A Framework For Making Affordable & Stylish Modular Controllers (USB to MIDI, HID, or Serial)

Step 5 Design, Layout & Body.

You may suspect I am some kinda master craftsman or something. No, I am terrible at working with my hands and thus must rely completely on laser cutting robots.

Ponoko is great for laser cutting services, they have an excellent material selection and super friendly staff. 

For my controllers I used the materials Bamboo Amber 3mm, Black Matte Acrylic 1/8", White Matte Acrylic 1/8", Clear Acrylic 4.5mm, and Clear Acrylic 3mm. 

In the diagram above you will see the sketch for my three layer design. This method of design allows components to be counter-sunk. Below is the breakdown of layers for both the decks and sampler.

• Layer 1: Clear Acrylic 3mm
• Layer 2: Matte 1/8"
• Bottom: Clean Acrylic 4.5mm
• Platter: Matter 1/8"

The bamboo mixer also uses a three layer design. Each layer is bamboo.

I designed my layouts in Adobe Illustrator (free one month trial). There are many other software options available, just ensure they can export the PDF-type document Ponoko requires (Inkscape is freeware). When using illustrator be sure to switch your units to millimeters and add a grid to aid in layout/spacing.

Very very very very very very helpful design tips (that I wish someone had told me)

• Most important: Do not overcrowd your board! Leave lots of space between components. Think minimalist. Although your Teensy++ has many inputs available it is foolish to try and make use of all of them. It is best to begin creating more modules rather than overcrowding a single board. Hookup will be a nightmare if your overcrowd the board.
• Don't start your design/cutting until you have the components in your hands.
• A shift button is a great way to reduce the number of pushbuttons. Using one shift button is highly recommended. When you hold your shift button, all the pushbuttons on your board will then send a different message thus doubling the total number of pushbutton messages available on your controller.
• If you use non-matte acrylics on the front face they easily become covered with smudges.
• All wood material will require a coating of polyurethane (or some equivalent).
• Etching is possible (although I did not use it on my design).
• If you design your front face to be large, there will be undesirable flexing in the center when you engage a pushbutton. Keep your modules a reasonable size. My mixer is 230x230mm.
• Bamboo is more flexible than acrylic. The acrylic is quite stiff.
• To reduce flex you can add tiny bolts which join layer one and two (see image).
• Do not try to glue the top two layers together.
• When creating your layout you need to reference the datasheet constantly to ensure your cutouts match the components.
• If the specific components cutout dimensions are not given, it is best to increase the size by 0.1mm. For example, the rotary potentiometers have a bore diameter of 9mm, thus the cutout should be 9.1mm.
• Errors in laser cutting can get pricey so be sure to check your design numerous times before sending it off.
• The upper and lower layers can be spaced using aluminum standoffs.
• I made the standoffs at the front slightly shorter than the ones at the back to created a tilted front face.
• You can 3D print some custom corners (shapeways, ponoko, imaterialise) and add walls to your design, much like I did in MK1. Personally, I prefer the no-wall design as it enhances the DIY aesthetic and reduces costs.
• The gap between the slide potentiometer body and slide knob needs to be measured carefully to ensure there will be enough clearance for the slider to slide. 
• If you are using bamboo, I would recommend using 3 ply for the bottom instead of single ply. It is a good idea to use a heavy/thick bottom for all of the modules. 
• Print out your layout on paper before laser cutting to get a feel for the spacing. 
• Pay close attention to the height of your components. Ones which are too tall will cause your controller to look bulky and odd. 
• When using the software, design all three layers at once then separate the layers before cutting (see attached pdf).

Get creative and have fun with the design!

I have attached the PDF files for the mixer to this document. I would not recommend copying these cutouts as It is best to make your own custom design.

Comments

[imovane]

Hi! I was wondering what the difference is between the two pdf's? Did you make both of them?

[Fuzzy-Wobble]

Yes, they are the same. One is specifically for laser cutting and the other was used during the design stages. It is easier to design with all the layers overlapping then separate them later.

[imovane]

Thanks for your reply! So what is all the different colours and stuff? Are the lines tha path that the cutter takes? Is much of this automated or did you manuallt have to draw all the lines and circles? I know what I want to cut out and all the spesifications, but that second PDF looks pretty daunting...

[Fuzzy-Wobble]

layout is easy and fun in illustrator.

[imovane]

Ok thanks, I'll give it a go! What do you think about using colours in the schematic so not to cut all the way through the material? Say you'd like to have some screws in the second layer but like the first layer to cover them up, you could cut half way through the material so the screw fits, and the first layer will still fit nicely with the second layer. Is this something you have tried/did in this design? Thanks again for answering my questions!

[Fuzzy-Wobble]

All laser cutting specs/guidelines can be found on ponoko.com. All the best!

[skmagiik]

Could a switch be used instead of a shift button? and could you use it for only part of the design? i want a row of hot cue buttons that plays the cue and when the switch is in the other direction it sets the cue...
same for looping except that switches between auto and manual looping functions.

[Fuzzy-Wobble]

I am a bit confused. A pushbutton is a switch. Are you talking about a toggle-switch?

[skmagiik]

Yes, I am talking about a toggle switch... wouldn't it just input the same as if a button is pressed?

[Fuzzy-Wobble]

Yes that is a great idea. The toggle on my sampler is a good example. It acts much like my shift button - when flipped back and forth the pushbuttons send different midi messages. Here is the best resource:
http://www.allelectronics.com/make-a-store/category/730/Switches-Toggle/1.html