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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!


Spectroscopy

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).


Various...

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 :)