Fuselage sides jigged and done

First pic is of the second side just popped outof the jig resting on the jig table. Second is of both sides. There are battens glued on to help hold together for travel before gluing together with ply insert bulkheads.

Fuselage longerons

 

cut guide set up

 
I sterted off with out a cut guide thinking I could control the cut ok, which I did for about 12 inches before the cut went inside the line! luckily I have more wood than I need and can flip over after one mistake. The guide can actually be a little rough on the saw but the cost of the saw over the cost of the spar makes it a worthwhile control measure.

Spar thickness cut layout

 
This is how the spar is not set up to cut the tapered thickness (smallest dimension 18ft(l) x 6.5in (w) x 2in (t))
where is tapers from 0.5in at the tips to in the middle. Note the aluminiaaum cut guides clamped on about a quarter of the way in with the saw through the cut. Long hard slog that cut is I can tell you.

Aeros

0.6 hrs solo yesterday in the Robin. Broken nimbo-stratus between 2500-4000 feet but clear over the coast so did some lazy eights, rolls and steep turns over Stockton beach. Couple of touch and goes

Port Stephens from the Robin

 

Maitland and back

I ducked into the club to get checked out in the 150 so I could get a little bit of cheap scenic flying in. I hadn't flown since January!!! so according to club rules I needed a quick check ride. Would I take P over to Maitland for the check and he could then pick up the Robin? Sure.

Nice takeoff when 100 ft off the deck my window blows open. No big deal. Check airspeed, balance, climb. Slowly reach out and grab it. I dont like my watch hanging out there. And bring it in. And shut it properly this time. Seemed closed on the checks. Oh well.

P had just set up a student for a solo nav into the Upper Hunter so the lifting of the fog was of vital interest. Willy was clear but west there was lots of low cumulus embedded in fog. It didnt look good from here, but as we reached East Maitland you could see that it was transparent enough for VFR and was dissipating in the very slight breeze from the west.

And at East Maitland, just over the top of the Model Aircraft field, P shouts look, two o'clock, model aircraft. What? Sure enough, perspective and distance making it look like a real low wing aircraft about 200 ft below our 1500 ft, a green radio controlled aeroplane. Flying straight and level parallel to our track about 200 m away. We are outrunning it (at 85kts!!) so I turn a little towards it to keep it in my view. It does a half roll then loops into a rolling hammerhead, then drops out of sight below us. We turn back towards YMND.

Nice approach into an empty circuit for 23 YMND and dropped of P while I fuelled up the Cessna. P wanted to wait to make sure the Robin started. It did after the usual pre0flight checks. By that stage all the fog-back-logged lessons and joy flights were starting up and I jsut managed to race to the head of the queue. Because of all the rain the grass taxiway was a big puddle so everyone backtracked to the detents and the 23 threshold. By the time they all arrived I completed my checks, and blasted off. The Robin two behind me.

Beautiful Saturday morning, traffic, coal trains, shopping centres, parks, sports, rivers and mountains. A lovely hour in the air.

Spar Trimming

It's taken a lot longer than I thought to get this spar done. Having finished the laminations and ending up with a spar sized "blank", worked a reasonable compromise between the plans' dimensions and the unexplained "750 lb mod" (enabling an extra 100lbs wt to be carried on the aircraft) drawing a (slightly) curved taper from the centre to the wingtips, I had to cut it down to size. By hand. Slow but safer. After an hour's cutting with handsaw, over a couple of days I think evilly what about the power saw? It's a hand drawn circular saw. Freak me out. I draw a parallel line 1/4" outside the actual dimension to allow for blade error and try to keep the cut outside that line. I test and am able to hold it parallel. Stop the saw to assess. But before the blade slows I relax my grip, it catches and propels back along the direction of cut. Yipes! The teeth cut outside the line perilously close to the actual line. In fact right on it. I could have trashed it. Finish the job with the hand saw. Use the electric planer to smooth the rest of the cut and bring the cut right up to the line with the belt sander. Success. But will not use the circular saw again. Too dangerous. That's cut one of four on the vertical plane. Three more then rotate the spar through 90 degrees to cut two cuts on the horizontal plane.

Fuselage Jig

 

Transferred the drawing onto the jig base thanks to the Corby Starlet Newsletter I bought from the editor Vic Boyce - handy builders notes. Gluing guide blocks onto it tonight. Does both sides.

Laminations complete. Let the trimming begin!

I finished the final laminate layer before Easter. Since then I've been sanding front and back faces flat and having chosen a most flat face, I went to the least flat face and practiced the precision drawing onto the spar blank - of The Cut. Having got that largely wrong (the plans says the spar has a straight taper, but that doesn't explain the 750lb mod to the top centre of the spar which distorts the calcs). I tried again on the other side and decided to compromise the straightness with a more even curve top and bottom. There's already a warp and washout built into the rib angles so a minor extra curve should be ok, (Wait for covering problems!).

 

Now I am read for The Cut. But how?

Hand saw. Slowly and carefully. I'm not taking it to a professional. If the they bugger it up there would be serious trouble.

I thought optimistically this could be done by the End of January! Anyway, I am building my fuse jig too.

Laminates 7 and 8

75% of the spar is now glued. At this rate another two weeks to start trimming it.

2nd and 3rd laminations

No i wasnt game to do two at once. Actually I have four laminations because the first gluing was between two laminations. The second added the third lamination, the third gluing added the fourth. Out of 12. 1/3 of the way through. And I've run out of big enough clamps to for the width. So I need to buy or borrow more.

M helped me with the first two gluings, and A helped with the third.

Horizontal laminations started - Spar

 

 
Going one by one rather than all at once. I discovered I wouldnt have enough glue for the "all at once" anyway. Must order more. I may try two at once next weekend. Getting there.

grain direction

 
The spruce was long but it was quarter sawn. To get it to "lay flat" within limits, meant having to cut narrower width pieces to length and then glue them side by wide to make up the 2.25 inch width of the spar blank. Then "brick" them so that the joins werent on top of each other and the grain all oriented the same way - up in the middle down at the sides. Once glued together it will have enormous strength.

The Spar Jig takes shape

 
Almost ready to go. Just need to add the wax paper to the battens. That's the laminate stack (spar blank unglued) to the right of the jig.

last spar horizontal lamination

Glued up number 12 this morning. That's the easy bit. Now how to do the vertical lamination - ? Have to build the rest of the jig appropriately and test before gluing. How exciting!