Some more instrument panel work. I have planned for 2 analog backup instruments : an airspeed indicator and analog altimeter.

After carefull measurements on the panel and some test cuts on scrap, I used the flycutter to cut out the hole and used a small 3M deburring wheel to enlarge the contour to fit the instrument.

The 4 screws are a bit of a challenge and I decided to make a template out of scrap which coult be used as a drill guide so that the screws would be in the good location.

Clamped the template on the panel and drilled the 4 screw attach holes.

Then did the same for the altimeter.

Drilled the holes as well using the template.

The altimeter has some additional challenge as it requires a cut out for the barometer adjustment knob.

Drilled out the rough contour and then used some key-files to get the final shape.

Then installed the panel and found out this disaster ! I did some serious miscalculation on the location of the instruments and the bottom flange of the center rib is in the way.

Fortunatly, it's only the lower flange and not the rib vertical part by itself. That would have been a major disaster. I did some bending on the flange but soon realised that this is not going to work.

There can not be enough cleance and the bending won't go far enough.

 My solution will be to cut off the lower flange of that rib and to install and aluminium angle on the opposite side. That will clear enough space for the instruments and ensures strength is still there.