Boomcrete - PLA/PETG version

While working on a concrete BT/Wifi 2.1 speaker for some years (source for name Boomcrete), I decided to get a working one in PETG/PLA for this season.

The box was designed to work without power plug (e.g. Makita Battery). A version without Battery holders is availble also.

You need a print bed with at least 230mm x 196mm space, if you don't want to cut the models again by yourself.

The total costs of the project are around 500€ to 600€.
This includes all parts of the BOM. Loudspeakers and AMP are ~470€.
So keep this in mind before you buy the model. ;)

BOM

• 4-6kg PETG / PLA (Recommendation: Eryone PETG CF 5kg)
• 8x 3mm Press-in threads (e.g. Amazon EU)
• 22x 4mm Press-in threads (e.g. Amazon EU)
• screws
  • 3mm screws - black [AMP + Battery holder] (e.g. Amazon EU)
  • 4mm screws - stainless steel (e.g. Amazon EU)
• 2x Tang Band W1337-SD (OEM)
  • Alternative W4-1320SIF (Amazon EU)
  • optional crossover:
    • Audaphon MKP CAP Superior: 15µF; +/-5%
    • Mundorf Backlack-Luftspule BL100: 0,39Ohm; 0,68mH
    • Metalloxidwiderstand MOX10: 10W4OHM7G
• 2x Bass reflex tubes BR-30HP  (Amazon EU or here)
• Tang Band PR15-A (OEM)
• Arylic Up2Stream Plate Amp 2.1 (OEM - world wide shipping)
• 6x Squash balls - 2 dots yellow (e.g. Amazon EU)
• Sealing tape for loudspeakers [10mm x 3mm] (e.g. Amazon EU)
• Good super glue for PETG (e.g. Amazon EU)
• Combine powder for sealing (e.g. Amazon EU)
• Rubber mallet mandatory (e.g. Amazon EU)
• If used with Makita Battery
  • Use this adaptor
  • 2x Makita contact plate (Amazon EU)
  • 8x 3mm Press-in threads (16 in total) (e.g. Amazon EU)
  • Wires for power connection
• Some silicone or other stuff to seal the cables

(I use Amazon affiliate links)

Print Settings

• Layer height - 0,25mm
• Walls - 4
• Infill type - Rectilinear
• Infill - 25%
• print slow (e.g. Up-Right takes arround 18h20m with X1C 4mm nozzle)

Assemble

First, test fit the parts. You can separate them by lightly tapping with a rubber mallet. If something does not fit, there may be excess filament or some other minor errors in the print. Grind off any excess filament or blobs.

Use a solid surface to join the upper and lower parts first. Apply super glue only to the lower part, specifically on the protruding edges (top and outer sides) and make a serpentine line around it. Arrange the top part and press them together. Use the rubber mallet to achieve a tight fit.

I sealed the middle part inside with “Combine Powder” and Super Glue. Add a little Super Glue on one internal side first and then use powder. Redo until you have a solid seam.

After assembly, grind the sides where the new left, middle, and right parts meet. Apply glue to the two tips for correct fitting and on one whole side. Press the parts together and apply a bit more pressure to the upper part. Depending on the calibration of your printer, there might be a gap at the lower part.

Insert the screws: 3mm for AMP and Battery, 4mm for Loudspeakers, passive membranes, and squash stands.

Apply sealing tape on top of the threads for the left and right speakers and cut free the threads afterwards. The passive membrane and the subwoofer should not require this tape, but you can use it if the fit is not airtight.

Now you should testfit all components. When result was positive (sealed loudspeakers, straight threads, etc.) you should prepare your cabeling and your optional crossover.
If you use e.g. the Makita Battery for your build, you should find the internal +/- connection on your AMP version to connect the batteries.
Dont forget to seal all three cable holes into the internal chambers.

As last step you can add the optional damping stands. Screw them in place and add the Squash balls afterwards.

Enjoy your speaker ;)