Hi Guys. I FINALLY finished mt DP Extra ARC. It ended up at 16 Lbs 1 Oz using the BME 50 and 1400/1100 battery packs. I did not spend alot of time trying to lighten it and built it exactly per the instruction book. I assume it will fly just fine at that weight. It is balancing around 5 3/4 with no weight added. I figure I will fly it here and move the Rx battery back until I like it.
Here is my question. I am at the point of setting it up. DP calls for 0-0-0 incidence. I figured the wings do not adjust so I will set the stabs to the wings. The problem I am having is that the wings at the root are 1 1/2 degree different and about 3 deg different at the tip. I guess this means that they are misadjusted and warped. I know I can not do much about the twist, but should I saw off the locator blocks in the fuse and realign the roots? And if so, what do I use as my datum. Is it safe to assume the firewall is set at zero. Any help will be appreciated. I will try to post pics later. Thanks in advance, cbk

Finally Done!!

cbk07,

Surprised there have not been any responses to your thread yet.

I find your discovery of a "wash-out" in the main wing interesting.

I'm sure other present, or soon to be, owners of the DP330L will too.

Your main wing may not necessarily be "misadjusted and warped".

If both wings have the exact same twist, it may be by design to provide a little bit more time for you the pilot to avoid that "point of no return" during an unintended stall condition at slow speeds.

In Wolfgang Langewiesche's famous book, Stick and Rudder, he wrote,

"By various arrangements designers make sure that, as the airplane is slowed up, the stall will progressively spread along the wing from the wing root toward the wing tip, rather than occuring perhaps at the tip first. Thus when the ship is all slowed up and the center part of the wing span is already stalled, the wing tips still have a reserve to lift which the ailerons can "get". The simplest way to achieve this is "wash-out", a twist of the wing that makes the wing tip ride always at (a) flatter Angle of Attack than the wing root."

""Wash-out". The wing tip is set at a lower angle of incidence than the the wing root. If the airplane's Angle of Attack is increased, the wing root will reach stalling angle first. The stall will thus extend out to the ailerons and the wing tips only if the pilot then pulls the stick back even more."

__________
Joe B.
[email protected]

I am presently completely one of the 330 L ARFs. Upon initial inspection, I had one wing that was warped! It was my right panel. If you look down the leading edge, it had a warp to it! No question about it. The trailing edge was perfect! The left panel was perfect! So, upon trying to iron the warp out, stare the warp out, and want to jump up and down to get it out, I also noticed that the right panel was thinner than the left! I finally removed the covering on the right panel, to find a nice warp, and lots of sanding by a factory worker! The panel was sanded so much, the sheeting was very thin. It was about an 1/8 of an inch difference in thickness or just under. Maybe it would not have mattered, but you know what, it bothered the heck out of me! Here is what I did: I cut into the wings leading edge and part of the sheeting, corrected the warp, and reinforced. It was at the 2nd or 3rd rib from the tip, so I added a shearweb and extra fiberglass ect. to reinforce my cut. Now the right wing was perfectly straight as the left panel. I next added some 1/32 sheeting to the top and bottom of the right panel. Yes, I added a little weight, and had to rip all the covering off the right panel. Yes, Im crazy! But it worked! I had to do some sanding, and fitting, but now I have two perfectly straight and strong wing panels. I realize no ARF is perfect, but that dont mean you have to settle for warped panels. I could have had them replaced, but customer service at Dave Patricks is very slow to respond. So I took matters into my own hands. Oh yeah, my stab tube was not mounted quite right either. I cut it, and repositioned, and added spacers and glued back together. Now the stab is in perfect alignment with the wing.

Now for the clincher! I have fitted a Zenoah G-45 Rock to my airplane, per Dave Patricks OK! Yes it is on the heavy side, but it sure does look sweet! Its the only engine I had, and have been wanting to use it for something! (other than a paper weight!) According to Dave Patrick models, CA hinges, and the Zenoah G-45 will be OK. (I put 5 CA hinges in ea. Elevator half, 8 CA hinges in each aileron, and 5 CA hinges in the rudder) So, Im going with it! I would put the robart hingepoints in, but you know these arfs, not enough trailing edge for proper glueing without modifying. By now, I have done all the "mods" Im going to do. Im using Hitec 945s on the elevators, Hitec 5645 digitals on the ailerons and rudder. Good luck with yours and wish me luck with mine! (Im gonna need it! ha!ha!) By the way, dont try to change my mind on the G-45, as this is what I have, and this is whats gonna fly her! Ive been hearing you need extra weight up front to balance anyway! I should not need any extra!