CNC 3018 Pro Upgrades

Here's a bunch of parts I made for my 3018 Pro hobby CNC machine. I used [Saur0n's cable chain](https://www.thingiverse.com/thing:2775316) as a starter, and modified the chain anchor to work for "pro" routers where a vertical plate is used instead of an extrusion to hold the gantry. I also modified the stepper end of the chain to hold a raspberry pi camera above the work piece.

In the past I had used [fastkite's X limit switches](https://www.thingiverse.com/thing:3625249) but I had to design something new so that they would work without fouling the chain. While I was at it I also threw together a holder for my z-limit switches (tiny 12.8mm microswitches) which I just hot glued to the side of the z-axis.

Lastly I designed a mount for a raspberry pi on which I run [CNC.js](https://cnc.js.org/) to control the router.