Posted by raz |
Jul 30, 2012 @ 04:29 PM | 3,433 Views
I am currently on my 5th BD-5 which this one is the HK version but since the AW & HK both share the same nasty issues the fix is the same for both models. One problem has been they were all pitch sensitive, like the full size. Another has been wanting to climb at full throttle and if you trimmed it there it had a lot of down elevator which made part throttle flying challenging and the last is wanting to shoot back to the ground (hard and fast) while trying to take off and I am happy to say all these bad habits are gone! I borrowed a friends incidence meter and after getting the rear stab level (0 degrees) I checked the wing and it had 3 degrees positive which is quite a bit and the motor thrust angle was minus 1 degree. I cut the firewall off 1" to shorten it for an out-runner and angled the motor so it's aligned with the stab now at 0 degrees so it no longer tries to push the nose up and I lowered the leading edge of the wing by 1/8" which gave the wing 1/2 degree + incidence and I put on smaller main wheels and added some weight to the nose. Now it takes off like it should and doesn't try to smack the ground again and after setting the trim it no longer tries to climb under full power, it just goes faster but stays level. Adding the 3/4 oz of weight to the nose set the COG a little farther forward than the directions call for but it totally cured the pitch sensitivity issue.
Posted by raz |
May 17, 2008 @ 05:26 PM | 13,033 Views
OK so here's how I did my clipped wing. I already had made ailerons and I wanted a little bit of wing left to extend past the ailerons, mostly to help protect the ailerons from hanger rash. After determining where I was going to cut on one end I marked it and using a thin razor knife sliced through the foam cutting off one tip. I then used that tip as a pattern to know exactly where to cut the opposite tip. After cutting off both tips I used some 200 grit sand paper to smooth the tips out and repainted. You can see how much the old paint had faded already in the last picture. I was going to cut the tips at an angle but decide to leave them square. A beveled cut would have made the small piece of fixed wing by the ailerons very weak and too easy to break off. I still may cut them at an angle at a later time depending on how it flies. With the wing clipped I lost 13 grams of weight and a total of 6.5" in wing length. In the overhead shot you can see the CF flat bar to keep the wing flat and strong. With some luck I'll get to try the new wing out this evening and will report back on how (or IF) it flies.
Posted by raz |
Jan 10, 2008 @ 01:01 AM | 16,298 Views
I'm not too good at "write ups" but here's how I made my ailerons. First I marked the ailerons out loosely basing it off my Cessna wing so the aileron measures 12" long X 1 1/4" wide. Then I carefully cut them out using a razor knife, it worked best in a sawing motion. Then I cut the under side of the wing and aileron at an angle so they could move up and down without binding. Next was I sanded all the cut areas with 220 grit paper to help smooth them out and also the areas that will be taped. I used a single strip of 'hinge tape' then to hold each aileron in place on the top of the wing then installed the control horns 1" in from the edge using foam safe CA to hold them in. When mounting the servos you want as straight of a shot to the control horn as possible. I marked out the servo locations in the thickest part of the wing then carved them out with the razor knife plus a valley for the wires to be inlaid in the wing. I used hot glue to hold each servo in place and clear packing tape to cover the wires so the wing would still be smooth plus no loose wires hanging down. The last step was to Z bend a small piece of piano wire on one end (aileron side) and the other end went into a Du-Bro mini EZ connector on the servo horn. Then plug in the harness to the rx and power up the tx with the aileron trim at neutral make sure the ailerons are even with the wing and tighten the set screw. Like I said I'm not good at write ups so I may have forgotten some things but I'm sure you get the idea. Now when my Pixie comes in I need to replace the planes servos, esc & rx but thats the easy part.
If your wing is painted (like mine was) make sure to remove all the paint before applying the tape or glue or it won't stick. After taping I repainted the wing.