Dave Patrick 330L Aileron Flutter
 

I appreciate all the info! I really appreciate C Earnest's coments that there are more out there flying than there are problem planes. That does make me feel a bit better.

There is something that worries me about my plane. Somewhere in this thread, someone stated that their ailerons only had partial bracing in only part of their ailerons. I checked mine, and they have NONE! This is an area that worries me. I do want to go with a gas engine, and I know that even though I know better, sometime or another I am going to open that puppy up! I want to have faith in my plane and my equipment, so I may be cutting into the bottom of the ailerons, adding bracing, and also adding an addition servo. This is a gorgeous plane and I have heard that it flies great, so I am really excited about it. I'd hate to fall victim of the flutter monster and think afterwards " if I had only done this or that!"

in mine....
 

In my ailerons, between each two adjacent "ribs" (in each compartment?) there is a single brace positioned diagonally....

Dave Patrick 330L Aileron Flutter
 

Mine does not have the diagonal bracing. I fly with a Taurus 2.6. I used 8411's with metal arms, carbon pushrods and the stock control horn. No flutter.

-Ben

Ailerons
 

Mine doesn't have any cross bracing either.

Ben Diss: I don't fly IMAC or full throttle down lines (not that any routine calls for it) and have never tried to blow one apart so I don't know, but I've seen others do it with catastrophic results. You never know who you are talking to online, nor how they fly.

Shortman: I have a recently broken in (good running) Moki 2.10 and purchased the $40.00 Mejzlik prop per the posters mention, expecting the same or similar performance. I tried it. Have you? Mine won't do what his does. I joked that his must be on steroids!!! Shortman, if you have the same combo, or know anyone else who does, besides that guy in the video, that performs like that, film it and submit to us please!! (with a note containing your secret modifications) Ha!

Razorback: There are definitely more trouble free DP Extras out there than ones with problems. I've seen others fly full throttle with no problems.

JW

Dave Patrick 330L Aileron Flutter
 

Interesting enough I called DP and spoke to them about some kits with and others without diagonal bracing. They told me that this was not something they were aware of and did not know how it could be? FWIW - Mine does not have diagonal bracing and according to a post I started others with successful Extra's don;t have bracing.

Just FWIW

they don't know?
 

DP doesn't know that some kits have bracing? Did I get that right?

I'll try to take a pic of it thru the ultracote....May have to shine a bright light thru it to show the brace.

Dave Patrick 330L Aileron Flutter
 

Mine has diagonal diagonal braces outside of the stock servos only. There are no cross braces inboard of the stock servo.

I also have dual 5625's on each wing so I don't blow up my airplane if my left thumb slips.....

Haven't flown it yet because the BME 44 wouldn't start. I think I have that figured out, so a "pucker" flight should be on the horizon.

Dave Patrick 330L Aileron Flutter
 

That's what they say...?

First Flights on Dp Extra
 

I flew my new Extra this weekend for the first few flights and must say this is one great flying plane. I was fortunate and read alot about this plane on this forum and made the appropriate mods before I flew the plane.

My plane came with the cross bracing in the ailerons. I uncovered them on the bottom and installed x-bracing and added 1/2" balsa blocks to use robart hinges. I also uncovered the bottom of the wing from the trailing edge to the spar and installed the 1/2" blocking on the trailing edge. While I was in there I also CA'd everything in site.

On the fuse since I was installing a ZDZ40 (which runs great also) I reinforced the engine box with basswood triangles at all corners using epoxy. Very stiff. I also CA'd or epoxied everything in site in the fuse also. Call it preemptive insurance.

I used single Hitec 5645's on the ailerons and a single on the rudder with JR 7005's on the elevators. Used carbon fiber rods with titanium 4-40 links on each end. Used the Sullivan horns supplied with the kit all around.

It weighs 14.5 lbs less fuel. Balance was 6 1/4". The elevator is sensitive. I may put some nose weight in it to see how it reacts.

The ZDZ40 had one tank of fuel through it on the bench. This thing idles lower than any gas engine I have seen and puts out great top end power. I am using a 20 x 10 initially with intentions of going to a 21 or 22 x 8 after about ten flights to give the engine time to run a little. I had no trouble with the throttle or choke linkage as some have complained about. Only trouble is starting with inverted engine. It is very easy to flood. Now that I have that figured out, it's no problem. I used the Amelung muffler like Dick Hanson has shown on his website. Relatively quiet and fits the cowl well.

I had reservations about using full throttle on this plane after all I read on this site, but my mods must have helped cause I can use any throttle setting and I get no hint of flutter. The Hitecs are strong and I am sure that helps.

I fly with some guys that fly 1/3rd scale and 40% scale aerobatic planes with 3W's and DA's and they all commented how well the engine ran and the how the plane flew BIG. Very stable, very responsive ( too much on elevator). I am using the full 3D throws with exponential and the thing does not snap out at low speeds. I was able to do very small positive and negative loops. It lands like a dream. It actually slows down too much.

I am very satisfied with my plane/engine combo. With the mods discussed I think this plane with give good service for the dollar.

Jeff

Dave Patrick 330L Aileron Flutter
 

Hi Jeff,

I'm glad to hear your first flights went well.
There typically isn't a "hint", that's what's so devastating about flutter. There is no warning and then bam! It's great to hear yours didn't have flutter.
I've been curious how that muffler performs. If you get some numbers on it with your 20X10 or a 22X8, it would be very interesting to hear.
My experience is that the elevator is sensitive at about any CG, even on low rates....which leads to my next question.
Are you saying you're not using dual rates? I can't imagine flying that plane, when not doing 3D, with 3D throws no matter how much exponential you're using. I was using 60% expo with 3D rates and 30% with low rates(as per the book) and the plane was still sensitive in pitch(6.25" CG just like you, but it was also pitch sensitive at 5.75"). If you really are using just 3D rates, even with expo, I would recommend setting up low rates for most flying. It will be much "safer" and flying "normal" maneuvers is bound to be smoother, more precise, and much easier.

Dave Patrick 330L Aileron Flutter
 

I'm really pumped about my DP 330L! I plan on doing most of the mods that have been listed here. ( Rather be safe than sorry!) Will definitely be going gas also. After everything that I've read about it, it sounds like a great plane (as long as you can keep it together) Thanks for all the input and words of encouragement. I'll let everyone know if there is a success story here or another uh-oh. Wish me luck!

Huge elevator isn't it!
 

Sorry to venture away from the original thread content but I too have that oversensitive elevator and I'm at 70% expo and afraid to add more...(never been there). I was going to move my CG forward from 6.375" but after Bill's reply I'm probably best just reducing my throws. Maybe should move forward anyway, I'm pulling to the wheels in knife-edge. Oh yeah, don't land too slow...this baby will fall on all 3 wheels in ground effect,,,bent my stock gear easily. Need to expo my throttle so I can find a happy landing RPM, I breath on my stick and get a 500rpm increase like right now with the Taurus.
Jack

First Flights on Dp Extra
 

Bill Pryor, I haven't tached the engine since the first tank on a test stand, but was turning a zinger 20 x 10 at 6500 rpm. As soon as I think to check it I will let you know. It is much quieter than your average Bisson or JA muffler. I know one thing, this ZDZ40 will melt a silicone header in 3 flights.

I am flying with the full 3D throws but I am using 75% expo and I like a very sensitive plane typically. Most people I let fly my planes don't like how sensitive I set them up. I tried dual rates and it doesn't provide the feel I prefer. The only problem is an acute sensitivity just off center of the throw on the sticks. My Airtronics Stylus has VTR which I haven't tried yet.

Dave Patrick 330L Aileron Flutter
 

I flew my plane this weekend for the first time and wow. Its a beauty. I flew it 3 times, with the low rates and everything . went fine except for the touchy elevators. Then on the last flight i had a gust of up wind when landing and landed the thing pretty hard. Hard enough to bend the stock landing gears, and the tail wheel. I just placed an order for some carbon gears. They should be here on Friday, just in time to take it out this weekend :D . when placing the order. I had talked to Rosa about some of the problems that people here were experiencing on the carbon fiber gears. She said "they were now much stronger than before." Hope shes right. Before i mount it on my plane i will give it the "Santi test" and put some pressure on them to make sure they will not snap. OK enough about the gears. Anyway. Thanks for all who helped me out on this project. Much was appreciated. Cant wait to fly it again this weekend. :D

Santi

Carbon gear
 

Where did you order the gear from?

Dave Patrick 330L Aileron Flutter
 

the website is www.troybuiltmodels.com But i called and talked with Rosa to place my order. TNT also carries them also. I looked into TNT gears and i heard that theres wasn't any lighters than the stocks on the DP. I really need to shed some weight on my Plane. since i dun up the floorboard and inst. panels from hangar nine.

Santi

Graphtec
 

Graphtec makes em for Troy. Since troy doesn't handle custom orders or returns, I'd go to graphtec. you'll find their info on the Troy web page.

Dave Patrick 330L Aileron Flutter
 

I can't remember who asked about a picture of my second aileron servo installation, but here it is.

Dave Patrick 330L Aileron Flutter
 

Can you reduce it so it will be accepted by the website?

Dave Patrick 330L Aileron Flutter
 

Never mind :) It just came up!

Second Servo
 

Did you have to take in consideration the length of the push rods? In other words, do they both have to be the same?

Dave Patrick 330L Aileron Flutter
 

My outboard pushrods are considerably shorter than the stock ones. The wing is so much more narrow out where the second servo is that it's impossible to use the same pushrod length.

new post
 

I know this is an old thread, but thought I would check on the progress of Dave getting his plane replaced. If there is/was a design problem with the DP 300L, I could see him replacing kits if the suggested engines and support equipment were used. What I don't understand is that if the designer/manufacturer suggests not to use a certain motor, and you go ahead and use that or a similar motor and something fails, how is it his fault, or even if it is, how do you prove it, since the plane wasn't set up as suggested.

Dave Patrick 330L Aileron Flutter
 

mine is of the 1st batch and still going strong:

http://www.davepatrickmodels.com/frame.htm

Dave Patrick 330L Aileron Flutter
 

Mine too. One servo on each aileron. No problems.