Stevens Aero Model microHawk User manual

microHawk
Capacitor Power – Free Flight –Motor Glider
Wing Span: 18 inches | Wing Area: 45 square inches | Average Flying Weight: 27 grams
Build Instructions - Version 1.12 (revised 10.11.2016)

WARRANTY
Stevens AeroModel guarantees this kit to be free from defects in both material and workmanship at the date
of purchase. This warranty does not cover any component parts damaged by use or modication. In no case
shall Stevens AeroModel’s liability exceed the original cost of the purchased kit. Further, Stevens AeroModel
reserves the right to change or modify this warranty without notice.
LIABILITY RELEASE
In that Stevens AeroModel has no control over the nal assembly or material used for nal assembly, no
liability shall be assumed nor accepted for any damage resulting from use by the user. By the act of using the
user-assembled product, the user accepts all resulting liability.
If the buyer is not prepared to accept the liability associated with the use of this product, the buyer is advised
to return this kit immediately in new and unused condition to the place of purchase.
THIS PRODUCT IS NOT INTENDED FOR CHILDREN 12 YEARS OF AGE OR YOUNGER.
WARNING: This product may contain chemicals known to the State of California to cause cancer and or birth
defects or other reproductive harm.
PRODUCT SUPPORT
This product has been engineered to function properly and perform as advertised, with the suggested power
system and supporting electronics as outlined within this product manual. Product support cannot be
provided, nor can Stevens AeroModel assist in determining the suitability or use of electronics, hardware, or
power systems not explicitly recommended by Stevens AeroModel.
For product assembly support, replacement parts, hardware, and electronics to complete this model, please
contact Stevens AeroModel at www.stevensaero.com.
Stevens AeroModel
26405 Judge Orr Rd. Colorado Springs, CO 80808 USA
719-387-4187 www.stevensaero.com
microHawk Build Instructions. © 2016 Stevens AeroModel all rights reserved. Page2

Wood Bundle
☐Illustrated build instruction manual
☐Laser-cut wood, 4 sheets
☐1 Carbon ber tail boom (5 in. length)
Hardware Bag
☐1 Plywood F3 fuselage joiner
☐1 Length of heat-shrink tubing, 3/8 in. diameter
☐Modeling clay, ballast, 12 grams
Introduction
The Stevens AeroModel microHawktm is a simple, all-sheet, entry level motor glider – designed to be powered by
popular 8.5 mm coreless motors and a 10 farad capacitor“fuel” system. When properly assembled and ight
trimmed, a single charge from a 3 volt source provides exciting powered ights of up to one minute in duration.
Kit Inventory
Required Electronics for Powered Flight
Available directly from stevensaero.com
☐10F Capacitor-Power Kit (SAP-CP/PK01)
☐Battery and motor connector (SAUMEXT/3)
☐Coreless motor (recovered from (PKZ3616 or PKZ3624)
☐Propeller, GWS HD 2.5 x 0.8 or GWS HD 2.5 x 1.0
☐3.7V 160mAh LiPo battery with suitable charger

Thank you for purchasing The microHawk Capacitor-Power Motor Glider from Stevens AeroModel. This model
has been developed and manufactured using state-of-the-art CAD/CAM systems. Our kits feature a unique
interlocking construction process, that when compared to traditional building methods, saves countless hours of
measuring, cutting, sanding, and tting. Also included in this kit are building xtures which will aid in assembly,
their construction and use will be described in the step by step build instructions. We are certain that you’ll nd
our kits to offer a truly exceptional build experience.
IMPORTANT!
Please READ and REREAD these build instructions along with any other included documentation before starting
your build and/or contacting our stafffor builder support.
Pre-Sanding (Optional)
Before removing any parts from the laser-cut sheet wood, use a sanding block loaded with 250 - 400 grit
sandpaper and lightly sand the back side of each wood sheet. This step removes any residue produced as a
result of the laser cutting process. This step also slightly reduces the thickness of each sheet of wood. We have
found that most stock wood sizes run several thousandths of an inch oversized. Leave all parts in the sheet
wood until required for assembly.
Protecting Your Work Surface
Use the poly tube that this kit was packed in to protect your work surface from the glues used during assembly
of the model.
Bonding the Assembly
This product’s tabs and notches interlock like a 3D puzzle. We strongly suggest that when tting parts, you dry
t (use no glue) the parts together rst. It is advised to work 1 - 2 steps ahead in the instructions, using this dry-
t technique. This allows the opportunity to inspect the t and location of assembled components, and shows
the benets of our construction technique. Once you arrive at the end of a major assembly sequence, square
your work on a at work surface or by using the included assembly xtures and bond the dry t joints with glue.
Using the dry-t process, you’ll be able to recover from a minor build mistake and will ultimately end up with a
square and true assembly.
When using CA, apply glue with a ne-tip CA glue applicator. Unless otherwise noted in the instructions, we nd
it easier to“tack glue”parts (temporarily bonding parts in assemblies, using a small dot of glue).
When using wood glue, apply a small amount of glue to the surfaces to be bonded. After assembly, pin your
parts into place and allow them to dry throughly.
Sanding
Do not sand the individual parts of this model. This kit is precision cut to assemble with the correct angles and
incidences to ensure proper ight performance. If desired the laser burn may be removed after assembly.
Never Force the Fit!
This is a precision laser-cut kit. Our lasers cut to within 5 thousandths of an inch in accuracy. Yet the wood stock
supplied to us by the mill may vary in thickness by up to 20 thousandths. This variance in the wood stock may
cause some tabs and notches to t very tightly. With this in mind, consider lightly sanding or lightly pinching a
tight-tting tab, rather than forcing the parts together. You will break fewer parts in assembly, and end up with a
square and true airframe.
General Assembly Instructions
microHawk Build Instructions. © 2016 Stevens AeroModel all rights reserved. Page4

Required Tools and Supplies
Flat work surface - Table top or building board, make sure the building surface is warp free
Glue - Medium Cyanoacrylate CA (super glue)* or Aliphatic Resin (wood glue)*
*Cyanoacrylate Glue (CA) also known as super glue, is a quick setting glue that bonds in seconds. Please use caution
with this type of glue. If this is the rst time using CA, we recommended that you keep nger tips away from glue joints
while assembling the model, CA can bond skin instantly. The use of a precision glue tip provides the most control of
glue application. When using CA to assemble this model tack glue assemblies rst, after the parts are joined revisit all
joints with a second application of glue. CA glue and glue tips are available from stevensaero.com. Follow all
manufacturers instructions for use.
*Aliphatic Resin also known as wood glue under the brand names, Titebond or Elmer’s etc., are also a good choice. This
type of glue takes much longer to cure. We recommend pining the parts together after assembly, allow ample time for
the glue to setup. Aliphatic resin is not an instant glue so be prepared to take some time with the assembly of the
model. Follow all manufacturers instructions for use.
Soldering equipment - 20W soldering iron and resin core solder are required to assemble the capacitor-power
parts kit and to install battery and motor connectors based upon your chosen equipment.
Optional Tools and Supplies
Our microHawk model, as delivered, can be assembled entirely without the aid of hobby knifes, pins, or
abrasives, making it ideal for use in instructional environments. As such the following items are, in-fact, optional
and suited for progressing builders, craftsman, and serious competitors.
Hobby knife - X-acto®or Excel style hobby knife with supply of #11 blades
Sanding block - Loaded with 250 - 400 grit sand paper (sanding blocks are available at stevensaero.com)
Straight pins - Secure parts to building board and each other while glue dries
Masking tape - Low-tack blue painters’ tape
Building board - Soft at work surface that will accept straight pins (balsa building boards are available at your
local hobby shop, or make one using a piece of drop ceiling tile).
Hobby clamp or clothes pins - Used to hold parts together while glue dries
Clear lacquer - Protects the nished model from moisture without adding signicantly to the models nal ying
weight. Use only one light coat. We recommend DEFT brand clear-lacquer in a spray can, available at most
hardware or home improvement stores.
Design Master Color Tool - If desired add a little color to the model. Use color sparingly, i.e., on a wing tip or the
tail planes. Paint adds weight and can effect the performance of the nished model, available at most arts and
crafts stores.
General Assembly Instructions
microHawk Build Instructions. © 2016 Stevens AeroModel all rights reserved. Page5

Assembly
Wing Assembly. The center wing section builds using an integrated jig assembly developed by Stevens
AeroModel. This build method ensures consistency in build and greatly simplies the assembly process. When
removing the W1 wing center section from the parts sheet, be careful not to remove the“frame”that
encompasses the right and left of the wing center section. Wing parts are designated with the letter “W”
followed by a number. Parts have been numbered sequentially. The wing build order includes parts W1, W2,
and W3.
1. Locate the wing center section (sheet 02/04, 1/16 in. balsa). Remove the part marked with a W1–
lay it on your work surface with the etch marks facing up. If desired you may pin or tape W1 to the
work surface. Note: There are two 1/4 inch diameter holes near the center section trailing edge
the side opposite the holes will become the leading edge.
2. Locate the two wing tip angle jigs numbered W2 (sheet 03/04, 1/16 in. balsa). Fit parts W2 within
the notches provided at right and left sides of the integrated center section wing jig. Bond parts
W2 with a small drop of medium CA glue to retain.
3. Locate wing parts numbered W3 (sheet 01/04, 1/20 in. balsa) wing tips. Use the interlocking tabs
and notches that resemble one-half of a “zipper” to place the W3 wing tips against the mating half
of the “zipper” at right and left side of W1 wing panel. Ensure that the leading and trailing edges
are correct and the wing tip panels are fully seated both within the slot and bottoming out
against your at work surface. The correct dihedral angle for the W3 wing tips will be set by parts
W2 as the wing tip will rest against W2 and within the slots at right and left of the W1 wing center
section.
4. Have a look at the photo for“Step 5” and note the future removal of the integrated jig from wing
center section. With this information in mind proceed to bond the wing tips to the wing center
section being careful not to bond any of the removable jig parts to the wing assembly. Use only
enough glue to retain the parts in their current position as you’ll have a chance in “Step 5”to more
thoroughly bond the wing tips after removal of the integrated jig.
If using CA, bond parts together by placing spots of glue at each toothed area of the“zipper”
along both top and bottom of wing panel to“tack glue”the assembly together. If using wood
glue, lightly coat the top/middle section of the “zipper” surfaces to be bonded then assemble,
allow ample time for the glue to dry. It may help to pin these parts into place to keep them
aligned while the glue dries.
5. Once the glue has cured remove the integrated jig from the completed wing panel by simply
snapping the two tabs offthe jig at the leading edge of the wing and exing the jig down and
away from the center section of the completed wing trailing edge. Discard the jig.
With the integrated jig removed from the wing center section, now is an excellent time to re-visit
the “zipper” joint with additional glue to ensure it’s thoroughly bonded. If using CA, wick glue
within each cavity between the teeth of the“zipper” at both top and bottom of the wing assembly.
If using wood glue, apply a thin bead of glue along the joint at both top and bottom of the wing
assembly then level (smear) it into the joint with a nger.
Build Instructions
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Build Instructions
Step 1
Step 2
Step 2 Cont.
Step 3 Step 5
Step 4 Cont.
Step 4
Step 3 Cont.
W1
W1
W1
W2
discard jig
W2
W2
W2
W1
W3
W3
W3
W1
Glue along “zipper”.
completed wing
integrated jig
integrated jig
wing center section
Do not glue where edge of jig meets W3.
W3
W1
Glue along “zipper”.
Bottom View
Bottom View
Do not glue at
circled areas.

Assembly (continued)
6. Assemble the fuselage over a at surface with the left side up.Begin by bonding the nose skid F2
within the main fuselage body F1 (sheet 04/04, 3/32 in. basswood).Place the 1/32plywood part
F3 (from hardware bag) on the left side rear of the main fuselage body – matching the edges of F3
to that of F1.
7. Carefully match the balsa forward fuselage doublers F4 and F5 (sheet 03/04, 1/16 in. balsa) to the
left and right sides, of the F1 main fuselage body – use a slow setting glue to allow adequate
working time to accurately position these parts.
If using wood glue (instead of CA), lightly coat the surfaces to be bonded then assemble.Allow
ample time for the glue to dry.Note: It may be helpful to pin these parts into place – keeping
them aligned while the glue dries.
8. Bond a 5 in. length of square carbon ber stock within the“pocket” created by part F1 and F3 at
the rear of the fuselage assembly.Accurately align the carbon tail boom so that it does not skew
right or left of the fuselage centerline.
9. Locate the stabilizer parts H1 and V1 (sheet 03/04, 1/16 in. balsa).With the etching on H1 facing
up, key the tab on V1 down through the pocket cut within H1.This pocket is slightly offset to the
right of centerline within the H1 assembly – offsetting V1 right.Align these parts perpendicular to
each other and bond.Note:The leading edge of H1 is straight while the trailing edge of both V1
and H1 are curved.
10. Place the stabilizer assembly on top of the carbon tail boom, so that the bottom surface of H1
rests at on top of the carbon boom, and so that the back edge of V1 nishes (but does not
overhang) theend of the boom.Note:The photo illustration depicts this assembly as viewed
from the underside of the fuselage.The tab on V1 should overhang the fuselage boom on the
right side of the assembly.Ensure that this assembly is bonded square to the fuselage.
11. Bond the lower n V2 (sheet 03/04, 1/16 in. balsa) along the underside of the carbon tail boom
resting against the tab on V1.
12. Finish the microHawk airframe by bonding the wing assembly on top of the fuselage, passing the
tabs on the fuselage wing saddle through the corresponding notches within the wing.Note: Use
a slow setting glue to allow you to properly square the wing to the fuselage sides and stabilizer
assembly.With the wing in position, add the F6 motor mount (sheet 04/04, 3/32 in. basswood) as
indicated in the photo.Finally, add a bit of left rudder trim by gently bending the rear of V1 left
until it centers on top of the carbon tail boom – bond the tip of V1 in this position to retain the left
offset which will later produce the necessary left-hand power and glide pattern.
Optional:!If desired, sand the model to remove the laser burn from the model.!You may
also paint the model with clear-lacquer to protect it from moisture, or spray a little color on
the model to make it uniquely yours.!
Build Instructions
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Build Instructions
Step 10
V1
H1
Step 8
Step 7
F1
F4
Bottom View
Left
F3
(placed on left
side of fuselage
matching edges
of F3 with F1)
F2
F5
F1
Step 8 Cont.
nest carbon tail boom within
pocket created by F1 and F3
F1
F3 opposite side
carbon tail boom
5 in. length
Step 6 Step 9
Step 11
Step 12
back
perpendicular
H1
tab on V1
left
right
V2
Bottom View
V1
F6
Gently bend V1 rudder
left to center on carbon
boom - bond with CA in
this position.
V1

Assemble the Capacitor-Power Module
The assembly details given within this manual apply to the 10F size Capacitor-Power partskit SAP-CP/PK01
available directly from stevensaero.com.
1. Purchase the 10F Capacitor-Power parts kit from stevensaero.com you’ll need to provide a
suitable motor and battery connector set based upon those required to t of your coreless motor
and charge battery.We used a micro battery extension cable part SAUMEXT/3 that is compatible
with the recommended 160 mAh 3.7V charge battery.
2. Install the capacitor.Position the PC Board (PCB) so that the“stevensaero.com” text faces up.
Pass the positive and negative wires of the 10F capacitor through the board as illustrated.Note:
The 10F capacitor is extremely sensitive to reversed polarity and will typically have a stripe
running down the body of the capacitor to identify the negative lead.The wire closest to the
stripe is negative and is typically shorter than the positive lead wire.Do not reverse the polarity
of the capacitor within the assembly as this will destroy the capacitor. Once installed
properly, with the PCB ush on top of the capacitor, solder the capacitor to the board and trim the
excess wire leads.
3. Install the resistor.Bend the wire leads perpendicular to the resistor and place through the top
of the PCB as illustrated.Solder and trim the excess wire as in the previous step.
4. Battery and motor connector.In this example we used a simple 3 inch micro battery cable
extension from stevensaero.com (SAUMEXT/3).Cut this part into two pieces – leaving 2 inches for
the battery side and 1 inch on what will become our motor-side connector.Note:In practice this
is a workable arrangement.However, depending upon the connector supplied with your micro
motor, you may nd the electrical connectivity through the motor connector to be quite poor – I
prefer to direct solder my motor to the capacitor assembly.
5. Solder the motor and battery connector to the PCB using the terminal designations for battery
(Bat) and motor (Mot) given in photo “Capacitor 3”as a reference.
6. Assemble the motor. We used an 8.5 mm coreless motor recovered from a damaged ultra-micro
model (PKZ3624). This motor is delivered in a gearbox and must be removed from the gearbox
and stripped of the pinion gear. Use a heavy pair of pliers to smash/crush the brass pinion gear –
the crushed gear slides offthe motor without damaging the delicate shaft. The motor housing is
then wrapped in masking tape or sleeved with a short length of heat shrink tubing. The propeller
GW HD 2.5 x 0.8 is press t to the motor shaft with the numbers facing the motor (pusher
conguration). So as not to damage the motor during installation, use a #11 hobby knife to
lightly chamfer and relieve the propeller shaft hole. Gently press the propeller onto the shaft
(numbers forward) while supporting the backside of the motor housing. Note: Using excessive
pressing force will damage the motor housing – slightly enlarging the shaft hole in the propeller is
always better than using brute force.
7. Friction t the completed capacitor-power module within the airframe (tape or glue in place only
if absolutely necessary). Pass the motor lead through the 1/4 in. diameter hole at the trailing edge
of the right wing panel and connect to the capacitor-power module. Glue the motor on top of the
motor mount centered along the centerline of the airframe. Continue to the “Flying Instructions”
to prepare the completed microHawk for it’s rst ight.
Capacitor-Power Module
microHawk Build Instructions. © 2016 Stevens AeroModel all rights reserved. Page10
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Capacitor-Power Module
microHawk Build Instructions. © 2016 Stevens AeroModel all rights reserved. Page11
Capacitor 5
Capacitor 4
Capacitor 1
Capacitor 2
Capacitor 3
Capacitor 6
Capacitor 7
Go Fly!
Resistor
Capacitor
PCB
Connector
Positive (+)
long
short
stripe
Resistor
Bat + (1)
Bat – (2)
Mot – (3)
Mot + (4)
Capacitor
Battery Connector
Motor Connector
Charge System
2 in. length
1 in. length
Battery Connector
Motor Connector

1. Balance the model. Balance the model 1-1/4 inches behind the leading edge of the wing – this is the starting
balance point (Center of Gravity or CG) and has been laser-marked on the wing of the glider as two small holes.
Suspend the model from your thumb and index nger at the balance points on right and left of wing. When
viewed from the side, the fuselage should generally hang level with the horizon. If the model hangs nose down,
remove clay ballast from the nose or add clay ballast to the tail. If the model hangs tail low with the nose pitched
up, add clay ballast to the nose of the model. Adjust the balance point then proceed to glide test your model.
2. Glide test. The purpose of this test is to check the overall behavior of the model prior to using it under a
powered launch. Do not neglect to perform this test as hard ground is a formidable opponent for the out of
trim motor-glider. Perform this test in near zero wind conditions outdoors or pick a large indoor venue such as
an auditorium or gymnasium. Pick a point on the horizon just to the right of the current wind direction
(outdoors) and aim for it (this will result in a more level toss). With wings level to the horizon, give the model a
smart but gentle toss. Resist the urge to toss the model up or shove it down.
Desired result: The model should glide in a lazy left-hand turn and land at a near level attitude.
If the models nose pitches up followed by an abrupt loss in both speed and altitude, the model is stalling. Try
adding a tiny amount of ballast to the nose and try your toss again. Likewise, if the model dives abruptly you
should try removing ballast from the nose and/or adding ballast to the tail.
Continue the glide test until you have achieved the desired result with your model.
If the model is not turning or gliding as expected, inspect your airframe for warps and proper assembly. Model
balance will generally control the gliders speed and stall. Rudder offset will control the rate of turn (Aim for a
gentle turn with about a 50 ft. radius.)
3. First Flight. After a successful glide test it is time to try the model under power. Your rst ight should be
performed in calm conditions – with less than one-half charge applied to the capacitor. The capacitor typically
reaches full charge in 12-15 seconds –charging longer than this is of no benet. To determine half charge count
out 6 or 7 seconds and listen to the propeller/motor noise to decipher the relative amount of power you’ve
added to the system by the audible pitch of the system under power. Remember, this isn’t rocket
science – you’ll soon become very skilled, using just your ears, at adding just the right amount of charge to the
capacitor to produce short, eye-level “boomerang”type ights as well as long, aggressive, circling climb outs
above the tree tops!
Clear the prop and add 3 seconds of charge to the capacitor from your battery. Remove the charge battery then
aim the model into the wind and give it a nice level toss (just as you did for the glide test). The model should
gently leave your hands in a left-hand pattern ying at about eye-level and maintaining level ight or slightly
descending. Add additional charge time, as desired, to begin increasing the climb and cruise altitude. Be
careful, a full charge with a smart toss can result in the model climbing exceptionally high and irting with
thermals that may whisk your microHawk into the heavens! The reduced motor RPM, and corresponding drag
from the propeller, of the last few seconds of ight tend to act somewhat as a de-thermalizer allowing the
microHawk to exit light lift. But don’t count on it! Enjoy your new microHawk, we hope it inspires you to try
capacitor power in other designs of similar size and propulsion!
Flying Instructions