I too, am having serious problems with the wing cabanes. 2nd flight, and the screws that hole the steel brackets were backing out. After dissasembly, (at home) I applies some aliphatic resin to ALL the wood screws on the plane. After a close inspection after the following flight, I couldnt believe my eyes! The steel brackets on the front cabane were cracked and seperated, and the one of the rear steel brackets was cracked too! The problem is quite obvious, GP has neglected to take into account the affects of high frequency vibration. Large olanes use large motors, and this vibration is unavoidable. Certainly, I balance my props and noticed no unuseual vibration on this model. I can only be thankfull it didnt go in like some of the others have/will. I designed a machined piece, that will replace the crappy little steel brackets that come with the kit. Also, I will have to cut the wing open, to make sure the supporting structure will support a slighty larger cabane mount. What a shame this was overlooked by GP. It kind of makes you wonder if they bother to test fly their stuff before it goes to market. Im bugged by this.

Harris,
I can assure you not only are our models test flown, they are test flown heavily, repeatedly, and with a large range of power plants.

Please advise what engine are you running in the aircraft?

This is the ONLY engine size we recommend based upon that testing:

Engine: 1.6-2.7 (26-45cc) 2-stroke
OR 2.5 cu in (41cc) gasoline/oil mix
OR FT300 (OSMG1250) 4-stroke

Ann, Im running an OS BGX on the Pitts. The prop has been balanced, and fits snugly on the prop shaft. First flights were with an 18/12, but later I switched to an 20/6-10. I mean no disrespect with this statement, but feel you will hearing more wing seperation stories now that warmer weather is here. As I stated before, I am having machined parts made that will replace those steel brackets. Since I have a strong desire for a "lasting relationship" with the Pitts, I am going to open up the upper wing to inspect the construction and see if it is adequate to support a modified cabane brace. I think the GP Pitts is beautifully finished. Its light and appears strong, but the affects of high frequency vibration cannot be underestimated. This plane is 1 of many giant scale models Ive owned over many years, and all the mishaps I experianced could be traced to high frequency vibration, specifically with the center sections of fuses. I wish you luck and sucess with this model.

Harris , I read your post and am glad you have given the benefit of your experience.I am in Australia and have the only G.P. Pitts sold here so far.I am assembling the aircraft right now and have been following all posts regarding this plane . My plan is to run an Air Hobbies 4.6 cui Thompson Trophy twin in this plane! After reading the post about cabane mounting problems and top wing failure i am convinced i'm going to have to strip the covering from the top wing and strengthen the cabane mounts.I also plan to resheet the centre section with one piece of aircraft ply sheeting so there are no joins in the top wing sheeting at all. What do you think? Also when i was assembling the lower wing i have fibreglassed the centre join with 3oz cloth and polyester resin.I know i am adding weight and the wing loading will be up there , but i figure i have more than enough power to offset this if the aircraft will hang together! I guess when the G.P Pitts was designed and tested they didn't have an engine in mind that would try to rip the wings off! I however have different plans. I know people will comlpain that there shouldn't be any problems if the aircraft is used within the manufacturers design specifications , but i feel if your putting one of these together you shouldn't be afraid to modify the design if you think that the structure isnt up to YOUR standards.Forget about what anybody else thinks , it's your plane , engine and radio gear that's at risk at the end of the day , not to mention the safety of innocent bystanders ! I don't care about complaining to a maufacturer if something goes wrong , after all it's my experience or inexperience that will make or break it! I'd rather rely on factual reporting on strengths or weaknesses from fellow aeromodellers at the end of the day to guide me on which way to go when building or assembling any model. So thanks again Harris as without people like you , people like me would end up finding out the hard way. When i finish the model i intend to have no mercy with g forces. I will post pics of my assembly / modifications so that people can decide wether they like what i've done or not.If i come up with anything that i think is a major safety issue i'll certainly post it on R/C Universe , after all thats what it's all about anyway isn't it?

Awesome,
Respectfully, that much power in this aircraft simply makes no sense. Please realize that, unless you're a structural engineer, there are many areas of the structure you may not realize are going to need structural attention to avoid failure as a result of your choice of powerplants. This model is intended for up to a 2.7, and your 4.1 SINGLE is going to shake the beegeebers out of this aircraft.

So while you may feel comfortable modifying your model in this manner, I can't encourage you strongly enough not to recommend such modifications as many modelers who might assume that this much power must be required based upon your post will likely NOT have the ability/know how to redesign the bird for this type of use.

in regard to the above statement concearning gas engines:

why do manufacturers fail to realize the wide availability of engines there are to purchase ( or already purchased and waiting to find a home), and why are these planes not desgned to handle these choices? you recomend ONLY a 2.5(41cc) gas engine for this plane. how about a g-45 for an example: 2.7 (45cc) is this not recomended then? who makes a 41cc soley for use in the pitts? other choices could be the brison and bmes 3.2. considerably lighter than say the g-45 so a better choice. or how about the DA 50 even, soon to hit the market. and im sure others are compareable. (anyone stuff a G-62 in one yet )

it just seems planes like this are introduced to make a buck and not to meet the consumer's stasfaction or needs. it really burns me up - like now. large companys should be working to push the hobby foward and make developments for the better of the hobby

I was going to purchase one, but not now. No GP arfs for me

Hubb

Hi Annmarie , Respectfully, in relpy I am running a 4.6 cui Twin engine in this plane. Its an opposed design that has MUCH less vibration than a single cylinder large cui engine. Why do i need this much power? I have flown and raced some large scale bipes before and i just can't seem to get enough! I guess i'm just a horsepower junkie. Anyway , if you read my post you'd probably pick that i'm not too concerned about manufacturers warranties as i'm modifying the design and hence have no warranty claim anyway. I just think that when you release a kit or A.R.F. that you might as well face facts that someone is going to push the envelope re:design and power plant choice , remember you pays your money you makes your choice. As well i'm in Australia and i really don't think it would be worth my while sending a broken plane O.S. for manufacturers inspection if i modded it , broke it and wanted to cry foul , do you? I'm a manufacturer / designer in the automotive trade and i know only too well the liabilty laws and resonsibilities that go with producing a saleable product. I just think that i'll go my own way one this aircraft and take a little advice from my friends , who knows we might all benefit from experience if we're prepared to be open minded.

Hubb,
The aircraft are extensively tested with engines within a specific range, and then engine choices are made based upon that. The models are tested with engines well above what we are calling for, and the need for ballast, vibration, etc help us determine the desired range.

Believe me, excluding engines intentionally does no good for us, as it only decreases the marketability as you just described, so it is not done to be intentionally exclusive....it is done based upon the model's flight performance in the manner we have to assume an AVERAGE modeler will fly the aircraft (ie WFO dives, etc).

Awesome,
I understand your direction completely.

As you're in a similar industry, you surely understand that we have to set our power recommendations after having done very extensive testing with the model flown as an "average" sport pilot will fly it and ensure the model holds up structurally, etc, and is safe, etc to ship in that configuration.

It being a twin will be far easier on the aircraft (sorry I thought that was a big single. ... gulp!), but that much power in the hands of someone who is not prepared to modify/set it up for it is scary for us as a manufacturer...

Like your professional attitude AnneMarie , (got the caps right this time!) It's refreshing to see a manufacturers rep. who is prepared to accept that some of us are going to do exactly what the company doesn't want us to do ! I think with people like you at the front line Great Planes could do a LOT worse. (compliment)
Anyway this aussie black sheep will give feedback on the product in question if it helps. Thanks for being so cool! Leon.

As a newbie who only has the skill and facilties to build ARF's and not kits, I understand that we are at the mercy of the suppliers to ensure that the quality of the ARF is 100% pre- sales verified. However, as an engineer, I understand that when I have been given specifications for a machine, I stick to these specifications like glue and will not deviate without prior consent of the manufacturer...in the industry that I work in, deviating from the rules can kill. Another way to look at it, I will not buy a device rated for 240v then modify it to suit 110v for here in the US....that would be crazy! Therefore why would I modify an ARF outwith the specifications of the manufacturer then add a bigger engine just because you are "a horsepower junkie"? Yes, R/C is a hobby, R/C can still kill!

Anyway, I'm not trying to put folk's backs up..

Happy Flying!
Flying Scotsman

Holy moly Awesome!! A 4.6?? And the guys here thought I was nuts!! Based on your post, you obviously have much knowlage on what your doing. I would prop that motor really hard for max torque, not speed. Plan on doing some reinforcing on the cabane mounting and wing struts. I used some 1/4 ply triangles and glass on the lower wing mounts in the fuse. You also may want to consider useing ball links on all the flying surfaces, instead of clevises. With that much power, I would definately can the ca hinges, and use a good quality giant scale hinge on all the surfaces. Although I didnt pin the hinges on this model, I do on super high performance models. My technique is to drill holes, and glue in toothpics. I then just cut them off close as possible, and machine the toothpics flush with the surface with a good sharp dremel cutter. A small square of monokote ironed in place, and you have a surface that wont pull out. BTW- Before i got into doing that, I had a few ailerons and elevater halves pull out, doing high speed power dives. No fun at all!!!

Hi ALL, I have been flying for 22yrs and I am only 28. I live her on the beautiful island of Guam where their is flying weather all year round. I was an Apache crew chief in the Army, so you are right about specifications in that aspect, but in this hobby in my experience. I have found that the engines a manufacturer recommendes flies the plane, but thats it. Some of us pilots need a little more. As for the G.P. Pitts I will be putting a Brisson 3.2 in it. it is lighter then the G45 and the US 41, but in turn has more power. I believe this will give me almost unlimited vertical. In my opinion it is better to have more power then not enough. You don't have to stay in specs all your life, have a little fun. Its ok to bend the rules now and then as long as know one gets hurt. As for the 4.6 WOOOOW. That is over kill. Hay, good luck anyway. I know I wouldnt mind watching it fly.
Best regards to all.
Duayne

Duayne:
You may not be able to watch since your on Guam, but I'm sure
you'll feel the impact shock waves. Sorta like your pet Gooney
Bird coming in for touch-down.

Randy

Hi annmarie this is larryboccio I'm sending you my plane you will see that the spar did sperate due to lack of glue. I follow all steps to the tee. i use the fpe 2.4 engine and had 7 flights in three weekends without mishap. myself and others wintess the failure of the upper wing. and the cement use in the construction isn't epoxy . please tell me what kind of glue. i'm a carpenter and it looks like hot glue. i'm sorry if its not. but whatever it is there wasn't enought apply in my opinon. I been using your products for years and i am happy custormer. please look at my plane , it sure be there by thursday. thanks a bunch .

hi guys:
i am running a g-62 in mine with no trouble so far, i will definatley check these area's on my plane, one thing i noticed on the cabane & interplane strut'swas that the bend in the mounting brackets was incorrect, after the first flight they were all loose, i bent the brackets to the right angle, applied more ca to holes, remounted them & i have made about 3 more flights with no problem. the vibration is worrying me, i will install ch ingnition to help this but i will check the area's metioned above!!! thanks

AnneMarie,

It is so nice having a manufacturer rep involved in the discussions on this website. I applaud the professional manner in which you addressed some on these questions and comments. I too am in sales and I understand the frustration that you can have as a rep when someone has negative comments on your product.

I wish that all manufacturers had representation on this site. It would had a different perspective to comments that are made on RC products. There is a gentleman from Creekhobbies that is introducing a new line of 1/4 scale planes from China Models who has been involved in several threads on his models. I found this to be very helpful.

It has been my experience that no matter how much you test a product, you will never test it as a consumer will. You need to remember that your testing with professionals that get paid to work in this hobby. Many of them were probably the ones who design the planes. Put it in the hands of a joe shmoe consumer who participates in this hobby once a week and you will get an entirely different perspective. It is here where problems and questions will arise that you may never have though of. Creek Hobbies has done and is doing an excellent job in addressing these unforseen issues.

Someone mentioned in another post that RC magazines are becoming a secondary source of information for this hobby. That the internet and sites like RC Universe, are the primary source. I can not agree with this more. Have you ever read a review in an RC magazine that had negative comments? Well Actually RC Report does a good job of telling the truth. Lets face it, it is the manufacturers that are paying for the ads that support the magazines. If you post a negative review, that manufacturer may threat to pull advertising. That is not to say I do not subscribe in RC Mags, because I get them all, but I would really like to hear more honest comments about how a plane, engine or radio is. Not all planes stall smoothly dropping the nose with a slight wing drop, yet most of the reviews that you read give this as a characteristic. I have a WM 40size Cap 232 that will snap like a monster if you let it get to slow.

Anyway, AnneMarie, keep up the good work. I look forward to reading your comments throughout this site.

ZXX,
thanks so much for your kind words!

Folks, if I may, please do not make assumptions of what we do and don't do to test models. The testing our aircraft go through is VERY extensive, including using local modelers, a variety of VERY skilled pilots who can not only say "something's not right" but exactly what and how to fix it, etc.

Trust me, I know what the pitts went through. (My husband is one of the test pilots, i get to hear the stories! :-) And i can stake my name, and reputation, on the level of testing multiple copies of that model endured without breaking a sweat, including production aircraft.

The solution to your 'problem' is to have modelers with the first name "Jerry" also test fly your production planes....

Jerry




Well you have to admit, it was worth a try

Out of curiosity does GP/Tower/Hobbico et. al. test the models they sell with only the engines that are available through GP/Tower/Hobbico et. al.?

It seems to me that if you tested the Pitts with the 41cc gas engine it looks suspiciously like you used the US Engines 41. Now I know you like to sell your planes with the motor you also sell (vertical integration at it's best ) but I have to wonder if you use engines OTHER than the ones someone would buy through Tower Hobbies.

What about the other gas engines out there? Brison, DA, Fuji, Zenoah? I think you know a lot of us are NOT fans of the US Engine ( I had one and frankly, it sucked IMO) I think that most of the guys that are going to buy this Pitts are going to get their engines elsewhere rather than Tower. (not meant to slam you but Tower is not know for giant scale anything)

I must admit I had looked at this Pitts quite seriously but since I finished my Eagle (http://www.geocities.com/jbrundt/eagle.html) the NEED to get one has waned. But I might like to get one of your Pitts' in the future and I'd like to feel confident it was a well put together airplane. Giant Scale ARF's are still relatively new to the scene. I only hope the manufactureres of these big planes are cognizant of the stresses they can be subjected to and build them accordingly. I have seen many a modeler progress from 60 size planes to giant scale but still use the techniques they used on their smaller planes in their big brothers. This will NOT work. Giant planes need to be constructed more stringently with stronger glue joints and stress areas properly reinforced.

I'll get off my soap box now, but this is something I feel quite strongly about. Giant scale ARF's are going to allow folks that aren't quite ready for a giant plane to start much sooner and perhaps bypass some critical learning steps. So therefore the manufacturer HAS to make sure their plane is purposely overbuilt to survive the 'rough' handling it may see.

just my .02 cents....

Jeff

Certainly, your comments comparing 60 size with giant scale are true. Im a big fan of lots of horsepower. There is of course, no substitute for power. When you build a plane from a kit, its easy to make modifications to accomodate extra power. With an ARF, its not too easy, but still possible/practicle to make some mods. I have this to say about GP's Pitts. There really isnt any reason to over-power it. That plane is SUPER lite, and performs fantantisticly with an OS BGX. Want more? How about a big MOKI? Larger gas motors will shake that model to pieces. I had a 1/3 scale Pitts that had a wingspan 2 inches less than GP's Pitts. It was scratch built from "Scratch-a plane" plans. It weighed in at a whopping 22 lbs, with a Sach's 4.2. A tad tricky landing, but barring that, the model flew great! Hmmmm, 22 lbs vs about 14, and the GP version is a tad bigger! My GP Pitts has unlimited verticle with a 20" x6-10 prop. If you chose a big gasser for this plane, look out below!! It appears to this meager reporter, a large glow powerplant is plenty for this plane.

I just bought the Pitts and now this! I kinda feel like when I was a little kid and brought a puppy home from a friends house. I really wanted this puppy but my mom made me take it back. I was thinking about putting the ZDZ 40 in it. What do you guys think about that? To much/not enough? I have a Byron Christen Eagle that I'm afraid to build because of gas and foam. I bought this Pitts so I could put a gasser in it. Hey GP, wanna buy my Pitts back? Also, this is for the guy who is putting the 4.6 in his. I think you will be blowing more than just wings off.....maybe something like.....O'......the RED off the Monokote

HI all

hi all
iiii spoke to gp yesterday and they were very helpful
today i shipped pitts next day air they will have it tomorrow.
i plan on calling them end of day. i will keep you inform.
also thanks for everyones input. i glad someone posted my problem on rc universe. thanks again

I got a GP Pitts ordered and I can't wait for it to get here. I will put it together very carefully as I always do on any ARF. I will pay particular attention to the mounting of the struts and make sure everything is tight and secure.

Most of the failures that I have seen on ARF's have been from poor assembly. I am not trying to criticize anyone who has had a problem. Things do happen. It is just an observation that I have made.

I will also not have a vibration problem being that mine will be powered with brushless electric. It will have plenty of power but will not be overpowered.

I am looking forward to many enjoyable flights with a good airplane. Read the review in RC Report and see what they think of the kit. How many do you think are out there flying that haven't failed. Remember they don't come assembled and that is a big variable in the success of an ARF.