Go Back  RCU Forums > RC Airplanes > 3D Flying!
 Great Planes 25% Yak 81" 12-lb, seen on Fly3D Magazine >

Great Planes 25% Yak 81" 12-lb, seen on Fly3D Magazine

Notices
3D Flying! Our 3D flying forum is the ultimate resource for 3D flyers. Also discuss the latest in "4D" flying!

Great Planes 25% Yak 81" 12-lb, seen on Fly3D Magazine

Old 07-30-2009, 01:54 AM
  #876  
Senior Member
My Feedback: (2)
 
jimmyjames213's Avatar
 
Join Date: Aug 2008
Location: L
Posts: 1,655
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

how much torque do you need on the servo's?
are these fine for ail/elev? http://www3.towerhobbies.com/cgi-bin...?&I=LXNRT1&P=0
and this one for rudder? http://www3.towerhobbies.com/cgi-bin...?&I=LXNRN6&P=0
are those servo's any good presicion wise. the first one is a little slow.
im planing on doing pattern/imac with the plane. maybe some 3d when im messing around
a friend of mine said digitals are a must and that you need 200 oz of torque or more and 300+ for the rudder.
do i really need that much torque? some of you guys are running 128oz of torque.
i plan on useing a dle55 for power, a123 for battery's and a futaba 10c radio. will the 10c be enough for 50cc gasers. mixing wise and such, will it be good for imac ?

thanks for dealing with all of my questions.
Old 07-30-2009, 05:11 PM
  #877  
My Feedback: (2)
 
Super08's Avatar
 
Join Date: Dec 2007
Location: Fort McMurray, AB, CANADA
Posts: 4,121
Received 1 Like on 1 Post
Default RE: Great Planes 25% Yak 81

You don't have to buy servos with that much power, but it does make it more responsive. Those servos are a great match and a good value.
Old 07-31-2009, 02:45 AM
  #878  
Member
 
Join Date: Jan 2007
Location: aberdeen, UNITED KINGDOM
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

The rudder fluttered on mine so i put a 7955 on it and its superb, i had one spare so plugged it in. I found that 12kg on all other surfaces works great and i fly my model hard.

Mark
Old 12-30-2009, 01:01 AM
  #879  
Junior Member
 
Join Date: Oct 2009
Location: laguna hills, CA
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

i am building yak electric.i have a 70cc equivalent outrunner with castle 110amp speedo.will be using 2-6cell in paralell to make 12s.hoping to swing a 22" prop without exceeding my amps.plane seems very heavy to me but then again im used to 3dhobbyshop planes that are lite.yah i dont even have any servos or linkage installed yet and the plane feels heavy.lucky for me my company manufactures cf controll horns,pushrods.so im hoping to shave off a little.this is my first 25%electric plane keeping my fingers crossed.i built the extra gp 55" and was able to get it to 4pounds all up weight.the manual for the extra says 5.75-6.75 pounds so you can see how shaving weight here and there goes a long way.yes with the glue in cf controll horns no need for nuts and screws,and nothing protruding on top of the wing.this makes for slitely less drag and improved weight loss.got this plane for cheap so dont worry to much about it.this is one of the nicest looking planes i have ever seen.
Old 01-01-2010, 01:23 PM
  #880  
My Feedback: (1)
 
Join Date: Sep 2003
Location: St. Peters, MO,
Posts: 744
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

You are unfortuanately correct it is a heavy plane. And it is also very nice looking. I would not recommend this plane for high alpha, harrier type 3D flying but it tracks really well for general sport, IMAC type flying.
Old 01-01-2010, 02:27 PM
  #881  
Member
 
Join Date: Jan 2007
Location: aberdeen, UNITED KINGDOM
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

This plane flies high alpha fine just build it as lite as possible.

Mark
Old 01-03-2010, 06:35 PM
  #882  
My Feedback: (1)
 
Join Date: Sep 2003
Location: St. Peters, MO,
Posts: 744
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

Mark,
What did your final weight end up at? I presume you are using the ZDZ-40. I was thinking of putting a DLE30 in mine.
Old 01-04-2010, 02:05 AM
  #883  
Junior Member
 
Join Date: Oct 2009
Location: laguna hills, CA
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

hey i did see some ytube video of this plane electric.the guy was putting it around like a foamy.not sure maybe he was just very good pilot and had extreme high power.another guy has one with a 60cc gas motor with all the fixens and his weighs 15lbs.still hoping for it to be much liter than that.i programmed my castle to my settings but cant get the brake dissabled.only can slow it to almost nothing.can put cowling back on and get the spinner,prop,etc. buttened up.only thing left pushrods,and pullpull.if i can keep this to 12.5lbs that would be great.i will send you guys motor ground test results next.
Old 01-04-2010, 03:14 AM
  #884  
Member
 
Join Date: Jan 2007
Location: aberdeen, UNITED KINGDOM
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

Im at just under 13lbs and it does throw about very well, ive watched the DA50 vids etc and the planes are well overpowered its pretty nuts with the zdz40, i used carbon rods everywhere and hacked the hell out of the firewall.

I could run a wooden prop and put a lighter main rx batt and not the duarlite a possibility!

Mark
Old 01-04-2010, 09:51 PM
  #885  
Junior Member
 
Join Date: Oct 2009
Location: laguna hills, CA
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

did you use 4-servos in the tail or pull-pull.how do you like flight characteristics?is it electric?if you are under 13lbs than that should be nice.cant wait to fly mine need to buy more batts.think maybe any bigger next plane will be pump gas motor.batts pane in bottom allways charging and they are dangerous.very expensive when you add it all up either way you do it.pay to play thats it im paying alright.went through about 15lipos today at the field by myself it was a blast.reminded me of when i started was so hungry to fly all the time no matter what.hey have fun and keep charging!
Old 01-04-2010, 09:55 PM
  #886  
Junior Member
 
Join Date: Oct 2009
Location: laguna hills, CA
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

oh yah as far as the flight batts even alot of the old gas guys have gone to 2400mah lipo.not sure of diff in weight comparison but its lite.this plane is small enough that you dont need a ton of power at the servos,just good power consistent.
Old 01-04-2010, 09:56 PM
  #887  
Junior Member
 
Join Date: Oct 2009
Location: laguna hills, CA
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

hope this turnigy motor doesnt fall apart on me?were gunna give it a try.i got tired of looking at the box.
Old 01-05-2010, 03:34 AM
  #888  
Member
 
Join Date: Jan 2007
Location: aberdeen, UNITED KINGDOM
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

this plane needs good servos at 6v and a very strong rudder servo, i have 2 in tail and one rudder servo up front, tried to keep wait forward.

Flight charecteristics are good , it does have lots of coupling in it on knife edge but it will fly very slow, before stall and do all the tricks.

A good hack plane.

Mark
Old 01-06-2010, 11:56 AM
  #889  
Junior Member
 
Join Date: Oct 2009
Location: laguna hills, CA
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

hey thanks so much for that info.im going to do the sAme with two elev servos and one pullpull servo up front.the paperwork says min of 70oz on servos.so from what you said it wouldnt hurt to exceed this with stronger servos.im so glad to here of the slow flight and good characteristics of plane.im allways iffy about electric conversions.but this plane seemed like it needed something good to happen with it because it is so cool looking.hp has some airtronics servos that are 130oz 16seconds on sale for $40 what do you think about these.now a days im looking at cost and overall function rather than just having the eyeball brand.anyway any information you can give me would be great thanks.
Old 01-06-2010, 12:05 PM
  #890  
Member
 
Join Date: Jan 2007
Location: aberdeen, UNITED KINGDOM
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

I have a 7955 330 oz at 6v on the rudder, makes high alpha knife edge very easy and 7965 on the elecvators 139oz at 6V, i ran 5645s but didnt like them the plane fishtailed so i went bigger and stronger.

This plane has large surfaces if you blow a lot of wind over them then you need good servos.

Im sure anybrand would be good.

It is a good plane just not superlight, but it flies real good.

Mark
Old 01-21-2010, 01:53 PM
  #891  
 
Join Date: Jun 2007
Location: Turku, FINLAND
Posts: 305
Likes: 0
Received 1 Like on 1 Post
Default RE: Great Planes 25% Yak 81

ORIGINAL: mark nichols

I have a 7955 330 oz at 6v on the rudder, makes high alpha knife edge very easy and 7965 on the elecvators 139oz at 6V, i ran 5645s but didnt like them the plane fishtailed so i went bigger and stronger.

This plane has large surfaces if you blow a lot of wind over them then you need good servos.

Im sure anybrand would be good.

It is a good plane just not superlight, but it flies real good.

Mark

Hi Mark, nice to read your posts on the GP Yak

I'm planning to buy one and put a Laser 240 v-twin glow on the nose but I am a little bit concerned about the power so I am wondering wether it will be underpowered. The Laser should turn a 20*6 at about 9000 and I just weighed the engine: 1430 grams or 50,5 oz (with the mufflers).

Based on your experiences, what do you think? I am planning to fly IMAC / sunday flying.



Old 01-21-2010, 02:56 PM
  #892  
Member
 
Join Date: Jan 2007
Location: aberdeen, UNITED KINGDOM
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

Hi Dont know much about laser engines

http://www.laserengines.com/spec.htm LASER-240v Smaller but similar weight to the 200v the engine is designed for FAI aerobatics. The engine has the highest power/weight ratio of all Laser engines. Due to the small size it is essential that good cooling is arranged in the model, it is not as tolerant as the 200v. http://www.youtube.com/watch?v=PODDkJk-O3Y sure this guy means OS200fs sounds a four stroke to me. Seems to fly a bit slugish, http://www.osengines.com/engines/osmg0979.html weight 993g.

http://www.rcuniverse.com/forum/m_9094927/printable.htm see this article here!!. The plane needs to be built as lite as possible, i cannot stress this enough, but if the engine is moved forward you can succeed see my zdz40 instalation pic. Also forget spinner, pilots large fuel tanks Lipo's only and no heavy duty heavy switches and i went carbon control rods all round very lite. Most of the guys who say its heavy have the full monty making it even heavier, can't quite figure it out.

Its a good IMAC plane and will fly 3D nice little plane what can you say.

Mark
Attached Thumbnails Click image for larger version

Name:	Sq46108.jpg
Views:	29
Size:	116.4 KB
ID:	1360907  
Old 01-21-2010, 03:09 PM
  #893  
Member
 
Join Date: Jan 2007
Location: aberdeen, UNITED KINGDOM
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

Another pic to show howmuch prop is forward of cowl. It was a freezing scottish winters day (bad pic).

Mark
Attached Thumbnails Click image for larger version

Name:	Wt59112.jpg
Views:	29
Size:	114.6 KB
ID:	1360908  
Old 01-22-2010, 02:26 PM
  #894  
Junior Member
 
Join Date: Oct 2009
Location: laguna hills, CA
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

thanks again for all the great info..will send photos when i get mine finished.
Old 01-22-2010, 03:00 PM
  #895  
Member
 
Join Date: Jan 2007
Location: aberdeen, UNITED KINGDOM
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

No Problem, im just looking at putting a vess prop on also and thats it then, i did think of a carbon uc but our field is quite
bumpy and i like the give in the alloy one.

Godd luck and feel free to ask any questions.

Mark
Old 01-23-2010, 10:01 PM
  #896  
Junior Member
 
Join Date: Oct 2009
Location: laguna hills, CA
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

hey what was your auw again in case you told me sorry?
Old 01-24-2010, 03:16 AM
  #897  
Member
 
Join Date: Jan 2007
Location: aberdeen, UNITED KINGDOM
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

just under 13lb.

Mark
Old 01-24-2010, 03:20 PM
  #898  
 
Join Date: Jun 2007
Location: Turku, FINLAND
Posts: 305
Likes: 0
Received 1 Like on 1 Post
Default RE: Great Planes 25% Yak 81


ORIGINAL: mark nichols

Another pic to show howmuch prop is forward of cowl. It was a freezing scottish winters day (bad pic).

Mark
Thanks Mark! Nice to see a picture of your Yak & Scottish landscape (Btw it's -15 deg celsius here in Southern Finland now..)

You say you had to mount the engine quite much forward of the cowling so do you mean there is no other way to get the the plane balance without such a procedure?

Supposing the Laser weights the same as ZDZ40 (as it does, if the ZDZ specs for 1300g engine+ign batt 50g and muffler maybe 100g is this about correct?) The Laser 240 twin weights 1430grams /with mufflers.

So if you put the rx batteries, switches, etc right after the firewall, and use pull-pull set-up for the rudder will it still become tail heavy?[sm=confused.gif] Well, if you say yes then I guess I could mount the elevator servos, with long CF pushrods set-up, somewhere near where the rudder servo sits ( if the rudder is a pull-pull set-up. )

Anyways, thank you again! this a great site with great people!

P.S. what might be the static thrust-model weight ratio to get unlimited vertical? 1,25:1? or what?



Old 01-24-2010, 06:02 PM
  #899  
Member
 
Join Date: Jan 2007
Location: aberdeen, UNITED KINGDOM
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Great Planes 25% Yak 81

Yes i mounted my ig batt just behind firewall and my rx on fueltank about 2-3 inches behind firewall.

I did look at mounting the ign batt on the firewall but as its a lipo it means cowl off to charge, i was tempted to use a
4.8 nimh eneloop pack up front.

I reckon putting the elevator servos further forward would not be good unless you used a wire cross over setup.

The zdz is very powerfull i have been amazed by it!

Moving the motor forward is only the same as my QQ yak which has the prop that far out anyway, also team Aeroworks
according to a build space ther motors further forward to balance better with less weight sepecially the large 100cc-150cc yak.

Mark
Old 01-30-2010, 03:12 AM
  #900  
 
Join Date: Jun 2007
Location: Turku, FINLAND
Posts: 305
Likes: 0
Received 1 Like on 1 Post
Default RE: Great Planes 25% Yak 81

Mark, Thank you for great help!


artto

Thread Tools
Search this Thread

Contact Us - Manage Preferences Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.