Scratch build partial stripdown Vickers FB 5 Gunbus 1/32 scale

Stevef
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5 years 10 months ago #222 by Stevef

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.

Stevef.

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5 years 9 months ago #223 by Stevef

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:

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5 years 9 months ago #224 by Stevef

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.

Stevef.

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5 years 9 months ago #225 by Stevef

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Evening All,

The first thing to do after the top wing was in place was to add the cabane struts and sort out the rigging - I had many lengths of monofilament thread hanging from the starboard (right) top wing and parts of the fuselage nacelle and these were constantly getting in the way. The double rigging wires were difficult because some of the threads would not pass through the lower wing - the brass spars were in the way. Also attaching the cabane strut wires into the underside of the top wing was a problem because I could not drill holes all the way through the hollow wing and be sure that the ends of the thread would pass through. Well all of that got sorted out eventually, (after a delay caused by a back problem which meant no modelling for nearly a week), and I riggied the port (left) wing at the same time. Now I just have the anti-drag bracing wires which run from the forward outer wing struts rearwards - they are currently wound around the wing tips. The elevator control wires ran parallel with and outside the lift wires at the rear of the inner bay of the wings - effectively this meant that I had to add the pulleys over which the wires passed. These were fixed to plates at the wing root and at the top of the inner rear struts: ading the extra control wires to run parallel to the lift wires was fun....! The rigging took three evenings by the time I had corrected various mistakes on the way. I have learned several things from this exercise for future reference if i ever choose to build another 1/32 model.

Now I could add the other booms and the horizontal tail surface that I had constructed some time ago. This was a simple procedure when compared to the rigging and a good deal quicker. I had already drilled holes in the rear of the starboard wings to insert the ends of the booms, so a mixture of 2-part epoxy provided the sticky bit to hold them in place and in they went. The upper boom needed support because of the weight of the horizontal stabilizer: to stop it from drooping and make sure that it was properly aligned with the rest of the structure I used a modified mk 1 jig and left the assembly to cure. A dob of CA at the V of the upper booms also helped to hold that part in place:

The set square to the left of the model is there to check that the booms and rudder post were vertical: they are and the upper and lower booms are directly in line. I was relieved that they structure has set like this - I have repeatedly been checking these alignments because if any of them is ever so slightly wrong the whole model would be a fiasco. I can live with errors of 1mm but I seem to have been able to reduce them to less than this. Yippee!!!!

The resultant structre was stronger than I had anticipated and allowed me to move it about freely ready for the next steps: adding the rudder post and lower boom cross bracing.

The rudder post is brass rod. I used CA to fix it to the upper boom because the presence of plastic precludes any idea of using solder. The addtional advantage was that the rudder post was held in place so that when I soldered the lower joint I did not need any extra support.

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5 years 9 months ago #226 by Stevef

Finally I added the horizontal bracing strut in the port horizontal surface from brass rod and soldered one end to the boom:

This structure is strong: there was no danger of anything beoming distorted by an accidental knock. To finish the boom structure I could add the struts - these were carved from thin basswood sheet like the other struts, sealed with talcum powder and dope mixture and painted. The horizontal tail surface structure was made up from 20 x 30 thou strip and the leading edge wire between the boom and starboard side was from a piece of telephone cable wire. I have not completed thie remainder yet as it is rather exposed and liable to damage while I still work on other parts of the model. I have however painted the booms and wood structures:

Now as is usual with scratch builds, I have to make up and finish some more parts including the fin and rudder, undercarriage, etc. I am also trying to work out how much of the boom I should rig before proceeding to much further with construction. In addition I have to be away from home again for an uncertain period so the next update will probably have to wait for a time until I can do more on the model and have something to report on.

In the meantime, thanks for looking.

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5 years 8 months ago #227 by Stevef

I tried to make my own wire wheel but after several unsuccessful attempts decided that life is too short at the moment so I bought one of the superb Gaspatch sets instead. I used the tyre from one set and made my own disc from plastic card which had been laminated and the filed to shape, while I used the other unit from the kit. I painted the spokes black and tyres grey:

The marks on the disc are where I wanted to add the threads which held the canvass covers to the wheels but my first attempts to achieve this have not been successful either.... Looking at photos of the machine that I am trying to depict the threads are not very prominent so I may not bother after all.

The undercarriage legs have also been made and await being attached to the skids and nacelle, but not just yet as I am not ready to do so.

Another important step was to add the trailing edge wires to the exposed control surfaces, wings and tail unit. These were made from telephone wire which had been rolled with a brass strip and then carefully bent to shape and C A'd in place:

When the wires on the ailerons had been painted the units were put on to the wings:

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5 years 8 months ago #228 by Stevef

The last image shows the rudder wires running between the two sets of pulleys at the trailing edge of the wing.

The engine was finished by adding EZ line for the wires to the spark plugs:

and then the engine was fixed to the rear of the nacelle:

I have rigged the first bay of the boom but more importantly I have put in the horizontal bracing in front of the tail: this is formed by 4 wires attached to a small ring. Once again EZ line came to the rescue so that I could get two symmetrical and even patterns:

Finally I have been working on the machine gun. This is a Vickers from Gaspatch, but unfortunately the guns used on FB 5's were of a slightly different pattern to that depicted by the AM issue, so I have removed some of the moukding and made an ammunition box and receiver for discharged cases as per a photo in the DataFile:

This will be painted later and will be one of the last parts to be added to the model.

I am still struggling with errant lengths of thread which will be attached as anti drag wires eventually, but cannot be fixed at present because they will get damaged if I do. So, ever so slowly and in a crabwise manner I am getting nearer to finishing this project. I do not know how long that is going to take but I will probably wait until I do before I make the next post. Hopefully that will not be too long now.

Thanks for looking.

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5 years 7 months ago - 5 years 7 months ago #229 by Stevef

I followed up with the undercarriage unit. The legs were C.A.'d to the skids and when these were set I could CA the whole unit to the underside of the nacelle. This was left overnight as it seemed to be rather fragile: the following day I added the bracing from EZ line which seemed to make the assembly considerably stronger.

The propellow was next as I was concerned that I might not be able to reach into the rear without breaking something off:

The step to the cockpit was made from 20thou sheet - it too was C.A.'d in place - again care was needed not to knock this off twice - yes I managed to do so once!

Final details were the pitot tube on the front inner port (left) strut, the wing skids and picket rings, wheels and last, the machine gun and mounting and wheel for moving the mount.

The project is finished and I have completed my first pusher biplane in 1/32 scale, (I have built 14 others as kits, conversions or scratch builds in 172 scale), - it was not a pushover but it did not push me quite as far as I had anticipated except at the very end when as described a wheel and the tail skid broke off when I was trying to fit the machine gun wheel. So the sting was in the nose and the tail of this project.

My thanks to all who have followed this marathon and left supportive and encouraging comments on the way. I will post more photos of the completed model later when I have a little more time.

So if you have been, thanks for looking.

Stevef.

Last Edit: 5 years 7 months ago by Stevef. Reason: spelling

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