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© 2005 - Bernard Burton                                                                                DRAFT 

11

Center of Gravity:  

 
The plane should be centered at 25% of the median chord or 147 mm from the leading edge of 
the top wing. The Center of Gravity can be moved backward for 3D acrobatics. 
 

 

 

Summary of Contents for Spirit of Pitts

Page 1: ... 2005 Bernard Burton DRAFT 1 Designed in 2005 by Bernard Burton Assembly manual ...

Page 2: ...ed to tell you how to build this aircraft each builder has their own approach to building This is only a guide which will show you how we built our Spirit of Pitts Use it if you feel that it may help NOT ALL STEPS ARE SHOWN IN THIS MANUAL Disclaimer This plane and plans are intended for ADVANCED BUILDERS and PILOTS ONLY The user shall determine the suitability of the product for their intended use...

Page 3: ... cure Î Step 3 Build crutch assembly upside down on a flat workbench We can not emphasize enough the importance of building this crutch square and also the alignment to the print This is as important as building a straight wing The flat surface of the formers should be placed on the workbench Glue with 30 epoxy the formers F5 F2 F2 doubled F3 and F4 on their respective places on the fuse sides S1 ...

Page 4: ...5 Glue the S1 doublers between F1 F2 and between F2 and F3 on the outsides of F1 This is to re enforce the position where the wing struts are attached Step 6 Glue F6 F7 F8 and F9 in place Verify and eventually adjust the alignments and let the epoxy cure Step 7 Join the formers with balsa sticks Helpful hint Use a piece of scrap foam or balsa to hold the fuse sides out against the formers while yo...

Page 5: ...four 5x5 mm Balsa stick on the former slots bottom half from F2 up to F2 Step 8 Prepare the removable canopy Put the canopy formers FT1 FT2 FT3 FT4 and F6a on their place according the plans on the fuse Do not glue the formers on the fuse Glue the 5x5 mm 10x10 mm balsa sticks on the formers according the plan Pay attention that the lower 10x10 mm stick is going up to F6a Do not glue the stick on t...

Page 6: ...asy sheet wrapping around the fuse you can spread an Ammoniac Water mixture on the balsa sheet Wrap the wet sheet in place and let it dry for a night Use CA glue to glue the balsa sheets according the plan drawings with special care for the wing join Step 12 Elevator and rudder assembly On a flat workbench build the elevator and rudder panels using a copy of the plans Use polyurethane glue for max...

Page 7: ...s and let the epoxy cure Glue all the 5x5 mm sticks between the three CF rings Verify and eventually adjust the alignments and let the epoxy cure Wrap the cowl with 2mm balsa sheet Glue with 30 epoxy Sand the concentric rings on the outside to have a smooth curved cowl noose Wait until the motor is installed before adjusting fixing the cowl on the fuse Helpful hint The length of the cowl should yo...

Page 8: ...balsa sheet Put a wire in the wing to ease the servo wires installation at a later stage When the glue is fully cured remove the wing aileron from the workbench Glue W9a W9b plywood ribs on W3 W9 with 30 epoxy The tabs should be placed on the lower side of the wing Remove the rib alignment tabs Except the W1 W9 alignment tabs If your job is well done the wing should rest on the four wing fixation ...

Page 9: ...ge spars square triangle and cover the top with a 2 mm balsa sheet Glue W9a plywood ribs on W9 with 30 epoxy The tabs should be placed on the upper side of the wing Put a wire in the wing to ease the servo wires installation at a later stage When the glue is fully cured remove the wing aileron from the workbench Remove the rib alignment tabs except the W1b W9 alignment tabs Continue to cover the w...

Page 10: ...udder assembly with the bottom wing o The distance between the trailing wing tip and the trailing elevator tip must be the symmetric for left and right o The wing horizontal axis must be parallel with the elevator horizontal axis o The elevator incidence compared to the fuse axis 0 o Glue the elevator rudder assembly with 30 epoxy o Verify and eventually adjust again the alignments before the glue...

Page 11: ... Bernard Burton DRAFT 11 Center of Gravity The plane should be centered at 25 of the median chord or 147 mm from the leading edge of the top wing The Center of Gravity can be moved backward for 3D acrobatics ...

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