To give a bit of background: When I was checking out bed leveling technologies I came across several mentions of work by Njål Brekke (aka elenhinan) on using piezoelectric disks to sense nozzle contact. A couple of quick tests showed that the sensitivity of piezo disk sounders as transducers is very high so I built a simple amplifier to precondition the signal. After a couple of itterations I built this into a printer and it has now been in use for a couple of months with no significant problems.
- So far I have checked for problems with the following:-
- Sensitivity: huge, possibly too much.
- Temperature: Even cheap ones are god up to 80°C, Murata to over 100°C
- Ageing: no problems after several thousand cycles.
- Humidity: looking good although I use a silicone compound to keep humidity out.
- Variability: No-name brands seem to be very well matched from disk to disk.
- Price: dirt cheap.
- Supporting electronics and hardware: not complicated.
A discussion on the RepRap forum at http://forums.reprap.org/read.php?1,635075
This is not an attempt to sell anything, I have no interest in commercializing it, just a genuine wish to know if this is as good as it seems to me to be.