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Old Dec 18, 2006, 06:33 PM
"How old are you?"
Brummeh's Avatar
Brum, U.K.
Joined Feb 2006
544 Posts
Well, My full-fuse Yak is in the bin and a new ul-Yak is coming together...

Its just over 34" ws and i want to get it flying before xmas..


Mike
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Old Jan 12, 2007, 01:24 AM
Registered User
Joined Jul 2006
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Your Yak turned out very nice indeed. [B]
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Old Jan 12, 2007, 08:07 AM
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Joined Jun 2004
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Quote:
Originally Posted by KAWE
Your Yak turned out very nice indeed. [B]
Thank you, my friend.
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Old Jan 18, 2007, 10:23 AM
Flagstaff, AZ
dawsonh's Avatar
USA, AZ, Flagstaff
Joined Mar 2003
3,837 Posts
Another Yak

Here is my Yak, version 3. I came out at just under 4.5 ounces with a MicroDan F3P motor and PQ 2S 300 pack. I used Pull-Pull on everything ("pull pull the simple way on the ailerons).

I got a short flight with it yesterday in my back yard in TOO much wind... IT FLEW! I even got it down in one piece (and not stuck in a tree). I hope to get a better test flight when I got to the NAU Dome this morning. I will let you know how things worked out.

This is my second effort in F3P. My Kestrel has been beaten to death and does not fly that well anymore... so I am have to have a "precison" aircraft again.

Dawson
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Old Jan 18, 2007, 02:22 PM
Flagstaff, AZ
dawsonh's Avatar
USA, AZ, Flagstaff
Joined Mar 2003
3,837 Posts
First trim flights

I got four packs worth of flights in the Yak this morning. I can see I have some work to do... this precision flying is HARD. I am used to a more "free form" flying style. This F3P stuff is going to be a great opportunity to improve my flying skills.

I need to to fix/tune a few things before the Saturday session.

I have a little too much up thrust on the motor (I climb when adding power).
Need a bit more aileron throw and much less elevator.
I popped out a wing brace during a minor cart wheel... a little glue will fix.
Tore off one of the Depron wheels. I think I need to make something stronger.

Well... first impressions.

I have plenty of power for pattern maneuvers, but a lot less than my Kestrel and other 3-D foamie. You actually have to "fly" this little guy.

The Yak flys nice and slow... especially considering my altitude, 7000'. It was fun to fly simple landing patterns or figure eights about six inches off the ground. I got a couple tip drags too.

Inverted flight was not comfortable, but OK considering the thrust and elevator issues.

I was able to fly nice round loops (not as good outside-thrust issue?)

I could hover... with good but not rocketship punch out.

Slow rolls and point rolls were OK, but not perfectly axial. I am sure that is mostly me. At slow speed it is very easy to see your mistakes!

I tried most of the F3P-A maneuvers and managed to link a few together.

I flew knife edge about as well as I have ever done... not saying much. My rolling circle was pretty sloppy.

I did some power off negative and positive spins from the top of the dome and could comfortably get three spins. (it's not F3P, but fun)

All in all I am very satisfied with this plane. It more than enough plane for my skill level. I look forward to many fun flying sessions.


Here is a shot of the Yak in the NAU Dome. Our club, Flagstaff Flyers, has just received permission to use this site. It feels like a lot of room in our "little corner." It will be down right humongous when the basketball court gets pulled up!
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Old Jan 18, 2007, 10:13 PM
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DBSkyout's Avatar
Monroe, Wa
Joined Aug 2005
350 Posts
Pull Pull

Dawsonh,
Good looking yak! How did the pull pull ailerons work for you? Did you have any issues installing them? Wish I had a place like that to fly!!!
Dave
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Old Jan 19, 2007, 04:27 AM
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Aio_1's Avatar
Ireland, Kildare, Leixlip
Joined May 2002
6,441 Posts
Quote:
Originally Posted by dawsonh
.....I have a little too much up thrust on the motor (I climb when adding power).......
.......Inverted flight was not comfortable, but OK considering the thrust and elevator issues.....
Did you try moving the CG further aft?
If your climbing excessively with power there are two possible causes and they're linked. Your CG may be quite far forward. When you trim for level flight you'll end up with more up elevator the further forward your CG. However the pitching moment due to the CG is constant while the aerodynamic moment varies with speed. So a plane with forward CG tends to dive below the trimmed speed and climb above the trimmed speed. The fix is to add some downthrust but when you're inverted this has the reverse effect and increases the pitching response to speed change which may make smooth inverted flight trickier than it needs to be.
So there's two possible fixes or preferably a compromise between the two:
1. Increase down thrust (which is likely to make inverted even worse unless you already have a very aft CG)
2. Move CG further aft to reduce elevator trim for level flight (of course too far aft and the plane will start getting twitchy and may not suit your flying style)
I think the best way to do this is concentrate entirely on CG first. Move it back until you find it becoming too unstable for your liking and then move it forward again just enough to get back in your comfortable range. Next trim for level flight and then adjust the thrustline and re-trim until you get the best compromise between upright and inverted flight.

You might already know all that in which case feel free to ignore me!

Quote:
Originally Posted by =dawsonh
.....Here is a shot of the Yak in the NAU Dome. Our club, Flagstaff Flyers, has just received permission to use this site. It feels like a lot of room in our "little corner." It will be down right humongous when the basketball court gets pulled up!
I'm not sure if that should count as indoors!

Aidan
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Old Jan 19, 2007, 08:21 AM
Flagstaff, AZ
dawsonh's Avatar
USA, AZ, Flagstaff
Joined Mar 2003
3,837 Posts
Quote:
Originally Posted by Aio_1
I think the best way to do this is concentrate entirely on CG first.
I think you are right! I don't know why I was fixating on the thrust thing. Maybe because I don't do much motorized flying.

The first thing I do with a new glider is do a "dive test" to check the CG. From level flight I do a 45° dive... if the gider pulls up you are nose heavy, if it tucks, it is tail heavy. A siight rise or neutral is OK (I prefer a neutral CG).

Quote:
Originally Posted by Aio_1
I'm not sure if that should count as indoors!
It is indoors in "name" only... 502' in dameter and 142' high! You could probably fly 1/4 scale models in there.
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Old Jan 28, 2007, 05:30 PM
"How old are you?"
Brummeh's Avatar
Brum, U.K.
Joined Feb 2006
544 Posts
Its not quite in time for Xmas, but hopefully if i can find a new esc and rec. it might fly before Easter...

Mike
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Old Jan 31, 2007, 02:19 AM
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boolat's Avatar
Turkey
Joined Oct 2005
170 Posts
I present to you the yak54 for my all first achievements





It remains that the assembly finished!

6mm depron !

@+

And OPSss I have just finished 88GR without electronics!!!











Soon torque…

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Last edited by boolat; Jan 31, 2007 at 07:35 AM.
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Old Feb 12, 2007, 03:04 PM
Mr. Mullins
Joined Jul 2006
66 Posts
Here is a winter video of my YAK 54.

...and I know the wings do flex, but I did't have carbon tubes to stiff it up.

http://www.heltpropell.com/video/YAK54.wmv
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Old Feb 12, 2007, 10:26 PM
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No wing flex when you are hovering…
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Old Apr 07, 2007, 07:57 PM
Max
Joined Jul 2006
411 Posts
Quote:
Originally Posted by Brummeh
Its not quite in time for Xmas, but hopefully if i can find a new esc and rec. it might fly before Easter...

Mike
Is it ready yet ?

Happy Easter
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Old Apr 25, 2007, 02:40 PM
Rave heaven
Chicago surburbanite
Joined Nov 2006
5,125 Posts
Hey guys. I really want to build this plane but Ihave a quetion about printing out this plan. I open it up on adobe and I try to print it out but it only prints on sheet out of only one part of the whole plan. I know I can tape it together but I can't the the other parts. AHH!!

Could you guys tell me how you guys printed it out?

Thanks
Eric
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Old Apr 25, 2007, 02:53 PM
Rave heaven
Chicago surburbanite
Joined Nov 2006
5,125 Posts
O yea, for the plans? I was wondering what those two long strips are for?

Thanks
Eric
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