Precision Piezo Z-probe Now available.

Well then, please enjoy your holiday!

I'm kind of working on some ideas, too. I'm also heavily tempted to just install the Orion hot end sensor and "be done with it."

To be clear: I don't blame the piezo board or the sensors for my problems, the issue comes down to trying to sense touches to too large an area with too small a sensor base. As such, I figured that I'd share my findings in order to prevent others from repeating my mistake.

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MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.

Leadscrew self-built printer (in progress)
Duet Wifi, Precision Piezo parts

SupraGuy, i'm testing out moriquendi's new part on a similarly sized bed with a 3 point mounting setup. I'm mounting under the bedsprings and it works pretty well. Although the whole thing is in bits at the moment so it's not had a tonne of testing, it does do a decent job across the whole bed.

SupraGuy, I have just seen your posting about your problems with underbed piezo sensors. Perhaps I can offer a bit of hard won knowledge on a possible cause of this.

Way back when I first started looking at Njål Brekke's piezoelectric sensors [reprap.org] I immediately ran into what I thought was a problem; something I called then "the three legged table effect". I thought initially that a force outside of the triangle formed by the three piezoelectric discs would result in one cancelling the others but I was wrong. The diagram below represents a section through a build stage with two of the piezos and the nozzle (Force) making contact outside of the piezos.

For the sake of this example one of the piezos is mid-way between the applied force and the other piezo: The downward force on one piezo is twice the upward force on the other while the upward force on the left hand one is equal to the applied force on the right. Adding the minus one and the plus two you get the same result as if you applied the force directly on only one piezo and this same mechanism works with three piezos: The resulting output is equal ove the whole of the build stage even outside the triangle of piezos - within reason of course.

In my earliest tests I did indeed get a problem but found that it was because the piezos I used had different sensitivities. If you look at the diagram again and imagine that the piezo on the left is twice as sensitive as the piezo in the middle than the sum of the two outputs will be zero. Genuine Murata piezos tend to have closely matched sensitivities as do some of the "No Name" piezos while others are very variable indeed and many have differing polarities. The cheap piezos are still quite usable but the unknown polarities and sensitivities can cause much grief.

Mike

Thanks guys.

I had come to that conclusion in my design phase, but the reality is that mesh probing on my printer is an absolute mess. Also the small degree of slope I had imagined wouldn't be a problem ... seems to be a problem. With the side of the mounting triangle being as small as it is, I imagine that I'm seeing larger issues with flex than I can tolerate for my desired print quality. As a remedy, I expect that increasing the overall size of the triangle will help, but no matter what else, I need.my bearing mounts to be stiffer than the design I'm using will allow, and then I need an adjustment mechanism that I can access without taking the whole assembly apart.

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MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.

Leadscrew self-built printer (in progress)
Duet Wifi, Precision Piezo parts

Hey guys,

First off I just want to say my orion module, once I figured out some kinks, has been great for the last 2 months.

However im hoping someone can help me figure out this scenario

So the most recent incident was this
Opened a profile with a Z offset that had been used for the last 2 months that I knew had a perfect first layer
-Printed a new object in black came out extremely overstuffed
-Reprinted thinking maybe lingering filament residue may have been on nozzle again came out overstuffed
-Printed same object in pink filament which I had used previous day unlike black which I had rarely used in 2 months again came out overstuffed
-Printed a known object that had a perfect first layer before in pink filament at same area again came out overstuffed
-Printed a known object that had a perfect first layer before at a different spot on print bed and came out PERFECT
-Printed a known object that had a perfect first layer back at problem location came out PERFECT
-Printed the original object I had wanted to print in black at the problem location came out PERFECT

So in the end it worked but I just really didnt understand why this was happening. My theory is that randomly the sensitivity of my orion module changes causing it to mess up when it detects contact with the bed. But I dont think that makes too much sense..any idea what I could do avoid this sort of scenario? I print for profit and have prints that can take a good hour to complete the first layer so to print this and find out its messed up is a big issue for me

Again dont want to knock this great piece of tech just wanting to figure out the root of the problem so I can guard against it.

Maybe it's room temperature changing the probing result?
I always print three perimeters of skirt around the part, to see if the nozzle distance is good. If it's wrong height, but evenly all around, I use 'babystepping' to correct height.
If the skirt is uneven, I have to cancel the print, wait until the bed is cooled down and start again.

Are you homing the printer at the same bed and nozzle temperature each time?

What kind of printer is it? Does the bed move in the Z-axis or the print head?

One possibility is that the temperature of the Orion module is upsetting your readings. The piezo disks on the Orion are temperature sensitive. If the Orion is over the bed while the bed is heating then the Orion will be heated too. If sometimes the Orion is heated and sometimes it is not, or the room is hotter or colder this can upset your setting.

Idris

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

I use an unheated bed so we can factor that out. The printer is a cartesian type where the bed moves downwards as the print progresses. I print in an enclosure so temp swings shouldnt be too major between prints. Lets assume ambient temperature may be causing the change, do you think cutting power to the system and rerunning might help?

It's possible though there's nothing to reset exactly on the Orion. Try it anyway.

Are you sure we can eliminate other factors? Filament diameter? Extruder variation? Temp nozzle/ambient temp variation?

What is your print sequence? Do you level before each print? Home z before each print?

How often does this problem occur?

Idris

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

Quote

Are you sure we can eliminate other factors? Filament diameter? Extruder variation? Temp nozzle/ambient temp variation?

Filament diameter unlikely as its from the same supplier and on a roll I have preivously used without issue (however obviously could still be some variation)
Extruder variation: no changes have been made to the extruder in terms of fan positioning, nozzle changes or anything like that
Ambient temp: it has gotten a bit cooler here as its changing from summer to fall but my printer is enclosed during prints.

Quote

What is your print sequence? Do you level before each print? Home z before each print?

I have a pretty long startup sequence I admit but my logic is I have 0 problem if it takes a few minutes before each print to run a sequence where I dont need to be involved and it will be repeatable. My code might seem a bit odd with all the delays and the multiple Z movements but here is why I do that. Before adding those in smoothie would on occasion act as if it would not see the Z movement command which at one time resulted in the nozzle moving to probe in the center of my bed and creating a nice guage in my $125 bed . Ever since adding those extra Z moves and delays I havent had and weirdness like that and my Z height has been repeatable.

The commented code is below

;GET PRINTER TO KNOW WHERE IT IS ON EACH AXIS
G1 Z3 ;lower Z first before any other homing to avoid scraping of bed
G4 P2000 ; wait for that movement to finish
G1 Z4 ;lower Z attempt 2 to ensure doesn?t ram bed
G4 P2000 ; wait for that movement to finish
G28 X ; home X
G4 P1000 ; gives it a second to settle down after homing bounce
G28 Y ; home Y
G4 P1000 ; gives it a second to settle down after homing bounce
G1 Z5 ;lower Z attempt 3 to ensure doesn?t ram bed
G4 P2000 ; wait for that movement to finish

G1 X296.5 Y304.5 F5000 ; move to center of bed to set the Z height or octoprint will throw error
G4 P1000 ; wait for any false positives to dissapear
G28 Z; home Z inaccurately but so octoprint doesnt throw an error
G1 Z3 ;lower Z before move back to wiping area
G4 P2000 ; wait for any false positives to dissapear
G1 Z4 ; lower Z attempt 2 to ensure doesn?t ram bed again before moving
G4 P2000 ; wait for any false positives to dissapear
G1 Z5 ; lower Z attempt 2 to ensure doesn?t ram bed again before moving
G4 P2000 ; wait for any false positives to dissapear


;PREPARE NOZZLE FOR ACCURATE PROBING BY CLEANING AND BRING TO TEMP
G0 X200 Y610 ;move off bed for the nozzle to heat up to avoid dripping on the bed any filament
M107 ; make sure part cooling fans are off
M109 S[extruder0_temperature] ; bring nozzle to print temp so accurate probing
G91
G1 E-3 F240 ; retract filament to avoid drip
G90
G4 P1000 ; gives it a second 
G0 X136 Y610 F7500; 
G0 X183 Y610 F7500; 
G0 X136 Y610 F7500; 
G0 X183 Y610 F7500; 
G0 X136 Y610 F7500; 
G91
G1 E-7 F240 ; retract filament to avoid drip moved here because found it was more often when filament had formed
G90


;PREPARE FOR PROBING SEQUENCE
M670 D0.5; setup a delay before each probe seqeunce
G1 Z5 ; lower Z attempt 1 to ensure doesn?t ram bed
G4 P2000 ; wait for any false positives to dissapear
G1 X0 Y0 F5000 ; move to first probe point
G4 P1000 ; wait for any false positives to dissapear
G91
G1 E-3 F240 ; retract filament up 5mm
G90
G4 P1000 ; gives it a second to settle down after homing bounce

;PROBING SEQUENCE
G32 ; create grid of current bed level

;SET Z HEIGHT AS RECOMMENDED AFTER PROBING
G1 X296.5 Y304.5 F5000 ; move to center of bed to set the Z height
G4 P1000 ; wait for any false positives to dissapear
G30 Z0 ; set Z height right against nozzle
M306 Z0 ; save the Z height

;MOVE TO PURGING LOCATION TO CLEAN NOZZLE 
G1 Z1 ; lower Z attempt 1 to ensure doesn?t ram bed
G4 P2000 ; wait for any false positives to dissapear
G1 Z2 ; lower Z attempt 2 to ensure doesn?t ram bed
G4 P2000 ; wait for any false positives to dissapear

G0 X200 Y610 F7500; move close but not touching the brush wiper and prepare to extrude
G91
G1 E40 F240 ; retract filament up 5mm
G90
G92 E0; Zero extruder to start print maybe add a pruge step here to get rid of bubbled filament
G4 P1000 ; wait forFILAMENT TO SOMEWHAT SOLIDIFY TO KNOCK OFF
G0 X136 Y610 F7500; 
G0 X183 Y610 F7500; 
G0 X136 Y610 F7500; 
G0 X183 Y610 F7500;

This problem does not occur frequently but its more that when it occurs Im not sure how to remedy it and when I have a print I need to have done that day for a client I go into a bit of a panic haha.

I have to admit that I'm stumped. I cannot think of anything that would cause this behaviour within the Orion. The only setting on the Orion is the potentiometer, nothing else should be able to change the sensitivity but I'm happy to send you a replacement PCB to see whether that eliminated the issue.

One thought occurs to me, is it possible that your z-axis is stopping at different full step positions? The weight of the bed causes it to stop at full step positions rather than microstep positions, most of the time it stops at a lower full step but occasionally it gets one step further.

Doesn't smoothie also have a setting for z-probe overtravel (for things like microswitches)? Is yours set to 0?

Idris

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

I feel bad having you send a replacement but if you dont think there is much of anything else to try on the software side that would really be appreciated. Just had another print act up after 2 or 3 that worked perfectly fine. I searched for over travel I dont see anything about that.

Edited 1 time(s). Last edit at 09/20/2018 08:17PM by singhm29.

If I'm honest I don't think that the Orion is the cause of the problem but to eliminate it as a possibility I'm happy to send you a replacement.

I might be mis-remembering the over travel thing. Are you using the zprobe.dwell_before_probing option?

Can you PM me your order number please?

Idris

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

Yes I am utilizing dwell_before_probing as I was getting false positives after movements without it.

Is there any drawings or models of the Orion pcb. ??


/Martin

Got a little problem with my Piezo. Piezo work correct, auto bed leveling A8 with E3D V6 short but when my printer reachs 190+ temperature Piezo trigger and don't wanna turn off, click on piezo disc and it's work but after that again trigger on. Why and how to solve this problem?? Got printed parts with HIPS, PETG, PLA (for test) and the same problem.

Edited 1 time(s). Last edit at 09/22/2018 10:13AM by krakow2000.

Hi,

where can I find "goldpin" pinout and dimensions of new PCB - v2.57 including the hole ?

I'm designing new version of my PCB where Precision Piezo PCB is snapped into. The best option will be Eagle Library Component but simple drawing or description will be fine as well.

As I can see the new PCB is using Triple Row Header Angled. Maybe I'm dumb but I cant find the compatible "Triple Row Socket". Do you have any idea where I can find them ?

regards

Slawek

So I am on my third printer using the orion module.

This is the first time I am using the screw mount version.

My issue on this one is that the probe is difficult to trigger vertically. It triggers easily tapping the side, or moving the hot end. But when I use the bed it pushed up the hotend before it triggers.

Hypercube printer with a Duet Wifi.

@Nitram;

I've added .step files to the thingiverse item HERE

@krakow2000;

The piezo disks are temperature senditive, changes in temperature will cause triggering. Either decrease sensitivity slightly or just ignore it, the firmware only checks the Z-probe when it's actually probing. Alternatively, if you want to probe at 190c you could try tuning the probe at that temperature.

@SlawekC;

I've not seen three row sockets before though they are probably available somewhere, it wasn't a design consideration.
Looking at the pins with the component side upwards the pin out is:

LED+ V+ GND PZ- PZ+
GND GND GND PZ- PZ+
NC SIG GND PZ- PZ+

The overall PCB is 12.7x40.64mm with the 3.2mm mounting hole 37.5mm from the pin edge of the PCB

@knabo;

Try loosening the four assembly bolts slightly, start with 0.5 turn and test again, repeat if necessary.

Idris

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

@Moriquendi;

thanks for the info. Its possible to order two PCB's without gold pins soldered ? Of course I can desolder them, but this is unnecessary thermal stress to the PCB

I'm designing Piezo Titan Aero mount for P3Steel Prusa i3 clone - it's not finished yet - when ready will be published as open source of course.The design has custom PCB on bottom collecting all cables (Motor, HotEnd, Thermistor, Hot End and Material Fans, Z probe (Precision Piezo PCB ), containing Neopixel LEDs). Was be perfect to have all Precision Piezo electronics etched directly on my PCB but I can live with board soldered on my board. Version with gold pin socket is to long for my design.

best regards

Slawek

Edited 3 time(s). Last edit at 09/25/2018 04:35PM by SlawekC.

I can do that, place the order as normal and add a note that you talked to me on here about it. It might take a little longer to ship as I will have to make a new batch of boards.

Idris

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

Done! But there was no place on the order process to put a note. So I PM you with my order no.

I have six screws holding the Piezo to the mounting bracket. For some reason I decided to test the probing as I removed each screw. When I removed one of the rear screws the unit worked as expected.

I had already tapped all the mounting screw holes to make sure they were clean. My screws did not protrude below the piezo top piece. My mounting bracket is flat, but maybe there is some material in there putting some torque on the assembly.

In any case the probe seems to work fine now. I did have to up the sensitivity a bit, so I will have to see how it operates.

Anyone use this sensor in Ender 3 or CR10 and got mount STL ??

It was a bad weekend for wires on my printer. One of the wires for my hot-end thermistor broke, right next to the bead, and my piezo sensor also packed in. What's wrong with this picture?

So yeah, I got no readings at all from the left hand side of the bed. A little touch with a soldering iron, and it's all good. Moriquendi has generously offered to let me test out a new solution, so this printer has just finished printing replacement mounts that won't be holding the discs anymore.

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MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.

Leadscrew self-built printer (in progress)
Duet Wifi, Precision Piezo parts

Pro tip: I use kapton tape over the solder points and wires of the piezo disc to prevent this kind of problem

Orion Piezo not triggering the bed.

I am currently rebuilding a Flying Bear Tornado 3D Printer with original E3D Hotend, Bondtech extruder, Duet Elektroniks and Orion Piezo.
I rebuild 3 Tevo Black Widows with the same upgrades and they work fine. I have also have a Delta with Piezo in the bed (I must admit its a China Piezo) which also works fine.

The difference between the Tevos and the flying bear is that the Tevos are direkt drive and I used the recomented Groovmount mounting stuff from Precision piezo. For the FB I desinged a new Ganty which grab the lower part of the precision piesos mounting braked. The Piezo Orion PCB has basicly the same contact point as the original ones in the Tevos.


When everything is mounted it is as sensitiv to the touch as the once in the Tevos, but it still does not trigger by contact with the bed.
I tryed different speeds and different stuff on the bed like Carbon fiber plate or metal tools. The Tevos trigger with 300mm/min to every thing you put in there way, but on the FB I tried speeds from 200 to 500mm/min nothing triggers.
knocking to frame triggers pretty well. The Springs of the bed are also pretty tight. I tried different tightness of the 4 scews as described before.
I drilled the holes of my gantry to 3.5mm so the screws can freely move up and down when the PBC is not mounted. The hotend with the whole mounting does not touch the gantry.
I have one virgin Orion I will test tomorrow but I have not much hope because the orion seems to work fine.

best regarts
Kevin

I cannot see easily from the pictures, does your mount hold the heatsink of the hotend?

Idris

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

it is not supposed to. I am not 100% sure, i ll check later. In Cad there is 0,5mm space, maybe not enough.

i still have the problem.
-I scraped away my part where it could have touched the heatsink.
-I oiled the screws so they have less friction an the upward force should bend the PBC more easily.
-I tested the other Orion, i have spare at the moment -> the same result

There is one small thing I changed compared to the original design and that is the chamfer of the hohle inside. At the moment there is a new version printing with the chamfer dimensions of the original.
The other hunch I have is that the screws have to much friction. If it doesn't work I make the holes shorter.

While extensive testing i noticed that the piezo is much more sensitive to forces to the hotend from the side (kind of a moment at the piezo) this could be caused by the leaver arm or by the interconnection of the two piezos?

Any Idea?

best regarts
Kevin