New Instrument Panel Overlay - Part Deux

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New Instrument Panel Overlay - Part Deux

Postby brian.olson » Mon Mar 21, 2022 1:26 am

Ok ... after a year of starts and stops, I think we finally have this one in the bag. I've been wanting to create a new instrument panel overlay for quite some time. The existing overlay in 62C is aluminum, but was created by a past owner or mechanic, many years ago, after - and before - flight instruments underwent many changes.

Over the past four years that we've owned 62C we incrementally took the panel from this:

621C Original Panel.jpg


to this:

62C Current Panel.JPG


... but up to this point I haven't successfully cracked the nut, so to speak, on how to create new new overlay and replace the old one. I've toyed several times - three to be exact - with carbon fiber, and the intent to create the plug for the mold, and the mold for the final product, and each and every time I've learned aplenty. I've been moderately successfully but abandoned the process at some point prior to success due to time or weather or a bunch of other cheap excuses.

That was, until my wife called me from work two weeks ago and mentioned that a co-worker had access to a thermal vacuform machine. And that, my friends, started the latest run at the thing.

Here is the step-by-step I used to produce a new instrument panel overlay.

(more to come...)
Last edited by brian.olson on Mon Mar 21, 2022 8:33 am, edited 1 time in total.
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Re: New Instrument Panel Overlay - Part Deux

Postby brian.olson » Mon Mar 21, 2022 1:48 am

PART ONE - THE PLUG

The first part of the process was to create a plug that would sit on the vacuform machine. In previous attempts I hand-drew a template and cut it out of 3/4" MDF. That produced an unreasonable number of failures: either the shape was wrong, or there were inconsistencies, or the alignments were off a fraction, or it just didn't look right. They were all abandoned. However - since that time we have procured a Glowforge laser engraver/cutter (which we used to produce a new plexi overlay for the panel) and it was a relatively simple process to use a design program and create a paper template of the panel overlay that I wanted to use. The purpose of this was two-fold: first, it allowed me to make sure I had the instrument holes and alignment spot-on, and second - it's significantly cheaper and easier to cut it on paper and make changes than it is to cut wood.

IMG_E8875.JPG

(Paper template cut and fit verified. Note that it took me three attempts to get the alignment right. For some reason the airspeed indicator (the instrument on the far left) is 3/16" higher than the rest of the instruments and just a smidge to the left. Visually inspecting the panel, there is no reasonable explanation for this. I guess it is what it is. But with a design program and paper it's simple to make changes and verify position. BTW, when we purchased the Glowforge, we bought the baseline version, which is limited to a cut size smaller than the panel, so I had to cut it in two pieces. Had I known this would have been an issue I probably would have forked out a little extra dough and bought the more expensive version which allowed a fixed width but unlimited length. You will see the problem re-surface with the wood template below.)

Once the fit and shape was verified and agreeable, I cut out a template from 1/8" MDF using the laser cutter. I actually cut two, but cut as mirror images with the cut line offset, so that when I glued everything together I had a 1/4" solid template of the outline of panel overlay.

IMG_E8906.JPG

(First of two template being cut.)

I rough-cut a piece of 3/4" MDF using a reciprocating saw, using the template as a guide but left a good 1/8" extra material in place which would be later trimmed off.

IMG_8908.JPG

(Template affixed to rough-cut MDF plug)

In past experiments I have used this approach to cut out 3/4" MDF plugs, but after pulling vacuum with carbon fiber I could never separate the cured carbon fiber piece from the plug. The problem is that the sides were a perfect ninety degrees to the top. So ... I ordered a special router bit that would allow me to impart a three-degree bevel to the plug sides. I installed the router underneath a portable work table that I use in the garage and within a few short minutes had a perfectly shaped plug.

IMG_E8909.JPG

(Router bit attached, and used to impart a three-degree bevel to the edges of the plug.)

I then used the router to cut a rounded edge on top edges ofthe plug. After an initial sanding, I drilled a plethora of holes throughout the plug which are necessary for the vacuum to do its work with the plastic.

(more to come ...)
Last edited by brian.olson on Mon Mar 21, 2022 8:39 am, edited 1 time in total.
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Re: New Instrument Panel Overlay - Part Deux

Postby brian.olson » Mon Mar 21, 2022 2:05 am

PART TWO - THE PLASTIC

Now that the plug was ready, I ordered a piece of ABS plastic sheet from Aircraft Spruce (see: https://www.aircraftspruce.com/catalog/ ... kkey=21974). I had several local options for ABS plastic, and my wife's co-worker offered up several contacts he had from which he regularly orders, but I felt that it was important to order something that I knew met the FAR burn requirements. It's significantly more expensive through Spruce, and if I was making fifty of the things I would have ordered burn-tested ABS from a local source, but since I was only making a single piece I felt the peace of mind was worth the extra cost. A few days later the piece of plastic arrived and I cut it to size.

Now, an interesting challenge: the vacuform machine that my wife's co-worker uses is actually quite small. In fact, it is so small that we had to lay the plug on a diagonal in order to make it fit (and even with that, there was only a scant inch of space on both ends). It made for a bit of waste with the ABF but again, I'm only producing one piece.

Here's the machine that was used. If you are unfamiliar with the operation: the plastic is affixed to the sliding upper brackets and held near a heating element at the top. When the plastic reaches a certain optimal temperature it begins to sag, and then it is quickly lowered over the plug while simultaneously applying a vacuum to the entire bed. The plastic is literally "sucked" around the plug, and once cooled, it's removed and trimmed.

IMG_0058.jpg


Here is a close-up of the piece while cooling:

IMG_0062.jpg


ABS plastic used in this process typically comes with a "smooth" side and a "bumpy/textured" side. Typically the textured side is on the outside. However, I asked that we keep the smooth side out as I wanted the finished product to have a finish as smooth as possible.

Here is the final trimmed piece of ABS:

IMG_E8930.JPG


I took several measurements of 62C's panel to determine the exact height at which to trim the piece of plastic, to include an accommodation for mounting Nulites for each instrument on the back of new overlay. Once I felt confident with the measurements I trimmed the piece to size using a cutoff wheel mounted on a Dremel.

(Author's note: so, this is rather funny. If you know me, you know I didn't order just one piece of plastic from Spruce. I actually ordered two ... because I was also going to try a second, slightly different approach to making the panel overlay. In the middle of heating the second piece of plastic the heating element burned out and the plastic was ruined. Glad it didn't happen on the first run!)

(more to come ...)
Last edited by brian.olson on Mon Mar 21, 2022 8:52 am, edited 3 times in total.
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Re: New Instrument Panel Overlay - Part Deux

Postby brian.olson » Mon Mar 21, 2022 2:22 am

PART THREE - THE PAINT

I was scratching my head a bit about how to actually finish the plastic and then it occurred to me: it's the same thing as an automobile bumper. Bingo! There is a ton of information on the Internet about how to re-finish an automobile bumper.

The first step was to lightly sand the entire piece with 150-grit sandpaper, followed by 400-grit sandpaper. I wasn't trying to get everything smooth at this point, just knock off the high spots and rough up the surface. I wiped everything off and then applied three light coats of adhesive promoter. I then added progressive coats of automotive primer/filler that slowly filled in the low points and any surface imperfections that were caused by the heating process. Once I was satisfied with progress I began sanding using 600-grit (wet) sandpaper between coats. A few more coats of primer/filler, some sanding, and I arrived at a surface I was very satisfied with:

IMG_8950.JPG


Once the primer was finished, I let the whole assembly dry for twenty-four hours. I used the paper template that I originally created for alignment to transfer the location of the instrument holes onto the primed piece. I used a box-cutter (with a new blade) to cut out the square hole for the Garmin G5. I used a 3-1/8" hole saw in my drill press to cut the remaining holes. Since I only had that one, single successful piece piece of plastic ... this was a most anxiety-ridden experience.

IMG_E8952.JPG


After wiping off the debris (and the sweat from my brow) I drove to the airport and did a test-fit of the new panel overlay on the plane. Thankfully, the care and precision from the paper template proved its value and the test-fit was a complete success.

I then loaded up a Preval sprayer with some of the remaining automobile paint that I had used to paint the backside of the plexi overlay we created last fall and applied two light coats and two heavy coats of paint, followed by two coats of 1K SEM clear coat.

And this is what I was left with:

IMG_E8960.JPG


IMG_E8961.JPG


(please note that the color is slightly off and appears more "purple" than it actually is, due to the time of day that I took the photo ...)

When I get back from my work trip this week, I'll post some photos of how we'll be mounting Nulite instrument lights to the back of the instrument panel overlay, so that each of the flight instruments will be lit - and dimmed, when needed - during night flights. We'll also tackle the question of how to mount the new overlay panel onto the instrument panel.

(more to come ....)
Last edited by brian.olson on Mon Mar 21, 2022 8:54 am, edited 2 times in total.
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Re: New Instrument Panel Overlay - Part Deux

Postby johneeb » Mon Mar 21, 2022 2:31 am

Brian,
Very interesting, thanks for posting!
John E. Barrett
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Re: New Instrument Panel Overlay - Part Deux

Postby mmcmillan2 » Mon Mar 21, 2022 2:05 pm

It looks great!
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Re: New Instrument Panel Overlay - Part Deux

Postby DaveF » Mon Mar 21, 2022 4:13 pm

That's an impressive array of equipment, but far more impressive is that you really know how to use it. Beautiful work!
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Re: New Instrument Panel Overlay - Part Deux

Postby cessna170bdriver » Wed Mar 23, 2022 10:54 pm

Brian, that vacuum forming machine isn’t nearly as small as the Mattel version I had in the 1960’s.

EB14FD89-3558-4477-AE8E-8F04FAA486FC.jpeg
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Re: New Instrument Panel Overlay - Part Deux

Postby brian.olson » Sat Mar 26, 2022 12:21 pm

PART FOUR - NULITES

After returning from a work trip to Dallas, TX this week and recovering from some serious meat-sweats incurred after wonderful dinner at Lockhart Smokehouse (important note: if you wear a suit to dinner, it will smell like BBQ the next day ... that is not a bad thing), I attached the Nulites to the back of the new overlay panel.

Nulites are available either in incandescent or LED format. I went with 14V LED to keep power drain to a bare minimum. We previously installed (PMA approved) LED map lights into the cockpit so the LED dimmer is already installed in the panel and operational, and keeping with LEDs will ensure power drain on the system is a bare minimum. According to the Nulite website, eight (8) Nulites will draw approximately 1amp total, so with our planned six (6) we will be underneath that.

IMG_E8985.JPG


With the panel constructed out of ABS I was a little concerned about finding the right adhesive to use to mount the Nulites. Historically I've had mixed results gluing ABS and have found that the longevity of joints is highly suspect, as they tend to break down and fracture. I cut several samples of the leftover ABS material and did tests of several different types of adhesives including cryoacetate ("super glue"), expoy, and solvent-based cements. In the end, the best performer was IPS #16 Acrylic Solvent Cement (which I had previously used to secure a new acrylic bracket on an exhaust vent in our camper). According to the manufacturer it works equally well on ABS, and I found that to be true as well. In my test the ABS ripped before any degradation of the joint occurred.

The first step was to get loaded up on coffee in my trusty Vintage Aircraft Assn coffee mug (circa Airventure 2018).

IMG_E8989.JPG


I secured each of the Nulites in position using the acrylic cement. I needed to work reasonably fast as the "work time" for the cement was five minutes max, so I affixed them one at a time. I weighed them down, in place, using a variety of canned goods from our pantry. I let the cement cure for twenty-four hours before switching my attention to the wiring. Before we go there, a bit of learning: apparently a 3-1/8" hole saw, when used to cut ABS, actually cuts somewhere closer to 3-3/16" or 3-1/4", so I noticed a bit of potential slop in the placement of the lights. Visually it's not really a problem but I did get a little bit of cement seepage. If I was to do it again I might have tested the hole saw first on a piece of scrap ABS, but we'll live with it.

I wired the lights in parallel per the manufacturer's directions. I elected to install a quick disconnect plug at the terminal end so that the entire assembly can be easily removed from the aircraft at any point. After securing all solder points with heat-shrink tubing, I attached a temporary 12-volt power supply to make sure everything was operational.

IMG_8991.JPG


IMG_8993.JPG


The lights actually pump out quite a bit of light. You can see that even though the LED elements are located at the top of the fixtures, the design of the device ensures it does a nice job of equally distributing the light over the entire instrument. In this example I'm using the old tach that we pulled out of 62C and replaced last fall.

IMG_8994.JPG


Now that the lights have been secured to the panel overlay and wired, the next step will be to affix the assembly to the instrument panel. The current overlay is secured using an odd mix of velcro and all of that will have to go. The standard clips and brackets that are typically used to affix overlays no longer exist, so we'll fabricate something simple and effective to keep the new overlay in place, while making it easy to remove if necessary. Most definitely NOT velcro.

We'll address that next step, as well as the test flight to see if everything actually works or if this just becomes another pretty piece of wall art, shorty.

(more to come ...)
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Re: New Instrument Panel Overlay - Part Deux

Postby brian.olson » Sun Mar 27, 2022 12:16 pm

PART FIVE - THE INSTALL and we are FINISHED

It was a good day to spend in the hangar. The sun was out, and it was a beautiful spring day with just enough cool in the air to warrant a light jacket in the morning. A day I would have typically taken my wife and 62C on a trip for a date-lunch someplace. However, the winds were 15 gusting 25 and firmly in my "no-go" zone, so I didn't feel bad about turning on some good music and finishing up the project.

The first step in the process today was to remove the old bits and pieces of velcro that were used to secure the old panel overlay in place. In some ways this felt a little bittersweet. Every time we change something small or large I get a little twinge of guilt, as if I'm removing a piece of 62C's (whom we will refer to as "her", or to her real name, "Baby") history. Or her soul. Ok - that's as far as I go with my romantic philosophical rambling ... but understand it occasionally haunts me. Let's move on: I removed the velcro and placed her old panel overlay in the backseat of my car.

I had some leftover .032" aluminum sheet tucked away in the hangar that I had used to create new heel scuff plates a few years ago. With some trusty aviation snips and a hand tool or two, I fashioned three simple "stand-offs" to hold the panel - one for the middle and one for each of the sides. The new overlay is/was not high enough to permit me to secure it through the sides, so I elected to use three machine screws through the panel. Once painted they won't be visible enough to really matter. Once I measured and fabricated the three stand-offs, I filed them down and hit them with a couple coats of primer. I then carefully secured them into the panel using 1/8" aviation pull rivets. Ok - an interesting side-note story: Aircraft Spruce's "East" store/warehouse is literally 100 yards from the airport gate, so it's not uncommon for me to drive over to pick up things that I need and don't need on the way to the airport. On today's trip I spent just over two dollars on pull rivets and screws.

IMG_8998.jpg


IMG_8997.JPG


(62C's panel certainly has seen better days. From the logbooks - and visually - it's clear that instruments have been moved, removed, changed over the years, and it's obvious each set of hands that has touched it has carved off bits and pieces. Someday, perhaps, the entire floating panel will need to be replaced. Today, however, is not that day.)

Once the standoff's were secured I slid #6 Tinnermans over the holes and then match-drilled holes into the new panel overlay (yet another pucker moment as I absolutely didn't want to screw it up). Thankfully, They-Who-Watch-Over-Fools-and-the-Foolish smiled in my direction for once and the hole alignments were right where they needed to be.

Next, I turned my attention to the wiring. Thankfully the majority of that task had already been taken care of, as we had PMA approved LED map lights and a PWM dimmer dimmer previously installed in the panel - so everything was ready. I won't go into any more details other than to note that a single two-conductor mil-spec wire was connected to the dimmer, run from the dimmer through a hole, and then soldered to the end of a quick-disconnect clip. It was important to me to make sure the new overlay was able to be easily removed as you never know when an instrument might fail and need to be replaced, and I've also been toying with adding a second Garmin G5 to the panel, just haven't worked up the courage to plunk down the funds for it yet. A discussion for another day.

The final step was to connect the quick-disconnects and secure the new panel overlay in place using #6 machine screws. I plan on priming and painting the screws with the panel color so that they blend in, but for now I've left them as-is. I have extra screws that I'll paint and can swap them out next time I'm at the hangar.

IMG_8999.jpg


IMG_9005.jpg


The previously-mentioned sunny day was a bit of a detriment to the testing of the panel, but once I powered up everything it's still easy to see light that the Nulites put out once the dimmer is cranked up to full. I did not have the occasion for a test-flight in the dark ... but weather permitting, I should be able to accomplish that sometime this week.

So, I guess we're done with this one.

(Final Post)
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Re: New Instrument Panel Overlay - Part Deux

Postby cessna170bdriver » Mon Mar 28, 2022 7:42 pm

brian.olson wrote:

The first step in the process today was to remove the old bits and pieces of velcro that were used to secure the old panel overlay in place. In some ways this felt a little bittersweet. Every time we change something small or large I get a little twinge of guilt, as if I'm removing a piece of 62C's (whom we will refer to as "her", or to her real name, "Baby") history. Or her soul. Ok - that's as far as I go with my romantic philosophical rambling ... but understand it occasionally haunts me. Let's move on: I removed the velcro and placed her old panel overlay in the backseat of my car.


(Final Post)


I felt the same way when I discarded a piece of masking tape from the back of my floating instrument panel that had ‘98C’s serial number penciled on it. I like to think the panels were assembled somewhere away from the airplane production line and that’s how they kept track of which panel went with which airplane.
Miles

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Re: New Instrument Panel Overlay - Part Deux

Postby c170b53 » Mon Mar 28, 2022 11:17 pm

I think Cessna moved away from tape, my 79 172XP was marked up from the factory with a grease pencil.
Really nice work on the new panel, will it be on display at Burlington ?
Jim McIntosh..
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Re: New Instrument Panel Overlay - Part Deux

Postby brian.olson » Mon Apr 11, 2022 11:18 am

Finally got around to a test flight both at night and during the day. Really happy with the way the project turned out. My first observation is that the Nulites put out significantly more light than I anticipated. I have the dimmer switch turned down almost to the point where it's off; however it's nice to have a full range of power available during dusk with the ability to incrementally knock it down as it becomes darker. Second observation: the lights offer a very consistent wash over the instruments. I was expecting more hot-spots that - thankfully - simply weren't there. Third observation, and one that I wasn't expecting: I didn't realize how much easier it is on the eyes to discern the real color of the artificial horizon vs. seeing it in shades of red/grey. I won't fly IFR at night, but even so - if it's black as a hole out there I'm effectively on instruments anyway, and with a red wash over the instruments the markings of the artificial horizon can start to get lost.

Final thoughts on the matter: this is definitely a game-changer for night flying. I love to fly at night and it's significantly upped the safety factor for me. This wasn't an inexpensive project (the Nulites come in at approximately $80/each) but for me it's one that was worth it.

IMG_9215.JPG


IMG_9020.jpg



Now on to the next project: replacing the hacked-up decorative panel overlays surrounding the yokes. But I won't bore you with that one...

IMG_9217.JPG
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Re: New Instrument Panel Overlay - Part Deux

Postby Ryan Smith » Sat Apr 16, 2022 3:51 pm

Brian, I will never cease to be amazed at your ingenuity and level of craftsmanship.

I’m very impressed. It looks amazing!
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Re: New Instrument Panel Overlay - Part Deux

Postby GAHorn » Thu Apr 21, 2022 5:08 pm

Who could possibly be “bored”..?? Great thread…Keep ‘em coming!
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