Re: Precision Piezo Z-probe Now available. December 12, 2017 03:01PM |
Registered: 8 years ago Posts: 3,525 |
Re: Precision Piezo Z-probe Now available. December 12, 2017 04:43PM |
Registered: 6 years ago Posts: 54 |
Re: Precision Piezo Z-probe Now available. December 12, 2017 04:48PM |
Registered: 8 years ago Posts: 3,525 |
Re: Precision Piezo Z-probe Now available. December 12, 2017 06:19PM |
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Re: Precision Piezo Z-probe Now available. December 13, 2017 11:09AM |
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Re: Precision Piezo Z-probe Now available. December 13, 2017 11:44AM |
Registered: 8 years ago Posts: 3,525 |
Re: Precision Piezo Z-probe Now available. December 13, 2017 02:51PM |
Registered: 6 years ago Posts: 54 |
Re: Precision Piezo Z-probe Now available. December 13, 2017 03:41PM |
Registered: 9 years ago Posts: 487 |
Re: Precision Piezo Z-probe Now available. December 13, 2017 04:04PM |
Registered: 6 years ago Posts: 21 |
Quote
CaptainHero
So while i am still trying to Frankenstein my way to a somewhat working hotend mount on my Wanhao I3 i made some progress recently which made me hopefull that there is light at the end of the tunnel however there are a few issues which i can't seem to pinpoint why they keep happening seemingly randomly.
So i have made a contraption to have a single piezo being triggered around my hotend carriage. I won't post pictures because a) its a work in progress and horrible to look at and b) its not yet working 100%.
I had some promising results with homing registering correctly so i thought i'd do a mesh. On a 10x10 mesh i have about 8-10 points where the probe either falsely triggers even tough no contact has been made with the bed or the head has already touched the bed but it didn't register so the z motion continues pushing down onto the bed further until eventually it registers and moves on. Now for the second part of the problem i think i have that solved mostly by using Double probing setting and also by increasing somewhat the velocity of the Z motion to have a more firm contact.
What i can't figure out is why i still get the odd false positive in mid air. I have tryed and failed with the following adjustments: disabled Z jerk, set z accelaration to 30 for the probing, increased or decreased general z axis movement speeds, increased wait between z probe movement from 400ms up to as high as 1200 ms, tryed to decrease sensitivity ever so slightly on the piezo board by adjusting the two screws (negative side effect was that with somewhat decreased sensitivity more contacts with the bed did not register correctly which is not good).
The weirdest part of the whole thing is still this: The false triggering of the probe seemed to occure exaxctly at the same probe points somehwat in the first 3rd of the mesh run. Now this is perplexing to me as if the sensitivity might be too high then i would assume false positives to happen randomly troughout the mesh probing but i did some repeat tests and sure enough about 5 out of 5 runs the false positive in mid air registered at basically the same probe points. It can't be ringing because that would have an effect at other points as well so i just don't get it.
So after the lengthy info do you still have some advice to further try to eliminate the false (mid air) positives?
Also for the life of me i do not know exactly what the second screw on the board adjusts exactly? The first is the sensitivity which is clear and i figure the second is somewhat the same???
Cheers
Re: Precision Piezo Z-probe Now available. December 13, 2017 06:40PM |
Registered: 7 years ago Posts: 31 |
Quote
CaptainHero
So while i am still trying to Frankenstein my way to a somewhat working hotend mount on my Wanhao I3 i made some progress recently which made me hopefull that there is light at the end of the tunnel however there are a few issues which i can't seem to pinpoint why they keep happening seemingly randomly.
So i have made a contraption to have a single piezo being triggered around my hotend carriage. I won't post pictures because a) its a work in progress and horrible to look at and b) its not yet working 100%.
I had some promising results with homing registering correctly so i thought i'd do a mesh. On a 10x10 mesh i have about 8-10 points where the probe either falsely triggers even tough no contact has been made with the bed or the head has already touched the bed but it didn't register so the z motion continues pushing down onto the bed further until eventually it registers and moves on. Now for the second part of the problem i think i have that solved mostly by using Double probing setting and also by increasing somewhat the velocity of the Z motion to have a more firm contact.
What i can't figure out is why i still get the odd false positive in mid air. I have tryed and failed with the following adjustments: disabled Z jerk, set z accelaration to 30 for the probing, increased or decreased general z axis movement speeds, increased wait between z probe movement from 400ms up to as high as 1200 ms, tryed to decrease sensitivity ever so slightly on the piezo board by adjusting the two screws (negative side effect was that with somewhat decreased sensitivity more contacts with the bed did not register correctly which is not good).
The weirdest part of the whole thing is still this: The false triggering of the probe seemed to occure exaxctly at the same probe points somehwat in the first 3rd of the mesh run. Now this is perplexing to me as if the sensitivity might be too high then i would assume false positives to happen randomly troughout the mesh probing but i did some repeat tests and sure enough about 5 out of 5 runs the false positive in mid air registered at basically the same probe points. It can't be ringing because that would have an effect at other points as well so i just don't get it.
So after the lengthy info do you still have some advice to further try to eliminate the false (mid air) positives?
Also for the life of me i do not know exactly what the second screw on the board adjusts exactly? The first is the sensitivity which is clear and i figure the second is somewhat the same???
Cheers
Re: Precision Piezo Z-probe Now available. December 13, 2017 06:53PM |
Registered: 8 years ago Posts: 3,525 |
Re: Precision Piezo Z-probe Now available. December 13, 2017 07:23PM |
Registered: 8 years ago Posts: 3,525 |
Re: Precision Piezo Z-probe Now available. December 14, 2017 06:05AM |
Registered: 6 years ago Posts: 60 |
Re: Precision Piezo Z-probe Now available. December 14, 2017 08:26AM |
Registered: 6 years ago Posts: 21 |
Quote
DjDemonD
Okercho (and others with bowden issues) - there is a sure fire solution. Design a place above the piezo sensor unit, to screw your bowden coupler into, then run a PTFE tube from the bowden coupler down through the piezo sensor unit into the hotend. This decouples the bowden tube mechanically from the piezo disc. I accept it might not always be easy or neat to do this, but if the bowden tube is pulling on the sensor and triggering it, perhaps it is too tight to begin with (just a thought).
Pyroball - that looks good, be keen to follow how well it is working.
In other news I am working with someone on a cr10 idea - and have a cr10 on order to play with, as I know how popular these are right now. Watch this space, or let me know if you want to try it (before me).
Re: Precision Piezo Z-probe Now available. December 14, 2017 09:56AM |
Registered: 6 years ago Posts: 7 |
Quote
DjDemonD
Sweet results 7 microns accuracy and 2 standard deviation - can anyone beat that?
Please add an image of your setup if you get chance Stef, it would put some context on it.
I hope your pleased with those results!
Re: Precision Piezo Z-probe Now available. December 14, 2017 09:59AM |
Registered: 8 years ago Posts: 3,525 |
Quote
whosrdaddy
11:57:22 AMStopped at height -0.175 mm
11:57:19 AMStopped at height -0.165 mm
11:57:16 AMStopped at height -0.175 mm
11:57:13 AMStopped at height -0.172 mm
11:57:09 AMStopped at height -0.172 mm
11:57:06 AMStopped at height -0.175 mm
11:57:03 AMStopped at height -0.175 mm
11:57:00 AMStopped at height -0.175 mm
11:56:56 AMStopped at height -0.170 mm
11:56:53 AMStopped at height -0.170 mm
11:56:50 AMStopped at height -0.168 mm
11:56:47 AMStopped at height -0.170 mm
11:56:44 AMStopped at height -0.172 mm
11:56:41 AMStopped at height -0.172 mm
11:56:37 AMStopped at height -0.170 mm
11:56:34 AMStopped at height -0.162 mm
11:56:31 AMStopped at height -0.170 mm
11:56:28 AMStopped at height -0.170 mm
11:56:25 AMStopped at height -0.168 mm
based on this data: I have mean dev of 0,087186958 mm, stdev is 0,00353181 mm
Re: Precision Piezo Z-probe Now available. December 14, 2017 10:03AM |
Registered: 8 years ago Posts: 3,525 |
Quote
aMpeX
Quote
DjDemonD
Sweet results 7 microns accuracy and 2 standard deviation - can anyone beat that?
Please add an image of your setup if you get chance Stef, it would put some context on it.
I hope your pleased with those results!
I can
Mean: 0.101750 Min: 0.98 Max: 0.102 Range: 0.005
Standard Deviation: 0.001601
Video of the setup here: Please forgive the mouthbreathing ._. [www.youtube.com]
Re: Precision Piezo Z-probe Now available. December 14, 2017 10:27AM |
Registered: 6 years ago Posts: 7 |
Quote
DjDemonD
Well I think you currently hold the record, and its not fair, you're getting way better results than me! Do you want a job?
Excellent, Mike/Leadinglights is quite convinced with enough trial and error, and big enough piezos, and accurate enough firmware we could go to 1 micron accuracy, with probing force 1g! Something to aim for although worth saying this is physics now not engineering.
Re: Precision Piezo Z-probe Now available. December 14, 2017 11:03AM |
Registered: 6 years ago Posts: 54 |
Re: Precision Piezo Z-probe Now available. December 15, 2017 03:35AM |
Registered: 6 years ago Posts: 60 |
Quote
DjDemonD
So range (accuracy) is 13 microns, dev 4 microns.
Great results from a bracket type system which by its nature is indirect.
If you get chance see what effect probing speed has between 240-1000 mm/min
Also worth trying the new M558 P8 mode which removes filtering to give an even more precise result.
Re: Precision Piezo Z-probe Now available. December 15, 2017 08:04AM |
Registered: 9 years ago Posts: 77 |
Re: Precision Piezo Z-probe Now available. December 15, 2017 08:07AM |
Registered: 6 years ago Posts: 21 |
Re: Precision Piezo Z-probe Now available. December 15, 2017 08:15AM |
Registered: 8 years ago Posts: 3,525 |
Re: Precision Piezo Z-probe Now available. December 17, 2017 07:09AM |
Registered: 7 years ago Posts: 8 |
Re: Precision Piezo Z-probe Now available. December 17, 2017 03:04PM |
Registered: 8 years ago Posts: 3,525 |
Re: Precision Piezo Z-probe Now available. December 17, 2017 04:01PM |
Registered: 8 years ago Posts: 3,525 |
Re: Precision Piezo Z-probe Now available. December 19, 2017 06:50PM |
Registered: 8 years ago Posts: 155 |
Re: Precision Piezo Z-probe Now available. December 19, 2017 07:20PM |
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Re: Precision Piezo Z-probe Now available. December 19, 2017 07:42PM |
Registered: 8 years ago Posts: 155 |
Re: Precision Piezo Z-probe Now available. December 20, 2017 03:51AM |
Registered: 9 years ago Posts: 77 |