Sport Flying This forum is for those that like to fly just for the enjoyment of flying, and all the airplanes that help them. Discuss here the joys of flying and the airplanes that help you enjoy it.

Great Planes Extra 300SP help

Reply
Old 06-16-2012, 06:20 PM
  #1
matt417
Thread Starter
 
Join Date: Aug 2011
Location: Binghamton, NY
Posts: 9
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Great Planes Extra 300SP help

hey guys, Irecently put together the Great Planes Extra 300SP ARF. I put an OS 46FX in for power. The instructions stated when using a glow engine to mount the rudder servo in the tail of the airplane. I mounted the battery right underneath the reciever as stated in the manual. Basically I built the plane just how the manual told me to. Iput the plane on the CG machine and it was extrememly tail heavy. Just wondering if anyone else has run into this problem. Idouble and triple checked the measurments from the lead edge. it says 3 3/4 from the leading edge. I double checked everything and still the plane is largely tail heavy. Just wondering if anyone else has run into this problem. Not sure if I'm doing something wrong or not. any help would be greatly appreciated as I am going to maiden her tomorrow..thanks!
matt417 is offline  
Reply With Quote
Old 06-17-2012, 03:42 PM
  #2
dignlivn
 
Join Date: Oct 2005
Location: Deland, FL
Posts: 1,993
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Great Planes Extra 300SP help





Which way did you balance, upright or inverted ?
Fuel tank empty? OS 55 might help add nose weight
also (jmo)

Bob
dignlivn is offline  
Reply With Quote
Old 06-17-2012, 03:59 PM
  #3
matt417
Thread Starter
 
Join Date: Aug 2011
Location: Binghamton, NY
Posts: 9
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Great Planes Extra 300SP help

I balanced it inverted, with the tank empty...ended up moving the battery up and mounting it above the fuel tank..and added a little weight up front...first landing was dead stick, and it floated in..gonna move the rudder servo up from the tail and remove some weight and should be good....fun plane to fly for sure!
matt417 is offline  
Reply With Quote
Old 06-25-2012, 12:46 PM
  #4
fly24-7
 
fly24-7's Avatar
 
Join Date: Dec 2005
Location: Shrewsbury, MA
Posts: 378
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Great Planes Extra 300SP help

As a suggestion, before I finalize mounting locations for batteries, switches, servos and such, I'll temporarily mount them in the desired locations and do a preliminary balance check. This will at least let you know your options before permanently mounting anything. Unless you use the exact equipment recommendations from the manufacturer, you can't go off of their mounting recommendations 100%. Even small differences in servo weight can mean a lot with balance because of the tail moment. Many airplanes have about a 4-5:1 nose to tail ratio. For every ounce of weight that's added to the tail, you'd have to add 4-5 ounces to the nose to offset. So, you have to be very mindful of servo weight for tail mounted servos.
fly24-7 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 02:57 PM.