Re: Plexiglass Panel Overlay - 170A
Posted: Thu Aug 19, 2021 4:21 pm
Some additional progress over the past couple of days, and some interesting observations to share.
First off, I did my first cut of the completed plexi overlay but enlarged the cutout holes to a point where they could slide over the top of the knobs on the panel and thus check alignment. Everything checks out perfectly - text, holes, grid, etc. So, we have that behind us.
Second, I decided to run a test just to see if there was any difference between painting the back of the plexi (after the engraving had been filled in) vs. painting a piece of aluminum with the back color and pressing it up to the back of the plexi panel. Big surprise for me: painting the back of the plexi toned-down the colors and in darker lighting it became very difficult to read the labels. However, the piece which was left clear positively glowed in all light. I should have expected this - undoubtedly the plexi's index of refraction is bouncing light all over the place when the panel is left clear. Additionally, it now seems apparent that one really solid reason the chamfer is at the top is to let more light in, and thus amplify the readability.
The results are pretty startling - note that both examples have the same engraving, the same paint used to fill the engraving, and the same back-color paint:
Last night I did a first-pass print of the final piece utilizing a piece of painted backing material. There will be another final-final printed that I will chamfer with a router and then polish.
For better or worse - this is as far as I can go before I find an A&P both smart and talented to pull out all the cables so we can install the new piece. Likely, this will wait until my annual inspection later this fall. At that point I'll be able to definitively answer - at least for my plane only - was the plexi painted or was there a piece of aluminum painted behind it. I'm very curious to see what we uncover
Thanks again for all the great input and discussion over the past week or so - it's been a fun learning experience.
(Pardon all the dog hair in the photos. You think you get it all cleaned off, and then more appears again before you know it)
First off, I did my first cut of the completed plexi overlay but enlarged the cutout holes to a point where they could slide over the top of the knobs on the panel and thus check alignment. Everything checks out perfectly - text, holes, grid, etc. So, we have that behind us.
Second, I decided to run a test just to see if there was any difference between painting the back of the plexi (after the engraving had been filled in) vs. painting a piece of aluminum with the back color and pressing it up to the back of the plexi panel. Big surprise for me: painting the back of the plexi toned-down the colors and in darker lighting it became very difficult to read the labels. However, the piece which was left clear positively glowed in all light. I should have expected this - undoubtedly the plexi's index of refraction is bouncing light all over the place when the panel is left clear. Additionally, it now seems apparent that one really solid reason the chamfer is at the top is to let more light in, and thus amplify the readability.
The results are pretty startling - note that both examples have the same engraving, the same paint used to fill the engraving, and the same back-color paint:
Last night I did a first-pass print of the final piece utilizing a piece of painted backing material. There will be another final-final printed that I will chamfer with a router and then polish.
For better or worse - this is as far as I can go before I find an A&P both smart and talented to pull out all the cables so we can install the new piece. Likely, this will wait until my annual inspection later this fall. At that point I'll be able to definitively answer - at least for my plane only - was the plexi painted or was there a piece of aluminum painted behind it. I'm very curious to see what we uncover
Thanks again for all the great input and discussion over the past week or so - it's been a fun learning experience.
(Pardon all the dog hair in the photos. You think you get it all cleaned off, and then more appears again before you know it)