Himark Grob G103C Glider.indd

Grob G103C
ARF Aerobatic Electric Glider with
Fibreglass Fuselage & Sheeted Foam Wings
Wing Area
Weight (inc. battery):
41.4 dm2
weee disposal .................................................................. 2
Vital safety info ............................................................... 2
About the flying area required ...................................... 2
spares ................................................................................ 2
Guarantee/warranty ........................................................ 2
Kit contents ....................................................................... 3
Fitting aileron servos to wings ..................................... 4
Fitting optional spoilers/airbrakes .............................. 6
Fitting servos & optional motor, folding prop & ESC 8
Fitting horizontal stabilizer & rudder ......................... 10
Fitting canopy frame and canopy ............................... 13
Fitting and securing wings .......................................... 14
Checking C of G & control throws ............................. 15
CAUTION! The Grob G103C glider is not a toy.
It can cause injury to persons/animals and/or property if
not used correctly. It is unsuitable for beginners or persons
under the age of 14. You should take care and observe
the principles of safety when flying this model. In the
UK, we recommend you observe the British Model Flying
Association (BMFA) safety code at all times, which can be
found at the following address: http://www.bfma.org
In Australia, please contact your hobby retailer or the Model
Aircraft Association of Australia (MAAA).
This is not a beginners kit. Before beginning construction,
please read this document thoroughly and familiarize
yourself with the construction sequence.
If any information in this manual is unclear, please contact
your retailer for help.
After reading this manual store it in a safe place for future
This kit is not suitable for beginners.
Intermediate to advanced skills are required to build it.
Intermediate to advanced R/C flying skills are required
to fly it.
Do not dispose of this product with other household
waste. Instead, it is your responsibility to dispose of
your waste equipment by handing it over to a designated
collection point for the recycling of waste electrical
and electronic equipment. The separate collection and
recycling of your waste equipment at the time of disposal
will help to conserve natural resources and ensure that
it is recycled in a manner that protects human health and
the environment. For more information about where you
can drop off your waste equipment for recycling, please
contact your local council, your household waste disposal
service or the shop where you purchased the product.
Only fly in large open spaces that are approved for R/C model
flying and that are away from people, animals, buildings,
power lines, water or trees.
No spare parts are available for this glider.
If you break something, you will have to repair it yourself.
Crash damage is not covered by warranty.
J. Perkins Distribution Ltd guarantee this product to be free of manufacturing and assembly defects for a period of one year from
time of purchase and Model Engines (Aust.) Pty. Ltd. is for 30 days. This does not affect your statutory rights. This warranty is not
valid for any damage or subsequent damage arising as a result of a crash, misuse, modification or for damage or consequential
damage arising as a result of failure to observe the procedures outlined in this manual. Operation of this model is carried out
entirely at the risk of the operator. Please note that, whilst every effort is made to ensure the accuracy of instructions and material
included with this product, mistakes can occur and neither J. Perkins Distribution Ltd/Model Engines (Aust.) Pty. Ltd. nor it’s
distributors will be held liable for any loss or damage arising from the use of this model or for any loss or damage arising from
omissions or inaccuracies in the associated instructions or materials included with this product.
We reserve the right to modify the design of this product, contents and manuals without prior notification.
© 2010 J Perkins Distribution Ltd, Lenham, Kent, UK ME17 2DL. www.jperkinsdistribution.co.uk
Model Engines (Aust.) Pty. Ltd., Noble Park, Victoria 3174, Australia. www.modelengines.com.au.
All rights reserved. E&OE.
EScale Grob G103C - Instruction Manual
Gel Coat pre-finished fibreglass fuselage
Film covered, balsa skinned, foam wings
Film covered, balsa skinned, rudder
Film covered, built up horizontal stabilizer and solid balsa elevator
Canopy and Cockpit set
Front wheel set
Screw set
Pushrods, control horns and Clevises
Steel wing joiner
Rubber bands and hooks
Servo Covers
Part No. JP10310 G103 BRUSHLESS MOTOR C3223-1200KV
Part No. JP10312 G103 13X6 FOLDING PROPELLER with 5mm HUB
Part No. 4406305 ELECTRIC AIR BRAKE SYSTEM (2) Electric ELF Spoilers/Airbrakes (left/right pair)
3x HiTEC HS-125MG or HS-5125MG digital servos or 3x 7720465 S/TEC Micro D BB M/Gear 28g digital servos
1x HITEC HS-85MG or HS-5085MG digital servo or 1x 7720460 S/TEC Naro Super-D M/Gear 19g digital servo
2x 600mm servo extention leads
1x 900mm servo extention leads
45Amp ESC (Minimum)
11.1V 2200mAh LiPo 20C Battery (Minimum) 3200mAh recommended
Battery/ESC connectors
Minimum 5 channel computer radio with mixing
Minimum 5 channel receiver
15min Epoxy, thin flexible CA and assorted tools (e.g. spanners, screw drivers, drills, hobby knife)
EScale Grob G103C - Instruction Manual
Locate the servo holes in the wings and
carefully remove the film covering using a
new blade in your hobby knife.
Trial fit your servo to the servo frame and the
servo frame in the hole. Adjust if necessary
Connect the servo to a servo programmer or
receiver to set for neutral position.
Attach a 600mm servo extension lead to servo
and use the cord provided to pull the servo
lead through the wing..
Use a ruler or straight edge to establish a
line for the control rod. Make sure the line
is perpendicular to the hinge line as shown.
Gently mark the horn position with a felt tip
Also mark the area to be removed to allow
the servo horn to rotate without fouling.
EScale Grob G103C - Instruction Manual
Use a sharp hobby knife to remove the film,
balsa and foam to allow the servo arm to
rotate without fouling.
Then glue the servo frame into position using
foam safe CA or epoxy. Screw the servo into
the frame.
Drill and screw fit the aileron horn into the
aileron, remove, then apply 15min epoxy and
screw it back into place. Wait until epoxy is
Centre the servo and cut and bend the
pushrod to size with a Z-bend one end and a
90 degree bend the other.
Fit the pushrod with the Z-bend on the servo
horn and the 90 degree bend on the aileron
horn along with the retaining clip.
Trim the servo cover to fit and apply clear
sticky tape to the outside edges.
Secure the cover in place as shown.
Repeat steps 1-8 for the other wing.
EScale Grob G103C - Instruction Manual
If you are fitting the optional spoilers,
carefully cut the film covering holes for the
spoilers. .
10. Using a hobby iron, secure the overlapping
film onto the sides of the hole for the spoilers.
11. Ensure you are installing the left hand spoiler
is the left hand wing and the right hand
spoiler in the right hand wing..
Using the pull cord supplied, attach the cord
to the plug end of the servo lead and pull the
spoiler lead through the wing.
12. Double check you are installing the correct
spoiler in the correct wing.
In the picture opposite, the right hand spoiler
is marked with an R and it is being installed in
the right hand wing.
EScale Grob G103C - Instruction Manual
13. Using a servo tester or receiver, check for
smooth operation of the spoilers. You may
have to adjust slightly to ensure the spoiler
operates smoothly.
The picture opposite shows a small section
being removed from the end of the spoiler
14. The spoiler is retained in the wing by two
small cross head screws.
15. Check the plastic cap strip for fit then glue in
place using flexible CA or epoxy.
Rough up the underside of the cap strip with
coarse sandpaper or a file to aid adhesion.
Be careful not get glue around the edges of
the cap strip or in the spoiler mechanism.
16. Your completed spoiler should now sit flat
with the wing surface.
Repeat steps 9-15 for the other wing.
We recommend you run a separate BEC or
receiver battery if you fit the optional spoilers
as the current drain when operating the
spoilers may exceed the built in BEC of many
electronic speed controllers.
EScale Grob G103C - Instruction Manual
17. Install the plywood formers for the front and
rear wheels as shown..
18. Front and rear wheel assemblies fully
assembled and ready to be fitted to the
19. Test fit the completed wheel assemblies to
ensure adequate clearance for the wheels.
Fit the wheel assemblies using a liberal
application of general purpose silicon.
Extend the silicon fillet onto the top of the
plywood as shown to reduce the risk of the
wheel assemblies popping out on a hard
After ensuring the wheels have been placed
vertically in the fuselage, set the fuselage
aside overnight for silicon to cure.
EScale Grob G103C - Instruction Manual
21. The optional brushless motor is fitted with an
unique extended shaft, specifically designed
for the Grob G103C to maintain its scale
22. Attach the motor to the plywood mount using
t-nuts and bolts as shown.
Apply a liberal bead of general purpose
silicon to the outer edges of the plywood
23. Insert the assembled motor mount into the
nose of the fuselage and position it so the
shaft evenly exits the hole in the front of the
Set the fuselage aside overnight to allow
the silicon to cure. (If possible support
the fuselage off the ground so the nose is
pointing down and let gravity do the work.)
24. Assemble the folding propeller and attach the
propeller shaft on the motor..
EScale Grob G103C - Instruction Manual
25. There are a number of ways of installing the
elevator servo. One way is to cover the servo
in heat shrink and glue it in the fin, as shown.
26. Another way requires a little more work, but
gives a nice result and it is easier to replace
the servo or make other adjustments if
Fit the servo to the plywood mount (same as
for the aileron).
Hold in place with tape as shown.
Establish the correct length for the pushrod
and put a clevis on one end and a z-bend in
the other.
28. When happy with the pushrod length, centre
the servo and mark and drill three holes for
the mounting screws in the left hand side of
the fin.
EScale Grob G103C - Instruction Manual
29. Insert the servo through the hole in the top of
the fin.
Depending on the servo you use, you may
have to use a rotary tool to make enough
room for the servo to fit in.
30. Guide the servo into position using the servo
Guide the pushrod down and back up through
the round hole as shown.
31. Carefully align the servo and use normal
servo screws to secure the servo in place.
As shown, you can gently squeeze the sides
of the fin to hold the servo in place while
putting in the screws..
32. The servo is now neatly installed and can be
removed or replaced if required.
EScale Grob G103C - Instruction Manual
33. Attach a 600mm(24”) servo extention lead to
the elevator servo and tape the connection
with masking or electrical tape for added
Feed the extention lead down inside the fin
and into the fuselage. Use a hooked piece
of wire to draw the end of the lead into the
cock pit area where it will be attached to the
receiver later on.
(Picture shows servo extention lead on the
outside of fuselage for illustration purposes.)
34. Cut the elevator horn to length so it will
not foul on the horizontal stabiliser at full
deflection. (Full length horn shown).
Drill and screw fit the elevator horn into the
elevator, remove, then apply 15min epoxy and
screw it back into place.
When epoxy is set, the horizontal tail plane
can be screwed in place.
Connect control horn to the elevator pushrod
35. Drill a hole in pushrod dowel and resess a
slot to receive the pushrod wire. Put a right
angle bend in one end of the long pushrod
wire add 15min epoxy and insert into the
dowl. Cover the wire and dowel with shrink
wrap as shown.
Cut a slot for the rudder pushrod in the
fuselage and test fit the pushrod. Cut the
pushrod t length and put a 90 degree bend for
the rudder horn.
Cut the dowel at the servo end and repeat
procedure using the short threaded pushrod
wire and clevis.
36. Drill and screw fit the rudder horn into the
rudder. Remove horn and apply 15min epoxy.
Screw back into place.
Fit the rudder pushrod and retaining clip, then
set aside to allow epoxy to set.
EScale Grob G103C - Instruction Manual
Carefully trim the cockpit to size and CA the
plywood frame pieces in place.
38. Assemble the cockpit instrument panels and
attach the stickers. Cockpit may also be
painted to add to scale realism.
Mask and paint the inside of the canopy
frame if desired.
Secure the canopy to the cockpit using a
suitable canopy glue or tape using clear tape.
39. CA the canopy locating pin in the front of the
Epoxy the plywood plate in place to receive
the canopy locating pin.
40. Mount the canopy latch on a piece of
plywood using 4 screws.
Cut a slot in the fuselage for the canopy
release lever. After test fitting, epoxy the
latch in place
Screw the brass ball in place using a small
drop of thread locking compound.
Test fit and drill a hole in the back end of the
canopy to receive the canopy latch pin (not
EScale Grob G103C - Instruction Manual
41. Test fit and epoxy the wing locating pins, two
in each wing.
Screw in the wing retaining eyelet. Use a
small drop of thick CA on the thread of the
eyelet to prevent it coming out.
Repeat for other wing.
42. Install the plywood servo tray using general
purpose silicon and leave overnight.
Mount your receiver, battery and ESC. Test fit
the canopy before securing anything as the
cockpit floor is quite deep.
Secure the battery, ESC and receiver using
velcro strips.
Our test sample required the 3200mAh battery
(to be installed back against the servo tray.)
Install the wing joiner bar and slide the wings
into position, being careful to feed the servo
wires through the holes provided, until the
wings are flush with the fuselage. Secure the
wings with the supplied retainer spring.
The spring will attach to the eyelet located on
each wing as shown.
44. Your Grob is now ready for radio setup and
balancing prior to flight.
EScale Grob G103C - Instruction Manual
45. Mark your center of gravity (C of G) marks
either side of the fuselage.
Balance the glider upside down on your
finger tips (or stand) on the C of G marks.
Remember to test C of G with your flight
battery installed.
46. Test flying has shown that 70mm back from
the leading edge at the wing root is a good
safe starting point. Do not exceed 80mm
back from the leading edge at the root in
subsequent flights.
If required move the battery forward or back until it
balances evenly.
If you cannot get the Grob to balance by moving
the battery, you may need to add lead to the
nose or tail.
If the lead you use is not self adhesive, secure in
place with double sided tape or epoxy.
47. Set up your model in your transmitter and
adjust the control throws to achieve the
figures shown. Differential is required on the
Now stop admiring what you have done and go
Remember to fully charge your batteries and
perform preflight checks including a full
range check.
47. Flight testing revealed the stall speed could
be dramatically reduced with the use of
Turbulators. Turbulators can be easily made
by cutting 3mmx200mm strips of self adhesive
velcro style “hook” material.
Place as shown in the picture opposite,
approximately 18mm from the leading edge
and 18mm apart.
Adding turbulators allows you to fly much
slower with much less risk of stalling.
EScale Grob G103C - Instruction Manual
Grob G103C
ARF Aerobatic Electric Glider with
Fibreglass Fuselage & Sheeted Foam Wings,
Australasian agents:
European agents:
Model Engines, Melbourne, Australia
J Perkins Distribution, Lenham, England
American agents:
Hobby Lobby International, Brentwood, Tennessee, U.S.A.
June 2010