Crab - a Synth Shelf

Crab is a shelf that gives your studio desk an extra level, helping you organize your synths and audio gear.

It was originally designed for the Korg Volca Synthesizer series, but the design is highly customizable to fit your unique setup.

The shlef is simple to make if you have access to a 3D printer and a few basic materials and tools.

• Plastic
• 3D-printer with approximately 360 g (12.7 oz) of filament (I suggest using PLA-filament)
• Wood
• Wooden board the minimum dimensions of 587 mm (23.11 in) x 117 mm (4.61 in) x 17 mm (0.67 in)
• Wooden rod with a diameter of 24 mm (0.94 in) and length of at least 610 mm (24.02 in)
• Handsaw
• Bar Clamp (Optional)
• Sandpaper (Optional)
• Screws
• 4x: 4 x 30 mm (0.16 x 1.18 in)
• 8x: 4 x 15 mm (0.16 x 0.59 in)
• 6x: 3 x 12 mm (0.12 x 0.47 in)
• Screwdriver
• Wood drill with a diameter of 2 mm (0.08 in) (Optional)

Crab is made of a combination of plastic and wood, all held together by screws.

Salvage and Re-use

I made the shelf using an old wooden board that used to be a shelf (before it fell off my wall). For the legs, I bought a broomstick, maybe you have an old broom dusting away you could salvage?

The plastic pieces are unique, so you will need access to a 3D printer for them.

End of Life

Nothing lasts forever, and neither does a synth shelf, so whenever Crab reaches its end of life, it's easy to take apart to re-use or re-cycle the parts.

The board for Crab is made by cutting a wooden board into desired dimensions.

Find a wooden board with a length of at least 587 mm (23.11 in), a width of at least 117 mm (4.61 in), and a thickness of approximately 17 mm (0.67 in).

• Cut the board into desired dimensions
• If you want you can use a clamp to hold the board while sawing and finish the parts with a bit of sanding

Customization

If you want to adjust the size of the shelf, feel free to adjust the length and width of the wooden board. As long as you keep the width of the shelf greater than the length of one of the front and back plastic leg holders, it will work to fasten the leg holders to the wooden board.

The length of the wooden board will impact the stability of the shelf, so it's up to you to decide if it feels stable enough before you put any heavy and expensive gear on it.

The legs for Crab are made by cutting a rod into four cylinders.

Find a rod with a diameter of 24 mm (0.94 in) and a length of at least 610 mm (24.02 in).

• Cut the rod into fours parts:
  2 x 160 mm (6.3 in)
  2 x 145 mm (5.71 in)
• If you want you can use a clamp to hold the rod while sawing and finish the parts with a bit of sanding

Customization

If you want to adjust the height or tilt of the shelf, feel free to adjust the length of the legs. As long as you keep the back legs the same length, and the front legs the same length you can go pretty crazy with the dimensions.

The plastic parts of Crab are designed to be 3D-printed without the need for a lot of support material.

3D-model files (CAD files) and customization

To build Crab you need to 3D print four different parts that act as joints for the legs of the shelf.

Depending on the size of the gear you want to put on it, you might need to print more or less of the front brackets.

I use the shelf for three small Korg Volca Synthesizers, so I have one bracket for each synth in this guide.

You can find the CAD files for the parts at the bottom of this step of the guide. If you want to print straight away, you just need to use the STL files, but if you want to customize the shelf you can import the STEP files to your CAD software of choice.

Filament and the Environment

For the version of Crab in this guide, you need approximately 360 g (12.7 oz) of filament. To minimize the negative effect on the environment I suggest that you find a plastic filament that is plant-based, such as a PLA-filament, instead of a filament made from fossil oil, such as an ABS filament.

In general, a PLA-filament is less robust than fossil-based filaments, but I find that you can compensate that with a higher infill rate (higher density) of your prints.

Part Orientation

The front bracket plastic parts are designed to be printed laying flat on the side on the print bed, while the parts holding the legs are printed in a tilt to minimize the support material needed.

I suggest rotating the leg holder models in the 3D printing software so that no support material is needed for the inside or outside of the leg holder cylinders. This is because support material can produce irregularities on the surface which looks pretty ugly.

Print Settings

I used these settings on my Creality CR-10 Mini 3D printer:

• Layer height: 0.24 mm
• Infill density: 60%
• Printing temperature: 210 °C
• Build plate temperature: 60 °C
• Print speed: 50 mm/s
• Wall and support speed: 25 mm/s
• Support: Everywhere
• Build plate adhesion type: Raft
• Raft extra margin: 5 mm

Print Time

This is the time it took for me:

• Front leg holders: 6 hours and 55 minutes per part
• Back leg holders: 7 hours and 50 minutes per part
• Front brackets: 2 hours 55 minutes per part

Stay Safe

As always when it comes to 3D printing, make sure you have your printer in a well-ventilated area to protect yourself from any harmful fumes.

When you have all the parts it's time to put it together.

Push the leg holders to the side of the wooden board and screw them into place with the following screws:

• 1 screw per leg holder going into the side of the wooden board with dimensions of 4 x 30 mm (0.16 x 1.18 in)
• 2 screws per leg holder going into the bottom of the wooden board with dimensions of 4 x 15 mm (0.16 x 0.59 in)

Pre-drilling (Optional)

If you want to make sure that the wooden board doesn't crack, I suggest that you use a pencil to mark where the screws will go and pre-drill holes before you fasten the screws. I used a drill with a diameter of 2 mm (0.08 in) for this.

Push the front brackets to the front of the wooden board and screw them into place with screws with dimensions of 3 x 12 mm (0.12 x 0.47 in).

It's up to you how many front brackets you want to use, and where to place them.

Pre-drilling (Optional)

For the front brackets, I chose not to pre-drill because the screws I used here were so small. If you want to be extra sure you don't crack that precious wood though - it's always safer to do some pre-drilling.

Crab is designed to be easy to take apart if you need to transport it or stow it away.

Therefore the legs are assembled by simply putting them into the leg holders with the shelf lying down, and then the shelf is rotated into the correct position while holding all the legs at the same time so they don't fall out.

The legs go into the leg holders quite a bit, to make sure that Crab shelf is stable even without using fastening screws for the legs.

Moving it around

If you want to move the shelf around with your synths still on it, I suggest taking it easy and holding all the legs firmly while moving, to make sure that you don't drop and damage your audio gear.

The Crab synth shelf can be used in different scenarios - for groove box sessions with electronic beats as well as to fit a second keyboard on a normal synth shelf.

Maybe you can come up with your own setup?

If you enjoyed this project, you might also like other guides in the same series:

How to make a laptop stand: Note - a Laptop Stand

How to make a table lamp: Lighthouse - a Table Lamp