3DHS Bigfoot 84" User manual

3DHobbyShop.com
Bigfoot 84” Assembly Manual
Thank you for purchasing this 3DHobbyShop ARF RC aircraft. If you have any issues, questions,
concerns or problems during assembly, please contact our tech department at:
[email protected] or 717-814-5316 10am-4pm Eastern Monday – Thursday.
SAFETY in Assembly
During assembly of this aircraft, you will be asked to use sharp knives, hot irons, and hobby adhesives.
Please follow all safety procedures recommended by the manufacturers of the products you use, and
always follow these important guidelines:
ALWAYS protect your eyes when working with adhesives, knives, or tools, especially power tools. Safety
glasses are the best way to protect your eyes.
ALWAYS protect your body, especially your hands and fingers when using adhesives, knives, or tools,
especially power tools. Do not cut toward exposed skin with hobby knives. Do not place hobby knives on
tables or benches where they can roll off or be knocked off.
ALWAYS have a first-aid kit handy when working with adhesives, knives, or tools, especially power tools.
ALWAYS keep hobby equipment and supplies out of the reach of children.

SAFETY in Flying
ALWAYS fly your aircraft in a safe area, away from spectators.
ALWAYS fly your aircraft in a safe manner, within your control.
NEVER fly too close to yourself.
ALWAYS wear eye protection while operating your model aircraft.
ALWAYS keep your hands and body clear of propellers.
ALWAYS observe lipoly battery safety procedures.
ALWAYS handle gasoline in a safe manner.
ALWAYS perform a ground test and range check of your radio system before flying.
REQUIRED ITEMS
CA Glue
Canopy Glue
30 Minute Epoxy Glue (NOT 5-minute Epoxy)
Hobby Knife
Phillips Screwdriver
Set Metric Allen Wrenches
Small Pliers
Wire Cutters
Rubbing Alcohol
Paper Towels
Blue Loctite thread-locking adhesive
Dremel-type rotary tool
Small adjustable wrench or wrench set
IMPORTANT NOTE: 3DHS Recommends ONLY High-Torque, Digital, Metal-gear Servos for this
aircraft. Suitable part numbers include Hitec HS-7955TG,and HS-7954SH. DO NOT attempt to use
nylon-geared servos on this airplane.
THIS AIRCRAFT IS NOT A TOY! IT IS A HIGH PERFORMANCE AEROBATIC AIRCRAFT AND
IMPROPER SETUP AND/OR USE COULD RESULT INJURY OR DEATH.
Assembly Instructions
UNPACK
Unpack your airplane and examine the components. Check for damage of any kind. If you find any
damage, contact 3DHobbyShop and report the damage.
COVERING SEAMS
There are many seams in the covering on this aircraft where one color meets another. We recommend
using a covering iron or trim sealing tool to go over all of the covering seams on your Bigfoot. This will
help to prevent any peeling of the covering. Repeat this periodically.

WRINKLES
Your Bigfoot was packed at the factory without any wrinkles in the covering. You may notice some
wrinkles now; more likely, you will notice a few in a day or two or the first time you take the plane out to
the flying field. These wrinkles are the result of wood shrinkage and/or expansion. Balsa wood changes
size and shape slightly as it is exposed to varying humidity in the air. This is a natural property of balsa
wood. As your airplane adjusts to the weather in your part of the world, wrinkles may appear and
disappear.
Wrinkles may be removed with the gentle application of heat to the covering material on your airplane,
using an iron and/or heat gun. Apply the heat gently: the covering material will shrink as you apply the
heat, and this will remove the wrinkles. BE CAREFUL! Too much heat applied too quickly can damage
the covering, either by causing it to pull away from the wood at seams and corners or even by melting it.
Wrinkles do not affect flight performance.
COVERING MATERIAL
Your Bigfoot is covered with genuine OraCover material. If you need to repair sections, matching
covering is sold at most hobby stores under the “UltraCote” brand.
Using a sharp hobby knife, a small-tip soldering iron, or a hot knife, remove the covering material over the
door and window openings on the fuselage.

Also remove the covering over the wing spar, wing pin and retainer, and servo wire openings as shown.
Remove the covering over the horizontal stabilizer slot and the rear servo openings as needed. NOTE:
Bigfoot includes two rudder servo mounts, one in the rear on the right side (shown below) and one in the
cabin for pull-pull cable arrangement. If you are using an electric power don't cut the covering away from
the servo opening on the right side of the fuselage, since you will be mounting your rudder servo in the
front. For gas power, mount the rudder servo in the rear.

Test fit the vertical stabilizer into the slot but do not glue it yet. The fit should be snug. If it is too tight,
sand the bottom of the vertical stabilizer slightly.

The main axles on the Bigfoot include a cross-drilled hole in the end of the axle for positive retention of
the main wheels with a cross-pin.
Bolt the main axles onto the landing gear as shown.

Your kit includes 3" wheels, which are a very lightweight option. If you wish to use them, install them onto
the axles along with wheels collars and pins as shown.

For a more scale look, you can use 6"-8" balloon tires, such as the pictured DuBro 6" balloon tires. Be
certain to use the cross pins as shown for wheel retention.
Attach the landing gear to the fuselage as shown, being sure to loctite these screws.

Use rubber cement or epoxy to attach the landing gear fairings.
Use tape to hold the fairings in place while the glue sets.

Use rubber cement or epoxy to install the landing gear cover plate on the bottom of the fuselage as
shown.

Installing the tail surfaces: Slide the carbon main wing spar tube into position. Without any glue,
temporarily install both the horizontal and vertical stabilizer as shown and check for alignment with each
other and the wing tube. Make any adjustments needed by sanding or shimming.
Do not remove any covering from the horizontal stabilizer. Instead, once you are satisfied with the
alignment of the horizontal stabilizer in all directions, apply thin CA glue as shown. It will wick into the
joint and permanently adhere the stab. We recommend this on all of our 30CC aircraft, gas or electric
powered. Clean up any excess CA on the covering with debonder.
Since there is bare wood exposed on the vertical stabilizer joint, you may use thin or thick CA or epoxy to
permanently install the vertical stab.

Install the control horns onto the rudder and elevator. Note that if you are using pull-pull rudder, you will
need to install control horns onto both sides of the rudder. If you are using gas power, you will only need
one horn, on the right. Note also that your elevator horn will be on the elevator half on the left side of the
fuselage. Use 30-minute epoxy to install these horns. Remove the covering over the slots for the horns,
liberally apply epoxy to the slots and the bottom of the horn, press in, and remove excess epoxy with a q-
tip soaked in rubbing alcohol.
Locate and open the hole in the rear of the fuselage for the lowest rudder hinge, as shown.

Apply a drop of vaseline or oil to the center axle of each hinge point. Be careful not to get it on the ends
of the hinge points.

Install the elevator joiner into the slot in the elevators with 30 minute epoxy, and install the hinge points
into the horizontal stab and elevators with 30 minute epoxy. Align everything and apply masking tape as
shown to hold elevators in alignment while the glue dries.
Install the rudder hinge points with 30 minute epoxy as shown.

Install elevator servo as shown, running extension forward through the fuselage. Install elevator pushrod
as shown.

If you are using the tail mounted rudder servo, install rudder servo and pushrod as shown.
IF you are using an electric power system and need to use the pull-pull rudder system, mount the rudder
servo as shown.

The pull-pull cables for the rudder are assembled as shown in the following diagram:
Assemble the forward ends of the pull -pull cables first. Crimp the brass crimp sleeves firmly, looping the
cable trough as shown.
Install the cables onto the rudder servo as shown.

At the rear of the fuselage, pull the cables taut and crimp the ends as on the front. NOTE: Do not pull the
cables too tight. They only need to be snug, so that they do not sag and the rudder does not flop back
and forth.

Locate the stabilizer brace wire hardware pack. There are a total of six cables. Four long cables for the
top, two shorter for the bottom.

Kiwk-links and a small threaded pushrod with a hole in one end are provided for the ends of the cables.
This allows for small adjustment once all the cables are installed. Each wire is made up with the same
technique as the pull-pull rudder. Insert the small pushrods 4-5 turns into the kwik-links. Then install the
kwik-links to each hard point. Note: the top of the vertical stabilizer requires two (on each side), all others
receive one. Now bolt the had points to the stabilizers in the provided holes. There is a small slit in the
covering indicating the hole locations. Use the pictures for reference.
The bottom two hard points attached to the fuselage are installed using wood screws. Best to install the
wood screw, then remove and harden the wood with thin CA. Once dry, reinstall.
Now attach the cables using one crimp sleeve to each small pushrod. Do one cable at a time, taking up
as much slack as possible. Once all the cables are completed, the pushrods may be threaded into the