Having checked all
parts were accounted for, all photography of the parts was complete and a
suitable set of flight battery packs was on charge we headed for the building
board.
All instructions were read through twice with checks made on suitable adhesives
- 5 minute epoxy in this case and tools (amounting to a sharp scalpel and
some small screwdrivers). The allen key required for the prop adapter is supplied
in the Competition Motor kit.
The first task in the instructions
is to cut out the control surfaces. We take note here that on the StarJet,
(the mini's bigger brother), the control surfaces would break off if cut and
moved too much before the hinging sticker is applied. Recalling this with
horror the hinge area was pre-taped to avoid the same thing happening. The
supplied sticker set makes provision for this. The ends of the control surfaces
are sanded so give them free movement. The inboard edge requires a few cuts
to make room for the control horn. Extra care is needed to prevent damage
to the control surface edge. We found making the first cut in line with the
end of the hinge slot then removing excess from the fuselage side the best
approach - again drawing experience from the original StarJet build.
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Make cuts to free elevons
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Sand elevon edges
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Use stickers to help hinge
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The control horn were then sanded to make a key
for the epoxy glue. These were then glued to the ends of the elevons
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Sand the control horns
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Mixing the epoxy glue
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Hold the horn until glued
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With the horn fitted we used the control rod
to line up where the servo needed to be fitted prior to cutting away the excess
required to fit the SD200s. A marker pen is used to draw round the servo and
the excess foam removed with a sharp scalpel. The servos are held in place
with the rather excellent double sided sticky pad provided, cut into 2 servo
sized pieces. A small flat blade screwdriver is used to make a hole in the
fuselage to take the servo leads into the radio bay.
Note: It is a good idea to plug the servos
into a powered receiver and setup the transmitter at this point to make sure
everything is centred with the servo arm at 90 degrees to the servo. Remember
its hard to adjust the servo arm once the servo is fixed into the wing.
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Fit control rod as a guide
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Cut the foam to fit servo
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Servo fixed in place
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The motor is glued in place next again using
5 minute epoxy, being very careful not to glue any of the moving parts of
the motor. If you are fitting the competition motor set, a small area of foam
under where the motor sits has to be removed. The circle in the first picture
below show the area removed. Using the same batch of epoxy to save time we
skipped forward and fitted the small ply tabs that the ABS motor cover screws
onto.
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Where to glue the motor
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Dry fit the motor
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4 ply tabs in place
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Fitting the receiver into the model and mounting
the prop as instructed, we double checked the motor was spinning in the correct
direction. With this model you will only get it wrong once - it's quite a
fragile airframe.
The receiver was fitted in the space provided
and we used quite a big 6 channel Futaba receiver but this still fitted in
place perfectly, held in with some of the supplied sticky pad. One of the
2mm steel pushrods was used to make a hole so that the ariel could be routed
through the fuselage to meet the channel provided. The ariel can be taped
into this channel with magic tape all the way to the tip of the wing.
The ABS motor cover has air vents which need
to be cut out, we did this using a soldering iron, if careful you can get
a good result. This ABS cover is then screwed to the ply tabs, fitted earlier,
with the self tapping screws supplied.
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ABS motor cover
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Cooling slots
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Screw cover in place
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The ABS fuselage bottom reinforcer is the next
item to be tackled, the inside of this was sanded to give a key and glued
to the fuselage using 5 minute Epoxy. This was held in place with a couple
of small clamps until set..
The canopy hatch mechanism is identical to the
one used on larger StarJet and when we built this earlier in the year we were
not keen on this idea and opted for a modified system utilising a bolt to
hold the canopy on. However we decided to stick with the suggested method
on the Mini StarJet and despite our initial reservations its actually a very
good method for holding the canopy on. So its definitely worth building as
per instructions which, by the way, are very detailed.
The mechanism essentially consists of one rod
which is bent as the first photo below shows and the long part of this is
glued to the top canopy part. A hole is made and the tube part is glued into
the fuselage (pic 2 below) so that when you slide the canopy on the rod goes
into the tube.
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Bend and glue in canopy
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Tube glued in fuselage
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Finished front catch
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The centre of gravity is described as at the back of the first finger hole,
this is not really critical as long as the model is NOT tail heavy and not
too nose heavy it will fly fine.
The battery of choice is secured using the supplied
Velcro and this is adequate to hold in place during flight.
We decided to add a splash of colour to the tip
tanks, the paint used was Solarlac Cub Yellow. Only a few of the provided
stickers were used as we had some Bumpy Green stickers left over from Sandown.
The suggested scheme in my mind looks good also with bright leading edges
and plenty of stars.
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| Just fancied a bit of yellow
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As the weather on the completion day was less
than ideal a few other tests where done. Current draw, RPM and Thrust testing
over the whole range would have been ideal but.... the rev counter
refused to register anything but 0.01 rpm and the thrust scales were otherwise
engaged so for now the only test information available is the current draw
using the following combinations of prop / flight pack on the same Speed 480L
motor
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Battery
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Current with
CAM-Speed 5.5 x 4.3 prop
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Current with
Kavan 6x4 bendy prop
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Sanyo Candica 500mAh 8 cell Ni-Cad
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10.5A
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10.5A
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Overland 1500mAh 8 cell Ni-MH
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11A
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11.5A
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Protech 2100mAh 7 cell Ni-Cad
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11.5A
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12.6A
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 Waiting for a suitable day to fly and film can be awkward.
Perfect flying conditions arrived early in May and as luck would have
it on a Saturday. A few nice days during the week had used up the
good weather ration and rain was forecast....typical.
With a light breeze gently swaying the trees in the Bumpygreen orchard
and the sun breaking through fluffy white clouds we decided to head
to the testing site and make best use of the ideal conditions. Armed
with cameras, 3 assorted battery packs and most importantly the model
we arrived to find most of the goal posts taken down for the end of
the season - too bad we enjoy a good game of plane limbo. The grass
had been cut recently and a circle of shorter grass (marking a novice
golfers aiming green no doubt) formed an excellent test flying point
as it was right in the middle of the field. Battery connected, C of
G checked, control throws checked, trim checked, motor checked and
finally wind checked.
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Fitting the first flight pack
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One
last balance check
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Ready
to fly
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 Tony took the controls whilst John gave the Mini StarJet
a firm throw, as flat as possible and into wind. The little delta
took to the air with ease, soon building up air speed and climbing
rapidly. At a safe height Tony trimmed the model and John got the
video camera ready to film the action.
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The first thing to say is that the Mini StarJet does fly extremely well, although
it could be tricky to launch when flying on your own - using a neck strap
does make it a lot easier, the model leaves your hand with amazing stability.
The climb rate is good and soon had some height on. Rolls nice and fast, especially
after building up extra speed with a small dive, loops are good too, although
vertical performance very limited with the batteries used. Inverted flight
is easy with only a little down needed but the right battery choice does help
with this.
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Nice angle of climb after launch
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How can you not want one
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Steep turns can lose a lot of speed
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But you soon get it back on
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Motor pitch begins to drop
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Circling wide
for landing
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Last turn on
approach
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The
finals are good
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The
glide goes on and on
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Comes
to a gentle rest
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No surprises on landing, but wow the glide is
rather long, which we conclude can only be a good thing showing no tendency
to stall as it greases in amongst the buttercups. The easy to remove front
hatch means the next battery can be fitted in seconds and away for your next
flight. Flight times were recorded between 5 - 8 minutes depending upon your
use of throttle. We were surprised at its low speed handling, and able to
fly it around at tree height on about quarter throttle having loads of fun
with low passes for the camera.
As a summary this model is very quick to assemble,
an evenings work to see it finished. The price is definitely right too at
£44.95 and great flying characteristics certainly means this has got the Bumpy
Green thumbs up. So why not pop along to Motors and Motors or give them a
call, I really don't think you will be disappointed.
Just what was said in the secret meeting
between Tony, the Transmitter
and the Mini StarJet is a mystery to all concerned.
The Mini StarJet is available from
Unit 2
13 Smith Street
Watford
Herts
WD1 8AA
Tel: 01923 465712 or 01923 466131
Fax: 01923 218840
Article by John Kent and Tony Brock
from Bumpy Green Model Aerodrome
25th May 2002
Small Things Come In Great Packages (or is
it the other way round?) With a box that can only be described as huge, the Mini StarJet
takes up a surprising amount of room when packaged. Taking its overall
shape from the original 1.2M twin motor StarJet, it looks fast even
sitting on the building table.
