Teenage Engineering Pocket Operator Case

Background

I was fed up with my naked Pocket Operators (PO) combined with my awful storage approach. This case meets my own needs. Specifically, the following requirements:

• It must use the existing metal stand that comes with each Pocket Operator
• I don't want to take it out of the case in order to change the batteries
• Can't block the audio in/out jacks
• Protects the buttons
• Edges are higher than the screen
• I don't want to remove the tab at the top (unlike the official case) - I like my tab!
  • I do want an option for folks who removed the tab
• I'd like to try a simple compliant button design - I've never made a compliant mechanism before, so this was for my own education.
• No need for glue, screws, or other additional parts
• Visible LEDs 

This is the result!

The design

1. The main body/back of the case - features openings for the stand to open and close, a gap so the batteries are available for removal, and both jack ports are open to a user.
2. Face plate - provides a lift away from the buttons of the PO so that the case buttons function correctly. Small tabs on the edge slot into the main body and hold the PO in place. 
3. Button plate - slots into the face plate. Allows for swapping of the buttons without reprinting large parts. Available with tabs and without, depending on your tolerances. 

The button plate could be part of the face plate, but the goal was to make a replaceable set of buttons that can be printed in interesting colors AND can be replaced if anything breaks without needing to print the entire face plate again. The separation also means every part can be printed flat on the print bed while still elevating the buttons relative to the PO buttons.

Did I meet my own requirements?

• It must use the existing metal stand that comes with each Pocket Operator
  • Stand can fold away and can still support the PO
• I don't want to take it out of the case in order to change the batteries
  • Battery compartment completely accessible
• Can't block the audio in/out jacks
  • Jacks are accessible
• Protects the buttons
  • Buttons are covered but still as responsive
• Edges are higher than the screen
  • Screen sits slightly lower than the edges
• I don't want to remove the tab at the top (unlike the official case) - I like my tab!
  • Tab can protrude without sacrificing protection
  • I do want an option for folks who removed the tab
    • Optional variant of the body is available with no tab slot
• I'd like to try a simple compliant button design - I've never made a compliant mechanism before, so this was for my own education.
  • All buttons are compliant mechanisms that are springy and have a good rebound
• No need for glue, screws, or other additional parts
  • All parts slot together and hold in place without additional parts
• Visible LEDs 
  • The compliant mechanism means the LEDs are visible through the gap between the buttons and the button hole.

I'm my own best customer/designer!

Printing 

• Go slow! 
  • I set my speed to 50% of my normal print speed. This ensures the compliant springs for the buttons are printed without issue.
• Layers
  • For the buttons, go for 0.16mm
  • For the rest of the parts, you can go up to 0.24mm
• Supports
  • While I tried to avoid the need, the audio jack cutouts have to be supported unless you really trust your printers bridging.
  • I painted the supports in the center of each supported span. This avoided issues with the supports bonding to the walls.
• Walls/perimeters
  • 2 walls/perimeters is what you will need (0.4mm nozzle) as that is the maximum that can be accommodated on several parts
• Top/Bottom layers
  • I found 2-3 were sufficient
• Infill
  • Rectilinear at 15-20%
  • You don't need gyroid or anything similarly strong, but 15-20% will help resist the pressure of button pushes

Since the face plate and buttons are relatively thin and rely on friction to stay in place, make sure you have tuned your printer so that its extrusion settings are accurate. Over-extrusion and under-extrusion are going to make fitting the parts together much more difficult.

Files

Initial release version noted for each. If new versions are produced, I will leave the initial version and subsequent versions available. Earlier versions than the initial release failed testing in some way, hence why some of the files are starting at v4.

• TAB_BACK_pocket_operator_v4.stl - This is the back you need if you have a PO with a tab. Initial release is Version 4.
• BACK_pocket_operator_v4.stl - This is the back you need if you have a PO without a tab. Initial release is version 4.
• MODULAR_PLATE_pocket_operator_V4.stl - This is the face plate that holds the PO in place and hosts the buttons. Initial release is version 4.
• BUTTON_INSERT_pocket_operator.stl - This is the button insert that slots into the face plate. I was able to use this one without tabs and have it remain in place without issue. Initial release is Version 1.
• BUTTON_INSERT_TABBED_pocket_operator.stl - This is the button insert with small tabs along the edges. Use this if you are having issues getting the button insert to stay in place. Initial release is Version 1.