Sunday, January 27, 2008

Not my day...

You know its not your day when....

Strike one. Raptor 50 "ops i did it again on autorotation". Last flight in the morning auto landing, misjudge height pull up too late.

Strike 2. Salto madien flight less than 5mins. Horrible tip stall from 5 storey high. Tried to pull out, it went down like an arrow, no chance. Cracked fuselage, canopy , V-tail reaped off.

Strike 3. Shark fin soup anyone? After having a blast with Le fish, someone decided to have some shark fin soup. Flying wing came along sliced off the fin.

Not forgetting the hit i got on my head from a fellow sloper's balsa glider. Ouch.

0wn3d. GG NO RE THX.

Thursday, January 24, 2008

Le fuse

The fuselage was sanded to fish shape earlier on, its time to add in the internal electronics. All the electronics will be buried inside the fuselage with the battery to rx connectors outside. The fuselage is strengthen with 3 pieces of CF rods. The rudder, elevator servos are placed one on each side for balance.

Rough layout

Mark out the lines and start dremeling

Everything was measured as precise as i could and dremel out. Turned out nice and clean.

Goop in the stuff

Close up. The elevator servo will be connected to the Rx just before gluing the halves together.

The tail felt quite weak, added some CF strips for reinforcement.

3M77 was used to glue the halves together. The battery connector to RX sticking out for on-off and charging.

Tried on the wings and it seems there is no way i can squeeze those connectors into the fuse. Will cut a slot near the wings for them later.


2 piece of filament tape across the fuse on each side first.

Tape the edges with smaller pieces of bi-directional tape to get around the curves

Finish up with tape running vertically.

Prepare the Elevator halves for connection
Drill hole and sand in a ditch for the torque rod

Make sure they fit nice n tight

There were reports of horizontal stab cracking easily so glassed it with 3/4oz cloth. Squeeze out as much epoxy as i could to keep the weight out. Vertical stab was also glassed.

Almost there...

Monday, January 14, 2008

Le wings

Been bz building and hoping to complete the fish soon for a slope trip, its nearly complete so a quick update. After shaping the fuselage, i proceed to work on the wings.

Electronics going into the fish. HS85mg x 4 , CC Berg 4 rx and 4xAA eneloop pack

Tape the alierons on and cut away the excess length.

Measure aileron servo location. Mark out location.

Dremel out the foam. Use a piece of masking tape as depth indicator.

Pot in the servos with epoxy and cling wrap.


Before taping up the wings, its time to toughen up the epp. The best way i learned from RCGroups is to apply thinned goop(TG) . TG to epp is like epoxy to wood, it adds a rubbery like coating that bonds the epp beads together making it much stronger. My first time trying this out and found out that it really works, the epp is much tougher, yet remain flexible and bounce back to shape. Apply too much however will add weight.

Here's what needed, Goop, Goop-off which acts as a solvent for goop, glass jar and foam brush.

Squeeze some goop into the glass jar, pour the solvent and start mixing till u get syrup like consistency.

Apply to the epp with foam brush. Solvent in jar will evaporate off quickly so add more solvent to maintain consistency. The fumes are not so good for the body, do it in well ventilated area.

See the film of thinned goop when i tried to peel off the masking tape. It sticks to epp really well. Add more coats for strength.

To keep the weight down, i applied 2 coats TG only to the leading edge and wing tips. It takes about a day or two to dry completely.

Taping the wings

At this point, its time to tape the wings.

Been looking for bi directional FG tape, finally found it at Its about SGD20 a roll and free delivery!, definitely much stronger than the normal unidirection filament tape.

3M 77 is first sprayed over area before taping. Tape is layered on smoothly and not stretched so that wing will not warp. I m quite concerned about adding too much weight so only keep the taping to key areas.

First taped a layer length wise top and bottom across the center to cover the spar area. Then a whole piece over the LE. Then also at the TE. Center the servos and goop them in and slice a path for the servo leads. Tape over the sliced paths.

Tape up the wing tips.

Add some X strips.
At this point, the wings still feels abit flexible around the center so added a few more pieces of tape.

Top of wing

Finish up with another coat of TG. The whitish parts are the TG areas after its dried. Wings feel stiff now span wise, but torsional stiffness still not as good. It should better after its covered.

A thicker layer applied at the tips to fill up the gaps.

Wings done, tackle the fuse next.