Stevens Aero Model RingRat 100 User manual

RingRat 100
By Stevens AeroModel
Length 17 inches | Span 18 inches | Wing Area 100 inches2| Flying Weight 5.5 oz.
Version 01/06/2010
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 1 of 26

Product Support
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 2 of 26
WARNING-DANGER!
DO NOT FLY CONTROL LINE MODELS NEAR ELECTRIC POWER LINES. INSTANT DEATH CAN
RESULT FROM CONTACT WITH, OR FLYING TOO CLOSE TO, ELECTRIC POWER LINES.
WARRANTY
Stevens AeroModel guaranteees 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
modification. In no case shall Stevens AeroModel’s liability exceed the original cost of the purchased
kit. Further, Stevensens AeroModel reserves the right to change or modify this warranty without notice.
LIABILITY RELEASE
In that Stevens AeroModel has no control over the final assembly or material used for final assembly,
no liability shall be assumed nor accepted for any damage resulting from the use by the user of the final
user-assembled product. 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

Project Checklist
Kit Contents
Laser cut wood (8 Sheets - See inventory on following pages)
Illustrated instruction manual
1 - Pre-bent Landing Gear (0.062 in. dia.)
2 - 1/64 in. (0.015) x 18 in. music wire (taped to back of wood brick)
1 - 1/32 in. x 12 in. music wire (taped to back of wood brick)
1 - 3/16 in. square x 18 in. length hardwood stock (Fuselage Stiffener)
1 - 3/16 in. square x 24 in. length balsa stock (Leading Edge)
Large Hardware Bag (4 x 6 in.)
1 - Du-Bro RC Micro Tail Skid [DUB853]
1 - 1/2 in. x 10 in. strip 2-sided velcro (Battery Safety Strap)
1 - Delrin Bellcrank
1 - 2 in. x 1/32 I.D. Nylon Tube (Lead-out Wire Guides)
1 - 1/8 in. x 2 in. Dowel (Gear Lug)
2 - Wheels
Small Hardware Bag (2 x 3 in.)
1 - 4-40 Blind Nut
1 - 4-40 x 3/8 in. Pan Head Machine Screw
2 - Du-Bro RC #4 Flat Washers [DUB323]
1 - Du-Bro RC 4-40 Hex Nut [DUB561]
1 - Du-Bro RC Micro2 Control Horn [DUB27800]
1 - Du-Bro RC Micro EZ-Link [DUB23610]
1 - Du-Bro RC Mini E/Z Connector
1 - Du-Bro RC Steel Landing Gear Strap [DUB158]
4 - Du-Bro RC E/Z Connector Washers [DUB9900] (Wheel Retainers)
6 - #2 1/4 in. Screws (Motor & Landing Gear Mount)
Small Hardware Bag (2 x 3 in.)
6 - Mini Rubber Bands (Landing Gear Retention)
3 - Silicone Bands (Propellor Retention)
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 3 of 26
Required Building Supplies and Tools
1/2 oz. Medium CA Glue
1/2 oz. Thick CA Glue
1/2 oz. Thin CA Glue
CA glue accelerator (kicker)
Balsa filler
Hobby Knife with ample supply of #11 blades
Small Phillips Screwdriver
Small Hammer
Sanding block with 400 and 600 grit paper
Heat Gun and Covering Iron
Small Needle Nose Pliers
Small Round Nose Jewelers Pliers
Small Flat File.
X-ACTO Pin Vise & Drill Set [XAC7155]
ZONA 4 in 1 Saw Set [ZON35251]
Scissors
Wire Cutters
Z-71 Thread Locker [PAAPT71]
1 in. x 4 in. length sticky back velcro
3/4 in. wide clear tape
1 Roll AeroLITE
1 - Shiny, New, Nickle (U.S. 5 Cent Coin)
Suggested Building Supplies
CA glue de-bonder
Long sanding bar
Razor Plane
Low Tack Painters Masking Tape
Design Master Aerosol Lacquer Paint
Deft Clear Spray Lacquer

Project Checklist Continued
Required Electronics & Equipment (Available at StevensAero.com)
The following system is plug-and-play and requires no soldering:
1 - E-flite Park 300 Brushless Outrunner Motor [EFLM1150]
1 - E-flite 10-Amp Pro Brushless ESC [EFLA1005]
1 - E-flite Control Line Motor Timer [EFLA172]
1 - Hyperion CX G3 240 mAh 7.4V LiPo Power Pack [HP-LG325-0240-2S]
1 - APC 8 x 3.8 SF Slow Flyer Propellor [APC09038SF]
1 - SIG 1/2A Control Handle, inc. Dacron Line and Connectors [SIGSH544]
1 - SIG Control Line Reel [SIGSH441]
The following system, while initially less expensive, will require soldering:
1 - Suppo Park 300 Brushless Outrunner Motor [SUPA2204-19]
1 - Suppo 10A Brushless ESC [SUP10AESC]
1 - E-flite Control Line Motor Timer [EFLA172]
1 - Hyperion CX G3 240 mAh 7.4V LiPo Power Pack [HP-LG325-0240-2S]
1 - 2.0mm Gold Bullet Connectors [EFLA248]
1 - Pkg. Female JST connectors [EFLA243]
1 - GWS 7 x 3.5 E Propellor [APC09038SF]
1 - SIG 1/2A Control Handle, inc. Dacron Line and Connectors [SIGSH544]
1 - SIG Control Line Reel [SIGSH441]
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 4 of 26

General Assembly Instructions
Thank you, for purchasing this Stevens AeroModel RingRat™100. A design inspired by the joy of flying.
This model has been developed and manufactured using state of the art CAD/CAM systems and features
a unique interlocking construction process that, when compared to traditional methods found in other
model aircraft kits, save countless hours of measuring, cutting, sanding, and fitting. We are certain that
you’ll find our kit to offer a truly exceptional build experience. As this kit is recommended for the novice
model builder and “pilot”; we invite absolute beginners to correspond with us, or to seek the help of
another seasoned builder. At any time should one run across a term or technique that is foreign please
don’t hesitate to contact our staff with your questions.
READ THIS
Please READ and RE-READ these instructions along with any other included documentation prior to
starting your build and or contacting our staff for builder support.
Pre-sanding
Do not skip this step. Prior to removing any parts from the laser cut sheet wood use a sanding block
loaded with 250-400 grit paper and lightly sand the back side of each sheet of wood. This step removes
any residue produced as a result of the laser cutting process and, as we have found that most stock wood
sizes run several thousandths of an inch over sized, slightly reduces the thickness of each sheet.
Leave your pre-sanded parts in the sheet until required in the assembly process.
Protecting your worktable
Use the poly tube that this kit was shipped in as a non-stick barrier between your worktable and the
product assembly. Promptly clean up any epoxy spills with rubbing alcohol and a disposable towel.
Bonding the assembly
As this product tabs, notches, and otherwise interlocks like a 3D puzzle we suggest that when fitting parts
you dry fit (use no glue) the parts together first. It’s advised to work 1-2 steps ahead in the instructions
using this dry-fit technique which allows ample opportunity to inspect the fit and location of assembled
components and realizes a benefit as each successive part contributes to pulling the entire assembly
square. Once you arrive at the end of a major assembly step(s) square your work on top of a flat building
table and revisit the dry fit joints with glue. Using the dry-fit process you’ll be able to recover from a minor
build mistake and will ultimately end up with a more square and true assembly.
Unless otherwise noted in the instructions, always use medium CA glue for bonding parts.
Never force the fit!
Remember this is a precision cut kit our machines cut to within 1 thousandth of an inch in accuracy. Yet
the wood stock supplied by the mill may vary in thickness by up to 20 thousandths. This variance in the
wood stock can cause some tabs/notches to fit very tight. Hey, dad always said it was easier to take
away material than add it back. With this in mind, should you find a joint or two to fit rather snug consider
lightly sanding a tight fitting tab rather than crushing and forcing your parts together. You’ll break fewer
parts in assembly and will end up with a more square and true assembly.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 6 of 26

Fuselage Construction
Fit 1/4 square hardwood Fuselage Stiffener to
Fuselage F1. For the strongest bond, lightly
sand bonding area along balsa part F1 to
smooth and remove laser cutting residue.
Measure and cut to length, leaving 1/8” to
1/4” extra to be trimmed off later.
Bond Stiffener to F1 with thick CA on top of
flat work surface. Lightly sand fuselage after
bonding.
Dry fit two motor mount parts M1 to fuselage
doubler F2L. Ensure that the etching on F2L
faces up. Tabs in M1 will extend proud of
backside of F2L by 1/4 in.
Dry fit motor mount M2a to M1’s and F2L
Test fit M2b to face of M2a then bond motor
mount assembly with medium CA glue.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 7 of 26

Fuselage Construction Cont.
Dry fit motor mount assembly to fuselage,
then, covering back side of motor mount
assembly at F2L with thick CA, bond/laminate
assembly to fuselage. Ensure that 1/8 in.
dowel hole and wing saddles in parts match.
Note that rear tabs on M1’s will protrude
slightly, allowing doubler F2R to key in place.
Fit and laminate/bond doubler F2R to F1 with
thick CA.
Revisit motor mount joints on both sides of
fuselage applying a fillet of medium CA.
Trim excess hardwood and sand to match
shape of fuselage at nose.
Cut notch with razor saw through hardwood
doubler to receive landing gear wire where
indicated on fuselage ply doublers.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 8 of 26

Fuselage Construction Cont.
The following steps prepare fuselage for
sealing with lacquer based paints. Should
you desire to cover the fuselage in film; steps
marked with an ◆are best completed after
covering has been applied.
Open landing gear notch with a small file, just
enough to allow landing gear to fit snugly.
◆ Bond F3 plywood pushrod guide to
fuselage so that it fits flush to right side of
fuselage and extends proud of left side
fuselage.
◆Cut 1/8 in. landing gear lug dowel to 1-1/4
in. and insert centered within 1/8 in. hole in
fuselage doublers, leaving 1/2 in. extending
on both sides of fuselage.
Sand slight bevel in surfaces to fit and bond
rudder (with medium CA) to vertical stabilizer
with 3/8 in. right offset. Refer to picture
below. Match rudder vertically along fin using
logo etching as a positioning guide.
Sand round leading and trailing edge of
rudder leaving the bottom surface of vertical
fin square in preparation for bonding to
fuselage.
Final sand fuselage in preparation for sealing
with Deft lacquer based sealer.
◆Match trailing edge of rudder to trailing
edge of fuselage then bond vertical stabilizer
to fuselage using medium CA glue. Stabilizer
must be centered to fuselage "top" and in-line
with canopy.
Seal fuselage with Deft brand lacquer based
sealer or nitrate dope. Paint to suit your
design . Remnant 1/32 in. ply sheet makes
an excellent paint mask for coloring the cowl.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 9 of 26

Fuselage Construction Cont.
Dry fit horizontal stabilizer parts H2’s to H1
then bond. Lightly sand the completed
stabilizer and elevator “E” in preparation for
sealing. Sand a 45 degree bevel to the
leading edge of elevator in preparation for
tape hinge method. Seal with Deft lacquer.
◆Tape horizontal stab. and elevator (bevel
side down) to table, leaving a 1/64 in. gap.
◆Apply clear tape over gap. Trim excess
using a sharp blade.
◆Fold assembly back on itself to flatten bevel
with stabilizer trailing edge. Apply second
piece of tape and trim excess.
◆Locate the two holes in the horizontal stab
and mark a center line between them.
◆Using center line as a guide, bond stab
(use medium CA glue) within slot at trailing
edge of fuselage, aligning perpendicular to
vertical fin and fuselage.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 10 of 26

Wing Construction
Locate the 4/40 blind nut within the hole in
W6L. Ensure that etching on W6L faces up.
With a hammer, seat blind nut firmly in W6L.
Secure with medium CA at edge of nut flange.
Bond together both ribs R1 with thick CA.
Align carefully, match at notches and profile.
Fit and bond trailing edge parts W3a and
W3b.
Dry fit R1 assembly to trailing edge. DO NOT
BOND AT THIS TIME.
Fit gussets W4 to trailing edge and R1
assembly. Align and bond.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 11 of 26

Wing Construction Cont.
Slide dovetailed end of W6L through the left
side of the slot in R1 assembly. Ensure that
etching on W6L faces up, and blind nut is on
top as shown. DO NOT BOND.
Note that dovetail will protrude through R1.
Dry fit left R2 to trailing edge and W6L. DO
NOT BOND.
Fit W6R to W6L. Fit left R2 to W6R and
trailing edge. Be sure entire assembly is flat
and square. Tack glue all joints with thin CA.
Note that W6R will “dovetail” into W6L as
illustrated below.
Fit ribs R3 and R4 to trailing edge. Tack with
thin CA.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 12 of 26

Wing Construction Cont.
Dry fit lower front spar part “W1” to notches in
ribs R1-R4.
In the same manner, fit upper front spar part
“W1” to notches in ribs R1-R4.
Insert rear spars W5 through all ribs. Ensure
that structure is flat and square, and bond all
joints with CA glue.
Mark center of 1/4 in. square balsa leading
edge stock. Align mark with center of wing at
R1, then bond leading edge stock within
notch at leading edge of all ribs.
Build left wing tip. Align and bond TL2a,
TL2b, and TL2c atop part TL1 with thick CA.
Align and bond TL3 to TL1/TL2 assembly with
thick CA. Ensure that lead-out slots are not
blocked with CA.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 13 of 26

Wing Construction Cont.
 Dry fit left wing tip assembly to left side of
wing at trailing edge.
 Carefully nest leading edge stock within
slot at front of wing tip.
 With wing tip fit flush to rib R4, leading
edge, and trailing edge, bond with
medium CA.
Build right wing tip. Align and bond parts TR2
atop TR1 and TR3 atop TR2 using thick CA.
Repeat prior steps to bond right wing tip
to right side of wing assembly.
Bond a nickel (5g tip weight) within pocket
created by TR2 at right wing tip. (Inflation.
Prior to going off the gold standard, a nickle
would have bought you this kit. Today, the
nickle is more affordable to use than lead!)
 Align part W2, leading edge sheeting, to
tip ribs R4, and bond only to top of the 1/4
in. leading edge stock.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 14 of 26

Wing Construction Cont.
 Starting in the center of the wing,
carefully bend down the sheeting and
bond to upper spar W1. Work from the
center out, one rib bay at a time.
Repeat steps above to install the lower
leading edge sheeting W2.
Fit W12 cap strip to top of rib R1 assembly.
Bond at leading edge first.
Press W12 flat against trailing edge and bond
with CA, then bond W12 to R1 rib assembly.
Carefully sand W12 to a smooth taper into the
trailing edge. Tip: apply making tape to areas
you wish to protect from the sanding process.
Invert wing and remove stand off tabs. Note:
there are two tabs on R1 assembly.
Fit and bond W11 to bottom of rib R1
assembly.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 15 of 26

Wing Construction Cont.
Fit and bond parts W8 to bottom of lower rear
spar, on each side of R1/W11 assembly.
Fit and bond ply W7 pushrod exit to R1
assembly. Ensure that slotted side of tab
extends to the left of R1, or the same side as
W6L/blind nut assembly.
Trim excess leading edge material.
Fit and bond tip blocks W9 at leading edge of
tips, top and bottom.
Bond W10 to W9, aligning edge with edge of
W2 sheeting.
With a razor plane and sanding block, shape
tip blocks to match contour of leading edge
sheeting.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 16 of 26

Wing Construction Cont.
Work tip blocks with sanding block to flow
smoothly into leading edge contour.
Continue sanding a nice, pleasing taper into
the tip blocks. Round off tips and leading
edge leaving trailing edge square. Gently
sand the rest of the wing smooth.
Cut yellow nylon tube in half and slide into
lead-out slots. Bond with medium CA. and
trim tubes flush with tip.
Optional. To move CG aft for better stunting,
battery may be mounted in the wing, install
safety strap should be installed at this time.
Install a 5 in. length of velcro strap through
slots in ply support from top of wing.
Fasten strap to itself to keep it out of the way
while covering the wing. Strap may be easily
removed later, but can not be installed after
wing is covered.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 17 of 26

Wing Construction Cont.
Bellcrank Installation: The following steps
may be done after covering, however, some
may find it easier to install the lead-out wires
through the bare framework before the
covering is applied. Refer to Flight Control
Setup instructions for information on
adjusting the sensitivity of controls.
Bend one end of 1/64 in. (0.015) wires
slightly. This bend will keep the wires from
sliding through the wing tip.
Insert other end of wires through wing tip and
rib holes, and down through bellcrank
compartment.
Install E/Z Connector, 4-40 x 3/8 in. machine
screw, washers & nut as shown...
...one washer on each side of the control
bellcrank. Do not tighten nut - it will snug
down on final installation.
On bellcrank end of lead-outs, bend a small
hook with round nose pliers. This hook must
be small enough to pass through the holes in
the bellcrank.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 18 of 26

Wing Construction Cont.
Bend hook over 90 degrees.
3/8” to 1/2” up the wire, make a 180 degree
bend, bringing the hook close to the wire.
After installation on the bellcrank, the lead-out
wire can be easily closed by catching the
shaft of the wire in the hook.
Connect lead-out wires to bellcrank .
Put a drop of thread locker on end of
machine screw and mount bellcrank
assembly to blind nut in mount. Gently snug
down screw until bellcrank is free of wobble
but moves smoothly.
Finish lead-outs by bending closures 2-3 in.
past wing tip, identical to those at bellcrank
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 19 of 26

Final Assembly
Cover wing with a high quality, light weight,
model aircraft film such as Stevens
AeroModel’s AeroLITE or AeroFILM.
If bellcrank assembly was not installed
previously, cut covering away between ribs
R1 and R2, leading edge sheeting and W8.
Install bellcrank following instructions in Wing
Construction section. Bellcrank access hole
may be left open without significantly affecting
performance of model.
For the best bond , remove a 3/16 in. wide
strip of covering from top and center of wing.
Center wing in fuselage. Make sure lead-outs
exit wing on the left side of the aircraft.
Check that wing is square with fuselage and
secure with medium CA.
Mark and drill holes for tail skid approximately
1/4 in. forward of where hardwood fuselage
doubler ends at tail of model.
Test fit, then bond tail skid with medium CA.
Make a 90 degree bend about 1/8 in. long at
one end of the 1/32 in. wire to form pushrod.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 20 of 26

Final Assembly Cont.
Pass straight end of pushrod through guide at
fuselage and lead out slot in wing.
Bond control horn to elevator on same side
as pushrod (use medium CA). Insert bent
end of pushrod through control horn and
capture with Micro E/Z Link.
Cut pushrod 1/2 in. over length and secure
through E/Z Connector at bellcrank. Ensure
bellcrank and elevator are in neutral position
when then snug screw at E/Z Connector.
Mount motor with supplied #2 1/4” screws.
Suppo motor may require shimming 1/8 in. off
of motor mount to accommodate certain prop
styles.
Pass a 5 in. length of velcro battery safety
strap through slots in motor mount and
fuselage.
Strap ends should extend equally through
fuselage.
RingRat 100 © 2010 Stevens AeroModel all rights reserved. Page 21 of 26