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Old November 7th 18, 05:17 PM posted to rec.aviation.soaring
Jonathan St. Cloud
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Default ASW 27 Instrument Panel Texture

On Tuesday, November 6, 2018 at 12:43:14 PM UTC-8, Andy Blackburn wrote:
On Tuesday, November 6, 2018 at 11:44:31 AM UTC-8, wrote:
Andy, when I was laying out my ASW 24 panel many years ago (OK, over a quarter century ago), I wasn't just arranging paper cutouts on the blank panel to see what would fit. There were other consideration such as clearance behind the panel, minimum distance from the edges for structural integrity, minimum distance between two instruments for structural reasons as well as interference between them, obstruction of the top edge of the panel by the glare shield (I have a Streifeneder panel with higher knee cutouts and a three-flats--vs. rounded--cover), instruments that fit 57mm or 80 mm holes but had larger dimensions behind the panel (e.g., the Cambridge and ClearNav ADCs), switches and fuses, ELT annunciator, sightline behind the control stick, etc. And now we have the larger, non-standard panel displays mounted on stalks, in the panel, behind the panel, etc. Making sure everything fit was an iterative process to a certain extent. I cut the first hole, test fitted it, then proceeded, making adjustments as necessary.

Any quick thoughts to share with the group on how you dealt with these other issues? I assume that's what's meant by cutting a trial panel and testing for fit. I've changed my instrumentation a bit in the last few years so am thinking about a new panel. The idea of unpacking a brand new, beautifully cut panel and discovering my favorite instrument doesn't clear something by a few mm is daunting.

Chip Bearden


Chip,

I measured and modeled all the instruments in 2D - including the holes and the case cross-sections. I managed to arrange them such that they form a near-solid block (many of them touch cases to add stability). I also measured the backside of the panel because there is some curvature and wall thickness to account for, so I created a standoff buffer/border around the edge.

I taught myself to use AutoCAD as part of this exercise, so I did some simple checks to ensure that there was clearance along the length of each instrument. With some additional effort you can create a 3D model of the instrument panel and cavity as well as each instrument. I didn't find this necessary for the -27. A friend who did a panel for his Ventus used SolidWorks to make a full 3D model (Fusion 360 will allow you to do this without spending $4000 on software). It may help for specific situations though generally there isn't a significant constraint unless your instruments are super-deep.

Here's a link to the panel layout I did. You can see each instrument case is modeled in addition to the cutouts - as well as the panel backside offset. I used very tight tolerances for the instrument holes - so much so that I had to do a little bit of sanding on some holes to fit the the instrument. Makes for a very clean installation - much better than you get using a standard hole cutter and suits my perfectionist streak.

https://drive.google.com/open?id=1YH...VONRIDR67sUJlY

Andy


I paid $500 to have someone else professionally do it.