Do you hate buttering toast? I've built a machine which does it quickly; so quickly in fact the toast often ends up in alternate dimensions. 

Solidworks and dxf files

Filmin by Camera Man John

Design

Mock Up 1

Here I've created placeholders which are just single feature parts which get refined and mated as the model evolves.

Mock Up 2

CAD models tend to become less fluid as they evolve, since changes made to early features will break the entire part. This won't make sense if you don't know how most CAD software works, but a model consists of a list of every step you took to get there. Later steps depend on early steps, so drastic changes to early steps can cause all sorts of problems.

The placeholders help to establish the general structure without making any real parts.

Here are actual parts coexisting with placeholders.

Actual parts

More actual parts.

Nearly Finished

At this point I think you can see how it functions. The linear stepper motor moves the bread back and forth while the jigsaw generously "gluestick's" the butter. The spikes are supposed to help hold the toast in place.

I started building the machine before coming up with a solution to mount the butter to the jigsaw, but here's the final completed CAD model anyways.

Finished CAD

All of the parts were exported as dxf's and cut on my homebuilt laser cutter.

RetnaSmelter9000

A pile of parts.

Cut parts

The entire build is documented in the video, but here's a zip tie holding the butter holder to the jigsaw.

Butter zip tie

Electronics

Motion controller

Demonstration

Here's the finished machine running:

Butter BOTTTTT

Notice how I said running... instead of working......

#rekt

The End