These panel design and making techniques evolved over the past few years, driven by the need to provide a useful hardware interface and to protect the internal circuitry. More importantly, the projects provided an outlet for refining my fabrication skills, learning new skills, and the stress-reducing therapeutic benefit of working mostly with hand tools.
Here is a sampling of projects from the past two years that may help to illustrate my continuing journey to discover the front panel fabrication holy grail.
The label on this guitar pedal was ink-jet printed on regular paper and decoupaged to the pedal case with three coats of brush-on polyurethane finish. The 3mm LEDs were mounted in plastic bezels.
A custom PCB was used for the internal circuitry. A custom panel drilling guide for the LEDs was included with the circuitry PCB order. The epoxy-fiberglass drilling guide made accurate drilling a breeze. (The guide survived many projects and is still in use today.)
Although the quality was excellent, decoupage was a slow process requiring four to six hours of waiting between coats. I needed to find a faster method.
This was the first attempt at the sandwich technique and was used to perfect the process. The photographic paper label was printed on an ink-jet printer, protected with two layers of glossy clear spray coating, then installed under a 1/16-inch thick clear acrylic (Plexiglas) layer. The mounting shafts of the pushbuttons and the potentiometers held the clear layer in place without glue or additional screws.
Workshop Corrosion Monitor
When the remodeled workshop was christened, this was used to monitor and predict corrosion conditions in the unheated shop. The main unit and the remote used twin Adafruit Feather M0 RFM69 boards to calculate dew point and comfort levels, transmitting the data to the small battery-powered remote unit.
The challenge of this project was to incorporate a large, rectangular opening into the panel. The custom display bezel was made using Plastruct architectural extrusions. The clear panel was made from a 1/16-inch clear acrylic sheet. The clear layer was attached to the enclosure with four knurled hex screws.
The controls on this 20 watt stereo audio monitor amplifier didn't span the entire guitar pedal enclosure so the front panel was sized to accommodate only two controls and the text labeling.
The connector panel on the rear of the enclosure (not shown in this photo) also had a sandwich label to indicate which connector did what.
Since the controls of this small stereo audio amplifier weren't part of the front panel, it provided the freedom to experiment with a more graphical approach to the label.
For the first time, a 1/16-inch clear polycarbonate sheet was used for the clear layer of a sandwich panel label. Polycarbonate isn't as brittle as acrylic, preventing breakouts when drilling holes near a cut edge.
FXM-8 Effects Mixer
The challenge with this project was to incorporate a removable sound effects legend card. The photo paper layer was trimmed away where the legend was to live, creating a nice thin gap between the enclosure and the clear polycarbonate layer to insert the legend card.
The rear panel connectors received the same sandwich label treatment as the front panel.
This project was used to play pre-recorded sound effects for my band's live musical performances. The mixer portion allowed relative adjustment of sound effect loudness with that of the attached keyboard so that only one stereo wire had to run to the PA system.
Snowman Holiday Lighting Controllers
The repeatability of the drilling guide technique came in handy for making six NeoPixel strip animated lighting controllers. Prepainted metal guitar stomp pedal enclosures (one-half size) were used (Hammond-DigiKey).
RetroMon USB Power Meter
This front panel was inspired by 1960's era test equipment. LED pilot lamps and switches similar to those of the period were selected to keep with the retro look. Illumination for the analog panel meter was provided by four white LEDs filtered through Kapton tape. The Plastruct bezel technique perfected earlier was used in this project, augmented by a graphic black frame that was part of the ink-jet printed label.
The project was designed to isolate incoming USB power while passing the data signals needed for attached microprocessor boards. An internal battery provides power to the load while being trickle-charged by the USB input.
Eurorack Modular Lunchbox Synthesizer
The colorful Crunchable Synth and blue Ice power distribution modules were the first attempt at using the Sticker label technique. This project also helped to perfect the method for hiding LED indicators behind a vinyl sticker label. The foundational panel material for this project was 1/16-inch acrylic plastic although other plastics or metal would work as well.
Yes, that's an AdaBot lunchbox used as an enclosure.