Precision Piezo Z-probe Now available.

The spare opamp will be used to implement the longer output pulse which probably won't be adjustable.

Nobody else has, to my knowledge, had issues that required shielding the cables unless they were using cables over 1M long. If it is an issue then I suggest extending the cable between the board and the controller which is a nice, strong, digital signal and much more immune to interference.

Idris

---

{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.

I think of the piezo as a very sensitive microphone. I have noticed erratic flashing of the blue led by placing my hand near the piezo /wiring. Using a length of shielded cable salvaged from an old cd rom drive ,there was no effect. The power supplies in 3d printers are terribly noisy along with the mechanical vibratons. The one shot you are proposing should be an excellent solution. Good luck.

S

IDris
Is the schematic available with the one shot? I'm in the process of building one on perf board want to experiment with band pass filter to get rid of low frequencies as the setup as exists is sensitive to someone walking or some other move event. My setup (under bed) is also very sensitive in the Y axis.
Consider old tech such as LP vinyl records using dynamic pick ups which used shielded wires connected to a pre-amp, or twisting wires to eliminate common mode hum?
Regards
Stef

Edited 2 time(s). Last edit at 09/25/2017 05:56PM by Chowa.

Sure, it's still in beta so I'm not ready to make it generally available but if you'd like to drop me a PM with your email address I'll send it over.

A couple of things to point out;

Strictly speaking I've added a monostable not a one-shot. My understanding is that a one-shot will give you exactly one pulse T seconds long, regardless of whether it's re-triggered within that period. The monostable that I've added will give a permanent output high if it is repeatedly triggered.

Adding a low pass filter to the output will not help you reject noise or spurious triggers, it's simply there to extend the output pulse to improve usability.

If you haven't already tried it I would suggest retuning to be slightly less sensitive, start by turning VR2 slightly further from the point where the LED goes out. If that doesn't work then try reducing the resistance of VR1, as measured between the PZ- pins and the top of VR1. From what you're describing it sounds to me like the resistance of VR1 is too high.

If you really want to play with the filtering function of the circuit my advice would be to replace the resistor in the differentiator (currently 82K) with a variable resistor, by adjusting this resistor you can tune the filter response of the circuit.

Idris

---

{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.

New stock in the shop, Modules and kits available.
We are also selling some tiny 30mm blower fans, for part cooling. They are very powerful and yet light, 5v but can be run on 12v, with a reduced service life.
We also have some 50w 24v heater cartridges, especially good with volcano hotends, but works with any standard heater block.
[www.precisionpiezo.co.uk]

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Hi DJ,
I have a small hiccup in piezo sensor. I mounted the drop in piezo sensor from one effector to another, the blue led flickered when I tapped the nozzle but after homing and before it hit the bed. I stopped and tried to tap the nozzle and the blue led is not flickering. When I rotate the left adjustment pot (VR2), the blue light comes on and then I rotate in the opposite direction so that it just goes off. After this routine, when I tap the nozzle it still doesn't flicker. I checked the resistance between reference pot and the terminal. It was 0.401 MOhm. I tried many times but still the blue light does not flicker. Do you have any solution for this problem.

Thanks,
Vasan

Are the leads still soldered onto the piezo? You can sort of check if the pcb works by just bridging the piezo pins on the front of the pcb with your finger, it should trigger when you do that.

If the leads are desoldered you might be able to remove piezo disc and solder it back, or get a new Piezo disc (or ill send you some).

Edited 2 time(s). Last edit at 09/30/2017 02:52AM by DjDemonD.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Hi DJ,
Thanks for your reply. If I understand you correctly, is it those two pins between GND,SIG, V+ pins and the letter Precision Piezo.

Yes if you tune it so the blue light is just out, then put your finger across these two pins the blue light should come on. This is a quick way of verifying the PCB. Then take the hot end out, turn the unit over and have a look if the positive lead is connected to the piezo, you can see it with the hotend removed. The negative is harder to see, but if you slide the plug off the pcb sideways from the piezo, then uncrew the pcb, you can gently tug the two leads, it will be obvious if one is desoldered. If it is, undo the unit, resolder it or get a replacement 20mm piezo and drill it (or wait for a spare to arrive) and then reassemble it.

If you dont fancy any of that and want to send it back to me you can.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

I have a green coloured piezo20 module left over from TCT special offer price £29.99 UK delivered £37.98 worldwide. Let me know via the forum if you want this one, its a bit of a pain to list a one off item in the shop.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Hi DJ,
I have an extra drilled piezo disk from you. I will try that. I took the hot end out and found that it is soldered properly. I will replace the disk and see what happens. If nothing works, I will order that unit from you.

Regards,
Vasan

Edited 1 time(s). Last edit at 09/30/2017 06:00AM by SM3D.

Its a groovemount module is that okay?

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Hi DJ,
It is a screw mount.

Regards,
Vasan

Okay well the one I have surplus/on offer is groovemount so probably won't be that useful to you if you need screw mount.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

OK then... I will try the extra drilled disk I have and report back

//Vasan

Hi DJ,
I don't see any desoldering and I am just curious about what could be the issue that is causing this. I disassembled and reassembled it again. Tried changing the polarity. Tuned the resistance from 0.4 to 0.7Mohm in VR1. Let me know your ideas for me to try. Currently replacing the disk.

Regards,
Vasan

Does the board trigger when you touch the connectors as described above? If not it could be a pcb issue.

Edited 1 time(s). Last edit at 09/30/2017 06:22AM by DjDemonD.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Hi DJ,
I changed the piezo disc. I had a random triggering issue and could not replicate it. I did not see the flickering also. I changed the pcb (I had one you gave me for titan aero bracket), now it triggers reliably. I think it was PCB that caused this problem. The PCB that works correctly does not have mounting holes. I have to think about how to mount them now.

Regards,
Vasan

Glad it's working, if you want to return the pcb please do (I'll pm address) as we'd like to know how/why they fail.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Quite a bad luck, this time it is my fault. When I was thinking about the possible mounting positions, due to mishandling, the negative lead came off from the soldering. I have to do the soldering now.

Please PM your address and I will send the PCB. Hope it can help others.

Regards,
Vasan

[www.precisionpiezo.co.uk]

Does this single sensor board have the same output circuit as the 3x board? I need one for my other printer but as I only use one input and the other board is not mounting friendly I would like this one if output can be analoge here also.

Yes it works exactly the same except it has one piezo connector (you could still connect multiple piezo's in parallel though). The only thing you CANNOT do is to operate it in NC mode (i.e. LED on when open, off when triggered) as the LED is higher power and might fail if mostly constantly lit. If you're more familiar with using the kit PCB in NO mode then just use it in exactly the same way.

Edited 2 time(s). Last edit at 10/02/2017 05:33PM by DjDemonD.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Version 2 of the kit board is in the works and includes mounting holes.

Idris

---

{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.

Hello. I am considering installing some type of piezo bed leveling system and I am sorta at crossroads (and confused).

It is a H-bot kind of setup with the following hot-end configuration:


That is a custom radiator with e3d parts connected to the bracket on top which is in turn affixed to the rail runner block. Can you give an advice on what is the better way install piezo system on such a config? And what kit I should use for this? Can leadinglights' system be used with your kit?

Regards, Perpetual.

Edited 1 time(s). Last edit at 10/06/2017 10:19AM by Perpetual.

Quote
Perpetual
Hello. I am considering installing some type of piezo bed leveling system and I am sorta at crossroads (and confused).

............................ And what kit I should use for this? Can leadinglights' system be used with your kit?

Regards, Perpetual.

The system that I wrote about on [forums.reprap.org] and also on [www.thingiverse.com] works well for me on three printers and many test rigs but to date I have not seen any confirmation that anybody else is successfully using it. Depending on your build stage mounting is should be either dead easy or somewhat awkward [forums.reprap.org]
If you should try this method please tell me of your results.

Mike

Hi, thanks for your interest. Looking at the image the standard Piezo20 module won't fit your setup as it needs the hotend to be groovemount fixed. However you could possibly use a really large piezo disc like a 35mm one with a large hole cut in it for your bowden adpator. Then screw the unit together sandwiching the piezo between the heatsink and the carriage.

Or you could use something under your bed. We have designs for height adjustable underbed mounts [www.thingiverse.com].

Edited 1 time(s). Last edit at 10/06/2017 03:07PM by DjDemonD.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

NEW Product available!!!

So we've decided that since we all love making things, why not make your own Piezo20 module from a kit? Best thing about it is we can sell it for £26.99 instead of £39.99!

It's available here:
[www.precisionpiezo.co.uk]

Everything is included that you need to make a Piezo20 module, just follow the video guides here [goo.gl] (skip the drilling a piezo video, as we'll drill it for you - unless you can drill it better than me in which case go right ahead).

Assembly takes from 20-40 minutes, the only tricky part is crimping the wires on the piezo leads, but if you haven't a crimper, you can solder then onto the crimps instead.

All the accuracy, with the added fun of building it too.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

My bed is sat on 4 corner springs. Will this work with the under bed setup? I only ask because the PCB only has 3 piezo inputs. Also, could we have a drilled piezo disc sandwiched between the the spring and the carriage or does it need a more elegant solution
?

Almost anything is possible but it might take some work. You can use four piezos if you want, simply connect them in parallel and wire them to one of the piezo inputs. One of the beauties of this system is that the piezo disks themselves are dirt cheap on ebay (and other places) so you can experiment with all sorts of different ideas without spending much money. Will it work? no idea, underbed piezos have worked, piezos in compression have worked but I don't recall seeing that exact system. One thing to consider is that piezo output falls with increasing temperature so you want to insulate them from a heated bed. Read through the development thread and you'll find lots of ideas, if you try something new let us know how it goes.

Idris

---

{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.

I'll post some design ideas in that thread and get some additional piezo discs ordered.