Plastic is Forever

Fomu (with case): an FPGA in your USB port. Crowdfunding now! One week to go. t.xobs.io/fomu

Plastic is Forever

Making Tomu's Injection-Molded Case

Sean Cross - https://xobs.io/ - @xobs

Tomu

Case

Tomu + Case

Tomu + Fomu + Case

About Me

Outline

Manufacturing the Case
Designing the Case
Understanding Plastics

Factory Tour!

It's hard to know when something is easy and when it's hard

XKCD 1425

Front Door

Bags of Plastic Pellets

Pellets of Plastic

Into the Machine

Into the Machine

Pulling a Shot

Factory Mold Bases

Tomu on its Mold

Both Mold Halves

Bottom Half

Ejectors

Cases on Runners

Factory Edits

Tool Model

Designing the Case

3D Printing

Reference

Reference

Hardware

Software: FreeCAD

FreeCAD can create STEP files

FreeCAD can read KiCad PCBs

1) Open the PCB

1) Open the PCB

2) Create a sketch

Creating constraints on the first sketch

2) Create a sketch

3) Pad the sketch

3) Pad the sketch

4) Repeat as necessary

4) Repeat as necessary

4) Repeat as necessary

4) Repeat as necessary

4) Repeat as necessary

4) Repeat as necessary

4) Repeat as necessary

Creating the sketch for the guiding slots

4) Repeat as necessary

4) Repeat as necessary

5) Check with reference parts

Here's what we submitted

And here's what they made

3D Printed Prototype

Cutting Steel - EDM

T0 Shot

T0 Shot - Annotated

Finishing

Manufactured!

Real World Fun

And the problems you'll face

Clothes peg

Aircon Remote (Front)

Aircon Remote (Back)

Aircon Remote (Back)

Aircon Remote (Front Cover)

Aircon Remote (Front Cover)

Wine bottle opener

Wine bottle opener

Some flashing on the wine bottle, plus overmolding

Summary

Understand production process
Design with open source tools
Take baby steps
Design artifacts are everywhere

Thank You

Questions?

Fomu:	t.xobs.io/fomu
Case:	t.xobs.io/tomu-case
Tool:	t.xobs.io/tomu-tool
Talk:	p.xobs.io/lca2019