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Top Gun - CML Me109e

The Messerschmitt Bf 109 (aka Me 109) was a German World War II fighter aircraft designed by Willy Messerschmitt and Robert Lusser during the early to mid 1930s. It was one of the first true modern fighters of the era, including such features as an all-metal monocoque construction, a closed canopy, a retractable landing gear, and was powered by liquid-cooled, inverted-V12 aero engines.

 The 109 first saw operational service during the Spanish Civil War and was still in service at the dawn of the jet age at the end of World War II, during which time it was the backbone of the Luftwaffe's fighter force. From the end of 1941 the Bf 109 was supplemented by the Focke-Wulf Fw 190.  Early models had Jumo engines but later the more powerful Daimler engine was used.

 There are not many scale models on the market but Cermark in conjunction with Top Gun produced this 60 size Me109.  The fuselage is grp reinforced with ply formers and coated in matt grey finish allowing modellers more options regarding which theatre of the war they wish to emulate.  The wings are fully sheeted and pre-filmed and the model even comes with air retracts.  These are air up/spring down which in itself becomes fail safe.  The cowling is beautifully finshed using grp and the exhaust ports are pre-fixed for you.  Albiet the cowling is not true to scale or the lovely matching yellow spinner but this is usually normal in rc models.

The large cowling meant that I could hide quite a few types of engine within it, a 120 four stroke or even a 108 2T glow.  I have opted for the Jen 90 two stroke which is no bigger than a 60 size.  This engine came recommended so I went along with it.  The model should weigh in at around 8lbs or so, so a 60 motor would've been adequate but this model may become the chase plane at our club so I needed an edge on 'em. (Dastardly Smile)

It came in a rather large box and was very well packed.  Initially I had no instruction manual so for the first few steps I just used common sense.  However, managed to find a pdf version on the "net".  The box contained the fuselage, the wings each bagged and supported by poly-foam.  The rudder and stabiliser were bagged and laid flat on the bottom of the box.  Two big plastic bags contained the fuel tank, lines, wheels, air-intakes, supercharger inlet and other scale items plus screw and bolts etc.  Hinges are CA types and were pre-slotted in the wing surfaces except for the rudder hinges which are in the bags.  The other bag contained the air-retracts, and the air kit and reservoir

First job is to glue the ailerons.  I marked where each hinge's centre was and marked with a light pencil line.  Ensuring that all the hinges slid in fully and easily I then bored some 1.5mm holes at the centre point of each hinge slot.  This is enable the CA to fully soak in to the contact surfaces.  Using "T" pins pushed through the centre of each hinge I slotted them in to the ailerons and then into the wings.  The pins stop the hinges sliding in any further and also act as spacers.  After removing the pins, flexing the ailerons each way added a few drops of thin CA to each hinge on one side and ensuring the gap is constant flipped the wings over and did the same to the other side.

 

 

 

 



The Fuselage

The Fuselage in the wing mount area is enormous.  The servo tray is pre-fiitted with cut-outs for the four servos and air reservoir.  The servo slots needed no modifying to insert two JR digital for elevator and rudder.  I used two standard Futaba S148's for throttle and air retract valve.  The receiver can sit on the servo tray above the air tank keeping cabling to a minimum.
As you can see from the photos the space between the servo tray and fuel tank bulkhead is enormous.  However, the servo tray is mounted in such a position that 5mm holes needed to be drilled through the fuselage above the servos to access the rear rudder, elevator, throttle servo mounting screws.  Why they could'nt have moved the tray further forward by 15mm I do not know.

Fitting the stabilsier was a little trying.  It is a sliding fit through a slot in the fuselage.  After marking the centre line of the stabiliser and trial fitting a pencil line was drawn top and bottom where the fuselage sides meet it.  Then carefully cut away the film covering 5 mm inside these lines.  Now here is the tricky bit!  A light coating of 30 min epoxy is coated on to this uncovered area.  Then slide the stabiliser through the slot till the pencil lines align up again.  Now measuring from the tips of the stab equal distance must be achieved using the forward wing mounting recess centre and a centre point.  I found this wasn't as easy as you think.  The slightest movement/adjustment on one side tended to throw out the other side enormously.  Once happy with the alignment a thread of epoxy is then applied along the point where the fusleage sides meet the stabiliser.  Wiping off any excess adhesive carefully.  Then recheck alignment. Allowed to fully cure.

The elevators now can be fitted.  Drilling a 1.5mm hole in the centre of each CA slot ensures that the glue soaks all the way down.  Aligning the elevators with the stabiliser is simple enough ensuring that they have adequate clearance on the outer ends where the stab curves round.

With the stabiliser fitted it was time to fit the control rods for the rudder and elevator.  These are dowel rods with pre-drilled holes for the threaded wire connectors.  Once the length of wire required was ascertained for the horn ends the wires were CA'd and then the supplied shrink wrap was shrunk over the area to secure.  Placing the control rods through the pre-cut slots in the fuselage it was time to mark where the control horns would be located on the control surfaces.  Once this was done the horns where fitted and with the clevis's wound on to the threaded end these were dry-fitted so as to ascertain where the straight wires would cross the servo arms.  Marking these points, pulled out the rods again and at the mark positions made 90 degree bends.  Measuring about 10mm from bend cut off excess.  Refitting the rods and now dropping the bent ends into the servo arms which were drilled out to 2mm.  Fitting the supplied plastic "keep" clips.  Using a spare receiver and battery tested the servo travel and direction, etc of the rudder and elevator.

In the servo tray is a pre-cut power switch slot which I used with a suitable sized switch/charge line component and connected all the servo leads to the AR6200 receiver.  To oprate the switch from the outside I drilled a 2m hole in the switch lug and a 2mm hole through the fuslage in line.  Using a short piece of scrap 2mm wire with a threaded end and 90 bend in the other end fitted this to the switch.  The threaded end gives you something to grip when operating the switch!

THe air retract valve comes from the bag of air kit bits.  A laser cut piece of ply is suppplied which you break out and assemble into a valve mounting.  With this screwed in to place next to the servo a small piece of 2mm wire connects the two together.  The servo only needs to travel 7mm to operate the valve.

The throttle control is operated via a snake, supplied and some spare 2mm wires in the kit.  Once happy with its position I epoxied the outer into place plus adding a support block on the side of the fuselage and secured by a cable tie  (See Photos)

The air reservoir slides into it's location under the servo tray and I secured it with a small blob of epoxy.  Made up the airlines to the valve and to the quick-connect.  The air fill valve was located into the side of the fuselage and connected up.

 

 

 

 

 

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