Ultra RC 87" Yak Build and Fly
#251
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ORIGINAL: JoeAirPort
Flight REPORT !!! PIC's !!!






Flight REPORT !!! PIC's !!!






ORIGINAL: AirWizard
I maidened my Yak today!!!!!!!!!!!!!!
I can't get the grin off my face.
I maidened my Yak today!!!!!!!!!!!!!!

I can't get the grin off my face.
#252
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Sorry no pictures.
Flight report: I'm using a DA50 with pitts muffler, nx 22x8
wind was around 10 miles an hour. This is a light flying plane so wind does effect it. Takeoff was nice and smooth with straight tracking down the runway, being light weight and having plenty of power the plane will lift off within 20 feet.
I'm using the Specktrum system and was pleased with the response of the control systems. KE loops are a breeze, rolls, loops, flatspins, blenders are great.
What really impressed me most was the hoovering.....this plane locks in. I have been flying a TOC (SD models) Yak for a couple of years and will now retire it. The Ultra flies lighter and has plenty of power with the DA.
Landing, this plane is a floater......set the glide slope and she floats in with just a touch of elevator as the wheels touch.
Flight report: I'm using a DA50 with pitts muffler, nx 22x8
wind was around 10 miles an hour. This is a light flying plane so wind does effect it. Takeoff was nice and smooth with straight tracking down the runway, being light weight and having plenty of power the plane will lift off within 20 feet.
I'm using the Specktrum system and was pleased with the response of the control systems. KE loops are a breeze, rolls, loops, flatspins, blenders are great.
What really impressed me most was the hoovering.....this plane locks in. I have been flying a TOC (SD models) Yak for a couple of years and will now retire it. The Ultra flies lighter and has plenty of power with the DA.
Landing, this plane is a floater......set the glide slope and she floats in with just a touch of elevator as the wheels touch.
#253
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did you have the 30% sd models? i was told if you step up the bigger ones they get better, but any "bigger" plane may fly better just because of the size, just curious because i have been looking at thier 30%er, but wondering about biting the bullet and steping up the 33%, i have a comp arf in the 80cc size range and i love that combo, would like to hear your opinion...
dave dont give up on me yet if you can
dave dont give up on me yet if you can

#254
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I have the 30% SD Models plane......don't get me wrong it has been a good plane. I think the big difference is the weight (wing loading), The SD Yak has a DA 50 and weights about 18 to 18.5 lbs while the Ultra weights 16 lbs.
#256

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I know this thread is on the 87", but I wanted to mention that I maidened my 107" a couple of weeks ago. Flies a lot like the 87", no bad habits so far. First landing was a bit bouncy due to idle too high but second was perfect. Stalls were gentile. I am going to increase the aileron rates, the recomended low rates (based on the 87" manual) are too soft for my taste.
Unfortunately I'm still having engine issues and ended up sending it back. So it's grounded for a week or so.
Greg
[img][/img]
Unfortunately I'm still having engine issues and ended up sending it back. So it's grounded for a week or so.
Greg
[img][/img]
#259
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David, I don't think it's a single stack, if you were to look closely, it seems that it has dual stack, DA-100 maybe !!
Ahmed
Ahmed
#260
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Ooops... I think you're right... after blowing it up on Photoshop it does look like two stacks and a twin cylinder... AT first glance it looked liek the spark plug boot was that other little bump... but it's the angle...
#261

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Mine is moving along slowly but surely. Rudder is all done. I'm installing the elevator servos now. Next is the aileron servos. Then I do the engine. Maybe by the end of March I'll be done. That's just in time for spring.
BTW, is there such thing as too much throw on the elevators for this Yak? I have about 52 degrees right now and still have another 5 or so degrees left. I purposely hinged them so the throws were huge. Waterfalls are better (tighter rotation). I heard these elevators are very effective so I don't know if this is too much. I am totally used to huge throws on all my 3d ARF's.
The ailerons can only get 45 degrees max, hopefully that's enough. One of them rubs on the root on the down deflection at 45 degrees so that limits the deflection of both ailerons on the up and down. I could always hack some of the aileron off at the root to free it up but I don't know if I even want any more than 45 on them.
BTW, is there such thing as too much throw on the elevators for this Yak? I have about 52 degrees right now and still have another 5 or so degrees left. I purposely hinged them so the throws were huge. Waterfalls are better (tighter rotation). I heard these elevators are very effective so I don't know if this is too much. I am totally used to huge throws on all my 3d ARF's.
The ailerons can only get 45 degrees max, hopefully that's enough. One of them rubs on the root on the down deflection at 45 degrees so that limits the deflection of both ailerons on the up and down. I could always hack some of the aileron off at the root to free it up but I don't know if I even want any more than 45 on them.
#265

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Sorry guys for the slow response.
It is a BME115 with stock mufflers. The plane was designed around the DA100, so you have to shift your batteries and about everything you can forward to balance with the BME. Dry weight is 26lbs 4oz.
Greg
It is a BME115 with stock mufflers. The plane was designed around the DA100, so you have to shift your batteries and about everything you can forward to balance with the BME. Dry weight is 26lbs 4oz.
Greg
#267

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Why does it break like the BME fiberglass gear? Graphtech sells some for the QQ 85 inch Yak that is very close to URC Yak. I just measured my URC Yak and it's roughly, 7 inch base, 10 inch height, 19.5 inch width at axle holes. That's very close to the QQ.
ORIGINAL: AirWizard
Anybody know where I can get a replacement CF gear for my Ultra Yak?
Anybody know where I can get a replacement CF gear for my Ultra Yak?
#268

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I'm surprised that there aren't more people building these here. I'm very impressed with mine. It's the best ARF I have ever bought. All I have to do now is mount the engine and cut the cowling. Can't wait to fly it. You can only appreciate the quality of these kits after assembling one.
One thing I'm wondering is how much to cut out for the exit air (using WA pitts). Also should I baffle the front and maybe add that air dam that creates a negative at the exit like a full scale plane (thinking about what the guy from Saudi Arabia did to his).
One thing I'm wondering is how much to cut out for the exit air (using WA pitts). Also should I baffle the front and maybe add that air dam that creates a negative at the exit like a full scale plane (thinking about what the guy from Saudi Arabia did to his).
#269
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The way I understand it, over 50 were sold... but perhaps not so many of those are on RCU.
I've jst got sooooo many projects to finish I can't get to mine... I am about caught up though.... but I need some "downtime"... burn out ya know...
Still I look forward to getting mine together... I already know it's a great flyer... just need to get some time (and room!)
I've jst got sooooo many projects to finish I can't get to mine... I am about caught up though.... but I need some "downtime"... burn out ya know...

Still I look forward to getting mine together... I already know it's a great flyer... just need to get some time (and room!)

#270

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Joe
what size of standoffs are you useing,i think you said you are going with the DA 50,i been doing some checking around,looks like 2-1/2 would work 3" might be better for balance,the reason i ask i just decided to go with a DA,instead of the Taurus 52,i am having trouble with the CH ignition,can't get a good range check,i recived a new style ignition with the bosch cap from CH friday and can't evan get it started,so i am going with the DA,NEVER!!!! had trouble with one of those.i know i will get a lot of heat from guy's about the CH ignition.
ENJOY!
what size of standoffs are you useing,i think you said you are going with the DA 50,i been doing some checking around,looks like 2-1/2 would work 3" might be better for balance,the reason i ask i just decided to go with a DA,instead of the Taurus 52,i am having trouble with the CH ignition,can't get a good range check,i recived a new style ignition with the bosch cap from CH friday and can't evan get it started,so i am going with the DA,NEVER!!!! had trouble with one of those.i know i will get a lot of heat from guy's about the CH ignition.
ENJOY!
#271
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I DO know his next revision is comign with 2 cell lipo/lion cell support! They are wll made, light, such...
Scott at Brillelli http://www.brillelli.com sells them... might be easier than reinstalling a whole new engine...
Otherwise the DA50... well they rock the house and you know that!

THe Taurus is a nice engine too.
#272

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I'm actually using a ZDZ 50 NG. I sold the DA 50 due to dead stick problems while inverted at idle. The DA will need 2 1/2 per the manual. Yes 3 inch would be better. My carb interfiered with the fire wall so my prop hub sticks out at least an inch.
ORIGINAL: closetguy
Joe
what size of standoffs are you useing,i think you said you are going with the DA 50,i been doing some checking around,looks like 2-1/2 would work 3" might be better for balance,the reason i ask i just decided to go with a DA,instead of the Taurus 52,i am having trouble with the CH ignition,can't get a good range check,i recived a new style ignition with the bosch cap from CH friday and can't evan get it started,so i am going with the DA,NEVER!!!! had trouble with one of those.i know i will get a lot of heat from guy's about the CH ignition.
ENJOY!
Joe
what size of standoffs are you useing,i think you said you are going with the DA 50,i been doing some checking around,looks like 2-1/2 would work 3" might be better for balance,the reason i ask i just decided to go with a DA,instead of the Taurus 52,i am having trouble with the CH ignition,can't get a good range check,i recived a new style ignition with the bosch cap from CH friday and can't evan get it started,so i am going with the DA,NEVER!!!! had trouble with one of those.i know i will get a lot of heat from guy's about the CH ignition.
ENJOY!
#273

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Some pic's I shot while I was down there.
I'm going to have to chop a lot more off the bottom of my cowling since the engine is so far forward. The muffer stacks ended up in front of that rectangular opening on the bottom. Also the chamber for the muffer is hitting the bottom of the cowling so I'll have to remove some fiberglass to clear that. I prolly will just cut off those sections that point down behind the muffler since the muffler is so far forward of it. Since I will cut so much out underneath, I will likely put a strap of fiberglass that will brace the cowling left to right so it doesn't flop around. I'll fasten the strap with cap head servo screws. That way I can keep the spark plug wire on the engine when I remove the cowling. All I have to do is remove one screw and the rotate the brace. Anywho when it's all done it will be cool, I just hate the chopping part of the process. I always think I'm going to screw it up....it's not a reversable process.
I'm going to have to chop a lot more off the bottom of my cowling since the engine is so far forward. The muffer stacks ended up in front of that rectangular opening on the bottom. Also the chamber for the muffer is hitting the bottom of the cowling so I'll have to remove some fiberglass to clear that. I prolly will just cut off those sections that point down behind the muffler since the muffler is so far forward of it. Since I will cut so much out underneath, I will likely put a strap of fiberglass that will brace the cowling left to right so it doesn't flop around. I'll fasten the strap with cap head servo screws. That way I can keep the spark plug wire on the engine when I remove the cowling. All I have to do is remove one screw and the rotate the brace. Anywho when it's all done it will be cool, I just hate the chopping part of the process. I always think I'm going to screw it up....it's not a reversable process.

#275

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Holy ***** did I work my ***** of on this plane today. Took a vacation day to try and knock it out. No way, too much work. Unreal how much time it takes to do everything.
This is my final to do list:
-bolt the engine in
-attach choke and throttle linkages.
-mount fuel tank,
-install fuel dot and run line to carb and run vent line.
-wheel pants
-Re-do pull pull cables with Dubro (stock ones are just not 3 feet off deck knife edge worthy).
-CG check to figure out where batts go
-Install switches and batt's
-Drill new prop and bolt it on.
Done yeah after another 8 hours that is
This is my final to do list:
-bolt the engine in
-attach choke and throttle linkages.
-mount fuel tank,
-install fuel dot and run line to carb and run vent line.
-wheel pants
-Re-do pull pull cables with Dubro (stock ones are just not 3 feet off deck knife edge worthy).
-CG check to figure out where batts go
-Install switches and batt's
-Drill new prop and bolt it on.
Done yeah after another 8 hours that is
