Undergrad. class (3hr per week x 26 weeks x 3-4 yrs) = c. 320 hrs at most. Say 350 hr.
"A typical TOF mass spectrometer is in essence, and on paper, quite simple," he said; you just need the following,
1) stainless steel flight tube, say 1m long,
2) high vacuum pumping system (turbos and rotary pumps) to give ca. 1 x 10-7 torr,
3) sophisticated electronics to measure very, very, very small differences in time-of-flight of ions of different mass,
4) detection system (multi-channel analyzer),
5) sample introduction and ionization source.
6) Software to control the system.
A typical commercial system will cost about $350,000 for a high resolution MS (about $1k/hr) with a scan range up to m/z 4000. Of course they make a profit on this, but these are VERY complex instruments.
A simple, portable device, such as carried on board subs. or spacecraft or at airport security will be miniaturized, with narrow scan range (up to ca. m/z 100) and altogether simpler electronics.
Suggest you search patents on-line to find designs.