jantrit

I have recently been looking for a nice 3d plane that I can mess about and have fun with. I picked the extreme flight yak 55 because I have always wanted to try a profile and thought it seemed a good place to start.
The set up:
- standard futaba servos (as I have them lying around, will I need something with more torque?)
-Sc 52 two stroke with (was going to go with an os 46LA but really don't think it will have enough power)
-Ar7000 2.4 with Dx7

The arf arrived yesterday, and like a kid on christmas I couldn't wait to get the box open and have a look. The outside shipping box was torn and crumpled in places but the contents were in perfect condition. Examining each piece of the kit I was very pleased with the quality of the kit, the fuse seems slightly week but having never owned a profile before I don't have anything to make a fair comparison with. If any body has any suggestions or questions they would be greatly appreciated.

Michael

jantrit

I have made a start on the build today. The covering was great but I went around the edges with the iron anyway to just make sure everything was stuck down nicely.
The first task was to remove the covering from the fuse for the horizontal stab, servos and wing. Once the covering was removed I sealed around the edges with the iron to prevent any of the covering coming away from the newly cut edges. The horizontal stab was then placed in the fuse and lined up, drawing on the guides for removing the covering. I then Installed the horn into the elevator with 30 min epoxy and have left it to cure.

Michael

jantrit

Today I started by epoxying in the horizontal stab and then hinging the elevator. Make sure you slot the elevator in BEFORE you glue in the stab, or you will not be able to get the elevator through (don't ask me how I know [:@] lol). I then epoxyed in the vertical stabilizer and and control horn on the rudder. The tail wheel assembly was then installed and the rudder was then hinged.
I have planned to use futaba standard ball raced servos, will they have enough torque for the job?

Michael

BountyHunter51

Just a tip. I built one of these for a friend recently. The fit of the wing into the fuse was very tigh and would push most of the epoxy out of the joint.
In hindsight, I would insert the wing first, then apply the epoxy through the inside of the fuse between the sides. The bottom of the fuse doesn't yet have the covering applied, and would be easy access. I would peel back the covering on top of the fuse and apply the epoxy the same way.
I hope that this helps, Cheers! BH

jantrit

Bounty, unfortunately I couldn't find a way to get the epoxy around the carbon tubes on both the top and the bottom, I did manage to use the wing openings to apply some epoxy to the inside or the fuse. I slid the fuse over the opening and spread some epoxy in that way. I have found it very difficult to get the control linkages set up and the ball links are extremely tight on the push rods, should i just cut some of the threaded section of the rods off to bring the complete linkages down to size?
I will add some pics tomorrow, this plane is looking sweet can't wait to get it in the air.

BountyHunter51

The ball links were very tight (Ihad forgotten about that). So tight in fact, that one of the pushrods snapped before it was threaded in far enough. You might tap out the ball links or drill them out just a tiny bit. I wouldn't shorten the threads any.
Also, when you attach the fuel tank, be mindful of the carbon reinforcement rods that run the legnth of the fuse. The first hole drilled in the fuse was into one of the tubes.
Cheers! BH

jantrit

I have found that by drilling out the ball links very slightly they are much easier to put on without compromising on strength.
All radio gear is now in and I have set up the linkages to the elevator and rudder. Pics will come soon.

michael

jantrit

Its all basically finished. Today I made up the aileron linkages and installed them, I also installed the Os 46 and tank, with this set up its going to need alot of weight upfront to balance, so I will probably be changing to a bigger engine at some point in the not to distant future. All that is needed is to balance it and test run the engine.

Michael

BountyHunter51

The Saito 82 seems to be a good choice for this plane. My friend's plane flies well on it.

Cheers! BH

jantrit

I was looking at the thunder tiger [link=http://www.sussex-model-centre.co.uk/shopexd.asp?id=944]F91s[/link] its a bit heavier than the satio, but should have good power, and is a lot cheaper which is helpful with my budget.

ArcherIIDriver

I am curious to see what you think of this plane with the .46 LA and the standard servos. How much weight are you using to balance it with that light engine? I am using an OS 55AX mounted all the way forward and I am still concerned that I will need lead up front to balance.

I am just wrapping up assembly on mine, but have to wait until my DX7 gets back from Horizon Service before I can complete the control linkage setup. Just an FYI - I have read of many instances where the factory pushrods/ball links have failed so I made my own out of carbon fiber, 4-40 rod, and du-bro HD ball links...just to be safe.

I look forward to your flight report!

jantrit

Just got back in from testing the engine, it feels like it has a fair amount of power, trying to pull out of my hand at full power when held vertical, unfortunately a prop hang at this throttle would leave nothing for the pull out lol, I will most likely be getting another engine soon, or putting in the Sc52 from my wildcard. I believe it balanced with about 125 grams of lead right out on the nose. I have a feeling this model is going to become a favorite of mine. The flight report will be in about a week, as I am away from tomorrow till next friday, and I don't want to maiden this thing anywhere but the club field.

Michael

flygilmore

Wow, of all the planes to pick for your first profile. Most guys start out with something like a Mojo etc and then work there way up to the Chinn Yak. It, (and rightfully so) has been deemed prob. the most manueverable profile ever! Set up right, it will fly very smoothly and in a nanosecond, chew it's own tail off with the right thumbs. One of its favorite manuevers is the Yak-Off @ 2ft. off the deck on take off You might as well forget the .46LA you were talking about [sm=drowning.gif] wont even come close to powering this bird the way it was meant to be flown. Do yourself a favor and get a Saito .82 #1 choice, OS .55AX #2 choice or a very strong .46 with a MCP-anything less and you will never unleash the potential of the airframe.

jantrit

Planning to maiden her on sunday if the weather is nice. Flygilmore, the 46 is really just to get her into the air and fly around to start with not expecting it to 3D, an engine upgrade has always really been on the cards.

Michael

RWP

My Feedback: (2)

This is my first Profile also and I'm have a ball with it. Have a Saito .82 on mine.
I'd also like to try a Mojo when they get the ARF back in stock.

jantrit

Well as the weather seemed better today, than the forcast for tomorrow of rain (welcome to the great British summer) so the maiden was brought forward a day. Got to the field and it was nice weather, if a little windy. got the Yak out and it started up perfectly, did a range check and taxied out to the end of the strip, the wind was blowing straight down the long grass strip so I had plenty of runway to get it of the ground. I throttled up and she rolled out and rotated, leaving the ground and heading skywards. Once up I did a few circuits and went WOT to test the vertical, as expected with this engine it climbed, slowly stopped and dropped out. I then went around to try a slow loop, and thats where it all went wrong, the engine cut out as it rounded the top inverted and the plane started to drop, heading for the plowed fields, I made several S curves to loose speed as I was quickly approaching the end of the strip but on the last leg of the curve she dropped a wing and hit from about 6 feet or so. The fuse cracked a little just after the trailing edge of the wing, the gear bent and the rudder servo had its gears stripped. I think the crash was mainly caused by my moment of panic after the dead stick and bad decisions there after. It was only some of the ply that cracked, the carbon tubes look to have held up fine, she will hopefully be back up in the air shortly, was defiantly the sweetest plane I have ever flown while it was up there.

Michael

ArcherIIDriver

Sorry to hear that. Might as well upgrade that engine now!

I maidened mine on Sunday also...sweet flying plane for sure. Unlimited vertical with the OS .55AX, snd it was slobbery rich for break-in.

Hope you get yours back in the air soon! Keep us posted.

jantrit

Sweet if you have some, stick some pics up, this goes for all EF chinn owners who are watching. Yeah the plan is to get a SC90 four stroke for it soon, as I figured I could also use this engine in some future planes, or to stick the SC52 two stroke that I have in my wildcard in it, anybody have any thoughts or suggestions on this?

Michael

redflyboy122

My Feedback: (1)

so is a a saito .91 too much for the airframe and cg range. i have one laying around and it would be fun i think?

majupo2

i think a .91 anything would be wayyy too much engine for this plane. a buddy of mine at the flying field has the older "extreme flight yak" profile and has a saito 82 in it. spins a 14x4 W APC prop and its ballistic!!

redflyboy122

My Feedback: (1)

thats what i was afraid of. what would the ultimate 2 stroke be for this plane. i have several os .46 engines but i heard that this was marginal power?

RWP

My Feedback: (2)

I'd try the .91 since you have one. I had to move my .82 as far forward as I could and still have to use a heavy prop nut to get it to balance so the .91 might be about right.

MetallicaJunkie

a 46ax would cut it, or a super tiger 50

KWJ48

I have a saito 91 on mine. The balance is good, and has insane power. Really too much for this plane, but the way a lot of them have been coming out tail heavy it works for me. I put my battery in the forward wing and started at the recomended forward CG. I have been moving the battery back as I get use to it.

jantrit

I will be sticking the SC 91 in when I get round to ordering it, looking forward to the power

Michael