Back in 2015, when the quadcopter boom was starting, I though I would get one to find out what the fuss was about. As described in the April 2015 Newsletter, I bought a 250 size quad, built it and (just about) taught myself to fly it. And there it ended, as I quickly lost interest and the machine spent the next 5 years on a shelf. It did seem a waste to throw it away, and due to the pace of development in quads there’s not much value in second-hand quads.
So, what to do with 4 motors? The answer of course is a 4-engined plane! Having built the Canadair floatplane last year, the Sunderland came to mind.
So I drew up my own plans in Fusion 360 and cut out the Depron using the needle cutter that I’ve described before.
Depron parts for Sunderland and Sea Harrier were cut out together
- Depron parts for Sunderland and Sea Harrier were cut out together
Fuselage construction was by a central box section with bulkheads around, and then panelled all in 6mm Depron.
The wing was also 6mm Depron top and bottom with 6mm ribs. Engine nacelles, floats, front hatch and the wing top fairing were CNC cut from Styrofoam.
Wing ribs and CF spar
- Wing ribs and CF spar
Nacelles etc CNC cut from styrofoam
- Nacelles etc CNC cut from styrofoam
Floats from styrofoam and CF struts, held on by strong magnets
- Floats from styrofoam and CF struts, held on by strong magnets
The cockpit, nose and tail canopied were vacuum formed over moulds CNC cut from wood.
Canopies vacuum formed from wooden moulds
- Canopies vacuum formed from wooden moulds
The whole model was then covered in light-weight tissue and light-weight glass cloth applied with Poly-C, then painted with acrylic paints. Cowls are 3D printed.
3D printed cowls
- 3D printed cowls
The motors now have 3-bladed 6x3 props and give a combined thrust of 1.42kg against a model weight of 1.44 kg which includes just 60g of nose weight.
Finished model
- Finished model
Finally it flew on a very dull and overcast day in December 2021, with very little trim required.
First flight
- First flight
Ian.
