Piezo20 probe and piezo kit now available
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You can adjust the debounce time by adjusting the threshold in the G31 P parameter. Lower values give lower debounce times.
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New boards have arrived and are made up, I'm currently testing them and they should be ready to post early next week.
Of the the first batch of 12 I've sent out 10 and donated I think £55 to the charity. Unfortunately I'm not in a position to keep doing that, I had to buy more parts to make the new batch and the boards are larger and more expensive so now I'm going to be selling them. If you've already been told that the money is going to the charity then that is where it will go but in the interests of transparency, from this point on, the money is going in my pocket.
I will be writing up documentation (hopefully this weekend) and I will publish that free for anyone to use.
I didn't foresee the demand for these boards so I only ordered six this time, I think three or four are already spoken for. I'll be ordering more asap.
I've previously discussed a piezo endstop handling board, they are also made up and being tested and will be ready to post next week to beta testers.
Idris
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Idris. That's great news. I think it might be a good idea to possibly start a wiki page on reprap for this system as it is coming together nicely, and all the relevant information such as how to use the board and how to assemble the units would be well placed.
David - I will experiment with this. I have been setting the P parameter dependant on the analogue value but it might be worth revisiting the digital setup as it does seem to work extremely well on smoothie as a digital sensor with 1ms debounce.
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Okay so this is the current incarnation of the sensor mounted in Lykle's latest effector system (which will be able to have a Nimble extruder bolted straight on - or just used with your current Bowden/flying extruder):
Nozzle wobbly practically non-existent and calibrating to a 0.02 precision over a 330mm bed.
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I have the stl's for this effector now on my thingiverse. Lykle will publish it also (with step files) if anyone needs to edit it to suit their setup. Please feedback to us on how you are getting on with it, any additions and improvement you make as well.
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DJ did you get his larger one I sent you you will need that to go with the Alloy carriages that I am getting cut it has a hole to take the Bardair cooling tube integrated into it (Reminder to self to order a bardAir system)
Doug
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Thanks Doug, I did get it yet. I will reprint and upgrade the effector when the carriages are in. I am looking forward to that.
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This seems to be a nice way to use the probe for automatic perfect first layers:
https://www.duet3d.com/forum/thread.php?id=940 -
Yes, DJDemonD did a great job there, getting it done.
I published the designs on our Thingiverse page as well. http://www.thingiverse.com/thing:2117069
Included is a 64mm wide effector and a Prism effector, which is the standard Kossel type width, but pretty looking. (I think)All three effectors already have holes in them for a Bard-air type cooling pipe.
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I'm writing up documentation for these new boards, does anyone know whether the inputs of the Duet are 5V tolerant?
Idris
Edit: Tuning instructions for the Z-probe v2 board are here https://www.dropbox.com/sh/3q38ew98kt7f8sq/AAB_uA6tQL2ETlGcnfdijm2Ra?dl=0, feedback would be very welcome, particularly from anyone whose using a v1 board.
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Although they are fairly tolerant of over-voltage, the Duet inputs should not be fed more than 3.3V under normal operating conditions. If you power your interface board from the 3.3V supply provided on the Z probe connector, all will be well.
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I thought that would be the case. The reason I ask is that I'm using a Smoothieboard which uses 5v IO. The board specifies 5v power so I'd hate for someone to give it 5v then plug it into the Duet and fry something. I don't have a 3.3v powersupply so I can't test the boards on 3.3v, nobody reported any problems with the v1 at 3.3v.
Idris
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Moriquendi, I'm using your one-Piezo board at 3.3v on duetwifi with no issue.
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Got my piezos today, a test fit is perfect, though I may need to get creative to insulate the edges of the copper from the retaining screws. I plan to use some nylon washers to insulate it from the mount plates, we'll see what I can come up with there.
I'll probably cut some small notches in the copper plate and put an insulator around the m3 screws.
Looking forward to getting the board from Moriquendi so I can try it out.
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What are the chances of this sensor also being used as a crash sensor during prints?
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What are the chances of this sensor also being used as a crash sensor during prints?
That depends on whether the sensor has any tendency to trigger during normal printing.
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As most firmware does not look at the sensor other than when probing this does not normally create a problem. However, the LED on the piezo sensor boards on my 3D printers flash a lot during printing so there is signal to work with. If the amplifier put out an analogue signal instead of a logic one then perhaps the firmware could be set to look for error indicating values.
Mike
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Well whether it's designed to or not it does put out an analogue signal. I can read from 216 to 1000 on the duet web control depending on rate of pressure change on the piezo. It's goes to around 500 during rapid moves or over rough previous layers. I set 600-700 as a trigger level for probing.
But even then what would we use as a stop trigger? 1000? Maybe a slowdown to half speed at 700 then gradual increase back to normal at the next layer? It would be interesting to develop as its not been done before that I am aware of.
700 equate to 15g of force on probing, I'll set 1000 (or 999) probing threshold and stick the scales under the nozzle.
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I'm on holiday at the moment but when I get home I'll dig out the protoboard version of the circuit and have a look at the output of the differentiator section on an oscilloscope during a print. The output of the differentiator should be an analog signal proportional to, in my case, movement of the bed.
If anyone has access to a 'scope you're looking at either pin 1or pin 9 of the IC or the centre most end of either C1 or R3
Idris
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So a bit of experimenting.
Set the probe to digital in config.g using
M558 P5 I1 F500 X0 Y0 Z0
G31 X0 Y0 Z0 P100And in this mode (I am using inverted setup for piezo board (active low), if you are using active high then remove I1) the G31 P100 is the debounce which filters the signal, so using this config I can probe at normal speed/jerk/accel which brings the probe performance into line with that on smoothieware, which has debounce parameter also.
However in this mode I think it would be less easy/not possible to use data from the probe for crash detection/quality improvement as discussed above by briangilbert, unless we take a feed from the pins Moriquendi suggested above and connect them to a spare analogue input on the duet. And then there is some coding required.
Here is it probing at normal speed:
https://youtu.be/MURqDTL9oVA
