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This page collects some projects, often in close collaboration with friends, or lab reports. Some "flesh and blood" stuff, finally!

The Vacuum Diaries

The vacuum diaries - [collection of pages]
Here are a number of notes and pictures of an ongoing effort to scratch-build vacuum systems (for cheapest possible). Starting from the jam jar vacuum, moving to larger reservoirs, silicone gaskets and standard ISO fittings, and then plasmas!

Plasma physics and electromagnetics

JxB Hartmann flow - [HTML page]
Stack together a DC plasma discharge and a bunch of neodymium magnets, and you have a Hartmann flow! The device in the picture accelerates the plasma in one direction, and is the little brother of a space propulsion technology called "applied-field MPD electric propulsion".

Planar magnetron configuration - [HTML page]
With a ring magnet and a disk one, you can confine electrons and accelerate them in the ExB direction, creating a magnetron. Kind of similar to the magnetron in your microwave oven, we consider here a slightly different configuration, used in the industry for sputtering processes.

Measuring strong magnetic fields - [HTML page]
Here's a page in collaboration with ChenYang Technologies. In this page, I explain how to use their Hall sensors CYL8403 and CYSJ902 to measure magnetic fields up to 3 Tesla. Also, you'll see how to reconstruct 2D fields and plot magnetic field lines.

Simulating and measuring magnetic fields - [HTML page]
This is a hands-on description on magnetic bottles, on the numerical computation of magnetic fields generated by multiple solenoids (Octave/MATLAB script inside) and some measurements of a simple magnetic bottle configuration using an SS495B Hall effect sensor.


Plasma jet spectroscopy - [PDF document]
This document reviews basic emission spectroscopy techniques, applied to a plasma jet and ablation of a carbon specimen. Atomic and molecular species are identified from the spectrum, and plasma and wall temperatures are retrieved.

Load cells & aerodynamics

Supersonic measurements & flow visualization - [PDF document]
This report details some measurements performed on a rocket ogive at supersonic speeds (Mach 3.5). The following points are covered:

  • Calibration of a tri-axial load cell;
  • Measurement of the ogive aerodynamic coefficients;
  • Schlieren and shadowgraph imaging;
  • Oil visualization & water table.
This report was prepared in collaboration with Ruben di Battista and Maxim Van Cappellen.

Data Acquisition on the Road - [PDF document]
This document is about the design and building of a full low-price system for measuring aerodynamic forces. The system is composed by a load cell and a data acquisition system to be mounted out of the window of a moving car: in this way, one can build a scaled wing or any other lifting shape and test it super cheaply. Done in collaboration with Davide Del Cont Bernard.

Road Spectra - [PDF document]
Me and my friend Davide Del Cont Bernard have instrumented a bicicle frame with strain gauges and then measured load spectra along some roads in Milan. The document describes the strain gauge configuration, a data acquisition circuit and of course contains some nice images!

Lab instrumentation and tools

Time controlled spot welder - [HTML page]
Some instructions and a few pictures for building a spot welder out of two microwave oven transformers (MOT) in parallel. A time control is built with Arduino Nano and a solid state relay.

Linear bench power supply - [HTML page]
Schematic and pictures for building a simple linear bench power supply. Voltage can be selected among: 5V, 9V, 12V. Maximum current: 1A, fused.

MKS 740B capacitance vacuum gauges - [HTML page]
A small tutorial on using an MKS 740B baratron vacuum gauge. Covers general information, KF-16 fitting and building a simple circuit to read and display the pressure signal. The sensor is rated from 10 to around 1E-3 Torr.

Dual ±15VDC / ±21VAC power supply - [HTML page]
Schematic and pictures for a simple dual power supply, based on MC7815 and 7915.

Welding table/cart - [HTML page]
Some pictures and notes on the realization of a welding table / welding cart (TIG/MIG/MMA).


Butane data acquisition - [PDF document]
This pdf is about a scratch-built system to compress a gas and find it's equation of state. The system is interfaced to the computer, using Octave to read data and plot it real-time: temperature, pressure and piston position are displayed. I experimented with a butane/propane commercial mixture: collected data is fitted on the van der Waals and Redlich-Kwong laws and compared to literature Span-Wagner model for butane.

Please note that a poor calibration for the pressure sensor and a little possible gas leackage while moving the piston made data unreliable.. Hope you'll find that useful anyway :)