Category Archives: Projects

Project Update 07/23/19: Raspberry Pi Keytar: SD Holder, Sticker Order, Tray, and Power Issues

So, I was working on a few different aspects on this thing that aren’t entirely related, so I figured I’d split it up into the relevant topics. I still haven’t settled on a format for these blog posts, but I figured this would work for this update.

SD Card Reader Holder:

I designed and 3D printed a holder for the SD Card Reader, which attaches via screws to the case. Just for fun I decided to mix in the model of a floppy disk (3.5″ design, not the 5″ design) to indicate that it was where the disk was inserted. Kinda like with the secondary cover, I had to go through a few drafts of it to make sure everything fit and the holes lined up so that when I drilled into the original case I wouldn’t run into extra structure. You’ll notice that there are only three holes and the upper corner is cut off. This was done because there really wasn’t a good spot to put a fourth hole, and I didn’t want an extra corner sticking out from the case.


SD Card on case.jpg

Sticker Order:

I’ve ordered a bunch of stickers to cover parts of the keytar case, wannabe rocker style. I’m keeping it to a theme of underdog/rebellious people from fiction, and with appropriate maker-themed stickers. The stickers are coming in piecemeal, but they are coming. Below is a list of the kind of things I was going for:

  • Rebel Alliance (Star Wars)
  • Black Knights (Code Geass)
  • Serenity Logo (Firefly)
  • Ed’s Smiley Face (Cowboy Bebop)
  • Triforce (Legend of Zelda)
  • Raspberry (Raspberry Pi)

I’ve considered loading multiple operating systems on to different SD cards, but for now this thing is primarily going to run on Pibian. I’ll label the appropriate OSes on the SD cards later once I spend more time installing them.


I finally found someone who could cut some material for me for the tray! I got them to cut several pieces of MDF for me to try different sizes for the tray, and to have spares in case I messed up the first time.


I’ve already attached the hinges, and the tray opens and closes fine.



It looks like since the screws were so long I needed to cut the screws shorter. My first thought was to cut it with my Dremel, but that throws off sparks and it was way too hot to be working on it outside over some concrete.


Me, preparing to use the Dremel… before realizing it was a bad idea. Safety first!

When it had cooled down some, I moved outside and cut one of the screws off with the Dremel. It was a pain, somewhat risky… and then I remembered I had lineman’s pliers, so I used that to cut the rest of the screws. It was a lot faster and safer than trying to use the Dremel. Not-a-pro-tip: I cut this thing while holding it inside a box, because I’ve had way too many things I’ve cut lately go flying across the room, and I didn’t want sharp metal objects on my floor.

I needed to wait until that is done before I take the measurements I need to fabricate the pieces that will hold the keyboard in place and provide a mounting point for the latch. I may also have to figure out how to add a handle of some sort to make it easier to pull the tray open, or else grab it by the latch when I need to open it. This is still on my to-do list.
Power issues:

In the past I’ve tried two different power banks, and kept getting a low voltage warning. I decided to try another recommended approach from a book I was using for learning about Raspberry Pis, which recommended a case for 6 AA batteries routed through a UBEC, which I then routed through a connector to USB so I could plug in the switch that I wanted.


My attempt at custom wiring

That gave me the same result. I sent a picture of my wiring setup (the picture above) to an electrical engineer I know, and he commented that it was a lot of wire, with the resistance making what should be adequate voltage drop to inadequate voltage. I went back to trying the power bank, and a much shorter cable that didn’t include a switch… and now the Pi only intermittently shows a low voltage warning, instead of constantly. Mostly when I try to get online with it. So… it’s an improvement. Not perfect, but still better than seeing a warning constantly that the system is probably gonna be unstable. Downside of the new arrangement is that I’m going to either have to keep plugging and unplugging the wire to the Pi or else opening the case every time I want to turn it on. Here’s the components laid out for when I was trying actually doing something with the Pi.


Here’s everything inside the case as it is right now. The components are just in there loosely for now, but will likely be mounted with command strips for most parts, though the ribbon cable will likely be secured with painter’s tape.

Current Status:

Here’s the whole thing as it currently stands, though I do take the components out while working on various parts.


  • The power connection uses a shorter wire than before, and there is a short wire from the outside of the case (through a pre-existing hole in the case) to the power bank. I’d prefer to include the switch in the design, but that will/would require cutting and splicing the cable to the minimum length that can still do the job.
  • I’ve routed an aux cable from the pi to one of the other holes to be plugged into speakers or headphones externally.
  • The SD card reader has it’s own spot, and the ribbon cable routes through the space between the keyboard tray and the case, and back up through the secondary cover to the Pi.
  • The tray functions on it’s hinges.

This thing is coming together, slowly but surely!
Upcoming plans:

I need to design and 3D print the mechanical interfaces between the keyboard, tray, and latches for the case. This is gonna take a while, because:

  • The parts will have to connect to each other
  • The top of the case, the tray, and the keyboard are all at different angles from each other, and all need to be correct to hold the keyboard and allow the latch to work.
  • The pieces will have to hold the nuts to allow screws to come in from the outside.
  • This will have to be in multiple pieces because my printer can only handle things up to about 4 inches in a given direction.

Project Update 07/16/19: Raspberry Pi Keytar; Secondary Cover

The casemod continues.  As I mentioned last week, I designed a secondary cover for the Raspberry Pi.  Here’s the Version 1 I mentioned messing up last week.  If you look at it, you’ll notice that the main case has rounded edges, the secondary case has straight lines.  This bugged me.  I continued the print for purposes of fit check and everything.

Top View v1.jpg

Below is what I’m going for with the case.  You’ll notice the rounded edges to match the overall feel of the case.  I’m actually not sure whether this is the version 2 or the version 3 of it in this picture, as the differences are not visible from this angle.

Top View v2.jpg

Here’s how it connects, btw:



For comparison of the versions, I’ve added the pictures below.  The main difference between the version 2 and the version 3 was that I forgot to include a very important hole.




Going from version 1 to version 2 I had added a piece to fill the gap that had existed in the portion that was overhanging the edge of the case.  I didn’t want stuff getting into the cover or into the case.  However… that gap is where I had been routing the power cable, and I had forgotten to add a hole for the power cable to leave the case.  So, pretty much the only change was adding a hole so that the cable could come out of the case.  Now that I’ve done that, I took the time to drill the holes to install the case on the keytar.  Here’s what it looked like.

Test Install.jpg

Top Back of Install.jpg

Back of Install 2.jpg

Note:  In this last image you can see more of the Pi’s case exposed, despite me saying I was trying to seal up the case.  That oval hole in the case serves two purposes, 1) to allow air circulation for the computer, and 2) I can carefully push the Pi out of the outer case if I ever need to access it or the screws underneath it.

I relearned a couple lessons in the process of drilling the holes that should have been obvious.

  1.  CHECK THE BACK SIDE OF THINGS YOU ARE ABOUT TO DRILL.  Especially when it’s into a case that you didn’t design/build yourself.  There were some connectors for holding the upper and lower portions of the keytar itself together that I may have messed up.  I did notice a few spots when I got partway into it that I very nearly damaged important pieces.
  2. CHECK WHAT STUFF YOU’VE REMOVED THAT YOU PLAN TO PUT BACK.  There is a piece that originally held the buttons into the case that I will need to put back before I close the whole thing up, as it contains a few clear pieces that precisely fill in some holes on the case.  I had to temporarily put it back in in order to drill another hole so I can put the screw for the secondary case all the way through later.  I also discovered that I will need longer screws so that it (and some components to be printed/installed later) can pass all the way through.

Here is the spot I was mentioning in lesson 2.  The holes to be filled in, the piece to replace, and what they look like together.  It’s a really important part, especially since I’m trying to keep the case as closed as possible.  Also, with those clear parts I might be able to put a light behind them later.  I thought I was going to be painting before long, so I had removed it.




Anyway, at some point I decided that the case was a bit too plain, and could use a greeblie (I had to ask around to be reminded of the term for this), and what better greeblie to start with than the Universal Greeblie?

Adam Savage explains it well here.  It’s fun learning these things as I go along!

The stl I used for the greeblie was from here:

Universal Greeblie on Thingiverse

The nice thing about it being a STL file is that I could make it any size I could print!  So, I upscaled it, and this is the result:

Universal Greeblie 2.jpg

I’m gonna superglue that sucker on later (it’s just held on by a bit of hidden tape for now) and then paint it with the rest of the case.  I like the extra bit of detail, and I might have to find some more types of greeblies to install elsewhere on the case.

Before I forget, I added a little bit to the wiring, but it was mostly plug and play, so I almost didn’t include anything about it.  I added a short micro-USB cable to the exterior of the case through one of the pre-existing holes, and a switch in-line between the power bank and the pi.  I still need to figure out how I want to mount it, though I guess that depends on whether I keep this power system.  It currently gives an undervoltage warning, even if I try to pass wall power through the power bank.


I also tried printing a small, angled SD card holder to fit inside the case (I plan on storing backup/alternate OS SD cards in the case)… but apparently the person who posted the model had scaled it up to be too big.  I’ll have to find a new one, rescale this one, or create one of my own at a later time.  It’s an internal detail that is subject to whether I decide to redo the power system, so it’s not urgent.

The Path Forward:

I’m still trying to get a a piece of material cut for the keyboard tray.  Until that is done I can’t really start on designing the pieces to hold the keyboard to the tray and add the latches to hold the tray shut.  I’m also not painting anything until I have most or all of the pieces so I don’t have to paint on multiple occasions.

I think the next thing on my list is figuring out how I want to design the holder for the SD card reader, and how I want to mount the power switch to the case.

Project Update 07/08/19: Raspberry Pi Keytar

I’ve been continuing working on the keytar casemod project.  Recently I got out my Dremel and some of the chisels I use for 3D print cleanup, and removed some of the internal structure of the case so I can fit a power supply in (a power bank in this case) and get the wires to cross from the keyboard compartment to the controls compartment.  The latter gap is located just up and to the right of the power bank.

Power Bank Removed Structure.jpg

I’ve further refined, published, and printed the “case case” for the Raspberry Pi, adding the holes for mounting the case to the keytar, and holes to later mate a cover for the wires coming out of the keytar.

The STL is located here on Thingiverse:
Raspberry Pi 3 B+ Case Case

You can see closeups of the case from all angles below (I apologize for the formatting):

Screen Closeup.jpg


Power and HDMI.jpg

 Bare Side.jpg

USB Ports.jpg

SD Card Port.jpg

I’ve recently designed a part using the holes in the last picture to cover where the SD extension cord comes out of the keytar and into the Pi.  It is currently on the printer.

D’oh!  I just realized that I never rounded the corners on that piece to match the other case.  And apparently it’s not evened out in the interior.  Oh well, this is gonna be a bit inconsistent.  Maybe I’ll print a version 2 that is neater later.

I’ve also recently tried to start changing some parameters within the Pi’s programming itself, using a guide I have on increasing the performance of the Pi.  The main thing so far has been attempting to move some of the functions onto the RAM internal to the Pi.  However, this seems to have caused the odd side effect (though it may be coincidence) of causing the system to start showing an undervolt message while on battery power, despite seeming to have worked fine before.  More experimentation is required!

I’m still trying to get material for the keyboard tray, but so far I haven’t had much luck finding a place that will cut the material I want (masonite/hardboard) to the dimensions I want (5.25 inches x 14 inches) with any precision.  I don’t want to cut this myself, as I’d need to purchase or rent more tools… and unless I get a lot of stuff to help guide the cut, I have trouble cutting a straight line if I go anywhere close to freehanding it.

Well, this definitely proves to me that I need to continue blogging while I do this project.  By trying to explain and show what I’m doing, I’m re-examining it and figuring things out.  If I ever do manage to finish this thing, hopefully I’ll come back and write a more coherent article on this process, but for now you get to come along on the ride for this.

Reasonable suggestions would definitely be welcome!

Project Update 07/04/19: Raspberry Pi Keytar

I’ve been a bit busy lately, but I am gradually making progress.

After the last update, I realized I had more components that I might be keeping, but needed to remove for when I paint the case.  I think this bit was some sort of capacitive input for they keytar.  I’m keeping it 1) because i need something to plug the whole it was in and 2) because I’d like to see if I could figure out how to use it for something one day.Capacitive Bar.jpg

Buttons to plug holes and/or be reused.Buttons.jpg

Here’s what the case looks like with most of the components removed.

Buttons Removed.jpg

I’ve also been taking a look at layout for the components with the Raspberry Pi, and finally gotten a screen to work.  I had to trade in the screen I had, and then order a combination of screen and case specifically for the Raspberry Pi 3 B+.

Working Pi.jpg

While I had the time on the 4th of July, I’ve also started working on some other things.  Here is picture of the current draft of my holder for the Pi inside it’s case.  I’ve been designing it in AutoDesk Fusion 360.  It’s supposed to allow me to put the Pi on the keytar while still being able to remove it if necessary, and allow for airflow.  I still need to figure out where I want to put the screws to mount it to the overall case, and put the appropriate holes in this case and the keytar.

Pi Holder.jpg

I also stopped by Home Depot to pick up parts so I could make some progress… and I need to do some rethinking.  I eyeballed the part I was planning to use for the keyboard tray.  Let’s just say… it’s thicker than I thought and the space for it is shallower than I thought.  I really should have measured that and taken it with me.  Now the top of the keyboard extends above the keytar case instead of being within it.  I need to pick a different material (I’m currently using PVC board) and get it cut to fit.  I guess I’ll just put something to cover up where the hinge screws are going to punch through, unless I decide to keep the ridiculously thick tray.

keyboard tray fail.jpg

If I keep it, here’s what it looks like.

current look.jpg

I have already slightly sanded the exterior to aid in later repainting, and I’ve got the paints on standby.  Black paint/primer, glossy clear coat, and matte clear coat.  I’m still deciding whether I want the eventual stickers to be sealed in by the clear coats, or to put them on the exterior of all the paint like it would normally be done.

Upcoming work:

Making up my mind on and purchasing the components for the internal electronics.

Figuring out how to have the power wires exit the case.

Completing the design of the screen holder and 3d printing it.  The design still needs screw holes, mounting points for a cover for the ribbon cable and the hole the wires are coming out of, and possibly a wedge of material to be attached as additional support behind the computer in the area where it overhangs the case.



Raspberry Pi Keytar

As you’ve seen references to before, I’ve been fiddling with a Raspberry Pi.  I was gonna use the case I posted, but the case is not designed well, and I decided to go another route.

I’ve going through a lot of cyberpunk stuff lately, so I thought I’d make my own “cyberdeck,” or at least a semi-functional prop of one.    I figured the idea would be that a decker or console cowboy character might want to be able to somewhat hide in plain sight… at least in a cyberpunk world.  In this heavily 80s inspired environment, they might try to hide their portable cyberdeck as an instrument for when they need to duck into a crowd and disappear.  What better instrument than a keytar?

I did some looking around, and I couldn’t find a keytar within a price range that I’d feel comfortable tearing it apart.  Also, it needed to have just enough space for the keyboard I had already gotten for the Pi.  I did find this, a keytar controller built for the rockband games.  Not even $30 at a secondhand store.

Unopened Keytar

Conveniently, it came with a strap for carrying.Keytar Strap.jpg

Here’s the case with the cover off.  I had to cut some of the wires to get it open.  They must have snapped the connectors in while closing it up, but I was unable to pull them apart, and I’m not planning on reusing most of them.  The ones I thought I might try to figure out later I cut, but left a lot of wire dangling.


Here is the case with the white keys removed.  Starting to reveal some of the underlying components.

White Keys Removed.jpg

This part threw me off.  Apparently the keys had some sort of silicone based lubricant on them, which.  I wasn’t so sure about it, so I used gloves to remove some of the internal components.


Like I said, gloves.  I didn’t want to mess around with it.


Here is the case closed back up after removing most components.  The components that remain attached are ones I’m considering keeping or modifying for the casemod.


Here’s the case with just the keyboard in it.  It’s loose, but I think I can fab up some pieces to hold the keyboard in place.


Now that I’ve ripped the case open, here’s the general arrangement I’m trying to get to.

Concept Arrangement.jpg

I’ve still got quite a long way to go, and I’m figuring out a lot as I go along.  I’m going to be asking around in my circles to figure things as I go.  I’m just learning the Pi, so that’s becoming an interesting journey by itself, and I haven’t done much painting or casemodding before.  This thing is probably going to come out rough, but I think I’m gonna have fun with it.  One of the hard parts is going to be remembering “better is the enemy of good enough.”  I keep thinking of more things that could be done on it, and I’m having to make myself write a list labelled “MK II.”

New Project Preview

So… I’m trying to build my first Raspberry Pi, and put in a case that I am 3D printing.  Supposedly it was snap fit.

How do you think that is going, based on the tools I have out?

Maybe it’s snap-fit when printed using SLA instead of FDM, but i’m having to carefully apply force at connection points, and edit others with the chisels.  I’m going to have to be really careful with this thing, and probably won’t be able to modify this thing after finally getting it in the case.  Adhesive may be required.