Climax Models Axon - RC Groups
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Nov 04, 2003, 01:00 AM
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Martin Hunter's Avatar

Climax Models Axon



| spec
| @904613: Axon
| Specifications
|> Wingspan: |< 28”
|> Wing Area: |< 224 sq in
|> Length: |< 28”
|> Flying Weight: |< 8.6 to 10.2 oz (10.8 oz as tested – see “final assembly”)
|> Motor: |< GWS/EPS 300C-CS, Brushless: Razor 400, AF010 (Razor 400 used)
|> Prop: |< Up to 12x6 as necessary (GWS 10x8 used)
|> Batteries: |< 2s to 3s 700 to 1200 mah li-poly (3s 700 etec lipoly used)
|> Available From: |< <a href="http://www.cl-i-max.com">www.cl-i-max.com</a>

!Introduction

The announcement of the Axon by <a href="http://www.cl-i-max.com">www.cl-i-max.com</a>
immediately had my attention due to the sleek lines and overall graceful beauty
of the flowing airframe. I knew I had to have one. Upon completion of the kit
and finding out just how well she flies, I couldn’t be more impressed. As a
kit, the Axon goes together in a very short period of time.
The end product is a very strong, sleek looking, and fantastically fun
flying plane.

!Construction
Construction methods combine the old with the new; the
yin with the yang; the old-world with new technology. Most of the kit is laser
cut to a high standard. Most pieces are interlocking providing a strong joint
even before adding glue. Woven into that construction method is the occasional
construction flash-back. This comes in the form of cross grain sheeting and
built in landing gear.

The kit includes laser cut wood, laser cut plywood fuselage
formers, a hardwood motor stick, carbon for the aileron torque rods, and a strip
of Velcro for the battery. You will need to provide your preferred pushrod
material as well as landing gear hardware.

A browse through the instructions showed a well thought out
and seemingly quick assembly.

!!Let’s get started!

@904614:Kit contents

!!Tail Feathers

The tail feathers are built over a flat surface. T-pins
need not apply. Medium or thick CA need not apply. The tail feathers are
partially interlocking and self aligning, making construction a snap. It’s as
simple as laying the parts in position and hitting each joint with thin CA. On
top of that, even parts as small as the stringers are laser cut, ensuring a
precision fit.

@904615:The completed fin and rudder. Note the fin’s protrusion as an optional tail skid.
@904616:The completed stabilizer and elevator. Note the additional structure between elevator halves.

!!Fuselage

The fuselage is made from an outer shell and the main
structure is contained inside. The fuselage sides are, in fact, free of holes
for the fuselage formers leaving a very clean and smooth finish, suitable to
transparent coverings if you so desire. The inner structure is made up from
1/8” balsa for side-rails and 3/32” plywood for formers, servo rails, and
battery tray. Combine this with some 1/16” cross grain sheeting (top and
bottom) and you have a remarkably strong structure.

Since the fuselage is a constant width back to the trailing
edge of the wing, very little thought needs to be done as to keeping it
straight. The formers lock in, the second side is pushed on, and voila! You have
a straight fuselage section. It is at this point that the middle section of wing
spar is installed as another former. It protrudes out both sides of the fuselage
for the wing to lock into later on.

The cross grain sheeting is done after the wing is
installed, which comes a little later on.

@904617:Fuselage sides, showing the inner 1/8” balsa side-rails. Be sure to make a right and a left!
@904618:Fuselage construction has started. Note the wing spar former
@904619:The fuselage is complete pre-cross grain sheeting. The rear is re-enforced with 1/8” sq balsa stock and as such no formers are required aft of the wing. Simple!

!!Wing

The wing is entirely built with entirely interlocking
pieces. Rather uniquely, the construction is started with the leading edge. The
leading edge itself is a T-structure, leaving it very strong but also light. The
ribs all slide into place in the main spars. The trailing edge slides onto tabs
on the ribs. Adding to this structure is a pair of 1/8” sq stringers, which
run along the trailing edge.

The wings went together in very little time and
have shown to be remarkably strong, even pre-covering! The ailerons are built
entirely interlocking as well and came out perfectly straight.

@904620:T-section leading edges before installation
@904621:Completed wing structures showing interlocking trailing edges at the join.

!!Completing the Wing and Fuselage

Rather unique to this design is that the wing, once
built, becomes an integral part of the fuselage structure as the fuselage
structure becomes an integral part of the wing

The wing leading and trailing edges are used as alignment
pegs as well as being key to the strength of the wing installation. There are
cutouts on the fuselage side to allow for this and to ensure no slop. The wing
spars themselves interlock into the protruding fuselage former. The only change
I’d recommend in this method is sanding the airfoil shape into the wings prior
to installation into the fuselage.

Once the wings are glued into position, a few
sub-ribs are added at the wing roots and some cross grain sheeting is glued into
place to both add some strength and to allow a flat surface to tack your wing
covering onto.

It is immediately prior to doing the cross grain fuselage
sheeting that the landing gear is added. It is mounted in place using a double T
section of plywood with small notches cut out of it for the gear wire itself.
This assembly uses the motor mount for additional strength. As with other areas
in this kit, in this case strengthening one area lends itself to strengthening
another.

As a final step prior to sanding, the fuselage cross
grain sheeting is added, totally solidifying the entire structure.

All told, I put in approximately 2.5 hours worth of
work before final sanding.

@904622:Wings slid into position, glue-less at this point.
@904623:Landing gear assembly in position. I re-enforced with rubber CA after this picture was taken.
@904624:Here is the radio and battery compartment. The receiver goes into the slot beneath the battery bay.
@904625:The completed airframe! Missing from this picture are the ailerons.

!!Final Assembly

My covering of choice for this airframe was black,
yellow, and silver Solite. I’m using three HS55 servos for control. My
receiver of choice is a full sized caseless Circus 7. Remarkably, this receiver
does fit into the fuselage! The fuselage is deceptively spacious. It is this
receiver, however, that hopped up my weight from the kits range (10.2oz max) up
to my reported weight (10.8oz). However, as flight testing will show below,
there are no adverse affects to this extra weight. My wheels of choice are Dubro
1.5” which seem a perfect match up to the size of the aircraft. For pushrod
material, I opted to use 0.055 music wire. This is sturdy enough not to require
any re-enforcement down the fuselage or any worry of bowing.&nbsp;<o:p>

The motor is installed using a typical GWS stick mount
and a single screw is recommended to hold it in position.

@904626:The completed airframe, minus electronics or pushrods. The weight so far is 4.1 oz
@904627:Here’s the neatly planned servo installation. Provisions and space are adequate for either one or two aileron servos.
@904628:She’s ready to fly! AUW at this point is 10.8 oz

!Final Check and Flying

It turns out that with my listed electronics, the CG
came out dead on the main spar. Kudos to <a href="http://www.cl-i-max.com/">www.cl-i-max.com</a>
for good planning in this area! I set my control throws up with dual rates and
no expo. All controls have the maximum mechanically allowable throws on high
rates (over 45 degrees each direction for each surface) and about 2/3 of that on
low rates, which is the manual-recommended 30 degrees. I set my controls up all
neutrally fully expecting to have to add some right rudder after takeoff. Rather
than guess on the amount, I winged it so to speak.

I should interject a quick word on my power setup
before getting to the actual flight report. My power setup is aggressive enough
to be straining the batteries if left to run at full throttle on the bench.
However, the motor does unload slightly inflight, bringing the overall
current down. Even still, I’d recommend my specific setup to a pilot
experienced with throttle management. Have no hesitations in propping down to a
9x7 with my very same setup if you feel unsure about your left thumb. The power
will still be tremendous and sure to impress your flying buddies.

A quick check over showed everything to be in order,
so off we went to a local ball diamond for a quick test flight!

@904613:Awaiting the fateful moment
@904629:From the front, showing her sleek lines.

!!Takeoff

The test flight was done on a recently used ball
diamond. As such the dirt was rather torn up and upwards of ½” deep in spots.
The Axon, however, had no problems with this. I advanced the throttle slowly,
lifting off at about ½ throttle in around 20 feet. The initial climbout did
indeed show the need for right rudder, which I promptly added. This amounted to
about 1/3 right rudder trim or about ¼” actual movement on the rudder itself.
The ailerons and elevator needed no trim movement whatsoever. Further flights
have shown the takeoff roll to be around the 5 foot mark, even in soft sand. The
Axon really gets up and goes!

@904630:Taking to the wild blue yonder
@904631:Banking to avoid the backstop after a touch and go

!!Low Speed

Slow speed flight shows no signs of any bad behavior.
Slowing the Axon down to the stall speed just causes her to mush along so long
as you’ve got a little throttle on. This presents a relatively automatic
harrier so long as you have enough elevator throw. With throttle off, the Axon
does have a pronounced nose drop, but with absolutely no hint of a tip stall.

@904632:Exploring low speed handling at altitude.

!!High Speed

The Axon shows no hint of any trim changes from low to
high speeds, which is important for a plane so very aerobatic (see below). With
my 10x8 on board, I find myself quite often surpassing the pitch speed of the
prop, producing a rather wild sounding but harmless hum. The Axon tends to pick
up speed in a big hurry with the nose pointing down, which is no doubt due to
her streamlined profile. This translates into fantastic energy retention when
transitioning to a vertical run after a dive.

@904633:High speed flyby
@904634:Rocketing vertical!
@904635:Quickly becoming smaller in a vertical run

!!Aerobatics

This is the Axon’s forte. She will loop any size
between about 10 feet in diameter (without flaperon mixing) up to as large as
you want to make them. Rolls at slower speeds are in the neighborhood of
1/second on high rates and progress up to over 3/second when up and moving a
little faster. The rudder is tremendously and remarkably effective on the Axon,
producing some quick rotation spins and true pivot-around-the-wingtip
hammerheads. Inverted requires a touch of down elevator with the stock CG, but
the Axon still has plenty of elevator to do outside loops with great authority.

@904636:Pulling into a loop
@904637:Vertical rolls par excellence
@904638:Rolling flyby
@904639:Inverted
@904640:Inverted flyby

!!3D Aerobatics

It should be pointed out at this point that I have
added about 12 grams worth of weight to the tail to move the CG to a spot which
produces close to neutral stability (zero elevator needed for upright and
inverted). This is neither here nor there as the default CG is perfect for sport
flying and aerobatics. However, for the scope of 3D, I wanted a little less
stability.

While not specifically designed for 3D, the Axon does
perform some of the standard moves rather nicely. Harriers, as mentioned
earlier, come relatively naturally when slowed down with some throttle on and
some up elevator fed in. Torque rolls can be rather quick and are relatively
trouble free. Hovering itself can be a mild challenge as the Axon is relatively
short coupled compared to other true 3D ships, but that is to say that she
shouldn’t be used as a hover trainer. Once a pilot is accustomed to hovering
in general, the Axon should prove no problem. She has plenty of rudder and
elevator authority to maintain vertical as well as more than enough aileron
authority to counteract torque with my current setup. Blenders are entered with
relative ease, though the flat spin never goes completely flat. This may be due
to my CG still being mildly conservative and I will continue to experiment in
this area. One maneuver which may fall under 3D, depending on your definition,
is the knife edge spin. The Axon does this one very well – in fact, better
than any plane I’ve tried it with. With so little fuse side area, she does
drop like a rock in a knife edge spin, so be warned.</p>

@904641:A high altitude hover
@904642:Hovering a little lower
@904643:Hovering and sparkling in the sunshine

!!Landing

Landing could be a challenge with power off, but so
long as you keep a few clicks of throttle on, the Axon is a pussycat on
approach. She will settle in at a nice 3-point attitude and rollout is minimal
(around 5 feet on either sand or gravel

@904644:Final for landing
@904645:Over the threshold

|
| +904651:Take a look at a video of the Axon in action.

* Hits:
* Quick and fairly easy build
* Solid construction
* Built up ailerons means no warps
* Open motor means good cooling and space for whichever power system you choose
* Superb maneuverability
* Overall very impressive performance inflight

* Misses
* One piece design can be a challenge for an inexperienced builder when covering

The Axon has quickly become
a regular flyer for me. The combination of semi-pattern with semi-3D has made
her a blast to fly. My flights vary from high speed passes and 200 foot diameter
loops to harrier passes with low hovering and everything in between. With the
stock CG and low rates, I can highly recommend the Axon as a second aileron
plane. With high rates and the CG slightly aft, the Axon is suited to the more
experienced flyer looking for an exciting 20 minutes of parkflying aerobatic
fun. In short, the Axon from <a href="http://www.cl-i-max.com/">www.cl-i-max.com</a>
has the performance to match her good looks.

@904646:The author with the Axon
@904647:Up close and personal
@904648:Climbing out
@904649:Short final
@904650:At rest
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Nov 05, 2003, 12:18 PM
Registered User
Nobert's Avatar
Martin,
Great article. Very impressive model.
I'd like to know how you do the checker board covering. Really neat looking.
Neal
Nov 05, 2003, 01:58 PM
Leave me alone!
Martin Hunter's Avatar
Thanks, Neal.

For some of my covering techniques, check out this article. I did draw up this design in autocad before doing it, though, rather than free handing it.

Martin
Nov 05, 2003, 04:16 PM
no place like cloudbase
freeflight's Avatar
Great article. Right after I read about it I ordered one of the first hotcakes. Course had to get the Wasp Max X too.

Looks fun fun

L
Nov 06, 2003, 10:00 AM
Registered User
Nobert's Avatar
Wow. Great article and technique. Gotta try it.
Thanks,
Neal
Nov 12, 2003, 01:40 AM
Leave me alone!
Martin Hunter's Avatar
I put up a new Axon video recently. You can get it here. It's 7mb in wmv format.

Happy viewing

Martin


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