Army_Air_Force Posted March 6, 2018 Author Share Posted March 6, 2018 (edited) 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. 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. Edited October 23, 2020 by Army_Air_Force 3 Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 6, 2018 Author Share Posted March 6, 2018 (edited) 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. 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. Edited October 23, 2020 by Army_Air_Force 3 Link to comment Share on other sites More sharing options...
Max Headroom Posted March 6, 2018 Share Posted March 6, 2018 Forgive my ignorance, but what is modelboard and how do you shape it? Trevor 1 Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 6, 2018 Author Share Posted March 6, 2018 It's a high density resin block that can be carved, sawn, sanded, drilled and tapped for threads. It is commonly used in professional modelmaking for patternmaking and prototypes. 2 1 Link to comment Share on other sites More sharing options...
stevehnz Posted March 6, 2018 Share Posted March 6, 2018 I'm enjoying watching this, as much for the process as for the prospect of a Broussard kit, really fascinating. Steve. 1 Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 6, 2018 Author Share Posted March 6, 2018 I hope my skills live up to everyone's expectations!! Link to comment Share on other sites More sharing options...
Bandsaw Steve Posted March 7, 2018 Share Posted March 7, 2018 Hi, am really enjoying this. Is modelboard the same stuff as ‘Renshape?’ Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 7, 2018 Author Share Posted March 7, 2018 I've heard the name Renshape, but never used it, but I expect it's the same or similar stuff. 1 Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 7, 2018 Author Share Posted March 7, 2018 I was having a bit of a ponder earlier this evening. Before I commit to sanding the fuselage, I may get some scraps of model board, and sand it to match the former templates. I can then see how the 3D shape looks compared to photographs of the real aircraft, and get a better understanding of whether any of the fuselage radii need adjusting. 1 Link to comment Share on other sites More sharing options...
Jonners Posted March 7, 2018 Share Posted March 7, 2018 Wow, every day's a school day! Watching and learning... Jon Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 7, 2018 Author Share Posted March 7, 2018 (edited) No progress on the Broussard today. After a bad night's sleep, I didn't feel I could focus on the job properly, so turned my attention to the final assembly of another ongoing project ( below! ). I had the seat and tank out over the winter for some welding work on the body. Today it all went back together and had the first engine run since September. It was also the first time outdoors in the new magnetic RAF markings for the RAF's centenary year. I have a meeting tomorrow morning, so may not get back to 'Bruce' until tomorrow afternoon. Edited October 23, 2020 by Army_Air_Force 2 Link to comment Share on other sites More sharing options...
k5054nz Posted March 7, 2018 Share Posted March 7, 2018 (edited) Magnetic markings? What a clever idea! Edited March 7, 2018 by k5054nz Link to comment Share on other sites More sharing options...
RidgeRunner Posted March 8, 2018 Share Posted March 8, 2018 She’s coming along fast :)... excellent! Martin Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 8, 2018 Author Share Posted March 8, 2018 (edited) After my 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. 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. Edited October 23, 2020 by Army_Air_Force 1 Link to comment Share on other sites More sharing options...
fightersweep Posted March 8, 2018 Share Posted March 8, 2018 (edited) Superb progress on the Broussard! Fascinating to see how you are tackling this project, and I think I'm going to learn a lot from following this thread. Top skills all round! Nice Jeeps too! Been a long time since I got behind the wheel of one. Still have an itch to buy another one day and paint it in 401st BG markings. Edited March 8, 2018 by fightersweep 1 Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 8, 2018 Author Share Posted March 8, 2018 (edited) 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. 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. Edited October 23, 2020 by Army_Air_Force 2 Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 8, 2018 Author Share Posted March 8, 2018 (edited) 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. 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. Edited October 23, 2020 by Army_Air_Force 2 Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 9, 2018 Author Share Posted March 9, 2018 (edited) 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. 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. Edited October 23, 2020 by Army_Air_Force 1 Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 9, 2018 Author Share Posted March 9, 2018 (edited) 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. The side and plan profiles were sanded first, wet sanding the resin block down to the edges of the brass. Edited October 23, 2020 by Army_Air_Force 2 Link to comment Share on other sites More sharing options...
Terry1954 Posted March 9, 2018 Share Posted March 9, 2018 Hi Stephen, This is fascinating stuff. I will follow this thread very carefully as I like this aircraft, am a follower of the one true scale, and who knows one day, may even scratch build something myself. Cheers Terry 1 Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 9, 2018 Author Share Posted March 9, 2018 (edited) 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. 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. Edited October 23, 2020 by Army_Air_Force 1 Link to comment Share on other sites More sharing options...
Army_Air_Force Posted March 9, 2018 Author Share Posted March 9, 2018 (edited) 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. Edited October 23, 2020 by Army_Air_Force 4 Link to comment Share on other sites More sharing options...
Gondor44 Posted March 10, 2018 Share Posted March 10, 2018 Facinating to watch how this all comes together Gondor Link to comment Share on other sites More sharing options...
fightersweep Posted March 10, 2018 Share Posted March 10, 2018 Sittin' back and lovin' this! popcorn 1 Link to comment Share on other sites More sharing options...
Bandsaw Steve Posted March 10, 2018 Share Posted March 10, 2018 Watching and learning! Thanks for the very clear documentation of your process. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now