Hi everyone! My name is Rob. I am an engineer, maker and father based out of Raleigh, NC. I am a long-time lurker of Elektronauts, but a first-time poster.
An early prototype
I have been down a massive rabbit hole of producing my own cases for my Elektron boxes (and other music gear), and I wanted to share my work with the community and get some feedback and opinions. This thread is me opening up my journey and in hopes that other people can help make the project even better. If you want to see how deep the rabbit hole goes, take the red pill and come along with me on this journey.
This started as a personal project, but Iām sharing it here while I figure out if itās useful beyond my own setup.
Why I Started This
Last year, after a weekend stay by my in-laws in our combination guest room/music room, I noticed a lot of my music gear on my desk had a thin, sticky layer of film on it. I quickly figured out that this film was a residue left by my mother-in-lawās aerosol hair product. I was frustrated, to say the least. After some careful and tedious cleaning, I knew I needed to figure out a way to prevent this from happening again and there was no way I could say anything to my mother-in-law without making her feel bad. I own Decksavers for some of my equipment, but not all of it. I considered buying more Decksavers but at the time nothing existed for my Moog outside of a fabric cover, and no one was making a cover for my trusty Tascam portastudio. Additionally the thought of spending $400 or more on pieces of plastic really pained me.
As a maker and engineer, my instinct was to build my own solution that would exactly fit my needs. Why spend $400-$500 on off-the-shelf products when you could spend hundreds of hours of your precious time and even more money building your own solution? And I could build covers for my old retro gear that no one supports. This is probably the most inefficient way to solve this problem. Maybe I should just be honest with my mother-in-law and ban all aerosol use in the house. Or take away her key. Alas, here we are.
My goals were to build something that:
- Protects my gear at home and in a backpack
- Doesnāt scratch or shift
- Looks good on my desk
- Cleans easily
- Is toddler-proof and aerosol-proof
The Rabbit Hole Begins
Rob, meet rabbit hole. Several months of ideating and experimenting has led me to building my own proper vacuum forming machine, finding and evaluating construction materials, and coming up with solutions for improving strength and protection of the hard plastic shell.
I am still very much in R&D and trial-and-error mode. However, I am close to finishing up a usable version for my Digitakt II and Digitone and thought it would be good to share what Iāve been working on with people who use Elektron gear day in and day out. I know this community will have some good ideas and questions that Iāve yet to consider.
Vacuum Forming Machine
I really like the concept of being able to see my gear while itās covered instead of covering it with something opaque, like a 3D printed cover, a custom cut felt cover, or a fabric cover which slips over your gear. Iāve known for a long time that Decksavers are produced using vacuum forming, so I decided to head down this direction and do some research on the process. After some time researching I decided vacuum forming was going to be the best method to produce something strong and with the aesthetic characteristics that I really wanted. Additionally I realized I was going to need a machine with some serious heat and vacuum power to create a thick and robust end-product. However, commercial machines were way out of my price range ($15k-20k), and the more āconsumerā friendly desktop models were still expensive ($1k-3k) and had a small forming footprint and lacked the power to form thicker plastics.
Through a random video from Adam Savage (Iām a huge fan of his), I found a person who sells DIY plans for vacuum forming machines. His name is Doug. Doug is a really nice, smart, and helpful guy. I ended up reaching out to him, asking him a bunch of questions, and eventually purchasing his plans. I modified maybe 10% of the design plans, and there were some areas of the plans that were lacking in dimensions, but the plans were great. I am happy to share a link to his website and plans if anyone is interested.
Working from Dougās plans, I was able to produce a vacuum forming machine for the cost of a āconsumer modelā but with the performance of a professional, commercial machine. There are lots of simple DIY vacuum forming solutions using shop vacs and wood boxes, but these solutions do not produce high pressure and are inadequate for more than really thin materials. This machine is capable of:
- Producing 30inHg of real vacuum
- Forming objects using molds up to around 16ā by 10ā over a hand-built vacuum plate
- Electrically heating large sheets with consistent, even heat
This part alone took me about 2.5 months working every evening after the children went to sleep. However, it was well worth it. Iām getting results Iām genuinely excited about with the machine. Every time I run the machine I am thrilled at the result. It honestly reminds me of how fascinated I was by my first 3D printer when I got it 10 years ago. I couldnāt stop watching. Vacuum forming is such a fun process to watch. Slightly magical. And I built the machine in such a way that I can give it to my grandchildren some day, if I ever have them. Hopefully they like grandpa because he gave them a cool machine?
Mold Creation
As Iāve learned, vacuum forming molds (or ābucksā) can be made from a variety of materials. The absolute best material to use is aluminum, but for me thatās prohibitively expensive. I went through various ideas with 3D printed molds (PLA, PETG, ASA, Nylon) and MDF molds that I made on my CNC machine. None of them can really withstand the intense pressure and forming heat of the vacuum former for more than one use. MDF also can off-gas or release captured moisture, so while itās pretty good for testing, I havenāt found it to produce a great end result. I have had some quite catastrophic failures with 3D printed molds collapsing under pressure after a few seconds. Equal parts scary and fun.
I eventually found a material called HDU (High Density Urethane) which comes in various densities. Itās relatively expensive but I found a supplier called Freeman which sells smaller āsample sizedā boards and I snagged a handful from them for testing. I am still reaching out to various suppliers and sign shops in the area trying to find more places which may have offcuts or discarded pieces of this material. I grabbed a handful of these sample pieces and the material is awesome! It machines super well on my CNC machine, it doesnāt produce fine dust like MDF, and itās able to hold up to repeated use on the vacuum former.
The objects Iāve made so far look great, but I do think clarity could be better. I only did light sanding with 220 grit after I machined the mold, and I believe if I sand to some finer and finer grits I can improve this significantly.
Finding a material
I tested a lot of plastic sheet materials before eventually landing on clear PETG with a ā ā (~3mm) thickness. Acrylic cracked too easily, Polycarbonate was overkill and difficult to form cleanly and consistently in a small workshop setting, 1/16ā clear PETG felt cheap, but ā ā thick clear PETG really hit the sweet spot.
PETG is a material which vacuum forms well and has a solid combination of clarity, strength and impact resistance to hold up to daily use. Additionally, PETG can be recycled in my area in North Carolina via curbside recycling, whereas many other plastic materials cannot. I am thinking that I can accumulate enough PETG sheet scraps to eventually recycle them into 3D printer filament for my 3D printer. Iāve seen some DIY recycling solutions on the internet, and I think it could be fun. Another rabbit hole for another dayā¦
Liner Experimentation
This is where I ended up spending way too much time but Iām super happy with where Iāve gotten. I didnāt like the idea of a hard plastic shell resting directly on the metal or plastic enclosures of my gear. My original idea was fairly simple: determine where the PETG case would make contact with the gear and design a rubberized interface/cushion layer which would prevent the case from moving or scratching my gear. Iāve ended up with a solution that not only prevents my PETG case shells from contacting my gear, but also spreads impact forces on the case and the chassis of my gear.
I tested a bunch of liner and bumper materials as well as various 3M industrial transfer adhesives that could permanently adhere this liner to the PETG shell without failing under daily use. For all of my testing I used a J-style roller to apply various transfer adhesives to sheets of these materials, and then cut the materials with a hobby knife and my cutting mat in various shapes to apply as a liner. The materials I tested included:
- Silicone (Spoiler: Bad idea)
- TPU sheets (various durometers, around 1mm in thickness)
- Polyurethane rubber (around 1mm thick and 80A and 85A hardness)
Silicone: Great cushion, terrible adhesion, poor clarity. Thereās a reason that silicone is used for a lot of cookware. It doesnāt stick to things! It ended up being a poor material choice, but I had to test it. For science! None of the tests I did with various transfer adhesives produced a result which would stand repeated use for years.
TPU: OK cushion, excellent adhesion, excellent clarity. TPU actually worked quite well in my tests. It has absolutely perfect clarity, and a decent cushion, although a bit hard. However, it is an incredibly sticky material. As a liner, it wants to constantly stick to the gear, which makes removal of the shell not ideal. Additionally, itās a magnet for dust and lint. Not a good option, but I had high hopes.
Polyurethane Rubber: Excellent cushion, excellent adhesion, good clarity. This ended up being a really good solution at roughly 0.75mm thickness. I purchased it in a sheet from McMaster-Carr. I was slightly skeptical by the product listing because it was labeled āsemi clearā but it is nearly completely clear when applied with adhesive to the PETG. It seems to provide a solid, permanent interface layer with the PETG and you can barely notice that itās there. Additionally it wonāt turn into goo or get gummy over years of time.
So far, polyurethane rubber has been holding up exceptionally well with daily use of my Digitone and carrying my prototype case around in my bag to work every day. Additionally, it has given the shell increased protection and robustness, which was not my original intent but a welcome bonus for sure.
However, even thin rubber is hard to cut with a hobby knife or scalpel. I need to find a way to cut this rubber a little more cleanly, as some of the strips I cut are only about 3mm in height, and long and skinny. Itās kind of a pain to cut with a hobby knife and metal ruler, and I want it to look nice.
Turning it into a case (maybe?)
The last part of my project idea is to extend the concept of a hard-shell dust cover into a full-on, lightweight case. And this is currently where Iām at as I continue my descent into the rabbit hole. The top shell can be used in my home office and sit on the device as a dust cover. When I want to take my gear with me, I grab a bottom shell and join the two clamshell halves with a simple strap system for full-coverage protection on the go. The clamshell halves sound good in theory, but we will see how it goes in practice.
Travel Strap
I have done testing with various ideas for a ātravel strap.ā Heavily inspired by what TE ships with their OP packaging, I decided to make some nice looking heavy duty elastic straps which could be easily pulled over the top/bottom halves to keep the whole package super secure. I purchased various types of elastic and ribbon from local suppliers like Hobby Lobby and some suppliers on Etsy to try out some things. Some of the thinner strap options I found looked more like I was wrapping up the case as a gift with ribbon, so those were a no-go. I eventually landed on a really nice 1ā wide heavy duty, tight woven elastic that I found from a nice person on Etsy. The material is high quality, the seller has it in a bunch of fun colors (I bought some orange and green), and itās fairly straightforward to cut and sew. Most importantly, it keeps the whole package nice and secure. I think this technique works really well and it keeps the design and the shapes of the case nice and simple. I donāt really want to add funky features or cutouts in the vacuum forms to accommodate a strap, as I think it would detract from the aesthetics.
Bottom Shell
This is where Iām at on my journey right now. This past week Iāve been pondering how I want to design the bottom shell. I am fairly constrained in the design. I think it mostly will just need to be a box, with the same cushion/liner concept as the top shell. I have considered making rubberized feet which could sit on the outside of the bottom shell, to give the whole thing a non-slip property. It makes the mold design slightly more complex, but still within reach.
Aesthetic
This is an area Iām still trying to finalize. I want this to be functional first, while also having some form that doesnāt fight the gear, but also doesnāt feel super utilitarian. I am a big fan of 70s/80s sci-fi, so Iām trying to come up with some simple shapes that subtly say āthis could be on a spaceship.ā Iām curious to hear what people think of the aesthetic. If these things are going to sit on my desk all the time, I want them to look cool but also not compete with the aesthetic of the gear itself.
In summary, the vacuum forming rabbit hole is officially my home-away-from-home. But Iām having a lot of fun along the way. Iām excited to see where I end up with everything. Thanks for taking the time to read along! I tried to get into a lot of details without writing a chapter book. I would love to hear what you think about the concept and any ideas you may have to make it better.
Things Iād really love feedback on:
- Does the bottom shell idea make any sense to anyone else, or is that me overengineering the problem?
- Is clear with a slightly frosted aesthetic cool? Itās hard to see in the photo, but because I didnāt sand my test mold enough, the PETG came out frosted. Does this scream more āsci-fiā or does a perfectly clear shape more fit that aesthetic?
- Have you had long-term issues with Decksavers scratching or reacting with finishes?
This is probably the most effort Iāve ever put into avoiding a conversation with my mother-in-law.
