Scratch build partial stripdown Vickers FB 5 Gunbus 1/32 scale: a tribute to Des

[lone modeller]

Evening All,

Thank you Gregory, Rick, Andreas, Ryan and Bud for your encouraging and supportive remarks. I have been in need of them recently because I have just tackled what has up to now been the most difficult part of the project: soldering the upper wing boom.

Some of you will be aware that I have considerable form when it comes to building pushers, albeit in the True Scale. My preferred method is to attach the tail booms to the wings, put the top wing into place with the rudder post in support at the rear, and then add the boom struts. In this way alignments are very much easier to achieve and the modeller does not have to handle two fragile structures while trying to attach them to the rear of the wings and align them correctly with the rudder post. I am using my tried and tested method on this model. However there is a big difference with this model because it is a larger scale and I have to solder 2 of the 4 booms to the rear spars of the wings which means that the boom alignment has to be very accurate or the structure will simply look awful or worse. I have been giving this problem considerable thought for some time but I could prevaricate no longer.... so I consulted William Heath Robinson for advice which he generously gave to me.

First I masked the solid part of the wing with a plastic bag and then laid the assembly on the plans and aligned them.



I placed the fuselage nacelle/lower wing assembly over the top wing:





The position of the boom/rear spar joint of the lower wing could be copied on to the rear spar of the top wing. This was essential because the two booms must align exactly even though they are not in the precise position over the plan (they are approximately 0.5mm too close to the fuselage nacelle). The lower wing assembly was set aside and the top wing laid on a block of balsa which will be the base for the soldering process. The balsa block was placed on the plans so that the wing is directly over the plan as allowed me to use it to align the brass rod which I will use for the boom. A second block of wood was laid on the plan with the edge along the leading edge of the horizontal tail unit. The brass rod was laid so that one end touched the rear spar and the other was resting on the second wood block and was over the boom on the plan. To get the correct height at the tail end of the boom I had to add some pieces of plastic card:



I will briefly explain the simplicity of this method which I have used many times - I have converted or scratch built 10 pushers this way so far, and have not had a problem yet. Tail booms have to conform to two angles as explained in an earlier post. Aligning the angle in relation to the vertical centre line is easy - just lay the wing and boom over the plan. The angle in relation to the thrust line can be achieved by using the height difference between two easy-to-measure  points on the boom:



The diagram above shows the distance 'a' between the trailing edge of the wing and the leading edge of the horizontal tail unit. The height 'b' is calculated from the side elevation of the aircraft in question by drawing a line (2 on the diagram) which touches the leading and trailing edge of the wing and is continued under the leading edge of the tail. Height 'b' is the distance on the plan between line 2 and the boom on the plan (line 1). Therefore the rear of the boom resting on the wood block has to be the equivalent of height 'b' above the balsa block on which the wing assembly is resting.

To lift the boom rod so that it made good contact with the centre of the rear spar I used a file and then held it in place with paint pots as advised by H R:





I checked the alignment with the lower wing assembly by placing the latter over the former:



I removed the lower wing assembly, put flux and solder paint on to the boom-spar joint, and after checking and adjusting one last time to make certain all was in its correct position I heated my soldering iron and used solder wire to reinforce the joint. The result when  I placed the lower wing over the new upper wing and it looked like this:



The remainder of the top wing assembly followed the procudures I have already described.



and the two wings look like this:



I have still to make the ailerons and add the trailing edge and tip wires to complete these structures.

Unfortunately this is as far as I will be able to take this project for the time being as I now have to go on one of my periodic journeys, this time for an undetermined period. I simply do not know how long it will be before I can pick it up again but I am hoping that it will only be 2-3 weeks: fingers crossed. Until then I hope that you all have an enjoyable time with your own projects.

Thanks for looking.

Stephen.

[lcarroll]

    The master of the improvised jig strikes again, sheer genius Stephen! This is going to be a Model to be reckoned with, it's already in it's own league. I'll be waiting for your return and restarting of this project with eager anticipation.
Cheers,
Lance

[kensar]

I'm just catching up with this thread.  Great work, Stephen!  This project appears very complicated and you are tackling it like a pro.

Kudos.


Ken M

[Bughunter]

Beside your great work I like the idea of half strip down / half real one model more and more.
I have to build another D.H.2 beside my strip down for the same effect.

Looking forward to next updates.
Cheers,
Frank 

[lone modeller]

Evening all,

Thanks Lance, Ken and Frank for commenting on my last post - your attention is greatly appreciated.

Frank: one of the problems that I will have to tackle when this model is completed is that it will be unbalanced insofar as the right side is much heavier than the left. I will therefore have to represent the model as if it is an aircraft that has been picketed, i.e. it has been tethered to the ground to protect it from strong winds. In that way I am hoping to be able to keep the model level and stable.

I have returned and restarted the project with a couple of relatively simple structures to get my eyes and hands used to working together again! I found that just before I departed I knew exactly what I wanted to do and how to do it but when I returned I had forgotten most of it, despite having written some (by now) cryptic notes.... (Note to myself, make notes more explicit next time).


I am approaching the stage that I have been delaying for some time i.e. how am I going to put the top wing on? So to avoid having to tackle that particular problem I distracted myself by making some small structures as referred to above. I started with the ailerons on the port (left) side which are represented by the frames. On my first attempt I tried to use 20 thou card for the hinge section and spar and 40 x 125 thou strip for the ribs. I drilled a small hole in those ribs which had been hollowed to save weight and then enlarged the hole with a sharp craft knife:





The ribs were cut in half and assembled. However the 20 thou card is too thin and warped when I used the cement to join everything up:





Start again. This time I used 40 x 125 thou strip for the hinge section and 30 x 125 for the spar with much more satisfacrory results. Rod was used to represent the bracing:


[





The slight curvature seen on one of the ailerons will be eliminated when it is finally glued to the wing. Control horns were made from 20 x 30 thou strip and added after the above images were taken.


Next came some control details. The control column was mounted on to a hollow bar through which the aileron wires were passed. The column was brass rod with a piece of bent plastic CA'd to one end to represent the yoke which joined it to the bar. The bar is brass tube - the column was CA'd to the tube. On the bar there were two small pulley wheels which carried the control cable: the latter was attached to the column on the aircraft, so I represented the wheels with discs of 10 thou card and drilled a hole through the brass rod column. After painting I threaded a piece of monofilament thread and CA'd the ends to the wheels. I also made up the rudder bar from rod and 10th card pedals:






Seat belts are a difficult topic on these very early machines - some pilots used them, others did not. I chose to make one for the pilot only and based it on photographs posted on Britmodeller of a belt from a BE 2c, a contemporary type: it is the best information that I have on this subject. A piece of 10thou card was cut to size and painted to represent canvass and leather with metal fixings :



Finally I have started to make the horizontal tail unit. One half is solid so that was easy to make - take a piece of 30 thou card, shape it, add ribs as per the wings and...... it was too thin! The booms which support the tail passed through the horizontal surfaces and as my booms are made from brass rod the 30 thou card was too thin, so I made another surface from 80 thou card. By carefully laying the top wing and right boom on the plans I was able to mark on the tail unit where the boom would have to be inserted. The tail unit was cut and then the edges filed until I could get the brass rod boom to lie between the two tail pieces so that the leading edge of the tail was paralled with the trailing edge of the wing. This assembly was CA'd together and the grooves filled and sanded:





The next step will be to add the tail unit spars of the uncovered port (left) side of the horizontal tail unit by cutting slots in the solid half of the tail and inserting two 30 x 80 thou strips. More on that in the next post. I have also been giving thought as to how to mount the top wing and whether or not to attach the tail unit first. Given the size of this model, and the absolute requirement that everything must be square and true, I am probably going to have to build a more rigid jig than usual. I am also still undecided about whether to use plastic or wood for the struts - both have advantages and problems. So if there is a longer than usual delay before my next post it is because either I am still trying to solve a problem or I have completely failed to do so and have given up.

Thanks for looking.

Stephen.

[lcarroll]

Welcome back Stephen, and it's nice to see you working at this one again. Just like you I find it difficult to get back into the "flow" after a break and find starting with some small and relatively simple component helps to get me back up to speed. Take your time getting back in form, this one promises to be a real beauty!
Cheers,
Lance

[lone modeller]

Evening All,


Thanks Lance for your kind comment: here is another update but not quite as I had planned as I have still to put the top wing into place. I am working on this but before I could do so I found that I really needed to add most of the remaining details to the cockpits and finish off some other items, so this is a short summary of those aspects of the build.


First I had to add the spars to the horizontal tail unit and paint the whole. This is because I may have to add this when I put the top wing on: it is all about getting alignments correct as I will explain later. Anyway here is the completed horizontal tail section with the spars: the ribs will be added after this has been attached to the wing and port (left) upper boom and rudder post.





The holes in the spars are where the port boom and a bracing strut will be inserted later.


I added the control column to the pilot's cockpit and have cut two horns for the elevator, but not added the latter yet as they are very likely to be knocked and damaged if I do. I have also made a seat cushion for the pilot from resin and added this and the seat belts before putting the seat into the cockpit - I am not sure whether I could do this with the top wing in place.





The wheel on the left of the image above is for the gun mount. Early gunbuses had a curved mounting with a bracket and short post for a Vickers m/g: this was moved by turning a wheel which engeged with a toothed mechanism which in turn moved the gun from side to side. The front bracket on which the gun mounting was fitted looked like this:








This was painted and then fixed in the nose with two support pillars from brass rod. Then the nose area was rigged:





I also added the port (left) side panel to the pilot's cockpit. The outside of this will be seen so I fitted the fuel pipes and a fine adjustment valve; again these had been left off for as long as possible so that I did not knock them off or damage them when handling the model.





I have been painting the fin and rudder while all of this has been going on, together with trying out various ideas for a jig with which I can fit the top wing. I am hoping that having cleared away all of these fiddly bits I can now proceed with turning this monoplane into a true biplane, and be hopeful that I am not going to knock anything off or find that I still need to add some fine details in a wholy inaccessible place in the future. If all goes according to plan my next post will show the top wing and booms in position and the jig that I will have used to get them there.


Thanks for looking.

Stephen.

[coyotemagic]

I'm at a loss for words, Stephen!  This is master modeling at it's finest!  You've certainly outdone yourself with this one!
Cheers,
Bud

[lcarroll]

Stephen,
    Your last photo (of the nose area) says it all, pure artistry! This is a great testament to your Scratch Building skills, just magnificent. This one's going to be a "classic"Cheers,
Lance

[Gisbod]

Great Job Stephen,

Way beyond my skill set!

Guy

[RAGIII]

I'm at a loss for words, Stephen!  This is master modeling at it's finest!  You've certainly outdone yourself with this one!
Cheers,
Bud

Well not surprising that I agree with my Amigo! Simply Superb Modeling!!
RAGIII

[Manni]

So many great details and so much to learn from this thread. Thank you for showing.
Bye,
Manni

[gbrivio]

So many great details and so much to learn from this thread. Thank you for showing.

I don't know how I missed so many updates in this thread and this can summarize the general feeling to look at a real aeroplane building, with this level of detail, and from scratch. Your build can be a superb scratch building manual, and the gunbus is going to be a great masterpiece.
Ciao
Giuseppe

[jeroen_R90S]

Fantastic work, Stephen! As good as it all looks, I particularly like the lacing!

[lone modeller]

Evening All,

Thank you Bud, Lance, Guy, Rick, Manni, Guiseppe and Jeroen for leaving such positive and encouraging comments: I really do appreciate them very much especially as they come from modellers whose work I very much admire.

Well I have got there at last - I now have a pusher biplane in 1/32 scale....well almost! Actually I have a nacelle, two booms and two wings and struts, but not all of the struts are in place yet. However I consider that I have taken a big step forwards in this project and am hoping that I now do not drop it or cause damage in some other way. There are still lots of challenges ahead, not least the rigging, but I will deal with those later. In the meantime I am enjoying the moment.

First I painted the serial and added a Union flag transfer to the rudder, but because it is half of the structure, the serial and Union flag will be visible as shadows on the reverse side so I painted the serial in reverse and put on a Union flag in the respective places before painting over with several thin coats of paint. The serial was hand painted as I could not find a suitable font to print from.





To complete both the rudder and fin I added the ribs from 10 x 30 thou strip on the inside surfaces:



I then realised that I had overloked the roundel on the top wing! This was printed and added and a shadow roundel painted on the undersurface of the wing. I only paint using a hairy stick, so the shadow effect was achieved in the same way as the serial by painting the base colours with thinned acrylic paint and then overpainting with several thinned coats of CDL until I had something that looks vaguely like a shadow:



Now I could set up the jig ready to put on the top wing. I model on a shoestring and small tray so making a suitable jig required some thought. I settled on this design:



which consists of a piece of wood which I found in my garage and was originally intended to be used as part of the base for the Dornier Flying boat that I scratch built last year, with 4 nails driven in to hold the lower wings rigid. Two supports for the ends of the wing were cut from cardboard. These latter went through several variants before I found a shape that would hold the top wing in place and not allow it to move about while I fitted the struts - these supports were used at each tip of the wings and a small piece of scrap plastic was placed to hold the trailing edge of the solid wing at the correct height:



After many trials and failures I managed to get this highly sophisticated and expensive piece of equipment to work i.e. I was able to start to add the struts to the wings so that they were square and properly upright. I had already drilled holes in the wings to take small wire pins on the ends of the struts. The struts were carved from basswood strip because this is more rigid than plastic, but I painted them with Revell Ocker because I could not find a suitable woodstain that woud give me the correct colour for  varnished pine. I also only used pins on one end of the struts because otherwise I could not get them into the holes in the wings. All is held together with CA which is strong enough to hold things together until I can add some rigging and thus strengthen the whole structure. The port (left) side struts were added first as these were easier to reach:



and here you can see the full jig in action:



The starboard (right) side was also added more easily than I had anticipated and the completed structure could then be lifted out of the wood jig:











I am rather keen to tie up and secure a lot of those threads because they keep getting in the way, but I am hoping that when in place they will provide extra strength for what is still a rather fragile structure. I have decided to defer adding the remaining booms and tail structure until I have rigged the wings because of the strength problem and also because of the need to be able to get into awkward places. Consequently it may be a little time before I return with the next update: this is only the second time that I have rigged a biplane model with thread and so this is yet another of those steep learning curves which I keep having to climb.

Thanks for looking.

Stephen.