Dave Patrick Extra 330L
 

I'm putting the finishing touches on my new DP Extra.This is the new version with the removable foward hatch,and the option of 2 servos per wing.I have been hearing nightmares of aileron flutter in the older versions of this aircraft.
I would like to know if anyone has flown a new version and what servos they are using and linkage.Also if anyone has experienced any flutter I would like to know.
I have equipped mine with a BME 50 and JR 4721's and changed the control linkages to 4/40.I'm hung between staying with one servo per wing or running two.
Any advice and input will be greatly appreciated.
Thanks for your time!!
Jason

Dave Patrick Extra 330L
 

I have the older version plane but i have since then purchased the new wings with the dual servo option the older fuse. I had to purchase new wings because i had a mishap due to pilot error. Not due to aileron flutter. I didn't want to spend the time to rebuild the wings so i ordered new ones. I did the cross bracing on the ailerons with 1/8 inch balsa sheet and installed robart pin points on the ailerons. I have 1 each hi-tec 5945 servos with carbon fiber pushrods per ailerons. I have 7 flights on the new wings and no sign of flutter. If you have done the mods on strengthening your ailerons such as sheeting or adding cross braces then you shouldn't have a problem. Hope this helps. Keep us posted on how the first few flights went. good luck.

Santi

Dave Patrick Extra 330L
 

i have the older one with 1-jr8411 155 oz at 4.8 volts. i am running 6 volts and not a hint of flutter; make sure you have the linkage set up correctly. look at some of the 33-35 % planes out there that are only running one good strong servo and bigger ailerons. I have seen full passes with full throttle and not a hint of flutter. i didn't try to make the plane into a race horse, but i did full throttle passes to see if i would have any problems. i am running a 3.2 brison gasers on mine so speed is not what i or the plane are after. Have someone look over all when the fly day is there........

ailerons
 

Hi guys,

Santi- did you ad 1/8" sheeting to top and bottom of your ailerons? I added 1/32" sheeting to top and bottom of mine. My DP extra is from the second batch. This has greatly strengthend the ailerons, and I have no flex. The airplane has not yet flown, but is getting closer. It does add extra weight by sheeting them, but I hope its worth it. As you know, I used the robart points for the ailerons, and rudder, Im still thinking about how to hinge the elevators. Ive been out of town for a while, and have not rehinged them yet.

Simply 3D-
Not sure about the new DPs, but I would check the ailerons for flex. Of course, if you put two servos per wing, it may not be necessary to add the sheeting????

Dave Patrick Extra 330L
 

flymyplane,
These are the new set of wings. They didnt have any kind of braces to keep em from flexing. So I used 1/8" balsa sheet and made cross braces on each of the aileron bays. Didint sheet em like the last set i did before i crashed em. I have also used Robart pin points on the ailerons.
Now for the elevators. I used Kleet hinges, 4 each side. There were two that i had to trim so they wouldnt hit the tube socket.
I also used pin points on my rudder. I had to do some ripping apart to get the blocks back there. But well worth it. I have no kind of flutter on any of the surfaces. Even on full throttle passes. :surprised

Santi

hinging
 

Santi,

Thanks for the tips! I decided to try the robarts for the elevators. I cut three down to a half inch, with one section of barb left (one side of hinge point only!) I sunk it into the stab to the spar tube. I put a total of 5 robart hinges per stab half, three cut down, and two full size. I feel pretty good about it, I think it should work out fine. They are in there very good! Much better than the CA hinges! Anyway, I did not add any wood blocks to the stabs, I may to the elevators not sure yet, as I have not yet glued the elevators in. When Im done, it will have robart hinge points all around. I have contemplated about this for quite a while, and put a lot of thought into it. It seems to me that as long as you get a good amount of glue to the hinge, these hinges will not pull out. I let the stabs sit with hinge side down while drying, so the glue will pool around the hinge. I also added some balsa filler within the epoxy to thickin it a little.