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Precision Piezo Z-probe Now available.

Posted by DjDemonD 
Re: Precision Piezo Z-probe Now available.
January 11, 2018 11:20AM
See if you can link a quick YouTube video of what it's doing. With the titan bracket you might need to set VR1 to 0.8Mohm which doubles the sensitivity. Then retune vr2.


[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 11, 2018 12:13PM
Also ensure your bolts through the sensor plate are not over tight it needs to be able to bend by 0.1mm or so.


[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 12, 2018 03:55AM
The store is now up. Everything is available again except for the printed parts while I dial everything in and make sure I can print the parts with the required tolerances.

Service may be slightly slower while I get used to how things work but hopefully there wont be too much disruption.

We would like to thank you all for your support and patience.

Idris


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
January 12, 2018 03:22PM
Designing a mount, so am I to gather that Piezo goes between hotend and it's mount, hole drilled in Piezo so the filament can go to the hotend? Hotend is pressed right up against Piezo, but is allowed to move a slight amount to apply pressure on the Piezo?
Re: Precision Piezo Z-probe Now available.
January 12, 2018 03:37PM
Pretty much, have a look at thingiverse for piezo mounts there's a growing collection. Squeezing the disc generates a usable signal but the tuning window between too sensitive (false triggers) and not sensitive enough (head crashes - use low motor current for z if feasible during commissioning) will be narrower. Bending the disc, achieved by supporting it on its periphery on one side I. E. upper or lower side, and pressing into it when upwards pressure on the nozzle occurs will give wider tuning window.

Try to keep the disc electrically isolated from the hotend (a printed washer is sufficient) to reduce risk that a shorted heater cartridge or thermistor causes damage to the piezo pcb (not that much of a problem they are economical to replace) or your controller board.

Post your idea here we will soon identify if it's feasible.

They are very sensitive so many possible configurations are workable some more reliably than others.

Edited 2 time(s). Last edit at 01/12/2018 03:40PM by DjDemonD.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 13, 2018 11:16AM
designing a new mount, wanted to run it by you guys before I got any further, and I need a break, lol
Attachments:
open | download - X5S Piezo Mount Small.jpg (292.3 KB)
Re: Precision Piezo Z-probe Now available.
January 13, 2018 02:11PM
no need to mount it like that, mount it on the carriage, this has the advantage that you don't need to drill the piezo.
I have a titan, but the principle stays the same:


Thingiverse link

for my new corexy I am designing underbed sensors as it will have a fixed bed.

Edited 1 time(s). Last edit at 01/13/2018 02:14PM by whosrdaddy.
Re: Precision Piezo Z-probe Now available.
January 13, 2018 02:47PM
Mounting it with filament path through the disc, by drilling, probably gives an easier unit to tune as the force is transmitted directly through the disc, however it's simpler to mount it undrilled, on the side of a bracket or carriage, or between two components within a plate, as long as the disc flexes (or is compressed) when the nozzle makes contact with the bed you should be able to tune it to give a reliable trigger. It's a precise instrument and a little experimentation is usually time well spent, they're very versatile if your patient with the tuning.

Edited 2 time(s). Last edit at 01/13/2018 02:48PM by DjDemonD.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 14, 2018 04:52AM
Hello,

I have a e3d chimera hotend.

The hotend is attached with 3 screws and an omega profile




I designed this 2 pieces




Used a big piezo

[www.gotron.be]

Drilled a lot of holes, cut of the edges, printed the 2 pieces ....



Replaced the metal screws by Teflon screws.
And this is the result, needs a little bit of tweaking.

[www.youtube.com]

Things to be aware off :

- tension on the mounting screws, give the piezo the possibility to flex.
- VR1 was set to 6M
- keep playing with the screws/VR1/VR2 and software settings

I'm willing to give the stl files to Simon ?

PS : English is not my native language, feel free to correct my text

Edited 1 time(s). Last edit at 01/14/2018 04:55AM by RKS7204.
Re: Precision Piezo Z-probe Now available.
January 14, 2018 05:18AM
Hi the stls will be great but if you can host it somewhere like thingiverse and provide a link that would be great. Do you have any figures for how well it performs? 30 probes with a range and std deviation is our standard test.


[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 14, 2018 05:40AM
Here are the stls

[www.thingiverse.com]

Quote
DjDemonD
Do you have any figures for how well it performs? 30 probes with a range and std deviation is our standard test.

How do I do that? Auto-Calibration or Mesh-grid?
Re: Precision Piezo Z-probe Now available.
January 14, 2018 06:29AM
If using marlin go to bed centre and send m48. Using smoothie or RRF, write a simple gcode file with home, move to bed centre, raise nozzle to 5mm,g30 then raise 5mm, G30 (x30). You should get the distance travelled for each probe, copy from consol into excel or similar.


[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 14, 2018 08:58AM
I got 30 times this

Quote

Stopped at height 0.008 mm

I don't know if that's good.
Standard deviation is 0.
Re: Precision Piezo Z-probe Now available.
January 14, 2018 09:08AM
So you got that 0.008mm result 30 times?

In which case your range is 0 (accuracy is 0) and std dev is 0 which would make it the best one ever. But if your first layers are good then you are there. Testing it is not obligatory.


[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 14, 2018 09:12AM
That's right I had 30 times 0.008 mm in the center (delta printer) after lifting to 5 mm and probing.

First layer is excellent.
Re: Precision Piezo Z-probe Now available.
January 14, 2018 09:14AM
Great news with a big piezo you get better accuracy, and with an accurate machine the system way exceeds anything you need in terms of levelling or first layers. There is no absolute limit to how much extreme accuracy assists with delta calibration apart from the accuracy of the firmware. Fantastic result.


[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 14, 2018 09:37AM
The 3d printer is a tripodmaker Black edition V1 www.tripodmaker.com
Upgraded with a duet3d ethernet board, a piezo and a buildtack flexplate

The small piezo was too difficult to drill all the holes in, there was no piezo left
Re: Precision Piezo Z-probe Now available.
January 15, 2018 03:46AM
Now I've got Precision Piezo working, I want to understand better the relationship between firmware Z=0, physical nozzle position, Z_PROBE_OFFSET_FROM_EXTRUDER, and any slicer G-code offsets.

Currently I follow your configuration with

#define Z_PROBE_OFFSET_FROM_EXTRUDER 0.2

Once I home Z, if I go to Z=0, it's very tight physically, there is high resistance to a 0.05mm feeler gauge.

So what is the offset from extruder doing exactly?
Is it OK to have nozzle so close? It seems when it was manual we're told to have paper-thin gap, I think that's about 0.1mm or more actually.

Thanks!
Re: Precision Piezo Z-probe Now available.
January 15, 2018 04:25AM
PP20 modules are now available again on the Precision Piezo website, get 'em while they're hot!

Idris


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
January 15, 2018 05:20AM
Quote
Ismangil
Now I've got Precision Piezo working, I want to understand better the relationship between firmware Z=0, physical nozzle position, Z_PROBE_OFFSET_FROM_EXTRUDER, and any slicer G-code offsets.

Currently I follow your configuration with

#define Z_PROBE_OFFSET_FROM_EXTRUDER 0.2

Once I home Z, if I go to Z=0, it's very tight physically, there is high resistance to a 0.05mm feeler gauge.

So what is the offset from extruder doing exactly?
Is it OK to have nozzle so close? It seems when it was manual we're told to have paper-thin gap, I think that's about 0.1mm or more actually.

Thanks!

0.2 sounds a bit much, this means that your probe triggers at -0.02 mm (0.02 mm under the bed surface),
0.10mm - 0.16mm are more common ranges for the probe.
My probe setup is so sensitive that it triggers at -0.07 mm (which makes it 0.07 for M851)
So in your case if you put 0.15 Z_PROBE_OFFSET_FROM_EXTRUDER, your feeler gauge will measure 0.1 mm (0.2-0.05), understand?

Edited 2 time(s). Last edit at 01/15/2018 05:25AM by whosrdaddy.
Re: Precision Piezo Z-probe Now available.
January 16, 2018 02:02AM
Quote
whosrdaddy

0.2 sounds a bit much, this means that your probe triggers at -0.02 mm (0.02 mm under the bed surface),
0.10mm - 0.16mm are more common ranges for the probe.
My probe setup is so sensitive that it triggers at -0.07 mm (which makes it 0.07 for M851)
So in your case if you put 0.15 Z_PROBE_OFFSET_FROM_EXTRUDER, your feeler gauge will measure 0.1 mm (0.2-0.05), understand?

I've lowered Z_PROBE_OFFSET_FROM_EXTRUDER to 0.1 there doesn't seem to be any difference in physical gap at Z=0.

And when I do M503, M851 is 0.00.

Is this also related to software endstop? I do have mine enabled, and set to 0.
Re: Precision Piezo Z-probe Now available.
January 18, 2018 06:59AM
I would think so I set my software endstop (also called travel limits) to z-1.0 mm so I can push the nozzle down below the bed in testing. If you define the probe offset in configuration.h you need to use a negative number I. E. -0.1 as the probe triggers below the bed, at the point where the nozzle contact has deformed the disc enough for a trigger. The opposite of an inductive probe which triggers above the bed.

It might be - 0.2 or - 0.05 on your setup changing this value is one way to adjust it. However it's easier on marlin to use m851 as it can be set before a print and then m500 to save. M851 offsets the nozzle by a fixed amount.


[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 18, 2018 07:30AM
Quote
DjDemonD
I would think so I set my software endstop (also called travel limits) to z-1.0 mm so I can push the nozzle down below the bed in testing. If you define the probe offset in configuration.h you need to use a negative number I. E. -0.1 as the probe triggers below the bed, at the point where the nozzle contact has deformed the disc enough for a trigger. The opposite of an inductive probe which triggers above the bed.

It might be - 0.2 or - 0.05 on your setup changing this value is one way to adjust it. However it's easier on marlin to use m851 as it can be set before a print and then m500 to save. M851 offsets the nozzle by a fixed amount.

This seems to contradict [marlinfw.org] which states inductive probes is negative offset for above the bed, and positive for nozzle probe for below the bed.
Re: Precision Piezo Z-probe Now available.
January 18, 2018 07:36AM
Okay thats fine use it as per marlin docs, I mainly use duet where it is the other way around. Depends if you're setting the offset of the probe from nozzle, or nozzle from probe.

But my point about software endstops stands, set it to a negative number or you cannot jog down below what the FW thinks is z=0 even if the nozzle is not physically at z=0.

You can babystep down below z=0 if you need to even with software endstop set to z=0, then record the amount you babystepped and change the offset either in config or by m851 for the next print.

Edited 3 time(s). Last edit at 01/18/2018 08:21AM by DjDemonD.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 24, 2018 05:09AM
Hello,

I've got a couple question about drilling piezo disks.


Quote
RKS7204
Drilled a lot of holes, cut of the edges, printed the 2 pieces ....

[attachment 101532 IMG_20180102_201221070.png]

I plan to drill 4 holes in piezo disks 1 in the center and 3 on the sides to accomodate my mount (my mount)

Is this possible?

What should be considered?
Re: Precision Piezo Z-probe Now available.
January 24, 2018 05:37AM
I'd say it should be fine so long as you avoid overheating when drilling. The more PZT ceramic you remove the lower the voltage generated for any given force applied to the disc, but our circuit is tuneable and sensitive enough to detect very tiny voltage rises.

Luckily piezo discs are cheap.


[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. Coming soon PT1000 cartridge sensors plug straight into duet boards.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
January 24, 2018 06:07AM
I'd buy some spares and plan on ruining a couple before you get the trick. The ceramic contains lead so wash your hands, clean up the dust and don't lick your fingers.

Idris


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
January 24, 2018 06:56AM
I wasn't successful with the smaller discs. The large disc did the trick for me. And it's easy to cut of the sides. Do this cutting last.

Drilling a hole that's not completely in the piezo always failed, and did always remove half or more of the piezo.
Drilling in the bare copper goes fine, and drilling in the piezo also. Just avoid the "border".

Steve
Re: Precision Piezo Z-probe Now available.
January 24, 2018 07:24AM
Wow thank you all for these quick answers.

So I'll drill my 27mm diam piezo quickly.

my 4 holes will remain inside the piezo, so It should be nice.
Re: Precision Piezo Z-probe Now available.
January 24, 2018 08:05AM
Best of luck but I think you'll have difficulty drilling four holes in the ceramic of a 27mm piezo. If you can't get it to work you might try using smaller, undrilled, piezos glued to a sheet of some kind with holes drilled in the sheet. I've had success with 10.5 and 12mm piezos glued or soldered to pcbs.

Idris


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