Extreme Flight 104" MXS-EXP ARF User manual

1
104" MXS-EXP ARF
Assembly Manual
Copyright 2016 Extreme Flight RC

2
Please take a few moments to read this instruction manual before beginning
assembly. We have outlined a fast, clear and easy method to assemble this
aircraft and familiarizing yourself with this process will aid in a quick, easy
build.
Please read the following paragraph before beginning assembly of your
aircraft! THIS IS NOT A TOY! Serious injury, destruction of property, or
even death may result from the misuse of this product. Extreme Flight is
providing you, the consumer, with a very high quality model aircraft
component kit, from which you, the consumer, will assemble a flying model. It
is beyond our control to monitor the finished aircraft you produce. Extreme
Flight RC will in no way accept or assume responsibility or liability for
damages resulting from the use of this user assembled product.
This aircraft should be flown in accordance with the AMA safety code. It is
highly recommended that you join the Academy of Model Aeronautics in
order to be properly insured and operate your model at AMA sanctioned
flying fields only. If you are not willing to accept ALL liability for the use of
this product, please return it to the place of purchase immediately.
Extreme Flight RC, Ltd. guarantees this kit to be free of defects in materials
and workmanship for a period of 30 DAYS from the date of purchase. All
warranty claims must be accompanied by the original dated receipt. This
warranty is extended to the original purchaser of the aircraft kit only.
Extreme Flight RC in no way warranties its aircraft against flutter. We have
put these aircraft through the most grueling flight tests imaginable and have
not experienced any control surface flutter. Proper servo selection
and linkage set-up is absolutely essential. Inadequate servos or improper
linkage set up may result in flutter and possibly the complete destruction of
your aircraft. If you are not experienced in this type of linkage set-up or have
questions regarding servo choices, please contact us at
[e-mail] or 770-887-1794. It is your responsibility to ensure
the airworthiness of your model.

3
Congratulations on your purchase of the Extreme Flight RC 104 inch MXS-
EXP ARF! The MXS is loaded with unique features, including first rate
hardware, components and thorough instructions to ensure a trouble free
assembly and set-up. Weight saving components are used throughout, such as
carbon fiber structural reinforcement, carbon
fiber wing and stab mounting tubes, carbon fiber landing gear, titanium
pushrods and a carbon fiber tail wheel assembly, all ensuring the lightest,
most high performance aircraft possible. You will notice there is a box built
into the bottom of the MXS fuselage. This is a
pipe tunnel and will accommodate most canister mufflers and tuned pipes sold
for the current makes of 100-120cc gas engines.
The performance ability of the Extreme Flight RC MXS-EXP is phenomenal!
This sleek, fast and agile airframe is completely unlimited in its ability to
perform the full range of full stall high alpha maneuvers and aggressive
gyroscopic tumbling maneuvers. The MXS is rewriting the rule book on ultra-
aggressive 3D maneuvers! Unrivaled in pitch and yaw authority, the MXS will
be the machine that introduces a whole new level of gyroscopic gyrations and
insane tumbles to the hardcore 3D masses. Rock solid in all aspects of current
3D maneuvers, the MXS will give those that fly on the bleeding edge the
confidence and capability to push through and break new ground in
expanding the rapidly evolving 3D flight envelope. Utilizing the same
lightweight interlocking laser cut construction and carbon reinforcement as
our Extra, the MXS is capable of handling the most punishing maneuvers
imaginable. We have spent a great deal of time and effort to provide you, the
discriminating aerobatic enthusiast, with the highest quality, most complete
package possible. We are very proud of the end result of our labor and wish
you great success with the assembly and flying of your Extreme Flight RC 104
inch MXS!

4
Items needed for completion:
Masking or painters tape.
Hobby knife with #11 blades.
Fresh 30 minute epoxy. Pacer Z-Poxy has worked very well for us for many
years.
Blue and Red Loctite.
Electric drill with an assortment of small drill bits.
Small flat head and Phillips head screw drivers.
Standard and needle nose pliers.
Side cutters.
Metric ball driver or allen key set. (especially 2.5 and 4mm drivers)
Sanding block and sandpaper.
7 x 500oz (min) torque servos. (8 servos if you use 2 rudder servos)
1 x standard size servo for the throttle.
4 x Extreme Flight 1.5” single aluminum Servo Arms for the ailerons
2 x Extreme Flight 2” single aluminum arms for the elevators (3 if using a tail
mounted rudder servo and 4 for double tail rudders servos)
1 x Extreme Flight 4” double offset aluminum arm for the rudder if using pull
pull rudder setup.
2 x 6” for inboard aileron Extreme Flight 20 AWG Servo Extensions (may not
need any if your servo lead is at least 12”).
3 X 24" Extreme Flight 20 AWG Servo Extensions (2 outboard ailerons 1 for
throttle).
2 x 48”- 60” Servo Extensions. If you need to remove the stabs for transport
use 54”-60". May need 3 or 4 if using tail mounted rudder servo(s).
5” Extreme Flight carbon fiber Ultimate Spinner, 85cc-120cc gas engine and
recommended prop.
Engine standoffs, 1.125” length if using the recommended DA120
Some type of engine mufflers (stock, canisters or tuned pipes and headers)
Receiver, batteries, switches, EF Flowmaster 34 ounce fuel tank and tubing.

5
Tips for Success:
1. Before starting assembly, take a few minutes to read the entire
instruction manual to familiarize yourself with the assembly process.
2. Go over all the seams on the aircraft with a covering iron on a
medium heat setting. Also, due to climate changes, wrinkles may
develop in the covering. These are easily removed with a little bit of
heat. Use a 100% cotton tee-shirt and your heat gun and
heat the covering while gently rubbing the covering onto the wood with
the t-shirt. Be careful not to use too much heat as the covering may
shrink too much and begin to lift at the edges. Take your time, and a
beautiful, paint-like finish is attainable.
3. Apply CA to high stress areas such as servo mounting trays, landing
gear mounts, anti-rotation pins, wing and stab root ribs, and motor box
joints etc.
4. By the time your aircraft arrives at your door step, it will have been
handled by a lot of people. Occasionally, there are small dings or
imperfections on some of the surfaces. An effective method to restore
these imperfections to original condition is to use a very fine tipped
hypodermic needle and inject a drop of water under the covering
material and into the ding in the wood. Apply heat to the area with a
sealing iron and the imperfection will disappear. Deeper marks may
require that this process be repeated a couple of times to achieve the
desired result, but you will be surprised at how well this technique
works.
5. Use high quality, fresh epoxy for installing the composite control
horns and hinges. We highly recommend Pacer Z-Poxy 30 minute
Epoxy as well as Pacer Hinge Glue. We are very pleased with the results
and ease of application and cleanup of these products.
6. Take the time to properly balance and trim your aircraft and set up
rates with exponential values. Your flying experience will be greatly
enhanced once your plane is properly dialed in.
7. Extreme Flight now has their own Vimeo channel. There are many
assembly videos providing extreme detail on certain aspects of the
assembly of this very model produced by Extreme Flight team pilot
Jeff Williams.

6
Let's Begin:
1. Locate the wing panels/ailerons and horizontal stabilizers/elevators and
associated hardware bags. We will begin by hinging all of these at one time. I
suggest you scuff/rough the surface of the hinges, they are slick from the
manufacturing process and the glue will adhere better to a non-slick surface.
Using 100-150 grit sandpaper works well to do this, be sure you don't sand the
barbs off the hinge, you just want a little scuffing on the hinge, do not sand
at the pivot. I strongly recommend 30 minute (or slower curing) epoxy for
installing hinges. I have found it easier to apply 3-5 drops of glue in the hinge
hole and then using a toothpick, or similar, spread the glue around the sides of
the hinge hole. Do this on just one side, either the wing or aileron it does not
matter which is first. Mix only enough glue to work with one panel at a time.
Before applying any glue to the hinge itself, I highly recommend you protect
the hinge pin (pivot point) from glue. I use Vaseline, but tape will work
however it is harder to remove later, in any case apply either protectant to the
center of the hinge so glue cannot penetrate that pin, it will cause binding.
Once you have the holes lathered with glue, apply a small amount to the hinge
barbs and insert into the hinge hole twirling it as you insert it until the pin is
even with the hinge line. Be sure your hinge pivots freely and is perpendicular
to the hinge line. Allow to dry then mate to the appropriate surface (wing to
aileron/horizontal stabilizer to elevator) and allow that to dry. Refer to figure
1 for the 3 clipped horizontal stabilizer hinges, all other hinges are normal
length.

7
Figure 1
2. Install the control horns for the ailerons, be sure to note that the outer
horns are the ones with the upper hole and the inner horns have it located
nearer the middle (Figure 2). Once you have them inserted into the holes I
advise you temporarily install the 3mm bolt and ball link, this is only to keep
the control horns spaced properly and evenly, remove them once the glue is
dry. You may also install the elevator control horns at this time. Be sure to
scuff the bottom portion of the control horn that inserts into the hole in the
control surface. Trial fit the base plate and control horn before gluing,
sometimes balsa pieces and/or dust will be down in the hole and need cleaned
to allow the control horn and base plate to fit down flush on the surface. (You
should not have to trim the portion of the control horns that fit into the holes.)
Once you have this be sure to trim the covering around the base plate but not
beyond the base plate. Install the aileron servos and orient the output shaft of
the servo towards the hinge line and install all the pushrods/ball links for the
ailerons. To do this use the 3mm bolt and washer thru the control horn, then
the ball link in the middle, then thru the other control horn, then the washer
and nylon insert nut onto the other side with blue thread lock, nothing goes
between the control horns except the ball link, no washers are necessary.

8
Then hook it to your servo arm in the same manner and use blue thread lock.
See Figures 3 & 4.
Figure 2
Figure 3
Scuff this portion only

9
Figure 4
3. Install the elevator servos, orient the output shaft toward the hinge line of
the horizontal stabilizer. It will be easier to install the servo arms after
mounting the servo. Make all hookups for the pushrods/ball links as we did in
the previous step. See Figure 5.
Figure 5

10
4. Hinge the rudder and install the control horns using the same technique(s)
as the wing. Then you can mate the rudder to the vertical stabilizer. See
Figures 6 & 7.
Figure 6
5. Mount your rudder servo in the rear (Figure7) or the center mount
location just aft of the wing tube inside the fuselage which will require a pull
pull setup (hardware is included). If you are running stock mufflers a rear
mounted direct drive servo setup works great for CG purposes.
If you want to run cans or pipes you can still use an aft mount servo setup and
then mount your Receiver/ignition batteries further forward if necessary.
Otherwise mounting the batteries in the same location/tray as the rudder
servo will work. See appendix A in the aft portion of this manual for a pull
pull installation.

11
Figure 7
6.Next we will install the main landing gear, axles, tires, wheel pants and
wheel cuffs. Now is the time to decide whether you are going to install the
wheel cuffs. If you do go with the cuffs then slide the black tubing and use
either Welders adhesive, Amazing goop or CA will work too. Install this
tubing on the open ended portion of the cuff since it will rest against the
fuselage, tape is very handy to hold the tubing in place. I recommend you start
on the back of the cuff and then wrap the tubing around so your slice is locate
in the rear of the cuff and allow this to dry. Slide them onto the gear before
proceeding with the tires/axles.
I feel it is easier to mount the axles/tires/wheel pants before installing the gear
onto the fuselage, however you could install the gear first then the
axles/tires/wheel pants. Proceed with your preferred order and use the
landing gear hardware bag. Now consider grinding a flat spot on the axles to
accommodate the wheel collar, this provides a small flat surface to fasten the
set screw against providing better holding power. Only grind a very small
amount, you should barely be able to see the flat spot, grinding anymore will
weaken the axle, therefore if you are not comfortable skip this technique. Now
fasten the axle to the landing gear by pushing the axle thru the hole then

12
tightening the nylon insert nut to the axle, be careful to not overtighten. If
you ground a flat spot I find it best to position that facing the bottom so future
wheel collar retightening is more accessible. Now install one wheel collar, the
tire then the other wheel collar but don’t tighten. Now position the wheel pant
onto the axle and determine the exact position of the inner and outer wheel
collars such that the tire will not rub against the wheel pant. Once you have
this location add blue thread lock to the set screw and tighten your wheel
collars, do this to the tires on each side of the gear in the exact same manner.
Now position the wheel pant(s) onto the axle/gear and tighten with the 3mm
bolts/washers and use blue thread lock on these as well. Now use something to
support the fuselage and install the gear onto the bottom of the fuselage with
the remaining 4mm bolts, washers and nuts, see figures 8, 9 & 10.
NOTE: I found it easiest to put my hand thru the pipe tunnel to support the
nylon insert nuts during tightening of these four bolts/washers, but you can
also use the access holes near the tank mount area. Once this is all complete
now align your cuffs to the fuselage such that they are barely touching the
fuselage and glue them in place, blue tape is helpful to keep them in place
until the glue is dry. Again see figure 11.
Figure 8
Figure 9

13
Figure 10

14
Figure 11
7. Locate your tailwheel package and have the fuselage supported to aid in
this installation step. Begin by drilling a 1/8” hole centered in the bottom of
the rudder approximately 3” aft of the rudder hinge line. Then insert the
white ball link that will support the tiller arm and use 30 minute epoxy
(suggest roughening the ball link for better adhesion). Now mount the carbon
fiber tailwheel gear using the 3 bolts/washers and blue thread lock. If you are
comfortable grinding flat spots on the gear then now is the time to do that.
Take the tailwheel gear and grind small flat spots for the wheel collars (such
as we did with the main gear axles) and another flat spot on the upper portion
of the wire that will insert into the tiller housing. You will notice on the tiller
housing there are two set screws, the lower is for the tailwheel wire and the
upper is for the tiller arm. Insert the tiller housing into the tailwheel bracket
and tighten the nylon insert nut onto the bottom side of the tailwheel bracket.
Once you have the flat spots then install the tiller arm thru the eyelet of the
ball link. Now install a wheel collar on the tailwheel wire and insert the
tailwheel wire up thru the gear bracket and into the tiller housing and tighten,
also tighten that wheel collar at the bottom of the tailwheel bracket and be
sure to use blue thread lock on all set screws. See figures 12 & 13.
Figure 12

15
Figure 13
Tailweel bracket
Tiller arm
Tiller housing
Nylon insert nut
Tailwheel wire

16
8. Locate your motor and we will begin the mounting process, 1.125” standoffs
will work perfectly for the DA120. If you are using a different motor then plan
on needing 7.25" from the firewall to the front of the cowling, you may want
toadd 1/8" for spinner backplate to front of the cowling clearnance/spacing
for an overall distance of 7.375”.
I will focus on the DA120, this motor is 6.25” overall so I used 1.125”
standoffs to yield my desired spacing. You could use more or even less, but I
recommend about .125” of spinner backplate clearance. You will need to use
¼” allen head bolts of about 2” to 2.5” length, depending on the amount of
threads you want exposed on the inside of the firewall. I also recommend
nylon inserts nuts, with washers and red thread lock for mounting the motor.
Once you have mounted the motor, you may install your desired exhaust
system at your discretion, however I recommend following step 9 before any
exhaust is installed. See figures 14 & 15.
Figure 14

17
Figure 15
9. Install the throttle servo, depending on your choice of setup and engine
brand you may have to drill a hole/slot thru the firewall to access the throttle
arm on the carburetor from your servo. With the DA120 motor we mounted
the servo upright in the engine box and cut a small slot in the firewall for the
throttle pushrod. I again chose to file a very small flat spot on the included
throttle pushrod to accommodate the bolt in the easy connector. When
installing the easy connector be sure the round nut is not too tight and to use
blue thread lock. It depends on being able to swivel, the ball link end to the
carburetor installs just like the other connections you have already
performed. Lastly be sure there will no rubbing or binding between the
throttle setup and the cowling or exhaust you choose. Again refer to figures
16& 17.

18
Figure 16
Figure 17
Slot thru firewall
Pushrod
Easy swivel
connector
Round nut
Slot thru firewall
Ball link
Washer
Nut

19
10. Trial fit the engine cowling to determine fit and any cutting of clearance
holes. With stock mufflers you will have to cut the cowling, using
headers/pipes/canister mufflers you will likely not need to cut the cowling for
clearance. Determine any cooling holes and cut accordingly. There is no way I
could cover every scenario, so I have only included pictures of my cowling
with stock mufflers. In my setup you will not see any cooling holes in the
cowling, I cut holes in the bottom of the fuselage, these are easily accessed and
can be seen by looking down the pipe tunnel and deciding which cutouts to
use. If you use pipes/canister mufflers then you will have to use the cutout in
the pipe tunnel for access and cooling. See figures 18 & 19 for cowling cutouts.
Figure 18

20
Figure 19
11. The basic assembly is complete, now figure where you want to install the
switches (there are
precut holes just aft of the cowling). Install your tank in the tray just in front
of the wing tube and secure with velcro/zip ties and put foam under tank.
Install any other components you plan to use at this time. Figure 20 shows
where I installed my electronics and accessories.
Figure 20
Receiver switch
Ignition switch
Receiver/ignition batteries
Aircraft receiver
Fuel tank
fuel dot
Second receiver battery
Small hole for access
to high and low
needles on
carburetor.
Typical slot cuts for
stock mufflers.