Hotend mounted Piezo Sensor Z-Probe (Alpha)

thingiverse

This is one of the early versions of what is now a mature product with over 200 units in the wild. Feel free to use this in any way helpful (which complies with the CCA license) but if you want the best probing, please see https://www.thingiverse.com/thing:2319993. Update 17-01-17. Latest version draft 5, now very firm nozzle and good clear triggers. Wider and taller flange on the lower clamp parts and slight recess in the upper part. I can't see this version changing unless longer term testing shows a problem, apologies for the rapid changes. Next step a delta effector with built in sensor. One has been created already by Lykle of Zesty Technologies http://www.thingiverse.com/thing:2047422. I am now testing this and it seems to work very well. My calibration deviation is 0.03 with this effector (I was getting 0.014 with my draft 5 version above, but the nozzle is firmer with this version so I am willing to accept the slightly less precise calibration). 3rd Update 16-01-2017. So I have added a subtle lip to the top of the lower parts to both improve clearance over the e3d bowden coupling, and to reduce the diameter of the contact area with the piezo so giving more flex and therefore a stronger signal. I have also cut away a small area on the top section under the piezo for the same reason. 2nd Update 16-01-2017. Slight modification to the lower parts of the assembly to raise the height above the hot end by a small amount (0.8mm) after assembling it I noticed the piezo was slightly pressing onto the bowden coupler and loosening the bowden tube. UPDATE 16-01-2017: Mk II now available, this is a smaller and neater version using all m3 bolts for ease of assembly. Needs plenty of support when printing it. Please use the shortest machine screws you can for each of the fittings. You need to heat press the nuts all the way into the recesses. Use countersunk head machine screws for the hotend clamp as the top piece fits over it with quite tight tolerances (0.2mm), doesnt matter if its a little tight. I have allowed a tiny recess for the solder pad on a 27mm piezo transducer. One of the photos shows the type of drill bit (spur point wood drill) I used to drill the latest piezo, place it on a wood board, mark the centre, then use firm pressure and low rpm to drill, cuts much neater than any previous attempt, hold the piezo firmly with fingers and pause your drilling if its getting hot. Use a needle file to smooth the edges afterwards.