CaseySP's blog archive for October, 2010 - RC Groups
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Archive for October, 2010
Posted by CaseySP | Oct 16, 2010 @ 05:12 PM | 8,587 Views
This is my second Alfa MiG15. I enjoyed the first one so much, that after the demise of the MiG21, I couldn't help myself. If there is a better looking, better flying small EDF, I haven't yet seen it.

This one was built using the tips and tricks from my first build, as well as lessons learnt along 2 and a bit years of flying my first one.

In my first one I used a single aileron servo, a HS-81 to ensure there was good torque to handle the (potential) speed as well as ensure decent centering over a 9g servo. The single servo made aligning the ailerons (especially the recommended 2mm of reflex) a pain, differential all but impossible and the servo took up valuable space inside the fuselage.

This time around I found some ultra thin servos from HK which fit inside the wing nicely. Once the control rods are removed from the wing the weight gain is minimal, only 1g heavier then using a single 9g servo or 6.6g lighter then the single HS-81 of my old MiG 15. And all with the ease of setting up a two servo wing plus the ability to use differential.

Next step is to glue the wings on. Here I used a similar method to last time. First and absolutely critical is to remove the paint from the fuselage join area. I use methylated spirits. Next, rough the surface up a little with fine sandpaper to remove the glossy finish from the Alfa mold. Then lots and lots of little holes (approx .5mm) are pricked into the foam at the join area to really key the glue into. Give the metal wing...Continue Reading
Posted by CaseySP | Oct 11, 2010 @ 03:55 PM | 8,396 Views
Having been meaning to post this for some time. Sadly the model is no longer flying.

The MiG21 is an old favorite of mine. I remember building a plastic 1/72 Airfix kit long ago as a young boy. I was toying up with either ordering a new Alfa MiG15 to replace my old worn-out example (almost 100 flights at the time) or the newly released MiG21. The MiG21 won this time around.

Onto the build.

[Photos 6 & 7] First step was to fit a bungee hook. I don't hand launch and the MiG21 won't ROG like the Alfa MiG15 due to the scale sub-fin. The hook is a 1.5mm piece of chromed wire glued to a plate made out of 3 laminations of the 3mm ply Alfa wrapped the box in. The wire is bent to a "U" shape, with a longer end forming the hook. The plate is drilled through for both ends of the wire, grooved (for the wire to rest in), shaped to the fuselage/duct curve, and fitted with 6mm depron front and rear streamlining pieces to make a teardrop shape (in plan view at least).

I chose a spot on the fuse between the nose and the CG - about 1/3 from the nose. It happens to be in the centre of a service panel moulding.

[Photos 8 & 9] Wing spar and servo framework (wing box) was then built. The die cutting is more die squashing, so the fit of parts is a bit ordinary particularly compared to the latest laser cutting. I tacked the bit in place with CA then built up some fillets with a bit of PU for strength. The wings have very slight andihedral, so the spar must...Continue Reading