Foam White & the Pageboy
With all the discussion about the
Pageboy, I thought it time to 'join the gang’ & build one. Just to be consistently different, I made mine out of 2mm foam. Only a few minor mods were made to the construction to accommodate the use of the foam, mainly on the wing. I added a 5mm balsa L.E. & a 12mm wide T.E., both out of 1.5mm balsa, glued to the bottom of the foam sheet, mainly to make the wing more 'ding resistant'. I also made the ribs out of balsa since the balsa grain provides longitudinal stiffness that the foam does not. The tail plane & fin are 2mm foam without any other reinforcement, decorated with coloured trim tape. The rudder horn is a piece of styrene sheet & the rudder is hinged with a strip of trim tape folded over on itself & then glued into a knife slit in the rear of the fin & the front of the rudder.
- cardboard templates were used to transfer the shapes to the foam
- ready for cutting out
There are 1mm ply reinforcements for the wing & u/c dowels, and the firewall and motor plate are 1.5mm ply. Since there is basically no access to the rear of the motor once construction is finished, I made a separate motor plate - the motor mounts on this plate, which is then screwed to the firewall. I also 'borrowed' Phil’s suggestion from Carl's version & made an externally accessible battery compartment under the nose in front of the undercarriage dowel so I wouldn’t have to pull the model apart to change batteries. Unfortunately I under estimated the impact of the larger & heavier motor (which was all I had at the time) on the CG, so had to move the battery back significantly - consequently another battery compartment was added behind the wing.
The original motor was an 1806 quad out runner running on a 2s 360mah lipo through a 12amp controller with BEC (again the smallest controller I had at the time). The first prop I tried was a 5” x 4.5” drone prop, but the thrust was way too excessive. I swapped to a Tornado nylon 5” x 3” prop meant for
Cox reed valve .049s & the thrust dropped to (hopefully) below
the rip the wing off level?!? I subsequently procured a smaller motor (HK bargain bin shopping again!) – a 1304 3100Kv micro-quad motor, still running off the 2s 360mah pack, driving a 4.5” x 2”
Cox Thimble Drome grey prop. A 6 amp speedy is still on the slow boat from China.
The Rudder servo & Rx were last to be located – they ended up on the CG! I’ve set the rudder throw based on previous comments/recommendations. Hopefully, test flying will be this weekend.
- ready for test flying
Total build time was about 4.5 hours, snuck in between babysitting the grandkids & outside work when it wasn’t raining. AUW is 95g, which under the circumstances I'm happy with. I reckon I could trim 10-12g off that with light weight wiring, an even smaller motor, an integrated Rx/servos/ESC and a single cell pack, but I still want to be able to fly it even if it’s a little breezy.
If you are contemplating a similar foam build, here are a few tips.
* Rudder hinging - as outlined above.
* getting the fin square to the top of the fuse or tail plane - use strips of 6mm sq. balsa (covered in tape) clamped to the sides of the fin as a jig while the thick CA dries.
* use balsa instead of foam for the ribs
* use balsa reinforcement along the LE & TE of the wing to prevent 'bruising' & improve stiffness
* if you get a twist in the wing, 0.8mm carbon rod can be used to stiffen & straighten the wing
* use foam safe thick CA - gives a little more working time & a
small window of opportunity to re position components
* I also paint all critical joints with thinned
Weldbond (or similar acrylic PVA type glue).
* score the inside of any curved surfaces with the back of a scalpel blade to facilitate bending. Closeness of the scoring depends on the radius of curve required.