|Jun 10, 2012, 03:27 PM|
Scratchbuild 80" WS Depron Vulcan B2
Probably going to get into bother with the moderators but I have moved this build log from the 'scratchbuild foamies' forum to here. My last two threads were here in the scale section. This build, although in depron, is being built very much with the scale aspect in mind so, here is where I think it is best suited.
After a year away from building, the desire to get out the building board has returned!
Friends have asked when and what the next build will be. I think the seed for this one was I fancied trying combining conventional building methods with modern materials like Depron. I’ve built many depron models in the past, parkjets, shockies etc but they’ve all had flat section wings and box-like construction fuselages. I scoured the web and flicked through a few books and one aircraft kept calling. The mighty Vulcan!
Firstly, I cannot claim bragging rights on this build as it has already been done, and done well by Glenn7e.
Credit where credit is due, this guy came up with some brilliant ideas and innovative solutions when he did his build.
If mine comes out half as good as his, then I’ll be more than satisfied. So, on with my attempt……
Well, I say day 1 but the past two days have been spent studying the 3 view drawings of the Vulcan.
Kindly supplied by Glenn, the drawings were emailed to me as tiled A4 images. Rather than possibly build – in discrepancies or innacuracies by sticking loads of A4 tiles together, I spent a few hours in my favourite drawing package and reassembled the tiled images back into one large image. Once I had completed this, I took the whole file to my local printers who plotted them off on A0 sized sheets.
Sized to Glenn’s original 80” wingspan, soon realised that this thing is larger than I imagined. Nevertheless, 80” is the size it’s going to be.
Bearing in mind that the whole model will be constructed from 6mm Depron with 3mm Depron skinning, looked for areas on the drawings where the 3mm skin would need additional support from additional formers.
Nose and Battery Holder.
This is one clever bit of thinking by Glenn. The battery tray, which will become part of the main fuselage slides into a box section within the nose of the aircraft.
My compass cutters were not big enough to cut out the cockpit formers so I had to nip out and buy a cheap set of compasses and substituted the pencil with a slim modellers knife. The formers and the profile cockpit shape (side view and top view) were cut from 6mm depron as were the component parts for the battery compartment.
As a rule of thumb, unless I state differently, I will be using UhU Por Foam-Safe contact adhesive on this build.
I glued the sides and bottom of the battery box and then sanded lightly to ensure the edges were clean and flush. I forgot to mention that I’m using a ‘mat cutter’ for cutting any straight cuts during the build. The cutter ensures a 90 degree cut so butt joints are much better than free-hand cutting with a straight edge and modelling knife. The mat cutter can also cut at 45 degrees. It cost about £10 and included spare blades. I’ll let you know how I get on with it but early indications show it to be spot – on .
So, day one over. Not a lot to show for my efforts but satisfying nonetheless. I can see the build throwing up many challenges but that’s what I enjoy about building.
|Jun 10, 2012, 03:31 PM|
Saturday 9th June
Had about 3 hours working on the build today. I spent a fair bit of time working out how best to lock the nose fuselage parts together. Wherever possible, rather than butt joining the formers onto the keel sections of the fuselage, I wanted to ‘slot and notch’ to offer more rigidity and strength.
Once I had worked out where I needed to notch the formers, dry-fitted the whole lot together to check alignment and I have to say, surprised myself at the strength of the structure before glueing.
Being that this whole section of the fuselage is ‘locked together like a chinese puzzle, had to use foam safe CA glue along all the joints.
I took a couple of pictures to show the formers and keel sections notched out ready for assembly for reference.
Not a lot more to add today. It’s been fiddly but the end results are pleasing and solid.
Day off the build tomorrow so it will probably be Monday or Tuesday before I update the log again.
|Jun 10, 2012, 05:09 PM|
This is going to be great! My current build (a Lancaster) is my first in Depron and it's been a learning experience. I'm looking forward to seeing how you tackle this one.
|Jun 11, 2012, 02:10 AM|
Following with interest – modern materials and building techniques have certainly made it possible to create some fantastic models (Steve85s Lancaster build). Look forward to following your build – good luck
|Jun 11, 2012, 02:42 AM|
Well, that confirmed the fact that I'm now in the correct forum! - Thank you guys for the comments and encouragement.
I was asked about propulsion....It will be a pusher powered by 2 x T3536/5 Thumper 1450 kv Outrunners capable of up to 650W each running 9 or 10" props. It will not be contra-rotating as I can't easily get hold of left and right-handed prop pairs.
2 x 2200 / 2400 3s lipo's and 2 x 40A esc's. The projected auw you might be surprised to know should be in the region of 4 to 4.5 lbs ( assuming no retracts however, they may be introduced yet). If this weight is achievable and more importantly, correct then the wingloading should be an incredibly low 5 to 6 oz. Areal floater!
Projected timescale to completion......3 months (the best laid plans etc.....)
|Jun 11, 2012, 01:32 PM|
Monday 11th June
Spent about 3 hours today on the nose section. I added some more curved formers to the section aft of what will be the cockpit and then gave the whole assembly a good sanding. I used a wooden sanding block to ensure I didn't introduce any dips into the formers or keels. There were some minor discrepancies in the assembly that required smoothing but they didn't cause any problems. I thought at this stage a little bit of video would make the nose section clearer to understand.
Skinning will be of 3mm Depron sheeting and to be truthful, I wasn't sure whether I was looking forward or dreading making my first attempt at skinning a structure with 3mm depron.
The 3mm Depron DOES have a 'grain' to it and it curves and smooths better one way than the other. On the stuff that I'm using, the shiny side is on the outside of the curve and the material is more pliable across its width rather than its length (hope this makes sense). With this in mind, I had to be careful when measuring out pieces so as to cut down on wastage. Prior to trying to fold the 3mm around the fuz, I gently rolled the depron over a curved counter top using the palm of my hand, the friction and warmth of my hand was sufficient to make the depron very maleable after only a few minutes.
I used a foam safe contact adhesive to bond the skin to the framework which enabled me to 'roll' the 3mm depron around the framework. I had to slice off the radar dome bump on the underside of the keel to make it easier to roll the skin around. I'll pop it back on once I have finished the skinning. Ok, so it is a fiddly job but worth taking the time as the finished results are incredibly goo. The additional strength that the skin is bringing to the structure is unbelievable! It's very sturdy, surprisingly rigid and generally, lovely and smooth.
So, all told, I'm very pleased with the progress today. I've added a couple of pictures to show progress to date.
I'll keep you posted..........
|Jun 11, 2012, 02:14 PM|
That certainly is a clever structure. Will the forward fuselage be removable as in your video, or will it be fixed in place?
|Jun 11, 2012, 02:41 PM|
|Jun 13, 2012, 01:58 PM|
Good to see another Vulcan taking shape Roy. Mine came out just shy of 5lbs but I think I could have got it 1/2lb lighter without too much trouble.
I have looked at the possibility of scaling up a bit more and it might happen one of these days
watching with interest
|Jun 13, 2012, 04:34 PM|
Thanks for the email. Good to have you along!
Today I have spent most of the afternoon skinning the front section of the nose. Maybe a more skilled person than I would have managed to do it in far fewer pieces but I found the closer I got to the pointed end, the more manageable it was to skin in quadrants.
Once the bulk of the front end was skinned, I turned my attention to the cockpit area. With hindsight, it would have been far easier had I removed the cockpit ' bump' from the keel before I skinned so that I could have wrapped the 3mm Depron round without having to stop for the cockpit. After spending the best part of an hour studying the 3 view drawing, printed out 3 x A4 tiles of the cockpit area (to scale) so that it would be easier for me to work out the former shapes.
It was reasonably straight forward to get the shapes and the curved underside of the formers was easy to get right because I still had the depron off-cuts of the fuselage formers from that area which I used as a template.
The faithful Ipad came in handy here because I was able to refer to many different photo angles of Vulcans that are to be found on the internet like the one in picture 1.
The windscreen is an area of the Vulcan that is very distinctive. Windows almost like square portholes which I really did want to reproduce. I found some quite stiff acetate sheeting (packaging from some drill bits) which had a yellowish tint to it but should do the trick. After measuring and trimming, I scored the acetate to allow it to bend in the flat window style of the vulcan. Before I glued it in place, I painted the inside of the cockpit area black. I used contact adhesive on the acetate so as to avoid any 'blooming' which CA causes.
All that was left for me to do then was measure cut and fit some 3mm depron window frames over the top of the acetate to give the glazing a bit of depth rather than just paint the window frames on the acetate. I painted the frames green before fitting so as to avoid getting paint all over the windows. Pleasing results.
Oh and finally, for reference, I have used one sheet of 6mm Depron (700mmx1000mm) and half of a sheet of 3mm (700 x 1000) to get me to this stage.
Getting a bit late now so have just finished going around all the joints with lightweight filler so that it'll be dry in the morning ready for me to crack on once again. So, for now...........
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