Building Instructions for FT EZ Pack V2 "Circular"

L Edge

Master member
Circular is a offshoot between my delta and geobat plane eliminating any vertical stabs to keep the weight down. Object is to see how many different shapes I can get that fly with the EZ Pack. Results from this one are impressive using the EZ Pack.

Concept:
Exploring weird designs requires some sort of stability so the first thing I did was give a 14 degree dihedral to the circle. Next, made the wing segments of the "Circular" level in X and Y planes with the tail up righted to 14 degrees to make this a one piece plane. Plane requires 1 cut(1/2 circle out) and 3 scores to assemble. After designing 5 planes, began to realize different foam boards makers play(weight vrs CG) an important part why some will not fly properly. Suggest everyone use Adams Readi-Board to eliminate errors. I am doing both.

Build:

1) With scraps, build 2 dihedral guides 14 degree so that each section is slightly less than 3 inches from centerline.
2) Take 4 scraps and glue together. This is for the levelness of the wings. If you glue right, will need no shims.

circular.JPG


Steps on paper:: I am old school, by paper, if pilots like, maybe someone can produce computer plans.

1) Draw 12 1/4" circle.
2) Draw 9" circle same radius.
3) Draw vertical centerline of 12.25 circle.
4)Draw 2 lines 3" parallel to centerline inside large circle.
5) Draw 2 lines 1.5" parallel to centerline (prop shaft) that ends at 2.5" down on vertical centerline. That is where your carve out motor mount that is pushed in to foam.
6) Prop slot is 9/16 wide by 2 3/8 long centered about prop shaft.
7) Cut out lower half circle of 9" circle.
8) Transfer to foam material.
Enough for today.
 
Last edited:

L Edge

Master member
Build Steps:
1) Cut out 1/2 circle from foam.
2) Score 3 lines for bending. (I used a pen)
3) Bent 2 outer segments down for wings. Be careful that back segment is deflected upwards.
4) Start with 2 14 degree jigs and push foam down until centerline of foam plane matches centerline of both jigs. Then glue and dry for awhile.

jig.JPG


5) Put plane back in jig and weight it. Now is the time to ensure the outer wing portion is scored for glue and it is absolutely level front to back with shims underneath. I also put an extra shim at tail end. Remove shims, fold down, glue and let it dry with shims installed.

Do not move weighted plane in jig. and do other side of wing with shims. The concept is that when glue is dry, the 2 wings are level across and also front to back.

shim1.JPG


shim2.JPG


Now you can glue the tail. If you did it right, it should be an angle of 76 degrees. Now you are ready to install electronics.
 

L Edge

Master member
circular.JPG


Next is to put the 2 slots (9/16" by 2 and 3/8") a distance of 1.5" out from centerline and 2.5" down from the nose. Then carve our the motor slot and tape motor mount to foam. I made this one out of Adams Readi-Board and weighed 17.8 grams and ready to fly at 45.4 grams. That included the packing tape for flight.(poor talent for decorations). Move the FC and battery to get the proper location.

The CG was located at 3.35 inch from the nose.

If you notice the other one below, it was made from Sturdy Board which was very much heavier and weigh in at 62.7 grams verses 45.4 grams and requires a different location of electronics to get the CG right.

h circle.JPG


Will provide a video of each on the field when weather gets better.

Next one I will do is a build of the delta version. Again, is a 1 cut after the delta shape and 3 scoring for a build. Simple build.


delta.JPG