. The tyres were Mittlegrau.

I have received the serial transfers from Arctic Decals and will apply them to the fuselage before I continue with construction.

(https://live.staticflickr.com/65535/51144755786_082ff8bcc5_c.jpg) (https://flic.kr/p/2kVuf3f)

(https://live.staticflickr.com/65535/51144078882_07482d30ab_c.jpg) (https://flic.kr/p/2kVqLPu)

(https://live.staticflickr.com/65535/51145860565_5c6940e2e7_c.jpg) (https://flic.kr/p/2kVzUsa)

(https://live.staticflickr.com/65535/51144078842_4cb1849fb4_c.jpg) (https://flic.kr/p/2kVqLNN)

When the new wing is finished (hopefully tomorrow), I can start on the final construction phase - wings, tail unit and undercarriage.

Thanks for looking.

Stephen.
Title: Re: 1/72 SIA SP 2
Post by: Bughunter on April 29, 2021, 06:57:13 AM
In your Gods own scale the small parts are even smaller :o
We have somehow a parallel build now: subassemblies painted and mounting starts (https://www.modellboard.net/Smileys/Modellboard/superwink.gif)
The beast with the four wings is so small, that is may be also in your scale :-\

Cheers,
Frank
Title: Re: 1/72 SIA SP 2
Post by: RichieW on April 29, 2021, 07:46:13 AM
Looking lovely with a bit of colour going on Stephen, nice and methodical as ever.

Yes, nothing at all against kits and the level of artistry and technical brilliance of so many of the modellers (yourself included) often leaves me in a state of shock of awe. I have frequented another forum for a few years and every now and then a stunning build is produced. Virtually everything that appears here is of the most incredible standard. Maybe, in a strange kind of way, that is the appeal of scratch building for me because I have absolutely no expectation of any great success. It might be fun to build a kit and do a scratch build of the same aircraft side by side. Hhmmmm...... ;)
Title: Re: 1/72 SIA SP 2
Post by: Alexis on April 29, 2021, 09:39:49 AM
Stephen , your up-dates always bring a smile and this one has me really grinning and I can't wait for the next one !

In the future if this helps you out . Remember on my Lloyd C.V build on how I made the gun ring ? This might work for you on warped wings . Boil a pot of water , dunk the part in the boiling water ( hold part with tongs ) for a few minutes . Pull out of water and place the wing on a flat surface and press the center on the warp down so wing is flat . Let set for a minute and pour cold water over top . This will re-set the memory to the plastic part .


Alexis
Title: Re: 1/72 SIA SP 2
Post by: DaveB on April 30, 2021, 01:40:35 AM
Good progress here, Stephen -

Great to the colours going onto the wings and your engine looks great now painted.

Looking forward to next update

Regards

Dave
Title: Re: 1/72 SIA SP 2
Post by: IanB on April 30, 2021, 03:26:28 AM
Sorry to hear of the warping problems, but I think you have it all in hand as usual.
The wing colours look pretty good to me!

Ian
Title: Re: 1/72 SIA SP 2
Post by: RAGIII on May 01, 2021, 04:09:13 AM
I am impressed as always with your work. The painted markings look excellent on all of the components! I am sure you will work out the warp issues.
RAGIII
Title: Re: 1/72 SIA SP 2
Post by: Rookie on May 02, 2021, 05:40:19 PM
I Love the beautiful curves of the fuselage Stephen!

Excellent work and great progress.

Willem
Title: Re: 1/72 SIA SP 2
Post by: Monty on May 02, 2021, 07:56:33 PM
Great progress on this one, Stephen. And great problem solving. Regards, Marc.
Title: Re: 1/72 SIA SP 2
Post by: lone modeller on May 05, 2021, 06:33:04 AM
Evening All,

Thank you Frank, Richie, Alexis, Dave, Ian, Rick Willem and Marc for your very kind comments which are very much appreciated.

Alexis I knew about the hot water method for restoring the wing but I think that the reason why it had warped was because I had sanded it too rigorously to get an aerofoil shape, so when I added the ribs that caused the distortion. I had not sanded the lower wing as roughly so it did not distort by very much and has been salvaged. Making a new wing seemed to be the quickest and easiest solution

Construction has restarted and I have now made the nacelle ready to be fixed to the lower wing. I have thought long and hard about the order of assembly of the major components and have decided to follow the sequence described here. More will follow later.

The first step was to put the radiators on to the sides of the nacelle. I had pre-drilled holes in the nacelle and radiators to take small pins to provide a strong joint, so a drop of cement and they were on. This was followed by the pipes to the top of the engine which were made from 20 thou rod which had been bent to shape and then painted:

(https://live.staticflickr.com/65535/51158766664_20a1f71b41_c.jpg) (https://flic.kr/p/2kWJ3Z7)

(https://live.staticflickr.com/65535/51158766694_74439a41f4_c.jpg) (https://flic.kr/p/2kWJ3ZC)

(https://live.staticflickr.com/65535/51159090425_cb7c55c24d_c.jpg) (https://flic.kr/p/2kWKHec)

The cabane struts were cemented to the fuselage sides and allowed to set properly. The length of these is the same but the front end of the nacelle is supposed to be slightly lower when mounted to the wing - getting the lengths right was a bit of a fiddle. Having got the cabanes in place there were awkward cross struts to add between the lower parts of the cabanes - I used 10 x 20 thou strip for those. The return pipes from the bottom of the radiators to the engine had to be added to the bottom of the nacelle after the struts were in place as the pipes ran outside of the struts:

(https://live.staticflickr.com/65535/51158766644_b88b01b529_c.jpg) (https://flic.kr/p/2kWJ3YL)

(https://live.staticflickr.com/65535/51157317742_7f257cae60_c.jpg) (https://flic.kr/p/2kWACgG)

The serlal was now fixed in place - it was from Arctic Decals and made to order. It is slightly oversize (my fault, not Arctic Decals!), but I do not think anyone will notice if I do not mention it. I also added the exhaust pipes but some of these are too long and I will have to remove and trim them later before I fix the top wing i place.

Now to mount the booms and tail. This is what I have been thinking about for some time. I have decided that the method I am about to describe is as good as any, but it varies somewhat form the method that I have used before. The rear of the booms were fixed to the rudder posts and the horizontal tail section sat on a cross member between the lower booms. The rudder posts passed through the horizontal tail surface, so I soldered two small rudder posts to the ends of the lower booms. I drilled two holes in the horizontal tail surface and squared these with the end of a small file and made sure that the posts would pass through properly.

The lower booms were epoxied to the slots in the rear of the lower wing and the correct angle achieved by using a standard boom jig - the height had been measured from the plans as described in previous build articles:

(https://live.staticflickr.com/65535/51158318723_b2811eea96_c.jpg) (https://flic.kr/p/2kWFKPZ)

The above shows the booms set ready to be epoxied, the paint pot was to help keep the rudder posts upright while I fiddled and checked that everything was square and true. After the expoxy had been applied and cured I had this:

(https://live.staticflickr.com/65535/51158078346_425ca16116_c.jpg) (https://flic.kr/p/2kWEwny)

(https://live.staticflickr.com/65535/51158318683_c6a09af156_c.jpg) (https://flic.kr/p/2kWFKPi)

In the images there is a piece of paper with a line and arrow with 19mm written on it: the line represents the height of the booms at the tail end relative to the rear of the wing - the edge of the paper was used to measure the height of the wood blocks that make the jig. The wing and booms were laid over plans to get accurate alignments. Simple and effective - scratch building does not have to be complicated or difficult. A simple check of the newly installed booms with the horizontal tail surface showed that the rudder posts would pass through the holes in the tail, so the horizontal bar between the rear of the booms was inserted. This was a piece of 20 x 30 thou strip:

(https://live.staticflickr.com/65535/51158866214_97a45732e4_c.jpg) (https://flic.kr/p/2kWJyzu)

The nacelle sub-assembly was cemented to the lower wing and the boom bracing at the rear painted. Finally the horizontal tail surface was CA'd to the rudder posts and booms:

(https://live.staticflickr.com/65535/51159190360_53be96106e_c.jpg) (https://flic.kr/p/2kWLdWd)

(https://live.staticflickr.com/65535/51157418257_f316a7bd87_c.jpg) (https://flic.kr/p/2kWB99H)

I have worked out how I intend to fix the upper booms to the top wing and then wing to the above asembly and will describe the process in the next update when I have completed that stage.

Thanks for looking.

Stephen.
Title: Re: 1/72 SIA SP 2
Post by: RichieW on May 05, 2021, 07:00:14 AM
Superb update Stephen, the delicacy of this build is amazing. I love the great care but simplicity of your method for attaching the booms. I'm beginning to think a pusher has to be in my future. This is so inspiring!

Richie
Title: Re: 1/72 SIA SP 2
Post by: Bughunter on May 06, 2021, 04:59:50 AM
Some small letters are bringing it to life :D
You are the master of effective simple tooling!

Cheers,
Frank
Title: Re: 1/72 SIA SP 2
Post by: RAGIII on May 06, 2021, 09:01:59 AM
The radiators look great and you are making the assembly look easy even though we know it is Not!
RAGIII
Title: Re: 1/72 SIA SP 2
Post by: DaveB on May 07, 2021, 01:21:28 AM
Brilliant progress, Steve!

Really starting to take shape now.   Your method of construction proves you don't need to invest in expensive after market jigs and iother specialist tools - clever work.

Regards

Dave
Title: Re: 1/72 SIA SP 2
Post by: kensar on May 07, 2021, 11:56:50 PM
Great work, Stephen.  You are demonstrating that scratchbuilding doesn't have to involve complicated jigs and techniques.
This one is coming together nicely, with significant progress showing now.
Title: Re: 1/72 SIA SP 2
Post by: lone modeller on May 08, 2021, 07:17:01 AM
Evening All,

Thank you Richie, Frank, Rick, Dave and Ken for your encouraging comments. I am pleased that my methods are clear and that I am able to show that scratch building does not require huge amounts of skill or expensive or complex equipment, because that is the primary aim of my build threads. If by chance I manage to make a half-decent model at the end that is a bonus for me.

Richie: pusher biplanes are not nearly as difficult to make as people seem to think. My first freelance WW1 conversions were pushers as was my first ever scratch build, and my only 1/32 scale scratch builds have been pushers. I have only used techniques and tools as described in this thread, plus of course the usual large quantity of smoke and mirrors....

I have put the top wing and upper booms in place, but followed a different sequence to one which I have used in the past. Formerly I would have attached the booms to the wings and then placed the wing/boom assembly on to the cabane struts and put the rudder post between the rear ends of the upper and lower booms. However in this case the rudder posts were already in place so if I got the angle of the booms on the top wing wrong, or the booms were too long or too short, the assembly would not work. The other problem was that I normally use epoxy to join the booms to the wings, but this would not set quickly enough to guarantee that the booms would remain in the gaps in the wing trailing edge: I had to use relatively quick setting CA instead.

The first step was to check that the booms would fit into the gaps in the trailing edge of the top wing and would align accurately with the rudder posts on the lower booms - a bit of filing was needed to enable fine adjustment:

(https://live.staticflickr.com/65535/51162805537_c70506881c_c.jpg) (https://flic.kr/p/2kX5KAR)

The booms are parallel and will fit exactly over the rudder posts - they were measured with dividers. The top wing was placed over the cabane struts and the positions of the strut ends marked on the underside of the wing so that holes could be drilled. This had to be done this way as I could not guarantee that if I drilled these holes based on the drawings, the struts on the model would fit: by using this method the struts do fit even though there is a slight mis-alignment. The misalignment is too small to be noticeable but would have been enough to cause construction problems had I not followed this procedure. With the holes drilled the wing was cemented to the struts. When the wing had set I put CA on one end of a boom bar and a drop of CA on the top of a rudder post. The boom was placed into the slot in the wing trailing edge and gently lowered on to the top of the rudder post. I could hold the boom to wing joint for a couple of minutes while the CA cured. This operation was repeated for the second boom.

Before I could damage the structure I cemented the outer and inner wing struts between the wings and left the assembly for an hour to set:

(https://live.staticflickr.com/65535/51162805482_90dd6fbf74_c.jpg) (https://flic.kr/p/2kX5KzU)

(https://live.staticflickr.com/65535/51164573720_e97521e513_c.jpg) (https://flic.kr/p/2kXePdL)

The addition of these struts makes the assembly strong enough to handle like any other model under construction and there is little risk of damage unless the model is dropped or struck hard. The remaining wing struts were easy to insert, followed by the boom struts:

(https://live.staticflickr.com/65535/51163712513_05befbf7a9_c.jpg) (https://flic.kr/p/2kXapdn)

(https://live.staticflickr.com/65535/51164254324_ee5b536db9_c.jpg) (https://flic.kr/p/2kXdbgW)

When I insert the wing and boom struts I always measure the gaps first and cut each strut to fit: when I make sets of struts I always make them too long so that I can cut them to the size needed to fit the gap. This is particularly important for the booms as small errors invariably creep in and there is no guarantee that the gap on the model will be exactly the same as the plans!

The tail structure was completed next. First I cut the upper and lower cross bracing between the outer rudder posts from 30 x 40 thou strip. The central rudder post and forward brace were cut from the same material and all glued in place and painted. The outer fins were cut from the fin/rudders and the fins cemented into place:

(https://live.staticflickr.com/65535/51164254299_a5d0ed08db_c.jpg) (https://flic.kr/p/2kXdbgv)

(https://live.staticflickr.com/65535/51164573740_fd4018da5d_c.jpg) (https://flic.kr/p/2kXePe7)

The main undercarriage was next. The struts were made from 30 x 40 thou strip which had been sanded to aerofoil section, and the skids from the same material with the front ends bent and sanded to shape. The axles were cut from a paper clip and the bungee cords represented by thread which was wound around the axle and skid with the end CA'd into place:

(https://live.staticflickr.com/65535/51162805412_eae6542feb_c.jpg) (https://flic.kr/p/2kX5KyG)

The wheels are discs of 60 thou card shaped to represent covered spoked wheels, with the tyres made from 60 thou rod wrapped around a paint brush handle and held for 10 seconds in boiling water. The wheels were CA'd to the axles and the bracing pieces cut from 10 x 20 thou strip:

(https://live.staticflickr.com/65535/51163712443_6016c63a4d_c.jpg) (https://flic.kr/p/2kXapca)

There are still some more bits and pieces to add but the next step will be to rig the model with rolled 40 SWG copper wire. I will add control horns, skids and propellor as I rig the model because that reduces the chances of damage. Hopefully in the next post I will be able to show the completed model: however there are approximately 170 -180 wires to be put in place so it may be a little while before I finish this.

Thanks for looking.

Stephen.
Title: Re: 1/72 SIA SP 2
Post by: RichieW on May 08, 2021, 07:30:35 AM
Another great update full of helpful construction details. I have been pondering wheels all week. Yours look perfect, I will try your method when the time comes.

Richie
Title: Re: 1/72 SIA SP 2
Post by: kensar on May 08, 2021, 09:37:22 AM
This is going to look fantastic!  Its such a complicated airframe.
Title: Re: 1/72 SIA SP 2
Post by: RAGIII on May 09, 2021, 01:44:52 AM
Your careful assembly methods worked great! This is really looking Fantastic!
RAGIII
Title: Re: 1/72 SIA SP 2
Post by: DaveB on May 09, 2021, 03:30:00 AM
Looking wonderful, Steve -

I'm glad your different approached worked out regarding the tail booms

Regards

Dave
Title: Re: 1/72 SIA SP 2
Post by: Alexis on May 09, 2021, 07:48:44 AM
Thumbs up Stephen , looking super !


Alexis
Title: Re: 1/72 SIA SP 2
Post by: Manni on May 09, 2021, 05:21:04 PM
Really great, Stephen. I looks so fragile and elegant.
Looking for the next progress.
Bye Manni
Title: Re: 1/72 SIA SP 2
Post by: lone modeller on May 17, 2021, 06:30:35 AM
Evening All,

Thank you Richie, Rick, Ken, Dave, Alexis and Manni for your kind and encouraging comments.

I have finished rigging this one and added the final details: propellor, windscreen, control horns, pulley wheels for control cables, gun ring, handle on the top wing.

Rigging was straightforward once I had finished the innermost bays: the bracing there is different to the other bays and has 8 independent wires in each bay, excluding the control wires. I am pleased that I do not use thread because it would be impractical in places on this model, unless one has the eyes of a hawk, patience of a saint and lots of time: I have none of those. Being a pusher it has lots of bracing and various control cables, but it was no more difficult that a conventional tractor to rig, just took longer because there are more wires to add.

I am pleased that it is finished as it has been on my to do list for a long time, and as there are no kits of this model in 1/72 scale, and none of the SP 2 variant, it is another different type to add to my collection.

(https://live.staticflickr.com/65535/51182377182_200272b2e9_c.jpg) (https://flic.kr/p/2kYP4z1)

There are more photos and some background to this little known type in the completed models section.

Thanks for looking.

Stephen.
Title: Re: 1/72 SIA SP 2
Post by: Alexis on May 17, 2021, 11:08:05 AM
 :)

Alexis
Title: Re: 1/72 SIA SP 2
Post by: DaveB on May 18, 2021, 03:46:00 AM
Wonderful work, Steve -

Look forward to seeing more pictures in the completed section.

Regards

Dave
Title: Re: 1/72 SIA SP 2
Post by: Rookie on June 17, 2021, 06:14:12 PM
It's beautiful Stephen!

An extraordinary machine and as I said earlier, it's refreshing to see another Italian bird on this forum.

Willem
Title: Re: 1/72 SIA SP 2
Post by: Naimbs on February 09, 2022, 08:09:49 PM
Incredible! Magnificent result!!

I'm a big fan of your work!

I have the SP.3 (1/48) to build, but it's rough...

Title: Re: 1/72 SIA SP 2
Post by: kensar on February 09, 2022, 10:53:07 PM
Superb work, Stephen.  I'll mosey on over to the completed section for a look.
Title: Re: 1/72 SIA SP 2
Post by: Borsos on February 10, 2022, 05:19:51 AM
Wonderful exotic bird!
Andreas