Hello everyone
The Curtiss f9c sparrowhawk parasite fighter was always for some reason one of my favorite biplanes.Surfing around in the internet I found one kit from Dumas and without further thoughts I bought it.A week later I got a box which had the kit of the F9c and it contained some plastic parts, plans, instructions,but no balsa parts....My fault I was so eager to buy it I did not read the description.....But, I was determined to build it I had the plans and the parts so I blackmailed and bribed my friend Tasos who converted the plan into a file the laser cutter could read and voila.I started building it the worst part being stripping the 1,5 and 2 mm balsa stringers.It will be powered by a CO2 engine.I will use the ABS parts to make a mold for the wheel pants and the cowl.The cockpit will be balsa .
The left half of the fuselage and the side stringer glued
This is a great subject and I look forward to following the build.
Almost done with the half left side cutting the stringers and sanding them to fit tightly was a time consuming work.Then the right side formers will be glued along with the stringers. At the same time I have applied 5 coats of release agent on the vac formed wheel pants and cowling provided by Dumas. I will then produce molds as the parts will be sturdier and lighter.
Empenage is started and after completed but not sanded put on the scale with 95% finished fuselage.
fuse and tail feathers.
Looking good. Am I correct in thinking that you halved the width of the empenage leading and trailing edges? Did you do so on the fuselage formers too?
Yes I simply followed the instructions of the kit. I made some alterations though as I want it to be more rigid. I hope that I will sand the tail surfaces to create some airfoil-ish finish so the wood thickness was increased by 0,5 mm.
I want to reinforce the fuselage also with some cross beams between the formers.
Built the wings yesterday, with the extra ribs for more scale appearance
Nice work, like the extra ribs.
The AUW of the parts I built so far (fuselage,tail, upper wing) is 26 gramms.Tomorrow I will start with the mold of the cowl belly and spats. I really hope with the epoxy parts that I will save alot of weight.....
Later today I will glue the extra airfoils and the strut reinforcements and the wing will be ready
The lower wing with all ribs in place.
Coming along nicely! 8)
The wood work completed is 43 gramms.I am happy with the weight so far now I work on the mold of plastic parts hopping that they will be at list 30% lighter than the ABS ones. They will be definately stronger.
Nick,
I would still try thinner plastic instead...
Maybe make molds for both ways without destroying the original parts.
Weight is good so far. What is the model wing area?
George I got 1532 cm² so 15,32 dm.
Positive molds is easy to do.Negative ones are a bit more difficult. But all depends on wax on wax off. Plus ABS plastic is a material which will not bond with epoxy
The wood work of the model finished except sanding and finishing. The weight came out at 46 grams which is good.I just hope the plastic parts I am working on now will come out lighter than the acetate original ones. Here some photos of the wing and the ailerons which will have some capability for deflection in order to counteract the powerfull rudder.