View Single Post
Old Apr 11, 2010, 08:20 AM
dz1sfb is offline
Find More Posts by dz1sfb
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
11,417 Posts
BF-109 Plans and Instructions for Version 3

Here are the plans for the BF-109! Now updated to version 3

This is a bit more complex of a build but still simpler than a full fuselage. Just some detail cutting involved. I will cut one on the machine today.


Here are the build instructions:

1. Cut out all parts.

2. Hinge ailerons and elevator.

3. Laminate the Fuselage Center Panel to Fuselage Intermediate Panels. Use painters tape to hold parts aligned to one another. Add 1/16" x .6" x 5" nose to wing reinforcement and tape in place. Clamp assembly between two pieces or flat 1"x 6" boards 2' long, or something similar while the glue cures. Note: clean up any glue that foams into servo mounting, wire routing, and motor mount openings. Needed for step number 8.

4. Prebend dihedral specified in the plans to both the Main Wing Panel and the KF Step Panel. Then glue together and clamp with the dihedral in place. Wing tips on the KF Step Panel will need to be sanded to match the Main Wing Panel once the adhesive is cured. See notes on plans concerning the use of spar material in place of strapping tape.
Optional: wings may be left flat for building ease, but dihedral is recommended for better stability properties.

5. Sand the leading edge of wing assembly so that the KF Step Panel is rounded down to the Main Wing Panel, giving it a bit of an airfoil. Add a strip of clear packing tape over the leading edges when done.

6. Add a 1" wide piece of strapping tape from wingtip to wingtip aligned with the back of the KF Step Panel at the tips. Do this to the top and bottom of the wing assembly. This step may be omitted if optional spar material is used in step 4.

7. Servos may now be installed after the build is complete.

8. Install LH & RH Fuselage Outer Panels to the fuselage assembly, along with the firewall. This locates the front of the panels together. Tape sides in place and clamp between 1 x 6 boards as before to allow glue to cure.
Note: be sure to keep the hatch openings clear of foaming glue. This will ensure a clean fit of access hatches.

9. Contour the fuselage as much as possible, then install elevator assembly and Rudder Panel to the fuselage assembly. Making sure parts are straight and square to the fuselage.

10. Dry fit wing into bottom of fuselage. You will need to sand the wing saddle area to allow full contact for gluing. Then glue the wing to the fuselage assembly.
Note: center the aileron servo with radio and install the long 2 arm servo horn. This is easiest done prior to gluing wing on.
Optional: If want to build your wing without dihedral you will not need to do this step.

11. Bend, fit up, and install aileron and elevator pushrods and control horns.

12. Install motor, and make a channel that will allow the motor wires to enter the ESC cavity. Either in the hatch or ahead of the hatch.

13. Check the center of gravity location. Should be at 2.2" from the leading edge of the wing at the root. Then check with the battery. Balance as needed.

14. Install remaining radio equipment. Tape esc and rx hatches in place. Battery hatch may be taped on one side as a hinge, and held with a magnet on the other. Use what works for you.

15. Paint or not, fly and have fun.

This model was designed to utilize the equipment in this thread. If you use something else you will likely get different results.
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Last edited by dz1sfb; Feb 01, 2011 at 06:29 PM. Reason: revised build instructions and plans
Reply With Quote