9.6. Specific tips for the MS Composit Hornet II

This is a very difficult kit to build. There are many tiny nearly invisible parts, so please be careful not to lose any parts! There are some parts which are too tight on the Hornet II. This is an explanation of the "enlarging the hole" trick used in many of the following Hornet II steps:

There are a few steps which involve CAing together two smooth plastic parts or a plastic part and a carbon fiber part. The CA will not adhere well to smooth parts, so you should roughen the areas to be glued with 400 grit sandpaper for better adhesion.

Making CA joints

Step 1 - Main Body Assembly:

The joint between the frame base (E402) and the frame support (E403) will be much stronger if you use 400 grit sandpaper to roughen the area underneath the frame support so the CA will stick better.

Step 2 - Tail Rotor:

Do not force the bearings onto the tail drive shaft (E417). If you try to force the bearings onto the shaft, the shaft may split. It is much better to use some 400 grit sandpaper to sand down the shaft slightly so the bearings will slide on.

Step 2 - Tail Rotor:

The pinion (E118) and the gear (E028) which are supposed to fit on the ends of the tail drive shaft (E417) have holes which are too small and the gears will get stuck halfway onto the shaft. Please use the "enlarging hole" trick so the pinion can be slid onto the shaft without becoming stuck. If you widen the hole too much, then the gear/pinion may slip. You can fix this by smearing some thin CA into the crack between the pinion and shaft AFTER you have put the gear/pinion on the shaft.

Step 2 - Tail Rotor:

The bell crank (E026) will not pivot smoothly on the tail gearbox (E425). There are multiple problems which must be fixed for this bell crank to pivot smoothly:

  • The bell crank is too tight on the tail gearbox. You will need to do three things to fix this problem:

    1. Polish the pivot pin with some extra-fine sandpaper (800 grit or better)

    2. Use the "enlarging hole" trick on the bellcrank pivot hole to enlarge it slightly.

    3. Use the "enlarging hole" trick on the bellcrank hole for the slider cage CP (E091). Be very careful enlarging this hole because it doesn't need to be enlarged much.

  • There are bits of flashing left on the tail gearbox (E425) in two places which rub against the bellcrank. These look like small circles. Use some masking tape to protect the bearings from the plastic dust, then use a small needle file to remove the flashing so the bellcrank (E026) pivots smoothly.

  • Use powdered graphite to lubricate the bellcrank pivot hole before using CA on the plastic retainer (E027).

Step 2 - Tail Rotor:

The holes in the tail hub (E431) are not tapped very well. Screw in a stainless steel M2 screw into both holes of the hub to clean up the threads before inserting the M2x8 bolts (E058).

Step 3 - Rotor Head Assembly:

At this point you will have six bearings: four 2x6x2.5 and two 2x6x2. Be sure to use the 2x6x2.5 for the main blade grips! The bearings look very similar!

Step 4 - Rotor Head Assembly:

Squirt some powdered graphite through the flybar hole in the stabilizer lever (E072) to reduce friction and allow the flybar to rotate smoothly.

Step 4 - Rotor Head Assembly:

Be sure to tighten the grub screw(E083) just enough so you can see a tiny gap between the stabilizer lever (E072) and the stabilizer bed (E073) on both sides. This will ensure the stabilizer lever pivots freely without rubbing against the stabilizer bed.

Step 5 - Rotor Head - Completion:

The ball link diagram labeled "2x" is incorrect. The diagram shows two short ball links connected by a bolt. The ball link labeled E021 should be a LONG ball link, not a short ball link.

Step 6 - Helicopter Construction:

There are two places in this step (4 and 14) where it calls the E419 the "Vertical Fin Holder". This is incorrect. It should read "Horizontal Fin Holder". There is no vertical fin holder.

Step 6 - Helicopter Construction:

If you glue the vertical fin to the tail boom, it will be difficult to remove when replacing the tail boom. I recommend drilling four 2mm holes in the vertical tail fin and using two nylon tiewraps to secure the tail fin to the tail boom without using CA.

Step 7 - RC Installation:

I recommend putting a piece of 1/8" or 3mm plywood underneath the front servo mount to give extra clearance to the servo arm. Additionally you should trim the same amount off the ball link to compensate for the raised servo.