Panel Upper - Part 2

This blog covers manufacture of the main panel

Panel Layout

The panel layout is heavily influenced by the prototype aircraft and created a mix of 1 1/4'' - 2 1/4 - 3 1/8 inch steam gauges plus a central GPS / EFIS to help create that military feel.

Some gauges are more that would be generally required like water temperature and EGT but as this aircraft is fitted with a number of experimental items and products that have not been used in this market this builder would like to verify the claims made for these items.

The panel logic will be examined in detail later in the build.

Marking Out
The panel layout drawing was drawn and plotted full size, then fixed to the blank panel using masking tape. Using a small hand punch all instrument centers were punched including the corners of the vertical and horizontal cuts, finally the hole's were marked using a 2 mm drill.

Template fitted

Drilling reference holes

Note: The centers were enlarged with a automatic center punch before drilling using a flat table. This allowed the initial center to be located by feel and re-punched. The same process was used for the initial drilling, with the drill located on the center mark by feel and then drilled. Later this was enlarged to 4.5 mm before drilling with the hole saw.

Once complete all holes were dressed and de-burred.

Drilling instrument holes
All initial holes enlarged to 4.5 mm to allow
hole saw drill to center

The panel was trial fitted to the cowl and the corner radius were found to be too sharp and had to be corrected. 

A copy of the panel was cut using 4 mm foam core sheet and a guesstimate radius developed after examining the gap on the trial install. 

The foam core was the cut and sanded with a trial fitting confirming the radius as correct. Using the foam core as a template the new radius was was transferred to the existing panel and the new radius created using a 300 mm disc sander.

Correcting corner radius

The lower mounting angle was installed after drilling to suit the isolation rubber. The angle was then drilled with a series of 9 mm holes pitched at 30 mm centers using the factory drilling jig. The angle was the match drilled using the panel and M4 rivet-nuts then fitted to the angle for panel mounting.

Mounting angle

The final task was to determine the location of the upper angle panel support. A scrap piece  of angle was clamped to the panel with all the items fixed using their respective mounts and a packer placed under the end of the angle to bring the face of the panel into alignment.

Setting alignment

With the panel aligned the front was position to the underside of the cowl, next a offset line was created to allow for the panel thickness and a 30 x 20 x 0.020'' 2024-T3 angle fabricated, drilled for 4 [four] large head 1/8'' rivets in two staggered rows to ensure the angle is flat.

Top mounting angle

The parts were reassembled and the angle match marked from the panel then removed drilled and 2 [two] M4 rivet nuts fitted.

Comment: Doing it again I would correct the radius before any marking out as this effected the instrument layout and required a new panel to be created.