Hi Guys,

I've built 2 Tiger 2's and here is what I have done so far. I ended up with an airplane that is still flying reliably after 3 years of continuous use.

1. That tail section is very weak in it's stock configuration, particularly the vertical fin attachment to the horizontal stabilizer, you may want to widen the horizontal stab center section by 10mm on each side, to give room for streamlined tri-stocks to attach on. The tri-stocks will strengthen the vertical fin attachment and will ensure that the vertical fin does not break easilly during handling and normal aerodynamic loads (i.e. while flying knife-edge). You would also need to widen the area on the vertical fin where the tri-stock will meet, to give the monokote some area to grab on to during covering. Attach the 3/4 x 3/4 inch tristocks on a location on the Vertical Fin where the "dorsal" butts-up with the fin leading edge. This will "lock" the vertical fin, horizontal fin and dorsal fin with maximum ridgidity.

2. Both vertical and horizontal stabs use 1/4x1/2 balsa sticks which have proven to flutter when performing high-speed/diving maneuvres, consider reinforcing them with 1/4" wide by 1/8" thick lite ply along the INSIDE perimeter of each panel (with the ply slightly soaked with thin CA to prevent delamination). This will give considerable strength with very little weight penalty.

3. Again, as reinforcement to the whole tailgroup, use basswood (or pine) tristocks to form a gusset between the ply stab platform underside and fuselage sides. Attach with EPOXY as you would do to the horizontal stab when attaching it to the stab platform. You'lle appreciate this modification once youve seen the whole tailgroup of a Tiger 2 come off during a high-speed dive!

4. WING - Those full-length 1/2 x 1/2 inch basswood spars are quite heavy and are not necessary on the outer halves of each wing panel. Consider using the basswood spars only on the center section of the wing, substitute 1/2 x 1/2 balsa sticks on the outboard side
of each wing banel. TAKE NOTE: You have to properly "spline" the balsa and the basswood spar so they attach solidly to each other.
Cut each part at an 8-degree angle so the glue-joint will be long enough to ensure that it is rigid. Position the joints such that they are covered by the shear webs for maximum strength. You'lle appreciate this mod in that it results to a better roll response.

5. WING JOINER- laminate some light ply to position itself between the upper and lower spars on the center section, this in turn will be "sandwiched" by the center spar joiners. The Tiger 2's wing center section is somewhat narrow and I did this mod so I could sleep better at night!

6. Landing Gear - whether you opt to have a tail dragger or tricycle gear layout, you will definitely have to strengthen the ribs where the gearblocks attach on to. I reinforced the stock rib with 1/8" thich ply (via tracing from the original rib) from the leading edge up to the part where the gear block attaches (the rest of the rib I left alone), and it also "locks" between the spars the same way the stock rib does. Those reinforcing plates that come with the kit are so badly cut that you would need to cut your own. I've seen stock Tiger2's "retract" their landing gear right throught the wing covering after a hard landing!

7. Ailerons - The ailerons have a notorious fluttering problem at high speed (when using the stock setup) and will definitely benefit from twin outboard aileron servos. I made my own aileron servo trays and located them at a rib bay that will position the aileron pushrods as closest to the aileron centers as possible (for maximum leverage and minimum aileron twist) I recommend robart 3/4" ball link control horns (the grey ones) for the ailerons and dubro swivel balls for the servo hook-up. This setup give minimum slop and a noticably better control response.

Depending on your style of flying, you would maybe want to modify the wingtips and wingspan as you discussed earlier. But the
Tiger 2 is such a sweet-handling airplane in it's original proportions (minus the weaknesses) that I didn't go that far. Reducing the dihedral does improve the tracking significantly (I also did the same!). You will end up with an airplane that tracks and behaves like a pattern plane yet lands so easy you'll forget you were flying a low winger to begin with! Good Luck!