My first small restauration - a small paint job, 3D printing and a mechanical repair

List of defects

  1. Volt gauge won´t go lower than 2.5 Volt
  2. Old paint peeled off


  • 3D printed dust covers

Lab_Powersupply_2 Lab_Powersupply_3

The modelnumber is blacked off, so my best guess for the build date is somewhere in the 80s. But i could be completly off. After taking of the top cover, one could really see its age - dirty but still impressive.

Lab_Powersupply_4 Lab_Powersupply_1

I tried to remove the gauges from the back, but after a quick glance it seemed that its way too much work.
So after some sweaty minutes of fiddeling with the front cover I had success and could remove the pointer assembly. Sadly I dont have any pictures of it. Turning on the powersupply shows that my repair worked. The analog pointer showed the exact reading as the digital one.


Second to last step was a fresh coat of paint, but first the old flaky had to be removed. I applied a thick coat of paint stripper and let it soak for a couple of hours. After the time had passed I could simply scratch of the old paint with a plastic scraper.
A quick sanding, degreasing and painting session later the powersupply looked 20 years younger.

Lab_Powersupply_3 Lab_Powersupply_7

Now it was time to apply the 3D printed dust covers. Some small dabs of superglue did the trick. A quick assembly later and the powersupply looked like a new one.

Disclaimer. The moon is not my model, I got it from moononournation over at Thingiverse. The rest of the project is all made by me.

Bill of Materials

  1. 1 m of white sleeved cable
  2. 12 mm 230V latch button
  3. 220lm LED 230V - warm white
  4. E27 socket
  5. EU style plug
  6. "Lüsterklemmen" - insulating screw joints


The hard Part
I bought a 150x150x150mm (LxBxH). For the moon lamp I just needed a 55 mm high wood stock - I don't have a bandsaw or something comparable, so I had to break out the japanese handsaw. The saw is very flexible, which caused the cut to become kinda uneven.

wood_prepare mill_surface_2


  1. Facing the top: My small hobby mill was not large enough, so I had to mount the stock in a way which allowed me to face off the first half and flip it around 180° and repeat the facing operation.


  1. Center hole:
    The first cut was with a two flute 20 mm end mill, which had to be enlarged with a custom-made boring bar with an HSS insert.

hole_boring_2 hole_boring hole_boring_3 hole_borin_fineshed

Once I reached the correct diameter to fit the E27 socket, a quick fitment check was made, and I flipped the part around to machine the underside.


  1. Underside:
    The underside had some requirements which needed to be fulfilled - host the power button, and route the cables.
    After some testing, I knew how to place the cables and button, so I milled the channels and pockets.

mill_1 underside_routed_1 knob_fitment knob_fitment_2


  1. Preparing the cable and plug:
    The sleeved cable started to fray on the end. To prevent further fraying some heat was necessary followed by wrapping the end in electric tape.
    The plug was just 3 screws, so nothing too difficult. My amateur wiring skills passed the check, so I continued to finish the wood base with some radii.

cable_1 bulb_socket lighting_test

Wood stain
I got just some generic stain which I found in my local hardware store and gave the wood base 3 coats with a thick soft brush. After 24 hours, I finished the base off with 3 coats of clear coat.
Don't get irritated by the spotty stain, this picture is with only one coat of wood stain.

pre_stained stained

The last step was to implement some sort of cable strain relieve, which I drew in my CAD of choice - Fusion360, and printed on my FDM Printer.


Money shot
The white balance is a bit off. The moon is much more yellow than it seems.

moneyshot_2 moneyshot_1

Credit where credit is due. I got the basic design and the wiring diagram from Donny Terek over at Instructables. You can find the wiring diagram with the needed BOM lower down in this post. This is no "how to" post, rather more a build log.

Bill of Materials

  1. TPA3116 Bluetooth Amplifier
  2. Tang Bang W5-1138SMF 5-1/4" Subwoofer
  3. Fountek FE85 3" Speaker (2EA)
  4. 5.5 mm x 2.1 mm DC Input Jack
  5. 16 mm Push Button
  6. 6S Battery Capacity Indicator
  7. 6S BMS Board
  8. 18650 Cells (6EA)
  9. Green 3 mm LED
  10. 3.5 mm AUX Input Jack (additional info down below [*])
  11. 3 Ohm 10W Resistor (2EA)
  12. 12uF 100V Capacitor (2EA)
  13. 100 uF 100V Capacitor (2EA)
  14. 0.50 mH Inductor Coil (2EA)


Woodworking Part
I assembled the outer shell/box from 12 mm MDF Wood. Before gluing everything together, I went ahead and layouted every side of the speaker box.

  1. Front Side:
    Hosts all three speakers - the subwoofer ind the middle, and the two toners in either corner of the panel.


  2. Right Side:
    fits the sub pipe, nothing more


  3. Top Side:
    has a cutout for the volume, treble, bass etc. knobs. They all sit in a custom made brass plate with laser etching

    IMG_20200717_105338 IMG_20200717_110832 IMG_20200717_112814 IMG_20200720_125349 IMG_20200717_101624 IMG_20200720_115624 IMG_20200720_121051 IMG_20200720_121749 IMG_20200717_181519 IMG_20200717_181525

  4. Back Side:
    Contains the voltmeter, power switch, DC jack, AUX jack and the toggle button for the voltmeter. Those also sit in a custom made brass plate.

    IMG_20200720_132542 IMG_20200820_132731

Assembly and modification of the Wood parts

I'll approach this part alá "a picture is worth a thousand words"

IMG_20200716_120150 IMG_20200720_192307 IMG_20200721_122702 IMG_20200721_123417 IMG_20200721_123424 IMG_20200721_140257 IMG_20200721_185420 IMG_20200723_110540 IMG_20200723_112108 IMG_20200723_112114


Yes, I know you shouldn't solder batteries, but it was my only choice, as I don't own a spot welder. I used the six 18650 batteries, the BMS board and a lot of kapton tape to assemble my 24V rechargeable battery.

IMG_20200710_140912 IMG_20200716_110406 IMG_20200716_110411 IMG_20200717_160210 IMG_20200723_113751 IMG_20200723_135559 IMG_20200726_162141 IMG_20200726_162153 IMG_20200730_180314

Speaker test

Leather wrapping

I bought some fake leather to use on my speaker which I glued with wood glue to the MDF

IMG_20200823_155345 IMG_20200823_155956 IMG_20200827_143441 IMG_20200827_144228

3D CAD and printing The Subpipe the speaker grills and the "top seam cover" was designed in Fusion360 and printed on my Prusa 3D printer. The parts got the usual finish e.g: sanding, putty, primer, painting.

BluetoothSpeaker_SubPipe BluetoothSpeaker_SubwooferGrill BluetoothSpeaker_TopCover BluetoothSpeaker_SpeakerGrill

Finished product

IMG_20200828_174548 IMG_20200828_174612 IMG_20200828_174620 IMG_20200828_174633 IMG_20200828_174644 IMG_20201227_170728 IMG_20210110_121204

SPM was built out of a necessarity. As a hobbyist 3D printer you accumulate a lot of 3D models which can get messy really fast. With SPM you have all your 3D models and a preview of them all in one place.


  • 3D preview of any *.stl and *.obj file
  • Open a *.stl file in your prefered silcer with one click
  • Set up to 8 booksmark directories, which you can open with one click
  • Treeview of your selected directory
  • Open file, rename file, open folder, move folder, create folder, delete file, unzip file

Set the most common slicers in the settings to be able to open the *.obj and *.stl with a click of a button.


You can assign up to 8 bookmarks. This could be a path to your files on an external HDD, or a direct path to a network share.

SPM_Booksmarks SPM_NewBookmarks

Rightclick menu
Simply right click the tree view to open up the context menu.


On the left-hand side you have your tree view which shows all your files from the set path in your settings. Right above the tree view is a simple search field, which highlights partial and/or full matches to your search string. In the middle top of the window is a quick folder creation tool. Just drag and drop any *.obj or *.stl in there to quickly copy it to your file path, which you set. Just below that tool is a quick text preview window, nothing special. The most prominent window on the right is the preview window for your 3D models.


Why buy a case when you can print one?


  • Prints without any support
  • Fits one HDD and one SSD
  • Build for an ITX motherboard and low profile CPU Fan

The whole case, which consists off of three parts, weighs a little bit over 600g. I printed it on my Prusa i3 MK3s with 0,3mm layer height and it took ~11 hours total. For the mesh I used a little trick and just used infill in the slicer. So no top or bottom layers and just 3 layers high in total.

3DCase_1 3DCase_2 3DCase_3 3DCase_4 3DCase_5