dphill2

My Feedback: (1)

Just thought I would throw my DB in the Ring as I have been flying it in SPA and CPA events. It has spring air RT and a NovaRossi R60F.
I use a stock Nova Rossi Pipe and header in CPA and Old Rossi Muffler in SPA. I don't normally fly ARFs but this one is a great airplane and the Nova Rossi seems to have all the power it needs. The airplane is just under 8 lbs ....

computermonkey

My Feedback: (90)

Mine came in at 8.5lbs with stock landing gear, Moki 61 LS and JETT gold tuned muffler.

jgracco

I am not sure about the ARF but if the ARF version is similar to the original kit build, you wont fit a 16oz tank. I have to look but I seem to recall a 12 oz tank was fine. I never got into trouble with running out of fuel.

JimDFlyer

David,
Thanks to all for their insight on this plane. Your thoughts on the 55 AX powered, lighter version mirror mine. Almost everyone commenting here and on thread on RC Groups have changed the fuel tank to a 12-16 oz to acommodate the 61-65 engines and most mention putting at least 2 oz of lead in the tail. It seems like there is about a pound difference in weight. The 55 AX is rated at 1.68 bhp and the 65 AX is rated at 1.73 bhp. This makes the 55 AX about 97% of the 65's bhp, with these numbers based on OS specs. Recommended prop size is about 1" less on the 55, which is an advantage in ground clearance. Loss would be in torque, which might be apparent in vertical. I'm not sure if I will try SPA competition or use this as a sweet sport plane, but I think I will build with the 55 AX as light as possible. I think it will be easier to "up-size" the engine later rather than go smaller. The physical size of the 55 AX is dramatically smaller than the 61 SF or the 75 AX.
I will continue to follow here and RCG and much appreciate all of the help on this thread. That's what makes this such a great activity.
Jim

Skylane

My Feedback: (3)

I'm flying mine with an OS 61SF-P with a Macs muffler. I use a 12 oz tank moved back into the radio compartment nearer the cg. I'm running an APC 12x8 on 15% Omega and getting about 10,800 rpm. I did add some lead to the tail (about 4 oz) to get the cg far enough back for my style of flying. This combination is wonderful and I have had great success with it flying the Expert pattern in SPA. The weight is 7.5 pounds. I have had a lot of experience with the OS 55AX in earlier planes. I ran one in a Cutlass (7 lbs) when flying SPA Sportsman and had great success. When I moved to Expert and put the 55 AX in a 7 pound Compensator I had trouble with the Top Hat - I ran out of steam on the upper corners and they became too sharp. I also had trouble maintaining heading and altitude on the top part of the maneuver - the airspeed was just too low. I went to an 11x7 three-blade and removed the inner cone on the 55AX muffler. This added nearly 500 rpm and I had better luck with the Top Hat, but it still wasn't enough. The OS91 four strokes will pull verticals out of sight and I was getting beaten by them. I put one in the Compensator and my scores improved. Later, I put an OS 61SF in (they use the same bolt holes) and I was in heaven. Plenty of vertical and I was able to go back to a 2 stroke! The Compensator is also now 7.5 lbs. So, would a 55AX work on a DB ARF. Sure. How well it would do in competition is another question. You could most likely fly Novice or Sportsman SPA with it. But if you need vertical performance as in the Expert pattern you will be disappointed.

Jeff

computermonkey

My Feedback: (90)

I used a Sullivan 16oz cylindrical tank (S414)in mine DB

doxilia

My Feedback: (3)

Jim,

I'm just over analyzing things a bit from a technical standpoint. At the end of the day we build with what makes us happy and like you say, you can always change your engine - particularly easy with an ARF that has a separate cowl.

Jeff,

you raise some good points. I can see how the Cutlass would have done well at 7 lbs with the 55. It is a smaller airframe than the Compensator and also has less drag in its airfoils what with them being ~2% thinner. I suspect the Cutlass can even be built to 6.5 lbs with a few changes in frame up. I tend of think of 700 squares as the upper limit to "50" sized power with anything over that calling for 60 size power. But weight and drag both also matter so vertical performance for a given power plant can vary between one design and another - even if they have the same mass.

I have plans to build a modified Cutlass with a Webra 50 for power which is even lighter than the OS 55 and NR 50. My goal is for a 6.5 model dry and 8 oz tank (and provision for an additional 4 oz header tank if desired) so we'll see how that turns out when I get down to it.

David

JimDFlyer

Jeff,
Thanks for your thoughtful and helpful input. I think my plan makes even more sense given your experience. If I build the DB ARF with the 55 AX I should have a great flying sport plane that will be capable of getting me started in pattern as a novice. My old club in PA had a history of pattern flyers (Tony Frankowiak was a founding member many years ago) and there are several pattern flyers in the club recently I joined in Hot Springs (Mike Harrison) who can mentor me in precision flying. I have a Tower Kaos that I have been flying for years and got an Extreme Flight Vanquist E a few years ago that is capable pattern plane and a joy to fly. I also have a Joe Bridi kit for a 60 sized "Killer Kaos", which is the plane originally planned for the OS 61 SF-P. I prefer precision aerobatics to 3D for sure, and now that I'm retired I have time to focus on that. I have been very impressed with the video of the Dirty Birdy in flight.
Jim

Skylane

My Feedback: (3)

The DB and the 55AX should do well for learning the entry-level pattern maneuvers. I'm sure that you will enjoy it. If you ever feel the need for more power, remember that you can pull the inner cone from the stock 55AX muffler and gain almost 500 rpm. You will be amazed at what a Master Airscrew 3-blade 11x7 will do on that engine. It is like lighting an afterburner. Those are two simple techniques that do not require airframe mods or rebalancing. A Jett muffler will provide even more of a boost. Good luck with your DB.

Jeff

Skylane

My Feedback: (3)

David,

Sounds like a great plan for the Cutlass. I originally has an OS 61FX in mine but it required a lot of lead in the tail to get it to balance. When I switched to the 55AX the total weight dropped by almost a pound since with the lighter engine I could remove most of the tail weight. It flew much better that way.

Jeff

TOYMAKER

My Feedback: (6)

I see a lot of people like this plane but I have had nothing but frustration so far.

I purchased my kit from a LHD and on inspection of the kit discovered a crushed fuse behind the wing saddle area. I also noted that the control surfaces were all off center about 3/32", NOT good.
Back to the LHD and they reordered me a new ARF. On inspection of the new kit we discovered the same issue with the hinged control surfaces off center about 1/16". They checked another kit there and said I wouldn't want that one either as the control surfaces were off center even worse. Being the optimist I took the kit home and proceeded to re-glue all the control surfaces, problem fixed. Glued the wing together (BTW... what is with using a 1/8" aluminum spar... way over kill. I took out the aluminum one and used 1/8" lt 5ply surfaced with 5mil c.fiber on both sides weights half as much and probably just as strong) and set up the stab and bang...another blow. This fuse was so warped the stab/fin to wing was over an 1" off level. Needless to say I emailed Great Planes over a week ago. No response so I called the tech line. He told me that air support would get back to me... still waiting. Is this a late production issue or has anyone else seen this problem? Seems a bit on the heavy side too.
I have flown these in the past and was really looking forward to having one again and flying in SPA... I may have to find an original kit and build it the way it is supposed to be built.

computermonkey

My Feedback: (90)

My first DB was a fuselage was a little warped too. Lesson learned, add glue to the landing gear blocks. Mine came out and took out half the elevator. Anyway my new DW I had to cut the ailerons and reglue also. I haven't had a chance to see if this fuselage is warped or not.

jet22b

TOYMAKER;
Sorry to hear about your frustration with the Dirty Birdy ARF!!
If you still want to build a Dirty Birdy, check out the link below.
http://bridiairplanes.com/hangar/dirtybirdy60.html
I have two and they both was spot on with the tail!!
Hope this help!!
Sonny
aka
jet22b

Tony Iannucelli

My Feedback: (193)

Hi Toymaker. Sorry to hear about your problems with the Dirty Birdy. That's unacceptable for a relatively expensive plane that is touted for precision flight. I must have been really lucky getting the one I got from Tower because mine built and flies really well. Zero problems.

I have done business with Tower since 1975. They are the best hobby company to deal with along with Horizon and a couple of others. That being said, you should email them and attach the pictures. I'd bet you get a new kit. It's pretty obvious to me you are an experienced modeler and even if you were a rookie, there's no way you could mess up that glass fuselage.

Please try. You don't have anything to lose by trying. Best of luck. ----Tony Iannucelli

TOYMAKER

My Feedback: (6)

Hey Tony,

It is just a shady job of inspection I'm sure. I have scratch built many airplanes since the 70's My last pattern plane I built in the 70's was a Trouble Maker. I currently build my own 2 meter planes and fly them the masters class of AMA.
I was hoping to get a straight enough airplane to fly the Expert class in SPA.
Hopefully Great Planes will recognize the issue and make due. Otherwise its get the heat gun out and try to correct this one.
There are plenty of other suppliers out there...such a shame you pay a premium price for this kit and it's not close to the quality of 90% of the arfs out there.

Wayne Galligan

WRM

ALL of the DB, I have seen are twisted and warped ( at least 10 are 12 of them ) . When I go to square the DB it is way off, and you will have to shim the horizontal stab on both sides . The Wing is off to one side and is way off on the incidence . The ailerons and elevators are off center . The fire wall was right on at 2 degrees down. Can you believe it. They got one right. What went wrong? If you do call , you get their standard answer . (This is the first we have heard of this.) Don't bother calling Tower, Tower does not care. Just give me the money and don't bother me.

TOYMAKER

My Feedback: (6)

Well Great Planes finally came through after a few phone calls. They sent me a new fuse and stab... but no stab tubes...go figure.
I was able to ge tmost of the twist out of the fuse by heating it with my Monocote heat gun and twisting it past center a little bit. This seemed to fix the twist at the time. It has gone back a little since I have flown it a few times, I will have to reheat and try again to see if it will set more permanent.

I electrified this one. First motor a, Turnigy G60 400kv, I tried didn't have the getup-n-go that I needed. So I upped to a Turnigy G60 500kv and 75amp Castle controller, 5cell 4500mil Hobby People battery and now I have the power I need. After several props a regular 14x12 APC pattern prop cut down to the specified 13.5" limit seemed to work best. Has plenty of pull and speed. Now its a competitive plane. I moved rudder servo to back as it was nose heavy. Even the rearward recommended cg is to far forward. With a tail dragger I can eliminate some nose weight. Maybe even move the motor back a tad if trimming the cowling will allow.
I had to get used to ballistic pattern flying all over again after flying 2 meter electrics at a much slower pace.
I think I will build a lighter wing and make it a tail dragger with this new fuse I have now.
Big Bird (electric Pentathalon EVO) and e-Dirty Birdy
battery slides down into a square tube I built through the retract bay, speed controller fits nicely behind firewall in retract bay
Spinner has a lightened back plate so cutting the nose off allows air into motor, air slots in cheeks of cowl
rudder moved to a rearward position, I left rudder push rod in and just connected up to front to retain nose wheel steering

keithtsr

My Feedback: (3)

I have two of them. They both fly great...guess I'm lucky. But I will say I think I'm over it. I'm headed back to electric I think.....so if anyone is interested I would make them a smoken deal on a one or both....both have Nova Rossi speed 13 in them.

jet22b

I built three of the Dirty Birdy back in the 70's. Two had the Nova Ross .61 in the nose and number 3 had a Webra .61. All three was a joy to fly!! They flew like it was on rails. The ARF just don't have that. I still hope one day I will run across a kit or a set of plans at a swap -meet. I did love the old Dirty Birdy!!!
Sonny
aka
jet22b

Timthetoolman1

My Feedback: (6)

Toymaker, all of them I have seen are messed up and everyone that I know that called the manufacturers got the same surprised response. If you're flying 2 meter I can see why you're upset. Mine has messed off centered hinges too. I'll end up using it as a practice plane.

I have a new wing and stab made and thought about putting it on the ARF but I figured why go through the trouble with a fuselage like this. I use the same layups as the 2 meter planes with the sandwich construction so I can get a 13 oz fuselage that is really stiff.

But in reality these are sport planes for the general public, I don't think we can require the precision we are use to putting in our own builds.

The CG really works better around 6-3/4", not the 5-13/16" they suggest...this also indicates its for the general public, to me anyway.

I mounted 3 servos in the tail which gave me 3 oz but I still had to add another 2 oz to the tail.

It should fly be able to fly the Expert pattern ok but you will have to learn it's little quirks.

One other warning is the fuselage material. If you can bend the fuselage by heating it then you probably already know this but it's not epoxy. After laughing at my buddy saying his has dents in the fuselage from leaving it in the cradle in the heat I did the same thing and now I too have dents in the fuselage. The only thing I have found that sticks well to the inside of the fuselage is Hysol. We tested epoxy and CA and they didn't work well.

I think the Phoenix 7 was much better built but then again they're ARFs and you can't expect too much. I did end up getting the weight down to 7 lbs 4 oz.

Tim

crankpin

My Feedback: (15)

Not good news on the DB - ARF. Has the QC been corrected ?

Crank

Timthetoolman1

My Feedback: (6)

I don't think so. I was warned of the issues before I bought it and purchased it around May or June so it's still an issue.

8178

My Feedback: (17)

Something happened today in the jet community that has be a long time coming with the cheap, poorly designed and built Chinese jet ARFs. The worst manufacturer of the jet ARF aircraft that have been falling apart the most in flight were banned by the CD at Florida Jets and the CD at Best of The West meet. These are the big, big jet meets and the ruling will most likely spread to other meets, club flying, etc.

Even though these ARFs are pretty much junk they cost major big dollars and these rulings will have a huge impact on the people that bought the defective ARFs. It is really a dumb situation because it has been going on for a couple of years and widely known that they are junk. But dumb people kept buying them. These are usually direct sales from China to the US.

The complaints about the poor quality of the pattern ARFs here sound somewhat like the early days of the jet guys complaining about their jet ARFs. Hopefully if the Chinese keep sending junk ARF pattern airframes to the US the same thing will happen at pattern meets and maybe in the end the Chinese and the companies that import them will get the message.

How does that go, fool me once, shame on you, fool me twice shame on me.

Skylane

My Feedback: (3)

Well, be that as it may, there have been many DBs successfully flown at SPA meets over the past few years with few complaints. I have over 225 flights on mine and many 1st place finishes with it in Senior Expert. It is not unusual to see 5-7 of these at a contest. So, at least some folks are having good fortune with theirs. The whole issue is rather perplexing since I have seen so many examples of this ARF be flown quite successfully.

Jeff

Ralph White

I guess we are lucky also. My son and I love the way our DB flies. About 300 flights on it. Built it completely stock with a Rossi Speed 13 in it. Checked on radar at 143 mph. Flies like it's on a rail with unlimited vertical. Flies the classic pattern maneuvers perfectly. Only problem we have had is keeping the nose gear retract working. Too many vibs for the electric retract nose gear. Wires kept breaking. Had to put in a mechanical retract unit. Electric retracts in wing have held up very well.

Ralph White
Neoga, IL