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Max Holste Broussard 1/72 Scratch Built Masters & Models

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At the back end of last year, I was contacted by a friend who was interested in a couple of Broussard models. After a quick search, I found there were no current Broussard kits available and because he wanted a couple of models, the most logical option was to scratch build a master model, then moulds and resin cast parts. It's quite some time since I scratch built something at this size. I'm more used to scratch building between 1/6 and 1/3 scales! 

 

I've just finished a project, and another is nearing completion, so I'm just about in a position to start working on "Bruce", the affectionate name for the Real Aeroplane Company Broussard that I'm using as reference. I have some drawings and photos of the aircraft, but I'm planning a research trip to the aircraft this weekend for further measurements and photographs. I should be in a position to make a start on the master parts soon after that visit. The model will be about 7.5 inches wingspan and about 4.7 inches long.

 

Here's a few pictures of the subject aircraft that I was lucky enough to have a flight in last year.

 

bruce5.jpg

 

breighton029.jpg

 

bruce15.jpg

 

bruce24.jpg

 

breighton24.jpg

 

 

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Here's some of my research tools for the trip! The large checkered rule is 4 feet, with the first 6 inches in 1 inch markings, and then 2 inch and 1 foot markers. There's a small 12 inch rule and a protractor with a weighted pointer that always points down. It also has a spirit level so the pointer can be aligned horizontally to measure angles. There's a plumb line there too. I also have a number of drawings that measurements can be added to.

 

broussard002.jpg

 

I use these tools in most of my photographs as a quick way to record measurements and angles. So long as the picture is taken square on to the subject, then can be a fairly accurate way of scaling details from photos.

 

scalerule.jpg

Edited by Army_Air_Force

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 It's actually a good looking airframe  . Looking forward to your progress .

 

 Cheers, Christian 

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I had a very busy 5 hour research trip at Breighton Aerodrome today. I came away with lots of measurements and just over 300 reference photos of the 'Bruce'. Because I was working in the dull hangar, I shot everything in RAW format, so it's going to take a while to adjust and save each image to bring out the details to their best advantage. But I have lots of data to work with now, so it shouldn't be too long before I make a start on the patterns.

 

Here's just four of the 304 images taken today.

 

broussard003.jpg

 

broussard004.jpg

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I'm very close to making a start. I'm just working my way through the photos and measurements taken at the weekend to finalise the size of the 3-view drawing I'll use for templates.

 

I'm much more practiced in scratch building hollow models at a slightly bigger size such as my 1/6 scale R/C B-17G seen below, but I did spend a couple of years working for a company that did a lot of prototyping for the MOD, building 1/16 and 1/35th military vehicle models and 1/100 and 1/200 warship models. I usually ended up with the job of making the helicopters, landing craft and deck vehicles which were all styrene and acrylic masters which were then moulded and resin copies made.

 

b17064.jpg

 

I'll be making the master patterns from 'modelboard' resin blocks - the green lump below! Scratch building should be moderately easy. All I have to do is cut and sand off anything that isn't Broussard shaped. What I'm left with will be a Broussard! How hard can it be?? :rolleyes:

 

broussard005.jpg

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I'm still plodding through piles of drawings and photographs! Here's my revised under-plan view on the left, compared with the original plan on the right. You can see there's a number of subtle and not so subtle differences in the size and positioning of the airframe components.

 

broussard006.jpg

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The side view is just about there now and I've also been working on the front view. While working on either of the three views and projecting the measurements from one to another, I find I keep making slight adjustments to all three. It's getting pretty close now, certainly good enough for 1/72 scale. Since the last picture, the prop, cowl and spinner have all been reworked along with the aerials on the roof.

 

broussard008.jpg

 

broussard009.jpg

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Great work, Stephen. You must have the patience of a saint. :thumbsup:

I kept hoping someone would do one of these in 1/72. Then after I switched to 1/48, I was hoping someone would do it in 1/48… :sunrevolves:

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Two weeks to the day from doing the survey of Broussard G-CIGH, I've finished my 4-view drawing. It won't be 100% accurate having only spent one day taking photos and measurements, but the 4708 x 4621 pixel image is much better than anything else I can find. Along with the photos that help to show the 3D shapes and curves, it will be good enough for a 1/72 scale model.

 

broussard010.jpg

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One last fiddle with one side view on the drawings removed the fin and dihedral on the main wing to show the wing and tail root ribs. I also drew in some sections. These will be the first job on the build, making some 'female' forms for templates to check the fuselage shape during sanding. Will it be tomorrow? Stay tuned!! ;-)

 

broussard011.jpg

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Nice work!

Can you elaborate on how made the sections in the last image?   I understand the process of getting the general arrangement views, but I'm not sure how you derive the sections from them, and the sections are definitely the most useful part for the model ;)

 

TIA!

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Interesting to see the process in action. Quite a bit of time and work in the creation, models don't just fall out of trees, even if all you have to do is merely take a stick and cut away anything which doesn't look like the subject!

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2 hours ago, Nate said:

Nice work!

Can you elaborate on how made the sections in the last image?  .......

 

Heights and widths of various parts of the former were projected from the other views, combined with measurements from the real aircraft.

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Chocks away! Here we go!!! The sections were taped to some 1mm styrene to form templates for the fuselage shape. Because of their small size and possible margin for error in trimming out the templates, they will be used as a guide to the shape rather than rigidly following their dimensions.

The larger dimensions of the fuselage taper for example, will dictate the overall height and width compared to the side view, so if the template is a little tight for its correct position, the template will be adjusted. The printed line for the templates is probably less than 1mm wide, but viewed through a x15 magnifier, that line looks really wide, and so there's a margin of error possible when cutting out the templates.

 

broussard012.jpg

 

It took quite a while and lots of scalpel sharpening to carve away fractions of a millimetre of plastic at a time.

 

broussard013.jpg

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A block of modelboard is the basic material for making the fuselage master. After cutting to approximate size, it was cut in half down the horizontal centreline. The surfaces were sanded, then wet sanded, before being glued back together again with cyano.

 

broussard014.jpg

 

It was then cut down the vertical centreline, sanded and glued back together again. This my seem a bit odd, but there's method in my madness! The cutting and gluing puts a glue joint all the way through the block of resin. This means that no matter how much I cut and sand away, I'll always have a horizontal and vertical centreline in the resin block as a reference.

 

broussard015.jpg

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Here's the fuselage block with the cowl rear template placed on top. You can see the resin block centrelines and the plasticard templates all have score lines to mark their centrelines, so it should be easy to slot the template over the forming fuselage to the correct depth to check shapes at each station.

 

broussard016.jpg

 

All too soon it was time for the school run to pick up my daughter and that was the end of day one. Five hours gone! I didn't actually expect to get much more done.

 

broussard017.jpg

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After a meeting this morning, I didn't get back to my workshop until 1pm. With little legs being chucked out of school at 3:15pm, it didn't give me long to get much done. I did however make some progress.

 

I started with some small scraps of model board and sanded them to match three of the fuselage templates. It's a tricky job sanding to such small tolerances and the experience pointed the way for tackling the fuselage.

 

broussard018.jpg

 

As the three sections were sanded, they were compared to the photographs of the real aircraft to see how the shaped compared. Overall, they seemed to work out well but of course sanding a fuselage that changes from a very rectangular section to more of an elipse with flattened sides, top and bottom was going to be challenging. 

I can see a jig coming soon that the fuselage blank can be slotted into to check overall widths and tapers before the shaping commences.

 

broussard019.jpg

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Having sanded a slight taper on the section just ahead of the tailplane, I realised how difficult it was going to be to create a symmetrical fuselage which also changes section shape, just by offering up the templates against the resin block.

 

I'm now considering cutting the fuselage black at the tailplane former, and making a complete male template that can be glued to the block at this tailplane position. I may even make it from aluminium or brass as a sanding guide a little tougher than the resin itself. I may do the same behind the wing and at the firewall position, using these styrene templates in addition to the template attached to the fuselage blank. I little more experimenting needed I think.

 

broussard020.jpg

 

I want to mould the glazing/cabin section from clear resin. A hollow, detailed cockpit isn't a requirement for my primary customer ( a rework may come at some point in the future, but right now it isn't a concern ). As a result, that part will need to be moulded separately, but I need the shape to flow with the rest of the fuselage.

 

It would be best shaped with the main block. I would then separate it, reduce its width by about 0.5mm each side, and add 0.5mm styrene window frames. The first step was to drill the cabin section with two 3mm holes vertically through the block. I then used the bandsaw to cut the cabing section off. That of course left harsh bandsaw blade cuts into the resin.

 

broussard021.jpg

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The cabin part had nice easy exterior faces to sand on a flat bench with some wet and dry paper stuck down. The fuselage part of the cut was more tricky to sand smooth and square, but I had an easy fix for that, brought from my days building large, multi-section R/C aircraft.

 

broussard022.jpg

 

After the cabin piece was nice and smooth, I gave it several coats of mould release wax along the mating faces. After that, out came the tin of P38 car body filler. A dollop was mixed up with the hardener and spread over the fuselage mating faces. Before it cured, the two parts were joined back together again with some M3 studding and the bolts tightened up, squeezing out excess filler. After it cured, the studding was removed and the two parts popped apart, leaving a perfect joint.

 

The cabin section can now be bolted securely in place for fuselage shaping and once sanded to section and glazing sorted etc., the two holes in the top of the cabin and bottom of the fuselage can be filled and sanded flush.

Once the silicone mould is made, I intend to pour the resin fuselages through the firewall end, so the sloped face at the rear of the cabin is to aid air bubble escape from the rear fuselage part of the moulding.

 

That was it for today. Not too bad for only a couple of hours of available time.

 

broussard023.jpg

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In order to make the fuselage sanding a little easier, I decided to make some brass formers as sanding templates to attach to the resin block. Sub-millimetre accuracy in cutting was important, and so the excess was ground away with a rotary grinding stone while peering through a x15 watchmakers magnifier.

 

broussard024.jpg

 

The first two brass formers were for the rear fuselage taper and it worked surprisingly well. They were tack-glued to the resin, carefully lining up the centre lines scratched onto the formers with those in the resin block. They were then drilled and screwed in place to hold them securely during sanding.

 

broussard025.jpg

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The resin was cut roughly to shape on the bandsaw, leaving around 1mm to 2mm of excess beyond the brass templates. After a rough sand on the belt sander until close to the templates, the rest was finished off with 240grit wet and dry attached to a flat acrylic block as a sanding tool.
 

broussard026.jpg

 

The side and plan profiles were sanded first, wet sanding the resin block down to the edges of the brass.

 

broussard027.jpg

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Next came rounding off the corners. It's a bit tricky as the fuselage isn't a straight taper. The sides and underside behind the cabin, have a slight curve in so the brass templates had to be used as a guide for each end, blending the shapes where the taper changes. Overall, it worked well.

 

broussard028.jpg

 

The third brass former made is for the firewall. The former from the front of the rear fuselage, will be reused on the back of the front fuselage block, with possibly one more former at the wing spar position through the cabin. The styrene templates made first, were used to score the outline of the former onto the 0.45mm thick brass sheet.

 

broussard029.jpg

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All too soon, it was school pickup time again and that was it for another day. Progress seemed slow early on in the day, and while I didn't have any targets for the day, I was pleased with the results so far.

 

broussard030.jpg

 

broussard031.jpg

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Cabin section today! While the firewall former is slightly narrower than the main cabin, it was attached to the front of the cabin block as a guide to the shape and size. The upper and lower edges were cut and sanded first.

 

broussard032.jpg

 

The sides were sanded next, running parallel forwards towards the firewall template. After sanding the upper and lower curves the brass templates were removed. Because of the saw cuts and sanding the ends smooth reducing the overall length of the front block, a new piece was cut for the cockpit window section up to the firewall.

 

broussard033.jpg

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