Go Back  RCU Forums > RC Airplanes > ARF or RTF
Reload this Page >

Ultra RC 87" Yak Build and Fly

Notices
ARF or RTF Discuss ARF (Almost Ready to Fly) radio control airplanes here.

Ultra RC 87" Yak Build and Fly

Old 12-21-2006, 03:06 PM
  #176  
bdbd
My Feedback: (62)
 
Join Date: Apr 2003
Location: Lilburn, GA
Posts: 62
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Check the incidence of the wings and stabs my wings were out 3/4 of a degree each in opposite directions thus giving me alot of aileron trim. Also I am having trim issues on the downlines with my cg at the rear end of the recommended value the plane still needs alot of up elevator trim for horizontal flight resulting in it pulling to the canopy on the downlines. My thought was there was too much down thrust on the engine so I checked. The firewall has zero degrees of down thrust so now I have 3/4 of a degree of up thrust. It will probably mess up my up lines but hopefully fix the downlines. I hope to find out this weekend. Also check the stab incidence mine are out but not bad enough to fix at the moment.
Old 12-21-2006, 03:54 PM
  #177  
664KIX
Member
 
Join Date: Jul 2004
Location: Burlington, VT
Posts: 81
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly


ORIGINAL: bdbd

The firewall has zero degrees of down thrust so now I have 3/4 of a degree of up thrust. It will probably mess up my up lines but hopefully fix the downlines.
Most of my planes pull to the canopy in down lines. I spend a lot of time setting up the incidence, and 1/2 degree here or there virtually has no affect on the way my planes fly. One thing I have done with all my planes, including the 50cc Yak, is to use a program mix low throttle to down elevator. In my Yak, the down elevator mix is only 1%. That is enough to keep the plane straight and true in the down line. I can not feel any affects in normal flight and I leave the mix on all the time. It also helps to keep the nose down in landing with a slightly more tail-heavy airplane ;-)

Further, I like to use mixes to dial in my right and up thrust issues as well. High throttle to right rudder and high throttle to up elevator. This will keep the up lines straight, improve the positioning in a hover, and most important in my opinion, keep knife edge in both positions more consistent. I would be happy to eleberate if anyone is interested.

Good Luck! And enjoy that Yak!!!! Happy Holidays.

Ryan
Old 12-21-2006, 07:22 PM
  #178  
bdbd
My Feedback: (62)
 
Join Date: Apr 2003
Location: Lilburn, GA
Posts: 62
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

I agree there are alot pf people who use the down elevator mix to correct down lines. My hunt was on due to issues with too much trim on the ailerons. Further investigation revealed twisted ailerons as reported in another post (thanks for the reminder) This is not uncommon and should have been on my check first list. I will probably end up with some down mix on the elevator but it flew so well inverted and with no up elevator trim the downlines were perfect. Just trying to get rid of as much trim as possible before starting to use mixes. This is possibly the best Yak I have flown it flys very light and response is immediate. I would definately recommend this plane to others ( and have already). Every plane has some mix in one way or another including my pattern planes.
Old 12-22-2006, 02:37 AM
  #179  
quist
My Feedback: (198)
 
quist's Avatar
 
Join Date: Jan 2002
Location: Glendale, AZ
Posts: 3,325
Received 9 Likes on 5 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Where did you check your incedence, Tip or Root? My wings were both zero at the root. One was 3 degrees at the tip and the other was 1 negitive. I twisted the wings and hit it with the heat gun and now it is Zero at the tips and the plane flys very well.

The cg is hands off for level inverted flight, on a 45 upline it doesn't climb while inverted.
The incendence on my stabs are also at Zero and I have up trim.
One thin shim of upthrust for a perfect upline, 1% down elevator to low throttle for a straight downline.
Old 12-22-2006, 10:33 AM
  #180  
bdbd
My Feedback: (62)
 
Join Date: Apr 2003
Location: Lilburn, GA
Posts: 62
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Thanks for the info. I had to realign the ailerons they each had some twist. Incedence is 0 at mid wing. I have also gone to one shim of upthrust. I am going to try to check this progress this weekend.

Thanks for this new info.

Dan
Old 12-22-2006, 06:47 PM
  #181  
Turbobruce
Senior Member
My Feedback: (3)
 
Join Date: Jan 2002
Location: Riverside, CA
Posts: 308
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Hey guys I need help,

I'm curious as to where you guys are putting your ignition box. I can't seem to find a safe place to put it and keep it away from the throttle servo. I do not want interference and would like to be at least 6 inches from the servo. Any pictures would help. I have mounted a BME 50 on mine. I mounted almost a half an inch foward from the recommended measurements so I can put my reveiver battery by the wing tube so I hope I don't have any cg issues. Thanks
Old 12-22-2006, 07:25 PM
  #182  
Maudib
Senior Member
Thread Starter
My Feedback: (51)
 
Maudib's Avatar
 
Join Date: Jul 2002
Location: Ashland, KY
Posts: 5,833
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

The stock position doesn't really allow you to do that as it's right up in the engine box...

On my EF I placed the throttle servo back in the fuse with a Nyrod...

In reality though... if you are gonna get RF at 6", you'll get it at 3"...

I made a servo plate and cut out a small cube of foam for the servo to fit in just ahead of the wingtube on the left side.

Old 12-22-2006, 07:37 PM
  #183  
Maudib
Senior Member
Thread Starter
My Feedback: (51)
 
Maudib's Avatar
 
Join Date: Jul 2002
Location: Ashland, KY
Posts: 5,833
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

For what it's worth... I'll be following many of the same steps I did on my EF Yak...

See review here:

http://www.rcuniverse.com/magazine/a...article_id=595

Not sure why they titled it "E-Conversion"... there is a sidebar on a e-version I assembled... but it's more about the DA50 setup...

Drilling the gear & block, Hatch Latch mod, canister pipe install, tank on CG (will use a DuBro tank from now on though... the B&B wants to loosen and drip a drop once in blue moon), extra cowl mounting block, canopy dowel doubler mod, rudder servo tray doubler, throttle servo relocation...

My goal here is to show the couple fixes mine needs (slight fuse twist and moving a couple hinge slots)... (later though I'm swamped!)
Old 12-22-2006, 08:00 PM
  #184  
Turbobruce
Senior Member
My Feedback: (3)
 
Join Date: Jan 2002
Location: Riverside, CA
Posts: 308
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Thanks Maudib,

I was wondering how to put it back in the fuse. I will do the same. I just hope the cg isn't thrown off too much.
Old 12-22-2006, 08:51 PM
  #185  
Maudib
Senior Member
Thread Starter
My Feedback: (51)
 
Maudib's Avatar
 
Join Date: Jul 2002
Location: Ashland, KY
Posts: 5,833
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

I din't have any issues with balance on mine... so I don't expect any here either... The only people experiencing CG issues were those that used the long tuned pipe... and even then got it done...
Old 12-23-2006, 09:07 AM
  #186  
RC_DESI
Senior Member
My Feedback: (44)
 
Join Date: Sep 2003
Location: Keller, TX
Posts: 164
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Well I finally started assembling mine (still waiting for a missing part to arrive, "just" been 1 month since I placed order).

Finished hinging surfaces (Rudder is removable).
Installed the Rudder Servo tray
Made a platform for the Fuel Tank so that it sits on top of the Wingtube (to minimize any CG changes)
Drilled Landing gear

Next is installing the Engine
Attached Thumbnails Click image for larger version

Name:	Ec88609.jpg
Views:	3
Size:	126.2 KB
ID:	582229   Click image for larger version

Name:	Gc91230.jpg
Views:	3
Size:	141.5 KB
ID:	582230   Click image for larger version

Name:	Xd80665.jpg
Views:	4
Size:	134.1 KB
ID:	582231  
Old 12-23-2006, 09:38 AM
  #187  
Maudib
Senior Member
Thread Starter
My Feedback: (51)
 
Maudib's Avatar
 
Join Date: Jul 2002
Location: Ashland, KY
Posts: 5,833
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Looking good Arvind... keep 'em coming.
Old 12-23-2006, 11:10 AM
  #188  
quist
My Feedback: (198)
 
quist's Avatar
 
Join Date: Jan 2002
Location: Glendale, AZ
Posts: 3,325
Received 9 Likes on 5 Posts
Default RE: Ultra RC 87" Yak Build and Fly


ORIGINAL: Maudib

I din't have any issues with balance on mine... so I don't expect any here either... The only people experiencing CG issues were those that used the long tuned pipe... and even then got it done...
This is correct, The KS 1060 uses the entire pipe tunnel. But I still didn't have to add wieght to make it balance, I just shifted equpment. SO I am happy and I almost have foamie power.
Old 12-23-2006, 01:10 PM
  #189  
closetguy
My Feedback: (13)
 
Join Date: Jul 2004
Location: berlin hts, OH
Posts: 1,462
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly


ORIGINAL: quist


ORIGINAL: Maudib

I din't have any issues with balance on mine... so I don't expect any here either... The only people experiencing CG issues were those that used the long tuned pipe... and even then got it done...
Quist
glad to hear that,i have been wanting to try a tuned pipe,i think this is the plane i am going to use for it,for me it's going to be a taurus 52 and a 1060 pipe so far.
This is correct, The KS 1060 uses the entire pipe tunnel. But I still didn't have to add wieght to make it balance, I just shifted equpment. SO I am happy and I almost have foamie power.
Old 12-24-2006, 09:48 AM
  #190  
RC_DESI
Senior Member
My Feedback: (44)
 
Join Date: Sep 2003
Location: Keller, TX
Posts: 164
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Quick question. For mounting the engine, manual states (Page 28)

"From the same perspective, measure up 1 13/16” and draw a horizontal line that intersects the line you have just drawn. This represents the vertical thrust line for the engine."

This means 1.8125" from bottom of the firewall & NOT from top of firewall correct? Pic does not look like its from top.

Just wanted to clairfy b4 I drill the holes...
Old 12-24-2006, 09:59 AM
  #191  
Maudib
Senior Member
Thread Starter
My Feedback: (51)
 
Maudib's Avatar
 
Join Date: Jul 2002
Location: Ashland, KY
Posts: 5,833
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

That seems correct... leaving you with something looking like the pics on page 29...

Or this one from the review I did... (not a good pic for this instance... but you can see the relation to the carb cutout hole...

Old 12-24-2006, 12:32 PM
  #192  
JoeAirPort
My Feedback: (41)
 
JoeAirPort's Avatar
 
Join Date: Aug 2003
Location: Milwaukee, WI
Posts: 10,259
Likes: 0
Received 1 Like on 1 Post
Default RE: Ultra RC 87" Yak Build and Fly

Yeah that's the way I read it too....measure from the bottom.
Old 12-25-2006, 09:05 PM
  #193  
marc 540
Senior Member
My Feedback: (6)
 
Join Date: May 2005
Location: HUNTINGTON, IN
Posts: 303
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Is it bad to have the throttle servo to close to the ignition? I'm doing an 85''QQ right now and I put the throttle servo inside the engine box.(probably about 4 or 5 inches fron the ignition.) Am I going to have trouble with this setup?

Thank's Marc 540[8D]
Old 12-25-2006, 09:19 PM
  #194  
Maudib
Senior Member
Thread Starter
My Feedback: (51)
 
Maudib's Avatar
 
Join Date: Jul 2002
Location: Ashland, KY
Posts: 5,833
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

You won't know until you do a range test... often it's fine... sometimes not...
Old 12-25-2006, 09:22 PM
  #195  
AirWizard
Senior Member
My Feedback: (3)
 
AirWizard's Avatar
 
Join Date: Apr 2004
Location: Coffeyville, KS
Posts: 1,228
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

as long as you don't attach it to the ignition you should be ok.....make sure you range check it for interference
Old 12-26-2006, 01:57 PM
  #196  
RC_DESI
Senior Member
My Feedback: (44)
 
Join Date: Sep 2003
Location: Keller, TX
Posts: 164
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Does anyone know if the elevator stab incidence on this plane is 0 degrees with respect to the fuselage top where the hatch sits? (I don't have a long bar to check incidence on the wing, can check only on elevator stabs ;-)
Old 12-31-2006, 04:03 PM
  #197  
JoeAirPort
My Feedback: (41)
 
JoeAirPort's Avatar
 
Join Date: Aug 2003
Location: Milwaukee, WI
Posts: 10,259
Likes: 0
Received 1 Like on 1 Post
Default RE: Ultra RC 87" Yak Build and Fly

I marked the mounting holes for a ZDZ 50 NG on this ARF today and it did not not work out the best IMO. With the 1 1/8 inch of stand off's required the carb ends up not going in the hole in the firewall (carb sits higher than center on ZDZ 50). I'd have to chop the entire top middle top of the firewall off. Then the needles would be totally inaccessable due to the top ply being in the way. So I figure it would be better to just stand it off another 3/4 of an inch. Think this would look bad? I know full scale Yak's have the props pretty far from the cowling. The second thing is that my two bottom holes end up really close to the edge of the big hole in the firewall. So there's not much wood to drill the holes. Might have to build up some extra little pieces of firewall in that area. Bummer that it didn't work out too good. I did not expect that.
Old 12-31-2006, 04:12 PM
  #198  
xtdsm
Senior Member
 
Join Date: Apr 2006
Location: , BC, UNITED ARAB EMIRATES
Posts: 118
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

Yeah that sure sucks. I mounted my DA with 2.5" stand offs and it was tail heavy till I moved most of the stuff up to the engine box. so I am thinking you should be fine (CG wise) and don't worry much about the prop sticking out a bit, it will actually fly better with the prop sticking out a bit, and it won't look unscale at all.


Ahmed
Old 12-31-2006, 04:17 PM
  #199  
Maudib
Senior Member
Thread Starter
My Feedback: (51)
 
Maudib's Avatar
 
Join Date: Jul 2002
Location: Ashland, KY
Posts: 5,833
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Ultra RC 87" Yak Build and Fly

I purposely stood my DA further out just for that reason (scale looks and CG)... 3/4" further isn't much, and isn't noticable because of the spinner not having anything to "align to".

The firewall was designed specifically for the D50... so the stock muffler/or pipe would fit without hitting the engine box. Kind of hard to implement a solution for a variety of bolt and carb patterns... like some engines don;t need the carb outlet at all becasue they are sidemounted.

Extending the firewall down for the ZDZ shouldn't be too big a deal.. but it is a delay...
Old 12-31-2006, 05:20 PM
  #200  
JoeAirPort
My Feedback: (41)
 
JoeAirPort's Avatar
 
Join Date: Aug 2003
Location: Milwaukee, WI
Posts: 10,259
Likes: 0
Received 1 Like on 1 Post
Default RE: Ultra RC 87" Yak Build and Fly

I should clarify that the bottom holes end up right at the bottom edge of the big square hole in the firewall. It's not at the bottom of the firewall like I made it sound. Building up a little bit of the firewall for the bottom bolt holes is no biggy either....like you said Maudib, just a delay.

Luckily it's a Yak or I'd have a huge gap on the cowling nose. CG wise, it will be better.

The reason the DA doesn't have this problem is that the holes are farther apart and end up centered between the bottom of the firewall and the bottom edge of that hole.

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.