MoJo 25 Build Instructions
Thank you for buying the MoJo25 Kit!!
This little bird was designed for electric power
or 25 size glow. Any decent 25 size bearing
motor should work great for glow. See
recommendation below for e power.
You should be able to build this bird at an
AUW of between 24 and 28 oz. Covering with
Nelson’s lite film or Ultrakote lite helps keep
the weight down.
A friend of mine, Jeff Williams (Chuck Auger) of Pampa Texas uses this setup. The vertical performance is
jaw dropping.
Lehner 1020/15 Phoenix 35 www.b-p-p.com
Cobri aluminum gearbox 12 tooth SS pinion, 70 tooth spur www.b-p-p.com
12X6 APC SF prop www.apcprop.com
For out runner guys:
AXI 281412 Motor with reverse mounting kit. www.hobby-lobby.com
Castle Creations ESC Phoenix 35 http://www.castlerc.com
Tanic 2500 mAh 3 cell LiPoly batteries, 12C discharge. www.tanicpacks.com
APC 11 x 4.7 SF prop www.apcprop.com
I welcome feedback. If you have any
questions at all, don’t hesitate to drop me an
email at PaulSwany@Swanyshouse.com or
post a question on www.theProBros.com and
I’ll answer it as fast as I can. Don’t forget to
visit me at www.Swanyshouse.com … You
never know what I might be cookin’ up!
Thanks again and have fun building and flying
your MoJo!!!
MoJo 25 Build Instructions
Here’s what’s included in the kit:
Precut CNC parts:
1/16” balsa ribs
1/4” balsa sub ribs.
1/4” balsa center half ribs.
3/8” balsa aileron leading edge.
1/4” ply motor mount.
1/4” upper and lower fuse pieces.
1/4” vertical stab trailing edge.
1/4” rudder leading edge and bottom piece.
1/4” horizontal stab trailing edge and center piece.
1/4” elevator leading edge.
1/4” ply landing gear support
1/8” ply landing gear blocks
Stock Wood
3 – 1/4" sq x 36” balsa
3 – 1/4" tri stock x 36" balsa
3 – 3/16" sq x 36” balsa
2 – 3/16" x 5/16”x 36” balsa
2 – 1/8" x 1/4" x 36 balsa”
2 – 1/16" x 1/2" x 36”
1 – 1/16" x 1” x 12”
1 – 1/8” x 1/4" x 36” hardwood servo rails.
1 – 1/4" sq x 3" basswood
Other parts included
1/4" Glassform tube
1/4" CF tape
1/8” music wire pre bent landing gear
Here's what you'll need to finish the kit:
1–
2–
2–
5–
4–
4 oz Hayes fuel tank
2.1/4" lite foam wheels
1/8" collars
2/56 x 12 pushrods and clevises
control horns
5 – micro servo's, I like Hitec HS-85’s or Diamond 200 servo's
1 – 4 channel RX, at least 5 channel if you want flapperons.
1 – Battery and switch. I like the 6v 720 mAh batteries from www.RadicalRC.com
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MoJo 25 Build Instructions
Build the Motor mount assembly
1. ___ Retrieve the ¼” ply motor mount. Roughen up the black glass form epoxy tube and fit to the motor
mount block. When you’re satisfied with a nice tight fit, epoxy the tube to the mount. See fig 1.
Fig. 1
Fig. 2
Build the spar assembly.
1. ___ Retrieve a piece of 1/8” x 1/4”sq. balsa, 36” long. Mark the center of the stick. Make a mark 5”
from either side of the center. See fig 2.
2. ___ Glue on a 10” piece of ¼” CF strip centered on the spar. See fig 3
3. ___ Glue on a 4” piece of 1/4” x 1/8” hard wood centered on the spar. See fig 4.
4. ___ Repeat steps 1 – 4 for the other spar.
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MoJo 25 Build Instructions
The Center Rib Assembly
1. ___ In this step, you will build the center rib assembly. Retrieve the two largest ribs from the rib set, two
triangle shaped half ribs and the motor mount (tube not shown). See fig 1.
2. ___ Lay the triangle shaped half ribs on one of the center ribs. They should line up with the outline of
the rib and the motor mount assembly should fit between the half ribs. When you’re happy with the
fit, glue the half ribs to one of the center ribs. See fig 6 and 7.
3. ___ Glue the other rib on top of the assembly being careful to align the spar and servo notches. DO NOT
GLUE TO THE MOTOR MOUNT ASSEMBLY. The motor mount assembly isn’t glued to
ANYTHING until final assembly. See fig 7
4. ___ Retrieve the two leading edge doublers and glue to the center rib assembly. See fig 8.
Fig. 5
Fig. 7
MoJo 25 Build Instructions, Rev 0
Fig. 6
Fig. 8
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MoJo 25 Build Instructions
It’s wing time Baybee!! Yeah!! ( I love building wings! )
1. ___ The first step is to layout the plans on your building board and cover with wax paper or parchment.
Now pin some scrap balsa blocks to the plans on the inside line of each rib. This will help when
pinning the rib tabs to the plans. See fig 9.
2. ___ The next step to build the wing is to fit one of the spar assemblies to the center rib. Check that the
spar is square with the center rib. See fig 10
3. ___ Position the spar over the plans (do not pin) making sure the spar and center rib line up. Apply some
thin CA. There is no need to shim or block up the spar. The spar alignment is set in the rib slots.
See fig 11.
Fig. 9
Fig. 10
Fig. 11
Fig. 12
4. ___ Now fit the rest of the ribs on the spar and pin to the plans using your alignments blocks you pinned
down in step 1. Make sure each rib is square to the plans. Do not glue at this time. See fig 12
5. ___ Fit and install both main sheer webs. Don’t force it, or you’ll break a rib. Make sure to open the
slots if the fit is overly tight with a sanding stick. No glue yet. See fig 13
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MoJo 25 Build Instructions
6. ___ Fit and install both rear spars. This piece is somewhat fragile, so be careful to relieve any joint that
is too tight.
7. ___ When you are happy with the fit, wick some thin CA into the joints.
Fig. 13
Fig. 14
8. ___ Install the top spar. Use some medium CA See fig 15.
9. ___ Install the 3/16” balsa sub spars and ¼” balsa leading edge. See fig 15
Fig. 15
Fig. 16
10. ___ Install the ¼” balsa trailing edge. See fig 16.
11. ___ Shape the trailing edge with a razor plane or sanding block to match the contour of the rib.
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MoJo 25 Build Instructions
12. ___ Install the 1/16” x ½” balsa trailing edge sheeting. See fig 17
13. ___ Install the 1/8” x ¼” hardwood servo rails. See fig 18
Fig. 17
Fig. 18
14. ___ Install the 1/16” x 1” center section sheeting. See fig 19
15. ___ Unpin and pull the wing off the board.
16. ___ Install the bottom side trailing edge sheeting and center section sheeting.
Fig. 19
Fig. 20
17. ___ Install the 3/16” bottom sub spar.
18. ___ Install ¼” gussets at the trailing edge to tip rib joint. See fig 20
19. ___ Build 2 ailerons. Use 3/16” x 5/16” for the ribs. Trailing edge is 3/16” hard balsa. Use a sanding
block or a razor plane to shape the ribs to meet the trailing edge. See fig 21.
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MoJo 25 Build Instructions
Fig.22
Fig.21
Fig.22
Fuselage Construction
1. ___ Lay some wax paper over the plans
covering the fuselage area.
2. ___ Pin and position the machined pieces over
the plans and wick some thin CA in.
3. ___ Cut 1/4" sq balsa to fit and wick in some
thin CA.
4. ___ Using the motor mount as a guide, position
the bottom fuse piece over the plans. DO
NOT GLUE THE MOTOR MOUNT AT
THIS TIME.
5. ___ Glue the 1/4” balsa gusset per the plans.
6. ___ Leave the 1/4” vertical stab post in one
Fig. 23
piece. This will make final assembly and
fuse alignment much easier.
7. ___ Cap the trailing edge of the vertical stab
with ¼” tri stock.
8. ___ Build the rudder over the plans using the
machined leading edge and ¼” balsa. thin
CA that bad boy together.
9. ___ Remove the assemblies from the board.
Fig.24
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MoJo 25 Build Instructions
Horizontal Stab and Elevator
1. ___ Pin and position the machined pieces over
the plans and wick some thin CA in..See fig
25 and 26.
2. ___ Use some ¼” balsa to frame the rest of the
stab per the plans. See fig 25 and 26.
3. ___Remove from plans, and install 1/4” tri
stock on leading edge of elevator. Sand
flush.
4. ___ Install 1/4” tri stock on trailing edge of the
horizontal stab. Sand flush.
5. ___ Mark the centerline of the stab assembly
using a ruler and a square. Measure 1/4” on
each side of the line and make a mark
parallel to the center line. Glue a piece of tri stock on both lines. This will help to strengthen and
align the horizontal stab during final assembly.
Finishing and final assembly
1. ___ Sand all assemblies lightly. Just knock off the high spots.
2. ___Cover all assemblies being careful to not cover the gluing surfaces. I like to use some balsa rite on
the ply motor mount before I cover it.
3. ___ Test the motor mount assembly fit into the wing. Once you are satisfied with the fit, install using
some wood glue or epoxy. Make sure the mount bottoms out against the wing spars. Fuel-proof the
motor mount with thinned epoxy or thin CA. Make sure to rough up the tube when it will mate with
the fuse. Gotta give that glue something to bite to.
4. ___ Glue on the landing gear plate to the bottom of the fuse. It’s the triangular shaped piece with two
holes in it. Use wood glue or epoxy.
5. ___ Dry fit the fuse assembly to the wing assembly
6. ___ Dry fit the stab assembly to the fuse.
7. ___ Hinge the elevator to the horizontal stab with CA hinges.
8. ___ Once you are satisfied with the fit, slide the horizontal stab assembly into the fuse. Slide the fuse
assembly on to the wing, motor mount and tube assembly. When you’re sure everything is gonna fit.
Slide the fuse over a little and apply wood glue or epoxy to the top and bottom of the motor mount
and wing.
9. ___ Check your alignment and clamp and tape the assembly so that the gap is minimized. It helps to
have a few extra hands here.
10. ___ It’s not necessary to glue the tube to the fuse just yet. Alignment is much easier if you do this in a
second step.
11. ___ Allow to dry
12. ___ Align the tube to the tail. Tack glue with thin ca in a few places.
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MoJo 25 Build Instructions
13. ___ Align the horizontal stab. Wick in some thin CA to set it.
14. ___ Mix up some epoxy and micro balloons on a piece of wax paper. Fold over the wax paper and roll
into a little cone. Cut a very small hole in the tip and squeeze into the fuse / tube joint. Thanks to
my fellow ProBro, Ron Ferrer for this method. I used it on the prototype and loved it!
15. ___ Hinge the ailerons and rudder. Use CA hinges.
16. ___ Mount the aileron servo’s per the plans.
17. ___ Mount the , rudder and elevator servo’s in the tail.
18. ___ Run your servo wires down the side of the fuse and tape them down. Poke a little hole in the
bottom of the wing and run the servo wires into the radio bay. If you’re going glow, make sure to
tape them on the non-exhaust side..
19. ___ Mount the throttle servo. I used a micro with a little mount made from 1/16” balsa and ¼” sq
hardwood. If you’re going electric, you don’t have to do this..DUH!
20. ___ Run the throttle push rod out the leading edge of the wing for a nice straight shot to the carburetor
linkage.
21. ___ Install the control horns of your choice on all surfaces.
22. ___ Install control surface linkage of your choice. I like 2x56 all-thread and swivel ball links.
23. ___ Mount the engine. Use two washers under the front motor lugs for right thrust. Approx 3 degrees.
You can move the motor fore or aft for balance.
24. ___ Install the fuel tank. I used a 4 oz hayes. Drill two 1/16” holes centered above and below the tank.
Bend a little hook on the end of a piece of scrap control rod. Run the rod thru the hole and bend a 90
in it. Attach the tank with rubber bands on these two hooks. Make sure to put a layer of foam under
the tank. Don’t wrap the tank down too firmly as it will cause foaming.
25. ___ Install the wire landing gear with the pre-bent wire gear and landing gear blocks. Attach with 4x40
x 1” socket head cap screws, washers and nylocks.
26. ___ Install the landing gear wheels of your choice.
27. ___ Load your RX, switch and battery. Start with the battery in the leading edge. I use a 6 volt, 720
mAh NiMh.
28. ___ Run the antenna out the left wing. Just let it hang out the end.
29. ___ Install a tail wheel of your choice.
30. ___ Double check your CG per the plans.
31. ___ You’re ready to fly!!! Control throws should be set for as much as you can get for high rates and
about 1” in either direction for low rates. Less if you’re new to 3d. I run about 25% expo on
ailerons, elevator and rudder. Flaperon mixing is fun for really tight loops, waterfalls and short take
offs… Spoileron mixing is fun for elevators and harriers… Now go have some fun!!!
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