Model Aero Polaris EX User manual

Designed by Steve Shumate
Adapted from the North Star design by Laddie Mikulasko
Model Aero Polaris
Polaris EX Introduction
We’re excited to introduce the Polaris EX seaplane parkflyer! Based on the Polaris design by
Steve Shumate and inspired by Laddie Mikulasko’s North Star seaplane, we’ve incorporated
some design changes worthy of a new model!
The most notable feature of the Polaris EX is it’s power system flexibility. It can be built as a
prop plane or EDF utilizing the new 10 blade RC Lander 68 mm EDF. And the power systems
can be swapped out in less than 10 minutes! She flies equally well on both power systems but
we prefer the incredible sound of the new lightweight EDF. With anAUW of 28 oz. the EDF
performance is exceptional!
The kit features simple sheet foam construction and the plane boasts excellent handling
qualities, both in the air and on the water. In flight this model is smooth and stable, yet also
very aerobatic. On the water it tracks straight as an arrow and takes off and lands effortlessly.
1

Recommended power setups include:
• Spin Max (Suppo) 2212-06 motor (high power), 1800 to 2200 mAh 11.1V lipo battery, 40
amp ESC with heat sink, APC 6x4E prop
• Spin Max (Suppo) 2212-10 motor (mid power), 1300 to 2200 mAh 11.1V lipo battery, 30/40
amp ESC with heat sink, APC 7x5E prop
•RC Lander 68 mm 10 blade EDF, 2500 to 2700 mAh 11.1 lipo battery, 70 amp ESC
Note that to achieve top performance, EDF’s require a higher quality battery relative to
prop driven planes. We recommend a 45C or higher rated battery.
Construction
It is recommended that you read through the construction guide completely and study all
the pictures carefully before you begin building.
Note that some photos may be different than your kit. For example, we have incorporated
some tabs and notches in the wing and fuselage that are not shown in some of the photos.
Additionally, some construction photos may show decals already on the plane. You may
find it easier to apply some of the decals such as the wing and tail during assembly, rather
than after the plane is built.
•Glue (Thick foam safe CA/accelerator, epoxy, Foam Tac, or the glue of your choice)
•Hinge tape-Blenderm or Scotch Transparent tape
•Power system: motor, ESC, battery, heat sink (optional but recommended)
•Motor/ESC connectors as required
•3 servos (minimum torque 17 oz-in) Most 9-12 gram servos meet this requirement
Additional Items Required
Specifications:
Wing area: 343 sq in
Span: 29.0"
Length: 38.4"
Weight RTF: 18 to 22 oz prop, 28 oz EDF
Wing loading: 8.4 oz/sq ft
Motor: Spin Max 2212-06 or 2212-10, RC Lander 68 mm EDF
Battery: 1300 to 2700 mAh 11.1V
Prop:APC 6x4E for 2212-6 motor, 7x5E for 2212-10 motor
Max Current: 16 amps (2212-10) to 22 amps (2212-6), 55 amps EDF
Watts: 240 watts prop, 550 Watts EDF
Power loading: 190 watts/lb for 2212-6 motor
Speed control: 30-70 amp with heat sink or venting recommended
Receiver: 4 channel
Flight controls: Elevator, ailerons, rudder, throttle
2

In this photo, we’ve assembled the 3 main wing panels and glued all the carbon spars into
their respective slots. At top right is the horizontal stab. The tail booms are shown alongside
the leading edge of the wing. If using epoxy, scuff the carbon with some fine sand paper before
gluing it in.
After the glue is fully cured, we have found that putting a strip of Scotch Transparent tape on
each side of the carbon pieces really helps stabilize the joint.
You may now cut the control surfaces free and bevel & hinge them using your preferred
method. We use simple tape hinges as shown above. The red lines indicate Scotch
Transparent tape or Blenderm tape. It’s important that the foam be very clean prior to
applying the tape. A tack rag or a piece of tape put down and then peeled off works well to
clean the foam of dust.
We recommend CA hinges or small nylon hinges for the rudder.
3

Next, apply the fuselage reinforcement
strips to the edges of the fuselage. Be
sure to make a left and right side!
Leave a 6mm gap next to the fuselage
step to allow for the rear fuselage
former.
Foam Tac adhesive works well here.
After the strips are attached, trim them off flush with the front of the fuselage.
4

Photo above shows the three fuselage formers in place. The middle former (notched) should
be positioned 2” back from the front of the wing slot.
2”
Photo at left shows the bottom
of the fuselage, with a small strip
of foam glued to the aft side of
the rear former. This piece will
help support the aft fuselage
bottom piece.
Front Center Rear
5

Photo shows the fuselage bottom glued into place. Once the glue is dry, sand the edges
flush with the fuselage sides. Leave the corners fairly sharp as this will improve water
tracking. Now is a good time to seal the inside of the fuselage. We run a bead of glue or
latex caulk around the inside of the fuselage.
Photo above shows the wing slid into the fuselage slots. Carefully fit all the tabs into their
respective notches. Our method for gluing the wing is to run a bead of thick foam safe CA
into the corners of the wing and fuselage joint, followed by a light mist of accelerator.
Next, install the battery tray. It should be angled downwards towards the front. Some sanding
of the battery tray may be required to get a perfect fit.
6

The vertical stab assembly consists of 5 pieces: two 3 mm outer pieces (left photo), two 6 mm
middle pieces (center photo), and the rudder (shown in center & right photo).
Start by gluing the two middle pieces to one of the 3 mm outer pieces. There will be a small
channel left between the pieces which will accommodate the plastic elevator pushrod guide tube,
which may be inserted at this time.
Next, glue on the other 3 mm outer piece. The assembly should be sanded to a pleasing rounded
shape at the leading and trailing edges. Then the rudder can be attached using CA or small nylon
hinges (not included).
This photo shows the tail booms, vertical and horizontal stabs, and small top fin installed. Note
the plywood vertical stab support glued to the wing assembly prior to attaching the vertical stab.
7

Assembled servo tray
The servo tray may now be assembled and servos mounted. There are slots in the foam
(not shown) for the servo tray. We prefer adjustable servo connectors on the servo arms.
Rudder Elevator
Aileron
8

Push rod assembly
Inset photo shows the push rod assembly. The shrink tube slides over the rigid tube and wire. Then
the shrink tube is heated to form a near watertight push rod assembly. Alittle Vaseline where the
wire exits the shrink tube will increase the water resistance. Use the photos as a guide to locate the
push rod exit holes. Note the plywood support for the elevator push rod.
Note that there will be some flex in the rudder push rod. It is designed this way as protection for the
servo since the rudder will be in contact with the ground. Some pilots may prefer a more rigid setup.
In this case, a stronger metal gear servo should be used.
Also, it’s a good idea to apply some type of protection on the bottom of the fuselage. We prefer
thin plastic such as used for school folders. These two page folders can be found in various colors
and only cost around $1.00. Another option is duct tape (Scotch Tough Transparent Duct Tape is
particularly good for this purpose).
9

This photo shows the aileron and rudder push rods exiting the fuselage.
Photos above show the two power options, EDF or prop. The spacing and location of the wood
mounts are the same. Pay careful attention to the measurements.
1.5” from spar
Werecommend epoxy for assembling the mounts. The wood strips are backer pieces that
go under the wing. Use the supplied screws to attach the mount to the wing. The mounts
should be 4” apart (on center) and 1.5” from the wing spar (see upper left photo). We use
servo mounting screws to attach the EDF or motor.
4”
1.5” from spar
Backer pieces
go under wing
10

Photo at left shows the prop version mount. Again,
epoxy is recommended for assembling the mounts.
We typically paint the wood black. It’s not necessary
but we think it looks nicer!
4” 16” 2”
Note that the top fuselage piece is supplied as one piece. Shown above is our method of dividing
and attaching the top. The 4” and 2” pieces are glued on and the 16” center piece is held on with
tabs at each end made from scrap wood or foam. We used a couple magnets (not included) in the
center to help hold it down.
Note the 3 mm foam servo cover. This helps keep the wires from interfering with the servos.
11

Note that we have attached the heat sink to the ESC and mounted the assembly to the top of the
fuselage. It is recommended that you seal up the ESC/heat sink with glue or silicone to prevent
water from entering. The battery location will vary depending on the battery size and power system
used.Adjust the battery location to achieve the correct CG.
Photo at left shows the tip floats and nose
pieces laminated using Foam Tac adhesive.
There are 5 pieces for each tip float and 10
pieces for the nose. Sand the tip floats smooth
and attach them flush with the wing tip.
12

The nose pieces have been laminated together using Foam Tac and sanded to shape. Then we
used some light weight spackle to smooth it followed by a coat of water based paint.
The canopy is supplied clear. After trimming it we painted the inside with black spray paint, then
finished the outside with some silver vinyl trim. Make sure the top of the fuselage is in place
before gluing the canopy on so it matches the curve in the fuselage.
Congratulations!!! That completes the construction of the Polaris EX. See below for setup tips
and decal application tips.
13

Setup and Flying
Adjust the flight controls to provide the following recommended deflections (all measured at
the root trailing edge):
High rates:
• Elevator: 1” each way (40% exponential)
• Ailerons: 3/4” each way (40% exponential)
• Rudder: 1 1/4” (25% exponential)
Low rates: 70% of the above settings.
Note: We recommend low rates for the first flights until you are familiar with the plane.
If using a radio without expo or dual rates, we suggest about 55-60% of the high rate throws
shown above for aileron, 70% for elevator, and about 1” each way for rudder.
CG: The recommended CG location is on the fuselage step.
To take off just add throttle and slight back pressure on the stick, and the model will leap off
the water in about 10 ft. Or you can bring the throttle up slowly and fly it off the water
gracefully.
You’ll find this model is smooth and well-mannered in the air, with no bad habits. But it's also
capable of excellent aerobatics!
Note: The Polaris EX is designed for intermediate and above pilots and is not recommended
as a trainer or beginner plane. It should be operated in accordance with AMA guidelines.
Waterproofing
It is up to the builder to ensure the plane is properly sealed for water operation. Model Aero
assumes no liability for damages caused by water intrusion, builder, or pilot error. It is up to
the builder to ensure the safe operation of this aircraft.
We have built and flown many models using the construction techniques outlined in the build
guide with no problems with water intrusion. Some pilots may wish to further waterproof the
electrical components using Corrosion X or other similar chemicals. Information on this can be
found online.
Disclaimer
14

Decal Application
Before applying the decals, clean the foam of
sanding dust. An effective way to do this is
with a tack rag or packing tape. Laying the
tape down and peeling it off removes all the
dust from the foam, allowing the decal to stick
better. Trim each decal as shown in photo,
leaving 1/16” to 1/8” of the backer paper
around the decal. Then, peel the decal/backer
from the sheet & place the decal in the
desired location and press down thoroughly.
Decal application procedure is the same for all kits. Reference Polaris photos for decal placement.
Very carefully peel the backer
paper off the decal, making
sure the decal stays on the
plane. If the decal lifts off the
plane, just press it back down
and try another corner.
Tweezers work very well for
grabbing the backer paper.
Additionally, a bit of Windex or
water applied to the backer
paper will soften it and ease
it's release. Just be sure not to
get any moisture under
the decal itself.
15

Please Consider Our Other Designs for Your Flying Pleasure!
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Polaris Ultra ARF
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Aqua Cat
Mini Polaris
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www.modelaero.com 419-966-2230
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Aqua Jet
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