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Precision Piezo Z-probe Now available.

Posted by DjDemonD 
Re: Precision Piezo Z-probe Now available.
July 17, 2017 05:19PM
Fantastic I'll link to it. Thanks.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
July 17, 2017 06:53PM
Your welcome
Re: Precision Piezo Z-probe Now available.
July 18, 2017 03:55AM
I had a recent message about power supply for the piezo PCB's please ONLY use 3.3v-5v to supply power v+ to the piezo board. They are NOT 12v tolerant (or any other voltage over 5v).

(Whether supplying them with higher voltage will destroy the piezo PCB is uncertain, BUT they will then output this higher voltage on trigger and 12v will destroy the endstop channel on your printer controller).

Edited 1 time(s). Last edit at 07/18/2017 04:01AM by DjDemonD.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
July 18, 2017 06:59AM
Vin must not be any higher than the voltage tolerance of your controller board. The output signal of the board is equal to the Vin voltage, if your controller only accepts 3.3v signals then you can't supply the piezo pcb with any voltage higher than 3.3v. If your controller supports 5v signals give the piezo pcb 5v, no more.

Moriquendi

(Ps. If you MUST supply the board with a higher voltage there are ways of doing it, PM me for details however you're entirely on your own if something goes wrong)


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
July 18, 2017 12:40PM
Just how sensitive is the under bed setup?
I noticed if I touch the bed support that the piezo's are stuck to the LED lights up. There is kapton tape in between the bed support and the piezo so it should be isolated.
Re: Precision Piezo Z-probe Now available.
July 18, 2017 02:03PM
It's probably not electrical it's probably mechanical. They are extremely sensitive. How is it performing when you probe it?


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
July 18, 2017 03:41PM
Underbed Piezos can be very sensitive, after all you have more piezos contributing to the signal. First off try reducing the sensitivity on VR1, this should account for the additional signal from the piezos, if that doesn't work then reduce the sensitivity of VR2 slightly. Turning VR1 can be finicky, if you have problems you might find this guide useful LINK

Idris


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
July 18, 2017 05:18PM
Thanks guys will give it a go tomorrow. It's in bits again to mount the case I made, been out this evening and not had time to put it back together yet
Re: Precision Piezo Z-probe Now available.
July 19, 2017 02:54AM
Hi DjDemonD,

When do you think the drop in piezo kit will be back in stock? I am planning to use with Titan Direct Drive. Here is my setup:



I hope it will work with my setup. If you guys spot any problem in using piezo with this set up, let me know.

//Vasan
Re: Precision Piezo Z-probe Now available.
July 19, 2017 03:29AM
Later this week pcbs are in the post to me.

As for that setup you can fit a piezo20 module below your effector and attach your hotend into it. But you'll need a flat bottomed effector so the fan arrangement you have now will have to be redesigned.

Watch this video [m.youtube.com] pause it. Imagine your titan sitting on top of the effector, which could be printed. You need a central hole for filament (obviously) and 2x3.5mm holes 25mm apart and equidistant from the centre hole to fix the module to the effector.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
July 19, 2017 07:25AM
Awesome work by Jardar Nordbo (4Mb give them chance to load):





Edited 2 time(s). Last edit at 07/19/2017 07:50AM by DjDemonD.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions

Re: Precision Piezo Z-probe Now available.
July 19, 2017 08:12AM
Thanks DJ, I think I have to opt for screw mount and run a short PTFE tube from titan to the hotend. Am I right? If I use groove mount, the thickness of the effector will interfere with the mounting. Correct me if I am wrong

Regards,
Vasan
Re: Precision Piezo Z-probe Now available.
July 19, 2017 08:16AM
It took time to load the screw mount animation! Great work! I think it makes more sense now to use screw mount for my set up.

Regards,
Vasan
Re: Precision Piezo Z-probe Now available.
July 19, 2017 08:17AM
I'd go for screw mount wherever possible. Run guide tube from in the titan down into the hotend through the module.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
July 19, 2017 05:00PM
Ok having trouble setting up the bed system. I have set the endstop to false and tried the polarity of the piezo both ways and I get the same trigger ether way it is. I have screwed the buffer until it just touches the piezo and then 1/4 turn more (without and bed adjustment nuts on) it needs an hard knock to make the led flash. When I screw the bed nuts down to adjust the be bed to something like level I don't get a trigger until the compression spring are nearly fully compressed.
Would like to get it running this way but if it too troublesome I will have to go down the extruder route.
All suggestions most welcome.

Ian
aka Suggy
Re: Precision Piezo Z-probe Now available.
July 19, 2017 05:24PM
Hi Ian, I am setting up a machine with underbed mounts now as I know little about how precisely to diagnose problems apart from first principles with Piezos and using fsrs a while back.

I think a lot has to do with how the bed mounts work mechanically. They need to hold the bed laterally whilst still allowing it vertical movement, but only 0.2mm this is not an easy thing to achieve.

Partly the reason I developed the hotend probe module was having no desire to go back to trying to hold my deltas bed on anything less than rock solid clamps. But for cartesian machines that's less of a consideration as the bed isn't fixed anyway.

I am hopeful that carefully setup it will prove to be very sensitive.

Ill leave this one to the underbed experts at least until I've had a play with these myself. I'm printing my own design of bed clamp right now.

Simon.

Edited 2 time(s). Last edit at 07/19/2017 05:26PM by DjDemonD.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
July 19, 2017 06:06PM
Thanks Simon let me know how you get on. I was thinking along the same lines, (new clamp) maybe putting the piezo on top of the bed support and having something like a bolt in between the hbp and the piezo. Only problem I haven't figured out yet is how to make it adjustable
Re: Precision Piezo Z-probe Now available.
July 20, 2017 03:22AM
Unfortunately I don't have any experience of that style of mount, the ones I used worked somewhat differently, have a look here shown in the bottom two pictures. One thing that does occur to me, are you sure the polarity of your piezos is right? If you have the piezo polarity the wrong way round, because of the way the circuit works, you will only get a trigger when the rate of change of pressure on the piezo decreases.

Idris


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
July 20, 2017 04:21AM
Quote
Suggy
Thanks Simon let me know how you get on. I was thinking along the same lines, (new clamp) maybe putting the piezo on top of the bed support and having something like a bolt in between the hbp and the piezo. Only problem I haven't figured out yet is how to make it adjustable

When you say adjustable do you mean for bed levelling purposes? If so I wouldn't worry too much about it, I will get some flack for this from the purists, but so long as your bed is reasonably level, the accuracy of the probing method coupled with grid/mesh compensation will mean you never have to turn a levelling screw again. If its leaning at an extreme angle then okay sort that out, but you would probably be best to do away with adjustable levelling screws and just fix the bed on the mounts as level as you can make it and let the software do the rest.

As for flatness, again if using grid/mesh then that's compensated for and some firmware will allow tapering off of grid compensation so that an uneven bed doesn't make uneven objects.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
July 20, 2017 04:54AM
Quote
Suggy
Ok having trouble setting up the bed system. I have set the endstop to false and tried the polarity of the piezo both ways and I get the same trigger ether way it is. I have screwed the buffer until it just touches the piezo and then 1/4 turn more (without and bed adjustment nuts on) it needs an hard knock to make the led flash. When I screw the bed nuts down to adjust the be bed to something like level I don't get a trigger until the compression spring are nearly fully compressed.
Would like to get it running this way but if it too troublesome I will have to go down the extruder route.
All suggestions most welcome.

Ian
aka Suggy

Hi Ian,
Can you check that the amplifier is in the right range by putting a piezo on a flat surface with a pressure pad on top. Pressing this lightly should cause the LED to flash either on pushing or releasing. If that was O.K. then try all three or however many) to see if they are the right way round. If that shows all is well then could you put up some photos of your sensors as they are mounted.

There is a few different options for mounting underbed sensors in this post: [forums.reprap.org]

Mike
Re: Precision Piezo Z-probe Now available.
July 20, 2017 12:10PM
Very difficult to gat any trigger using light pressure. I did notice with NO pressure pads on at all, if I knock the carrage the led flickers. Same results if there is1 or all 3 piezos connected to the board
Attachments:
open | download - 20170720_171721.jpg (595.1 KB)
Re: Precision Piezo Z-probe Now available.
July 20, 2017 02:49PM
Photo is nice and clear but I can't see the bed level adjusting nut - I assume that tests must have been done with this in place since this is the bit through which the pressure is transmitted to the piezo.
Try very lightly flexing the piezo - if this gets no response I think that the amplifier may have failed for some reason.

Mike
Re: Precision Piezo Z-probe Now available.
July 20, 2017 03:09PM
New Stock Available. Thanks to Moriquendi/Idris for the PCB's

5 Ready made Modules - revised, optimised PCB
10 Piezo Kits - with new light blue PCB

Are now available in the shop at
www.precisionpiezo.co.uk/shop

Many thanks. If it sells out within a few hours please give me 3-4 days to build them.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
July 20, 2017 03:18PM
Quote
leadinglights
Photo is nice and clear but I can't see the bed level adjusting nut - I assume that tests must have been done with this in place since this is the bit through which the pressure is transmitted to the piezo.
Try very lightly flexing the piezo - if this gets no response I think that the amplifier may have failed for some reason.

Mike
There are no level nuts on when I took the photo. Yes done in place as they are glued to the bottom to the kapton tape. Will try with a different piezo

Edited this is with the nut on

Edited 1 time(s). Last edit at 07/20/2017 03:55PM by Suggy.
Attachments:
open | download - Small size.jpg (135.9 KB)
Re: Precision Piezo Z-probe Now available.
July 20, 2017 04:11PM
Don't think there is a fault, see 2 vids. 1 with normal polarity and 1 reversed. Firmeware changed back to true

[youtu.be]

[youtu.be]
Re: Precision Piezo Z-probe Now available.
July 20, 2017 04:31PM
Those videos are exactly what you should be seeing. My only thought is that because in those mounts you're using planar pressure as opposed to flexing the disk the signal generated isn't large enough (piezo disks like these produce a much larger signal through flexion than through direct pressure). When LeadingLights designed the circuit he was using the same style of mounts you're using, when I started making the PCBs I changed some of the values to suite how I was using the piezos (flexion).

Do you have spare piezo disks? If you do you could try superglueing one over the living hinge of the mount so that when the mount moves it bends the piezo. Might need to redesign the mount slightly to allow clearance.

Idris


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
July 20, 2017 04:36PM
Yes I have around 12 left (I think) will give it a try. May be Monday as going away for the weekend, big partysmileys with beer Turning 50 on sundaysad smiley Bloody old age gets in the way of all the good stuff

Edited 1 time(s). Last edit at 07/20/2017 04:37PM by Suggy.
Re: Precision Piezo Z-probe Now available.
July 20, 2017 04:55PM
Happy Birthday smiling smiley have a great time.


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
Re: Precision Piezo Z-probe Now available.
July 20, 2017 05:12PM
Thanks, if its owt like my 40th wont remember much the day after
How did you get on with the mount your working on?
Re: Precision Piezo Z-probe Now available.
July 20, 2017 05:25PM
Yep been there.

Mount not very far yet. I have a design I think will work, now to install it. But there's a few orders to fulfil right now. smiling smiley


Simon.

[www.precisionpiezo.co.uk] Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters. PT1000 cartridge sensors plug straight into duet boards and others.
Published:Inventions
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