Park Scale Models

AT-17 Bobcat

Assembly Manual

Fuselage Construction

1. Glue the two ¼” balsa servo rails SR to BB5.

2. Assemble the wing mount block by gluing WM1(x2), WM2 and WM3 together as shown.

3. Epoxy two of the supplied nylon nuts into the wing mount block as shown. Be very careful not to get any epoxy into the threads of the nut.

BB5

SR

5

WM3

WM2 WM1

4. Assemble the servo tray by gluing BB5 to BB7 as shown. Ensure that BB5 is perpendicular to BB7.

5. Fit and glue the servo try assembly to BB3.

6. Fit and glue BB1 to BB3 Fit and glue the wing mount block to BB3 and BB7.

7. Fit and glue BB2 to BB1, BB5, BB& and the wing mount block.

BB5

BB7

BB3

BB1

Wing mount

block

BB2

8. Fit and glue BB4 to BB2 & BB3. Fit and glue BB6 to BB2, BB3, BB5 and the wing mount block. It is recommended to install your rudder and elevator servos into the servo tray at this time.

9. Fit and glue FL7A (x2) to F3.

10. Fit and glue F2 to FL7A.

11. Fit and glue FL4(x2), FL5(x2) and FL6(x2) to F2 & F3.

BB6

BB4

FL7A

F3

F2

FL4

FL5

FL6

12. Fit and glue FL10 into the center notches of F2 & F3. Fit and glue FL9, FL8 and FL7 into the notches in F2 & F3 on both sides of FL10.

13. Slide this assembly onto the wing mount/battery box assembly as shown, do not glue in place!

14. Fit and glue FL1 into the center notch of F3, unsure that the notch in FL1 is facing up. Fit and glue FL2 and FL3 on both sides of FL1 as shown.

15. Fit and glue F1 to the wing mount/battery tray assembly first. Carefully align and fit FL1-FL10 into the notches in F1, ensure that they are fully inserted into the notches and then glue in place. Glue F2 and F3 to the wing mount/battery box assembly.

FL10 FL9

FL8

FL7

FL1 FL2

FL3

F1

16. Assemble formers F4 and F5. Glue F6 to the motor mount assembly. Fit and glue F4 and F5 into the notches in the wing mount assembly. Glue F4 to F3 and the wing mount assembly. Glue F5 to the top of the wing mount assembly only! See the end of the manual for how to assemble the fuselage formers.

17. Assemble the fuselage sides as shown below. Fit and glue the fuselage sides to F4-F6.

18. Fit formers F7-F9 into the fuselage sides.

19. Fit and glue F10 and F12A to the fuselage sides. Ensure that the fuselage is straight before gluing the formers F7-F9 in place.

20. Fit and glue F12 to F10 and the fuselage sides.

21. Fit and glue F11 to F12, F12A and the fuselage sides.

22. Epoxy F11A to F11, F12A and the fuselage sides.

23. If you plan to install a steerable tail wheel it is recommended to use a Dubro 1/2A steerable nose wheel. Screw the mount to F11 using the pre-drilled holes in F11. You will need to install the control linkage to connect the tail wheel to the rudder servo. If you do not wish to install a steerable tail wheel, a fixed tail wheel can be installed later.

24. Install the rudder and elevator pushrod sleeves. Use Dubro Lazer Pushrods or similar.

25. Fit and glue F12B in place.

26. Fit and glue FS4 to F6-F10. Glue two pieces of 3/16” sq. balsa sticks into the notches in the bottom of F6-F10 and also to the fuselage sides.

27. Glue two pieces of 3/16” sq. balsa sticks into the notches in the top of F4-F10 and also to the fuselage sides.

FS4

28. Fit and glue FS1A to F4-F6. Fit and glue FS2A to F4-F8. Fit and glue FS1B to F6-F10. Fit and glue FS2B to F8-F10. Fit and glue FS3 to F4-F8.

cop

29. Glue SH2(x2) in place where indicated, lightly dampen the outside surface to help bending if necessary. Fit and glue SH1 in place.

30. Glue SH3(x2) in place where indicated, lightly dampen the outside surface to help bending if necessary.

31. Fit and glue B1-B16 in place. Start with B12 and work forward to B1.

FS1

FS2

FS3

SH1

SH2

B1

B16

Wing Construction

1. Start the center wing section by fitting R1(x2) and R2(x2) to WS1A and WS2A. Ensure that the ribs are perpendicular to the spars before gluing.

2. Fit and glue WS3, WM5 and TE1 to ribs.

3. Cut two (2) 5” lengths of the supplied 3/16” hardwood dowel. Insert the dowels into the wing spars as shown and epoxy in place. Allow the dowels to extend past WS3 by ¼”.

R1

R2

WS2A

WS1A

WM5

TE1

WS3

4. Fit and glue WL1 and WL2 in place.

5. Sheet the bottom of the center wing section with 1/16” balsa.

6. Cut the electronics tray from some scrap wood using the template at the end of the manual. Glue to WS1A, WS2A and R1(x2).

7. Sand TE1 to match the contour of the ribs. Sheet the top of the wing center section with 1/16” balsa. Cut out the sheeting around the electronics tray area.

WL2 WL1

8. Cut the leading edge sheeting from1/16” balsa to size using the measurements below, ensure the long edge is straight. Glue WS1 on top of the 1/16” balsa sheet along the straight edge.

9. Cut a sheet of 1/16” balsa to size using the measurements below. Edge glue to the leading edge sheeting.

10. Fit ribs R5-R14 to the spar, do not glue yet.

11. Fit and glue SDF between R7 and R8, ensure it is tight up against the wing spar. Fit and glue the 1/16” balsa servo door sheeting between ribs R10 and R11, ensure it is tight up against the wing spar.

2.5”

22.75”

3.75”

7.25”

11”

8.75”

straight edge

glue on top of sheet

straight edge

SDF

servo door sheeting

WS1

12. Fit and glue SDF between R10 and R11, ensure it is tight up against the wing spar. Trim any overhanging balsa sheeting flush with R8.

13. Fit and glue TE2 to R5-R9 and the balsa sheeting. Glue R5-R7 to the balsa sheeting.

14. Fit and glue R9A to the outside R9 and TE2.

15. Fit and glue TE3 to R9A – R14.

trim sheeting flush with R8

SDF

TE2

R9A

16. Fit WS2, S1B and S2B in place where shown. Do not glue in place yet.

17. Fit R3 and R4 in place where shown. Ensure that all parts are fit together tightly and then glue R3 and R4 to WS1, WS2, S1B, S2B and the balsa sheeting. Glue S1B to WS1 and the sheeting. Glue S2B to WS2 and the sheeting. Remove any excess glue at the joints between S1B/WS1 and S2B/WS2.

18. Fit and glue S1A to WS1 and R3-R5. Fit and glue S2A to WS1 and R3-R5. Fit and glue TE1 to R3, R4 and the sheeting. Remove any excess glue at the joints between S1A/WS1 and S2A/WS2.

19. Fit and glue the 1/32” plywood shearwebs to S1A/B and S2A/B. Epoxy shearwebs to R3, R4 and the balsa sheeting.

S1B

WS2

S2B

R4

R3

S1A

1/32” ply

shearweb

TE2A

20. Fit R3A in place.

21. Fit and glue LE1 to R3A-R14. Sand LE1 to match the top and bottom contours of the wing ribs.

22. Trim the excess sheeting along R3.

23. Glue the bottom sheeting to R3-R14 and LE1.

LE1

24. Fit and glue some 1/16” balsa sheeting to the bottom of R13 and R14.

25. Sheet the top of the wing as shown with 1/16” balsa.

26. Trim away the excess sheeting along LE2 and R4 as shown.

27. Fit and glue TE2A to TE2 and TE3A to TE3. Use hinges to ensure that the hinge slots line up properly.

TE2A

TE3A

28. Sand the sheeting flush with LE1 and then glue some 1/8” balsa to the leading edge of the wing and sand to shape.

29. Align and glue F15 to F14.

30. Fit and glue WTS into the slot in F15.

31. Fit and glue WT to F15 and WTS as shown.

32. Cut away the leading edge sheeting between R5 and R6. DO NOT cut through the spar!

33. Epoxy two FW1 together and glue to nacelle frame NF1 as shown. Fit RB1 (blue) and RB2 (red) into NF1, do not glue yet.

34. Fit and glue FW2 to NF1 and FW1.

35. Fit NF2 in place as shown. Check that RB1 and RB2 align properly and fit into the slots as shown. Remove NF2, epoxy RB1 & RB2 together. Fit and glue NF2 to FW1 & FW2. Epoxy RB1/RB2 to FW1 and FW2.

RB2 (red)

RB1 (blue)

FW1 (x2)

FW2

NF2

36. Fit your retracts to RB1/RB2. Use the template supplied by your retract manufacturer to cut the opening for your retracts.

37. Fit and glue NF1A, NF1B, NF1C & NF1D together.

38. Fit NF1 and NF3A in place where shown, do not glue yet.

39. Fit and glue NF3B, NF3C & NF3D and NF4B, NF4C & NF4D together.

NF1A

NF1

NF3A

NF1B

NF1C

NF1D

NF3C

NF3B

NF4B

NF4C

NF4D

NF3D

40. Fit NF3, NF4, NF5 & NF6 in place as shown. Do not glue yet. Test fit the nacelle to the wing to ensure the formers are oriented correctly. Remove nacelle from wing and glue the formers in place.

41. Fit and glue NL1, NL2 & NL3 in place as shown.

42. Fit and glue NF2A, NF2B, NF2C & NF2D together.

43. Fit and glue NF2 in place as shown.

NF6

NF4

NF5

NF3

NL3

NL1

NL2

NF2

NF2A

NF2B

NF2C

NF2D

44. Fit and glue the nacelle blocking rings NB1, NB2, NB3 together. Each ring is made up of three pieces; you will need two of each ring. Epoxy three ¼” magnets into NB1 where indicated, ensure the polarities of the magnets are oriented in the same direction.

45. Stack and glue NB1, NB2 and NB3 together and then glue to former NF2.

46. Temporarily fit the nacelle to the wing and mark where the former NF1 come in contact with the leading edge.

47. Remove the nacelle from the wing and remove the 1/8” balsa leading edge where marked so that the nacelle will sit flush against LE1. Refer to step #21 to identify LE1.

NB1

TEA

NB2

NB3

¼” magnets

48. Fit the nacelle to the wing.

49. Cut an 8” length of the supplied 1/8” carbon fiber rod and slide it all the way into the wing and nacelle to align the nacelle and lock it in place. Glue the nacelle to the wing and use thin CA to glue the carbon rod to the wing ribs and nacelle frames.

50. Glue NF4A in place as shown.

51. Fit and glue the pre-cut nacelle sheeting/planking to the nacelle formers and longeron.

1/8” carbon fiber rod

NF4A

Pre-cut sheeting/planking

52. Fit and glue the pre-cut nacelle sheeting/planking to the nacelle formers and longeron.

53. Fit and glue the pre-cut nacelle top sheeting/planking to the nacelle formers and longeron.

54. Fit and glue the pre-cut nacelle bottom sheeting/planking to the nacelle formers and longeron.

55. Fit and glue nacelle blocking NB4, NB5, NB6 and NB7 to the nacelle and wing as shown. Sand blocking to shape.

Pre-cut sheeting/planking

Pre-cut sheeting/planking

Pre-cut sheeting/planking

Cowl Construction

1. Fit and glue the cowl formers CF1 and CF2 together. Epoxy ¼” magnets into CF2 where indicated. Ensure that the polarity of the magnets in CF2 match the polarity of the magnets in the nacelle.

2. Fit and glue six (6) CL to CF2 as shown.

3. Fit and glue CF1 to the six CL as shown.

CL

CF1

CF2

¼” magnets

CF1

CF2

4. Edge glue three (3) of the precut 1/16” balsa cowl sheeting pieces together to form a ring. Lightly dampen the balsa sheeting inside and out to make it swell slightly. Place the cowl framing on a flat surface with CF1 down. Fit the sheeting over the cowl framing, ensure the sheeting joints are lined up with the longeron CL and that the sheeting is flush with CF1. The sheeting should extend past CF2 by approximately 1/8”. Set it aside to dry. Once dry, glue the sheeting to the cowl framing.

5. Fit and glue the cowl blocking rings CB1, CB2, CB3, CB4 together as shown.

6. Stack and glue the cowl rings together.

7. Glue the cowl blocking to CF1 as shown.

8. Sand the cowl blocking to shape.

9. Cut three (3) ¼” long pieces of 1/8” wood dowel and glue into CF2 as shown.

Horizontal Stabilizer Construction

1.

2.

3.

HL2

HL1

HL3

HR1

HR7

HB2

HB1

HB3

4.

5.

6.

7.

HL2

HL1

HL3

HT1

HT2

EB1

EB2

8.

9.

10.

11.

CF1

EL1

1/32” Ply ‘Trim tab’

EM

EL2

ER1

12.

13.

14.

15.

1/8” carbon rod joiner

VL

VB1

16.

17.

18.

19.

VT2

VT1

RB1

RB2

RL1

20.

21.

22.

1/32” Ply ‘Trim tab’

RL2

RM

Tailcone Construction

1.

2.

3.

TB2

TB7

TC2

TC1

TB1

4.

5.

6.

7.

TB8

TB9

8.

1/16” Ply ‘seam’