re-re-building the 1200mm Spitfire- yes a second attempt.

Started by Frank v B, August 08, 2023, 09:45:19 PM

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Frank v B

The re-built Spitfire (https://temac.ca/smf/index.php?topic=8699.0) took off fine.  After 3/4 lap the plane shook itself apart.  The hatch flew off and the fuselage ripped apart on one side.  It spiralled into the ground.

- the wing was in one piece- no damage
- the rear fuselage was fine as were the tail feathers.
- one side of the fuselage was ripped through.
- the nose was bent back.

Did the same trick of minute epoxy with round toothpicks.  Six mixes of epoxy later the fuselage was back together again.
Letting it cure overnight.  Then will fibreglass the inside of the fuselage so it cannot tear apart again.

Note: I counted 35 toothpicks used in the two repairs.  Does that make it a wooden airplane??  ;)

Frank

"Never trade luck for skill"

Frank v B

To strengthen the fuselage sides I installed a piece of balsa on each side.  The wood was longer than the hatch opening.
This is aimed to stop the foam sides from ripping apart....again.

Frank
"Never trade luck for skill"

Frank v B

Strengthening the hatch/battery area

- glued the liteply battery tray hold-downs in place.  Originally the battery tray was secured to the rails with 4 - #6 wood screws.
- glued balsa cross braces in place to strengthen the battery tray ply.  It had bent, cracked and started to de-laminate.  This way the battery tray becomes a strong cross brace and the balsa pieces strengthen the tray from below.
- glued the battery tray on top of the rails and the cross braces.

Letting it cure.

next- build the battery hatch.  The old one has been planted in the field.

Frank
"Never trade luck for skill"

Frank v B

Making the hatch.

Approach
- make a framework around the perimeter.  Note the balsa is high compared to the fuselage top.
- trim the top to match the curve of the fuse.
- cut the frame smaller by the thickness of the balsa used on the hatch top.
- contour and sand.

Frank
"Never trade luck for skill"

Frank v B

Hatch mostly done-  just some filling and minor sanding.
The joint in the top is to transition between the round fuse top at the rear to the flat top at the firewall. 
Also, to handle the curve in the hatch when looking from the side.  The fuse opening is not flat.  Compound curves.

Had to make 3 new exhaust stacks.  Fashioned out of balsa.
A Spitfire on 9 good cylinders is not very good. ;)

F.
"Never trade luck for skill"

Frank v B

Locating and installing the hatch magnet.

Step 1- randomly put a magnet in place (circular magnet) on top of 2 metal plates on the fuse. Photo 66
Step 2- press the hatch closed in the proper position and squeeze a bit to indent the magnet on the balsa of the hatch. Photo 67
Step 4- drill out a hole in the hatch larger than the magnet.  I used an X-Acto blade.
Step 5- place waxed paper on the metal so the glue will not ooze out and permanently close the hatch.  Add 5 minute epoxy on the hatch where the magnet will be positioned. Photo 69
Step 6- keep the hatch shut while the glue dries. I used rubber bands.  Photo 70
"Never trade luck for skill"

Frank v B

FINITO!!

or should I say re-finito!!

Close enough to meet the 50/50 rule.

Now that the hatch is finished, someone will find the original one by the end of BBQ day. 
It is somewhere between the pilot stations and Glenn's Lysander Forest (the clump of trees)

Frank

ps: the colours were just Dollarama Acrylic paints mixed together to somewhat resemble the colour.  For the exhaust stacks I had to mix black in with the brown to darken it. 
Don't worry Cadez, your title as TEMAC Paint Master is not in jeopardy.  Mine are at best CNIB mixes. ;)

"Never trade luck for skill"

msatin

Looks great Frank!
I did not think this repair was possible
You never fail until you stop trying