Justin's Raven

[justin.schoeman]

Oh yes - and to add to your instructions - some tips I got from Mike at Plastocure regarding the PU foam:

1) Warm the mold and the foam components.
2) Get a cheap steel whisk from Checkers, pull of the handle, and put it in an electric drill. Use this to thoroughly mix the PU foam components QUICKLY.

This got me nearly 50% more volume than hand mixing, and throwing into a cold mold.

Thanks again for all the help and advice, Boet!

[justin.schoeman]

The pre-lunch session...

The big stick in front is my sanding block - the general idea is to use a long, straight sanding block to sand the plug parallel, and flush with the fuselage skin, so that it blends in cleanly all around. Once I have a nice clean reference shape, I will start profiling it to blend nicely with the nose.

Just need to figure out why it is not symmetrical - it does seem to be parallel to the fuselage skin...

[Jean Crous]

Justin wrote
The big stick in front is my sanding block -

Looking good Justin, funny how the discipline of a good job and a BIG stick work together......
Regards Jean

[justin.schoeman]

Made some good progress towards the final shape, but discovered an important caveat for building a tight cowl: The difference between 'That looks perfect', and 'What the hell is the exhaust pipe doing there?' is just one pass with a surform...

I will need to get some XPS sheet tomorrow to glue onto the plug to put a gap in around the exhaust pipe and oil lines.

[t-bird]

Hi Justin
What is XPS sheet ?

[justin.schoeman]

Hi Justin
What is XPS sheet ?

Extruded Polystyrene.

Expanded Polystyrene is the usual stuff made of 'bubbles' - it is difficult to form nicely with sandpaper, as the bubbles break loose.

Extruded polystyrene is the same plastic, but formed as a continuous foam sheet - forms and sands easily...

In the end, I managed to get Polyurethane foam sheet though, which is better as it matches the rest of the plug.

[Tailspin]

Hey Justin

How much you pay for the Polystyrene ?

[justin.schoeman]

I found PU foam instead. Didn't find an (open) supplier of XPS foam, so didn't get a price yet.

[t-bird]

Cool keep the pictures coming.

Cheers

Callie

[justin.schoeman]

OK, I quite literally have PU foam dust coming out of my ears now, but I am finally approaching the shape I had in mind. Much sanding, swearing, filling in, and sanding again involved. Still a bit of tweaking to do, but definitely getting there.

Boet makes it sound so easy, but unless you are a sculptor at heart, it is a serious pain in the *rse...

[t-bird]

Hi Justin

What is happening wiht the build ?

[justin.schoeman]

Not much... My 16 year old nephew was selected to play for the Mozambique T20 cricket team, playing a tournament (ICC Africa Division 2) in Benoni. I am the only family member in Gauteng, so I have been running around fetching various bits of family from the airport, and shuttling them to the cricket games. And of course watching some cricket myself!

I also had to get my license current, which meant I had to go out to Rhino Park during the day, and work late at night.

Between all of this, I have lost about 3 weeks of building time - but I still have managed to do a lot of body putty and sanding sessions. I almost have a usable surface for taking a mold now...

[t-bird]

Cool keep us updated.
I have aslo started with my PPL at Rhino yesterday morning.
Those Jabs are slippery compared to Gyro's and Thunderbirds.

[justin.schoeman]

Cool keep us updated.
I have aslo started with my PPL at Rhino yesterday morning.
Those Jabs are slippery compared to Gyro's and Thunderbirds.

Enjoy it! I really like flying the Jabis. Takes some effort to grease a landing, but once you get the hang of it, they are really sweet to fly!

[Boet]

Justin, ALLES in die lewe is "maklik"........ as jy dit al n paar keer gedoen het. As ek nader aan jou was, het ek jou gou kom help. Maar ek is 1000 km van jou af. Die inlet gate se vorm kan jy so bietjie modify. Ek merk ook so n bietjie skeef op die "wange". EYEBALL Boet, eyeball. Maak net seker dat die gat onder groot genoeg is, sodat die warm lug onder kan uit. Ek sit liewer te veel as te min koue lug voor in. Volla enjins loop sommer gou te warm, en dan collapse die ou ringetjies. En dan is die ou vollatjie SISM, SISM.