I've built a high vacuum system off of mostly ebay parts plus custom electronics and software.

It's a bell jar type chamber with a diffusion pump, with thermocouple, capacitive and cold cathode gauges, and mass flow controllers for process gas. Two microcontroller boxes control the high vacuum system (valve control and thermocouple gauges), and the process side (gauges, MFC). These communicate over USB to a laptop running Labview. The vacuum obtained is about 1e-5 Torr, which is limited by the conductance of the rather long and bendy path to the pump and leakage (probably mainly from polymer seals).

The Labview control software visualizes the gauge readings and controls the valve sequencing for the high vacuum system. It also implements pressure control for plasma processes using the mass-flow controllers and Baratron capacitive pressure gauge.

I made an induction vacuum furnace. In this rough vacuum mode the entire chamber can be tilted to pour metal for casting.

A temperature compensated photodiode acts as a pyrometer to measure the crucible temperature. This was calibrated using a thermocouple.

I did some copper casting (notice bright finish right out of the mold) and after improvements to the insulation got it hot enough to melt chromium (1907 degrees C).

I made a hollow cathode sputter gun and created some interesting dilectric coating effects:

This uses a custom high voltage DC power supply.