I'm not really a warbird fan. However, I built another plane with an eliptical wing that kept reminding me of a Spit so I decided I better make one. It turns out it's really a good plane; perhaps that's why its held in such high regard!
This one is really simple being entirely blue foam. Its not even covered. It's been flying for a year and a half as I write this. Other than gluing the motor, stab and fin back on from time to time it's still in original form and gets flown almost every weekend.
The model has a 36" wing. It weighs under 16oz with a double-length CDRom brushless motor, three 1800mAh Lipos and three small servos. It does huge loops and rolls well although needs loads of down elevator. It slows down nicely and is easy to land. The stall is predictable and easy to control. With smaller Lipos (800-1000's) the plane with fly is very tight spaces although would be too large and fast for indoor. However, I prefer the power I have now and speed I get with a fast turning 6x3 folding prop.
The wing is solid blue foam hot wire cut with the end templates provided. It is then trimmed to the eliptical shape and sanded back into an appropriate airfoil. Try to avoid scratching the foam deeply if you don't intend covering it. A ply wing joiner and epoxy holds the two halves together. The ailerons are then cut out and hinged with mylar or pinned hinges. I use torque arms and a single central aileron servo.
The fuz is made from five foam components hot wire cut to shape. The wing profile is cut first in the center section followed by the 'cross-section' of these parts. These build the wing fairings in automatically. The parts are epoxied together and everything sanded smooth.
The nose section has proved to be a bit flimsy for higher power setups such as I have. The firewall should be good quality ply epoxied to the foam. I then have four bamboo skewers strengthening the nose from the firewall through to the front of the wing area. This is almost but not quite OK because the motor resonates anywhere near full power and in fact I can only go to full bore in a vertical climb. It might be better to glass the inside of the nose or reinforce it better than I have described. I have a 1/2" hole under the firewall to provide cooling for the Lipos.
The tail surfaces are 3mm Depron. These have not failed in flight but 'hanger rash' usually results in them breaking away from the fuz every so often. Cyano is an amazing glue! Maybe a length of carbon across the stab would be helpful.
You could cover the model with film or tissue but I did not bother. My Spit is sprayed with water based acrylic directly on to the foam and left natural underneath. The roundels are marked out around cardboard templates and painted by hand. You might get away without a rudder if you also go with a fast prop. However, at lower speeds the plane turns much better with a bit of rudder so I recommend one.
Free plans are provided below. As usual you may build the model but may not profit from the design. Check your printer settings (don't 'fit to paper') to avoid distorting the size. Page 1 should print a reference line to check. Let me know if you have any queries.
|'PDF' A4 paper
|'PDF' Letter paper
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