"1/2 A" & "1/8 A" airplanes These are the small ones...more popular now than ever.

A Great (Blink) Success, if a little fat.

Reply
Old 11-25-2013, 05:18 PM
  #1
Aussie Damo
Thread Starter
 
Aussie Damo's Avatar
 
Join Date: Jun 2004
Location: Geelong, Victoria, AUSTRALIA
Posts: 153
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default A Great (Blink) Success, if a little fat.

Well my blink is back up and flying and what a hoot it is.

Its E powered with an outrunner brushless and a 2S 1300mAh battery all spinning a apc 6x4. Its rather fat in its current state after a few repairs at 9.6 oz but still has some go but not outright vertical. repairs are new tougher vertical stabilizer, reinforce leading edge on one side, some extra covering and some ballast in the tail to balance it out (all from putting it in a tree the other week after loosing sight of it trying to trim it out)

Apart from my habit of putting it in trees at the end of the flight while trying to land the only problem (if it even is one) is that I need a fair bit of up trim to get level flight, and as a result im loosing a fair bit elevator authority especially at slower speeds (hence the trees).

Here is what it is trimmed to for level flight at about 2/3 throttle (which it is motoring along at)



What do you guys think??? its balance is about 3/16 forward of where the plan shows and ive read on here with people having the CoG about 3/4 forward of what the plan shows (which would be about 17% of the MAC which i dont thing would be right)

Second question, what is it when the tail sort of corkscrews following the nose (ie the tail if traced from behind would be drawing .5-1 inch circles), it only happens at low speed in shallow angle of bank turns?

Any tips would be appreciated

When this one eventually dies I will definitely build another with a slight wider center box and no panel between the box and servo tray so I can lay my battery flat and slide it back as necessary to balance

Damo
Attached Thumbnails
Click image for larger version

Name:	IMG_0740.JPG
Views:	63
Size:	429.0 KB
ID:	1942280   Click image for larger version

Name:	IMG_0741.JPG
Views:	63
Size:	383.7 KB
ID:	1942281  
Aussie Damo is offline  
Reply With Quote
Old 11-25-2013, 10:48 PM
  #2
combatpigg
 
combatpigg's Avatar
 
Join Date: Nov 2003
Location: arlington, WA
Posts: 19,891
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

At 9.6 ozs the CG will be more critical than if the plane weighed 7 ozs, so work the CG back in 1/4" increments even if it means moving the motor back.
The fishtail at low speeds is from marginal fin area. The small fin gains effectiveness at higher speeds. The highly tapered wing doesn't help either. Wing tips with less than 4 inches of chord aren't doing much at this sort of wing loading.
Increasing the fin area [add a section in the middle of the existing fin] would shift the CG in your favor without a noticeable difference in weight if you choose good wood.

Last edited by combatpigg; 11-25-2013 at 10:56 PM.
combatpigg is offline  
Reply With Quote
Old 11-26-2013, 12:51 AM
  #3
Aussie Damo
Thread Starter
 
Aussie Damo's Avatar
 
Join Date: Jun 2004
Location: Geelong, Victoria, AUSTRALIA
Posts: 153
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Thanks Combat pig,
The fin size thing makes complete sense, is there a technical name for this??

CG wise I cant really move the motor back, its a x mount brushless so its attached directly to the firewall and that is epoxied in there well and good, also if i move it any more the prop will come close to hitting the leading edge.
I dont quite understand what you mean by adding a section in the middle of the fin.

Dont get me wrong, it flies pretty good, just a bit of a dog trying to land/slow speed, I guess that's to be expected from a heavy delta
Aussie Damo is offline  
Reply With Quote
Old 12-03-2013, 07:10 AM
  #4
MJD
 
MJD's Avatar
 
Join Date: May 2003
Location: Orangeville, ON, CANADA
Posts: 8,606
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

On mine I ditched the pointy fin tip - pointy tips are nothing but drag generators - by clipping it to about 1-1/4" tip chord.

At almost 10 oz I think your days of flying slowly may be over..?
MJD is offline  
Reply With Quote
Old 12-03-2013, 10:34 AM
  #5
Andrew
 
Join Date: Feb 2003
Location: Murray, KY
Posts: 3,193
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by Aussie Damo View Post
Second question, what is it when the tail sort of corkscrews following the nose (ie the tail if traced from behind would be drawing .5-1 inch circles), it only happens at low speed in shallow angle of bank turns?
Where does the front of your rudder terminate? It should be even with the forward spar, but from your pics, I can't tell.
Andrew is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 08:54 PM.