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Last Modified May 5th 2002.
1st April I clecoed the two halves of the cowlings together then, at the suggestion of one of the other builders, I cut out a hole the same size as the central extension of the propeller mount. This gave me a third hand and allowed me to do a basic check of the cowlings on the aircraft. I will now wait until I have the latest version of the firewall forward manual before continuing with the cowlings.
I think I
just set a new record for the length of time it can take to do a bolt up. A fair
portion of the afternoon was taken up trying to get the lower firewall onto the
aircraft. The top left bolt proved to be extremely difficult and in the end I
resorted to enlarging the holes in the top two layers of stainless steel in
order to give the bolt a bit more freedom.
At the bottom of the picture can be seen the two screws holding the firewall to the underside of the aircraft. These screw into nuplates mounted on the outside surface with the head of the nutplate (and shaft of the screw) set into a hole drilled in the underside.
2nd - 3rd April No building, getting ready to travel.
4th - 15th April No building, at Sun 'n Fun in Florida.
16th April Tried out the Cylco polisher I brought back from the US. It certainly makes cutting and polishing a lot easier.
17th - 18th April Cut and polished most of the port side of the aircraft. Assembled the instrument panel breaker sub panel
19th April No Building. My Airmaster constant speed propeller was delivered today.
20th April Finished cutting out the holes in the radio panel and sprayed it.
21st April Spent the day trimming the cowlings. This is a messy job as it can't really be rushed. I made myself a marking tool out of a piece of spare aluminium sheet. The tool has a small edge that runs along the fuselage lip where the cowling will sit. The aluminium then bends around the cowling and has a hole to hold a marker pen in line with the lip. I trimmed back four times during the day and now have most of the trimming done.
22nd April I spent the evening drilling holes in the radio panel.
23rd April Trimmed and cleaned up the radio panel and applied the first coat of primer.
24th April Applied the second coat of primer on the radio panel and also resprayed the instrument panel moulding. I also sprayed the spinner with etch primer.
25th April Sprayed the radio panel and instrument panel moulding with satin finish polyurethane.
26th April Populated the radio panel and started adding wires to it and the breaker panel.
27th April I was determined to have the cowlings on the aircraft by the end of the day. Following Bob Berube's advice to trim the top molding first I put the bottom molding away in the corner. The airmaster hub drawings show that the face of the cowling should be 25mm back from the front face of the engine flange so I opened up the hole in the front of the cowling to 64mm to permit it to sit flush with the front of the gearbox housing. The front face of the gear box is a very convenient 25mm back from the front of the flange. I then marked out the trim line and trimmed the back of the cowling. With the top cowling trimmed I drilled out the nine mounting holes and clecoed the cowling in place. The fit is good with the exception of a small section on the port side below the window where the cowling shape sits proud of the body. After much soul searching I have decided that I am going to have to strip the paint back in this spot and build the body shape up to match.
I repeated the mount and trim process with the bottom molding which was much easier to fit with the top moulding providing a fixed reference point. The bottom molding fits well apart from a small section of the port side where it sits below the section I built up for the wing sockets. I'll mount some washers on the inside of the cowling at this point to push it out. I drilled the six holes each side of the bottom molding and clecoed it in place before removing both top and bottom moldings to open up the front hole to 20cm diameter.
I test fitted the Airmaster bush housing and opened up a small section of the flange around the front hole to clear the bush housing.
The exhaust pipe on the 914 engine has a removable curved extension on it and it is necessary to open up a hole in the side of the cowling to permit this to pass through the cowling. This is very much a visual fit so I opened up the hole little by little until it looked right. I could probably have made the slot a bit smaller but it still looks OK.
The air inlet to the engine has a small plenum around it. I had made this earlier and trial fitted it. One little trap here is that if it is mounted too high it will clash with the oil cooler so I verified that its position was correct.
28th April In order to support my instrument panel air vent I needed to add a NACA scoop to the port side of the lower cowling. I had the shape pre drawn on a piece of paper and, having verified where the scoop needed to be added, I transferred the shape to the cowling. I cut out the trailing edge and the two sides, leaving the leading edge to act as a hinge point. With the shape pushed in to the required angle my next challenge was to make the sides of the scoop. After a bit of experimenting I used a couple of pieces of card with aluminium foil taped to it to act as a profiler. The aluminium surface was coated with release wax and then three layers of bid with floxed corners was laid up over the scoop on the inside of the cowling. My other bit of work for the day was to scrape back the paint where I needed to build up the fuselage and apply superfil.
29th April Peeled off the former for the NACA scoop sides and was pleased to see that I had a good looking scoop. The air, once entering the scoop will enter a plenum which I proceeded to carve out of foam. Once the shape was established I covered it with packing tape and also lined the inside of the cowling where it would be located with masking tape. I covered the former with 2 plies of bid and left it overnight to set.
30th April No building, working in Lower Hutt
