Overview
On the last visit by the factory the C.O.G issues were discussed and Franco indicated that the new aircraft kits feature a baggage compartment behind the existing one. At the time I had the parts for a battery access hatch and chose to install the battery on the existing battery compartment shelf along with the pump.
When the new hatch arrived I was stunned by its size compared to the original hatch.
After a bit of thought it was decided to install the hatch so in case of issues with c.o.g. at the final weigh in the pump could be relocated back further or the same battery that the factory installs fitted.
Put simply a back door to escape any issues that may be created by the selection of the lighter battery.
Installation
The first task was to mark out the opening this was done by sticking the laser cut doubler to the side of the fuselage and then marking out the cut line with masking tape. With the outline marked a metal guide was fixed to the cutting line and the four side scored using the Ofla knife and then the scrap broken out.
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| Marking the opening |
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| Scrap ready to be removed |
A steel ruler was fixed to the opening edge and then opening slowly dress to a final size.
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| Fitting filing guide |
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| Finished opening |
With opening prepared the cover was checked for fit and final adjustments made. Next the the cover was refitted and the 2.5 mm holes matched drilled into the fuselage skin, at this point the factory flange was removed and the doubler clecoed into position on the inside face.
Note: The opening was meant to be installed into the opposite side but this clashed with the circular opening installed to access the antenna base - this opening renders that access hatch of no value.
At this point it was decided to install a C channel at the top edge using the existing holes to secure the channel.
The external door was curved by hand and by rolling across the builder leg to pre form the profile to the fuselage side to reduce the possibility of distortion when installed.
With the channel installed a piano hinge was trialled but it proved not to be suitable so an alternative was required. It was decided to use a series of plain M3 rivet nuts as studs engaging into the channel using a series of the original rivet holes.
A 0.020'' [0.5 mm] angle was folded to accommodate the angle created between the door and the fuselage this was riveted to the door cover using the same center as the doubler. Next the 5 [five] selected rivet holes were transfer to the angle and then the rivet nuts installed then the corresponding holes were enlarged to 5.5 mm to accommodate the rivet nut shank.
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| Channel detail baggage compartment Larger holes are for the studs to engage into with the other smaller holes left over from the piano hinge installation |
A quick check revealed it would work and a large sigh of relief was exhaled.
The factory doubler is cut for quick release fastened so this required the holes be filled for M3 rivet nuts. This was achieved with 0.020'' aluminium fixed across the opening using the two rivet holes provided, dimpled and riveted with 3/32 pop rivets.
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| Door - upper locating lugs created from plain shank M3 rivet nuts |
With opening covered the mounting holes were drilled from the cover, enlarged to 5.8 mm and M3 rivet nuts installed. The cover holes were now enlarged to 4.5 mm for ease of assembly.
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| Baggage compartment and frame M4 rivet nuts installed to fix door |
A 5 degree fold was applied along the lower fixing line stiffening the lower edge of the cover.
After a few final adjustments the door fitted reasonably neatly and is now ready if needed.
Tools
A new dimpler was purchased to supplement the existing dimpler - proved its worth on this job and created a fairly crisp rows of countersunk holes for riveting.
Comment
Done and I will finish the back end if it kills me....!
Did not take a happy snap of the door installed but it fitted with a 9.0 out of a possible 10 with the lugs working well.
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