bzyguy01

Just purchased a new Great Planes yak 54 and I have had a few problems with the elevator breaking. First flight lasted about two minutes as the elevator fluttered so bad it cracked both sides of the elevator. Put some pinholes in the covering and bled some thin CA into the wood to stiffen it up. Next flight I was sure it was ok as it was much stronger with the CA now but it did it again and this time the elevator completely broke off both sides and folded up to the vertical rudder and straight in she went completely destroying the craft and most parts. The plane was a total loss, the 4 cell 2100 lipo thunder power and the motor shaft and berrings were mangled, 3 of 4 HS55 Hitec servos stripped, Broke the nose cone and prop to boot. The only thing salvageable was the berg7 receiver and the great planes ESC. But I hate to fly with a receiver and ESC that have hit the groung this hard as the board or caps might have been harmed in the crash.
My friend that flies with me also purchased one of theese great planes yaks at the same time and decided to try his luck.....The same thing happened to his elevator after 5 minutes of flight time and he was able to save his as they did not fold up like mine did. There was another pilot at the park that had one as well but decided to take his home and add some carbon fiber into his elevator before his first flight.
The plane flew AWESOME!!! But the elevator needs a carbon fiber strip added. PLEASE do this to yours if you have one before its too late. You will love the way this plane flies. [:@]

bzyguy01

Just got word that another Member lost his Graet Planes Yak due to the exact same problem on 2nd flight. Thats a bad sign!

Tom_J

Yea I got one up and ready last thurs, tested it on the sat after, perfect taxi and takeoff, 1 click trim on ele and 1 click trim on ali, went up leg turned around and BAM the ele fluddered took out the servo and nosed in. Took out the esc also. I fired a note to the service dept at GP they told me I got a 90day warranty and to send the intire plane, receipt, and a copy of the note for another kit. Well don't that beat all, I'd have to cut off the wings with the band saw and stomp it a box to ship it. The cost of shipping alone would negate any freebee back from them. I thought there is a law regarding painless warranty. That ain't painless by any means. fyi. the Brio has the same prob, both the Brio and the Yak need wire supports at the tail to stop the fludder. To me it seems like a defect that they know about and don't want to take the time to re tool.

lionel2341

Question, I'm about to fly one this coming weekend. what actually broke. The 2 elevator halfs or the horizontal stab?? and how do you suggest it be fixed.

Thanks , Ernie

bzyguy01

Yeah Tom ...Don't that beat all! I took my plane into the hobby shop and they are waiting on a reply to what they are going to do about it.
I'm way to anxous to wait for them so I purchased a new kit the other day and decided to fix the tail issue myself. I purchased some flat carbon fiber peices and peeled the covering back to slice the balsa wood to make room for the carbon fiber spars. Once the spars were placed in the tail I used CA to adhere it all together and used an iron to put the factory covering right back on. I think that this simple fix will be the answer to the issue. I have taken a few pics to show you all what my answer to the fix is. I hope this helps you GP yak owners keep them in the air longer than my first one did!

bzyguy01

Oh Yeah...The Modafied elevator stab feels MUCH stronger and I actually put ALOT of pressure on it! I'll have it done tonight. I gotta give the credit to my buddy Paul Sheffeild as he is the master builder that did the fix for me as I was too bzy tinkering!


Check out the Veiw from the garage!! This is how every day should be!!!

bzyguy01

Ernie,
The previous post should answer your questions.... Good luck buddy. Post your success!

Shayne

bzyguy01

Ouchie!

bayoung

So you feel that the elevators are OK just the fixed Horizontal Stab needs the carbon?

Thanks,
Brad

bzyguy01

Brad,
I do beleive that the Horizontal stab is the only issue and the only thing needed modified. The elevators seem ok. The plane is not built like a tank but this is also why it flys so nice and has a great float. I've only got a few flights on this craft so it has not had the test of time yet but they all have a #! I'm not real easy on my planes....I tend to enjoy extremely fast flying and violent rolls and blenders w/power. Thats what makes me laugh I guess. Anyhow, the plane should be ok as it has held up to a few violent flights with the repairs I have made to mine.

lionel2341

Decided to go to the field today even though the wind was nutso. Flew the Mini PulseXT for about 5 minutes, but quickly landed. the wind was insane. Decided to do a taxi run with the new Yak 54 mini. just to see how she would handle a grass takeoff. My intension was not to take off but just ground handling, well, it handles pretty good, in fact it took off in about 6' surprised the HELL out of me. I took it for a loop and decided to do a couple of turns around the field. Wow this thing really flies good. can't wait for a good day, maybe tomorrow. Landed because of the heavy winds. hope to give it a good ringing out soon. But I'm impressed.

Ernie

lionel2341

Ok! got to fly today. no wind what so ever. Yak54 flew very well, however I found it a little slow using
the factory recommended rimfire 35-30-950 KV motor and 11.4.7 prop. With 2100/20C lipo. what are you guys using??

Higher KV Motors/Props???

I want to increase the flight speed IE: bigger prop/smaller pitch or smaller prop/higher pitch??

Don't get me wrong it flew nice but a little to slow for a 3D airplane.

Ernie

Doc Austin

I'm curious why the elevators didn't fail when Great Planes was testing the planes. They did test them, didn't they?

bzyguy01

lionel2341,
Are you using the 3 cell or a 4 cell? The yak was a good but slow flying plane with a 3 cell and it helped alot when I put in a 4 cell 2100 Thunder Power lipo. The plane has a very low wing loading weight and the flying characteristics were almost the exact same with the slightly heavier 4 cell.
I tried a few APC Slow fly props such as the recomended SF prop and even tried a "E" Prop. The Rimfire motor flew the best with the recommended SF prop by APC. BUT....The Hacker powered Yak flew the best on a 3 cell 2100 lipo and an APC"E" prop. The Hacker bird was much more impressive than the Rimfire powerd bird.
The Hacker was an A30 but I forget which # it was. I'll look at it later and post it.

bzyguy01

Good question! I think that they may have put some testing into effect but extensive testing.....No. Some birds may have come out of the box with a denser balsa than others and our production birds might have gotten the light stuff is all that I can imagine. Remember....Test birds are just that, one off test birds and not actual production models. they don't make a run of production models and then test them. They test them and then build production from there. And theres the chance to differ the products from test to production.

lionel2341

bzyguy01,

Thanks for the info, I'll do some playing around.

PS 3cell TP 2100

Ernie

bzyguy01

Yeah Lionel2341,
Its kinda boring with the 3 cell on the rimfire but better on the 4 cell. I gotta admit tho....I like my birds overpowered rather than under.

DaveH2

bzyguy01,

Did you ever check to see which motor it is that you're using? 16M?

Thanks,
Dave

bzyguy01

Hacker A30-22S To keep the weight down. Use an "E" prop instead if a "SF" with the Hacker as it flies great this way, Same size and pitch. You may have to try different pitches due to altitude.

DaveH2

Thanks.

airracer2004

My Feedback: (16)

Please check the area around where the engine box meets the fuse, I just saw one this morning on its 3rd flight and the engine box broke off clean at the fuse in level flight, plane belly flopped and only bent the landing gear, the engine and cowling was still intact, just not part of the plane,lol. It's fixable, but I thought I'd throw that little bit of info out here because this could have happened during harder manuvers and caused total crash damage!! I suggest putting some epoxy where the box meets the fuse.

WGRoper

My Feedback: (2)

I'm thinking of powering one of these machines with a Rimfire 1250 or 1450 so it'll bolt up to the factory mounts. The Hacker A30-22S is rated for 290 watts, the Rimfire 1250 is rated at 333 and the 1450 is rated at 388. Of course the 950 is rated at 296, which is more than the Hacker. Maybe Greatplanes is a little too optimistic in the motor specs?

I've got some 10C 2100 packs, I guess I'll have to get some 15C cells and make up a few more packs for this bird if I go with the 1250 or 1450.

Hacker specs - [link]http://www.hackerbrushless.com/motors_a30.shtml[/link]
Rimfire specs - [link]http://www.electrifly.com/motors/gpmg4505-35mm.html[/link]

aviationinfo

My Feedback: (3)

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bzyguy01

What does ... mean?

aviationinfo

My Feedback: (3)

I didn't know of another way to subscribe to the thread without typing something, so I just did the dots to avoid the usual dumb blather that escapes from my keyboard.

However, now that I'm here...on your CF reinforcements---they are stiff pieces of CF, right? I have some floppy iron-on CF that becomes rigid when you put CA on it. I'd rather use that and then not have to do too much to the wood to get it to fit on smoothly. What do you think? Is one stronger than the other?

Thanks.