Precision Piezo Z-probe Now available.

I have a spacer that fits underneath the bracket that will allow it to work inverted, I'll try and track it down.

Idris

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

@DjDemonD & @ElmoC

I want to thank you, now my config is great, the probe work perfectly (special thank to DjDemonD for the 25mm spacing custom, works like a charm on my effector), My heat map is a green field.

it wasn't easy since I just swap to a Duet, but damn this probe is so precise. As one of the "20 first", I volunteer for any new futur version of the probe as a beta tester, it'll definitely worth it. @ DjDemonD keep my damn email


I searched for a great probe for so long, tried everything... Next step : printing, and improvement of the mounting piece.

Very pleased you're happy, the 25mm spacing mod is neater and is actually a little bit easier to build (using brass inserts rather than m3 nuts), so I might switch over to that design at some point. I suspect it will be an improvement for some, who have the metal effectors with the 6 holes around the hotend, but for others 26.5mm or 25mm probably makes no difference.

They are very sensitive units, can be tricky to tune in but hopefully once you're there its smooth sailing.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Still Sold out
Any idea when new stock will be in?

Well pcbs are in the post to me, so likely I can release another 5 modules and 10 kits over the next few days. Watch this space.

We are discussing our future direction, modules (and pcbs) are all hand made by me and Moriquendi in the UK so quite labour intensive. As I see it we can move to larger volumes with populated pcbs or preassembled modules, and we are looking into this.

For now we are going to focus on the kits, but you can print the module, it's all open source, and build one yourself using the parts in the kit and a few screws etc. Costs are lower for you, as you do the assembly and you can opt for our Piezo20 module, Lykle's effector, Moriquendi's underbed mounts, Leadinglights underbed mounts or our new beta titan bracket with built in Piezo (you can use it for other hotend/extruder systems too).

I will still make preassembled and tested Piezo20 modules but I will need to review the price to cover the time taken to put them together. I would like to enhance our offer though by having custom colours and intend to move to a neater solution with brass inserts instead of heat pressed m3 nuts.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Ok thanks. Building one out of your kit is not beyond my capabilities. It's going on a e3d v6 on a printer I am building. Count me in for 1 when there ready so I don't miss out. You should put a pre-order button on your website?

Cheers

Ian

Edited 1 time(s). Last edit at 06/28/2017 03:15PM by Suggy.

Yeah I've considered it, it's tricky at this stage as I only have the time to make so many, especially Piezo20 modules, if I had a lot of preorders I'd feel I was letting people down not making them faster.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

You could sell them as a build it yourself kit even the board, just sell all the components, I would imagine anyone that can make a 3d printer can use a soldering iron.
Just a thought

Yes that would be possible or perhaps sell the piezo kit and then the printed parts separately. No soldering is required. You might need to extend some cables or crimp on a dupont 2 pin female plug (I suppose you could solder the wire to it if you don't have crimpers).

Right now theres a lot of info on making piezo probes (there's 16 pages on the other thread here) and in many cases people want to make their own design.

Ill tryout a few ideas see what flies.

Edited 1 time(s). Last edit at 06/29/2017 10:36AM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

So I have released a new stl for the screw mount version of the Piezo20 Module, this one was Hergonoway's idea. Its got 25mm spacing for the mount holes to your printer, which wasn't previously possible with heat pressed M3 nuts as they got in the way of the piezo disc, but now I'm using brass inserts. Its on Thingiverse and our site. I also intend to move the groovemount module over to use the brass inserts, as they are smaller, neater and easier to work with.

I will be releasing some more stock very soon, PCB's are in. It will be announced here.

As previously discussed we will be focusing on the kits, and trying to keep the price of the kit low. The idea is to buy a kit, and then print your own parts you need to implement it from the now fairly long list of piezo sensor assemblies available. Kits are available with 20mm or 27mm piezos, they can be drilled for hotend assemblies or undrilled and supplied in three's for underbed use. You can select which you need on the shop if you're not sure ask here, for everyone's benefit. if people want I will print and list the printed part packs as separate items on the site, which you can order with your kit.

To keep the costs of the kits down we are going to make the modules a premium item, and therefore they will increase in price to £39.99 UK delivered, (and £47.99 worldwide shipped by regular mail - untracked) I will also try to add a premium courier shipping option (with tracking) for those who want them faster. Custom colours will be available, if you want a colour I do not have then request it, I will get it in for you (unless its really ridiculous and no one else in their right mind will want another one ever ).

Edited 1 time(s). Last edit at 07/02/2017 01:59PM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Glad to see you're progressing with the piezos

Few questions..

-- if the piezo fails, what precautions are there to stop the nozzle smashing into the bed? This is a worst case scenario assuming the printer was left to it's own devices and the user was not there to stop it. Can it be written into firmware to issue an emergency stop? With an IR probe the Z end stop will stop damage since the probe senses 1mm~ above the surface (Cartesian only I guess), but this may cause a severe nozzle collision with the piezo before the end stop is triggered.

-- does under bed sensing work, what are the pros and cons of placing the piezos on the bed / hotend / extruder mount?

Good questions

Fail safe. It is possible with some of our boards. The boards supplied with the piezo kit can be setup to operate normally closed, thereby failing safe in the event of a failure of the system, such as a wire break/disconnection. However like most Z probe technologies that are already in common use, eg inductive/capacitative sensors, IR etc and due to the way some of our boards work they are setup normally open as standard.

We recommend in the instructions that before each printing session the user taps upwards on the (cold) nozzle, to check the led indicates a trigger. We also recommend sending a G30 and tapping upwards on the nozzle to ensure the firmware recognises a trigger and stops, or reverses the z axis as it should do. If either of these tests fail then to investigate and take action.

We also recommend probing with a semi heated nozzle, rather than fully heated, to ensure any residual filament doesn't overly affect the reading (even if recommended cleaning has not taken place), but also to limit the damage to the printing surface if a head crash occurs. Lowering motor current (where easy to do digitally) also helps lower risk of damage.

However we have had no issues reported to us so far.

With our Piezo20 modules we cannot recommend setting NC "mode", as it would require the triggered LED to be constantly lit, only blinking off when there is a trigger. The issue there is to get the module to light up the LED has to be fairly high powered and will fail if constantly lit, we had to accommodate 3.3v and 5v VCC power so at 5v the LED is being a little overdriven, which in NO mode isn't a problem as its only lit for a few milliseconds every now and then. We can address these issues, and thereby hopefully surpass a great many of the sensors already in use, which also do not fail safe.

Underbed sensing works, I hope Moriquendi and Leadinglights will chime in as they have been using this method for quite a while now. The piezos are very sensitive acting almost as microphones in some setups. Compared to FSR's which need 50-100g of force, the slightest pressure on the bed causing bending or compression on a disc beneath is enough to cause a trigger, 10g of force is all that is needed (depending on the mechanical design in use). I pioneered the hotend method as a way to simplify the system, reducing the number of piezos to one from three, by drilling through the disc, and taking the piezo further away from heat, which does affect the way they behave. One thing we are considering is a micro-controller version, which might include a thermistor (mainly for those using them in heated chambers) to alter the trigger threshold depending on temperature.

So plenty of work to do moving forwards, but so far once tuned and operating (which in some setups can take a little patience - like everything else about 3d printing) the feedback is very positive. Its fixed, no X & Y offsets, accurate and repeatable to very high degree (0.01mm accuracy and 0.007mm repeatability standard deviation), and as it is fixed unlike deployed probes, repeatability between probing sessions is also very good.

Edited 1 time(s). Last edit at 07/03/2017 05:48AM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Hi Origamib,

Having two piezo based systems in frequent use for over a year now I have not had any failures except as detailed below. Electronically I think that the reliability is at least as good as other systems so I guess that likelihood comes down mostly to connection failures either in the connection from the controller (RAMPS, Duet etc.) to the signal conditioner board, or in the wiring to the piezo itself. For the first situation, having the equivalent of a normally closed output should be satisfactory - i.e., with no nozzle contact the output to the controller board should be high, going low only to signal a nozzle contact. To minimize possibility of disconnection of the piezos I would recommend that the piezo leads should be short and soldered directly to the conditioner board.

For full disclosure, the failure mentioned above: Having developed an underbed piezo system on a Cartesian printer I found that I had to set the trigger point very high (ca 100 grams) because the shake at the end of an X or Y movement was giving false triggering. Setting up the same system on a Delta printer I was immediately able to reduce the trigger pressure to about 10 grams with no false triggering. On the first hot test I had a nozzle crash and it took several repeats to find that it was failing to trigger because the piezo was generating an output in the opposite sense to the expected nozzle contact output. This is the Pyroelectric Effect and is caused not by temperature but by change in temperature - analogous to the Piezoelectric effect caused not by pressure but by change in pressure. The solution was to put a sheet of insulation to keep convected, conducted and radiated heat from the bed heater from reaching the piezos.

There are several schemes for underbed sensing detailed in this forum entry [forums.reprap.org]

I am quite partial to the parallel mechanism sensor, not only because it was invented here, but also because it protects the discs from any impacts. It also offers the possibility of having Z-min microswitches in parallel to the piezos to offer a fail-safe backup.

Mike

I wish there where some mounting holes on the PCB. Any specific reason why you dropped them? Not enough space maybe?

Jardar

Edited 1 time(s). Last edit at 07/03/2017 02:23PM by janor.

The kit PCB has no mounting holes, but the Piezo20 PCB does. We are going to list PCB's as spares so you can buy a Piezo20 PCB at some point soon. These are the component that is the limiting factor at present, we are looking into larger volume production.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

I used under bed sensors for months and I was very happy with them. I've now swapped to a piezo-in-effector method and my results have improved. This doesn't mean that under bed sensors are inherently worse but for me, on a delta printer, it worked better to have the bed rigidly mounted . I think the optimal solution will vary depending on the arrangement of the printer, if your bed moves anyway them it might be better to put the sensors there or if you can engineer a better mechanism than I could.

There are mounting holes on the PCBs supplies with the PP20 module. The PCB supplies with the kit is the fourth version of the first ones I started making when I was first experimenting with piezos, there are no mounting holes because I never needed any and nobody asked for them. The cost of the bare PCB is directly related to the area, mounting holes use up large amounts of space and therefore drive up the price. It should be pretty easy to design a simple mount for the PCB and I think someone may already have, check thingverse. If lots of people feel that having mounting holes is important I'll design them into the next batch though that might take a while as there's already another batch on order.

Idris

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

I'll find a way to fasten the PCB to the hotend mount. For the time being a dash of glue does the job.

Jardar

I'll knock up a bracket for 1.21/2 boards, there is one for the tiny v1.0 board. That one was quite tight and I always felt I'd snap the pcb getting it in and out. Maybe a recessed plate with holes for a cable tie?

Edited 1 time(s). Last edit at 07/03/2017 02:55PM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Guy's
Much appreciate all the effort and time you have put into the project but is there any chance you can upload the printed parts separately ?
ie Hot end clamp 25mm
Hot end clamp 26.5mm
Upper part screw mount
Upper part clamp mount
That way there is no need to print all the part's again if the censor is swapped to machine that requires a different mount!

It's on thingiverse and our site go to www.precisionpiezo.co.uk and click resources-osh.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Iv downloaded them but there a complete print (main and top), what I am trying to say is, I have printed the clamp mount (main and top) but I would like to print just the screw mount upper part so I can try with different mounting options without printing the lower/main body again.
Hope this help's to what I am asking?

Just put them into slic3r and right click and select "split".

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

If other slicers don't offer this function then shame on them.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Using S3D will have a look, thanks

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Suggy
Using S3D will have a look, thanks

In S3D, it is under the Mesh menu option. Separate Connected Surfaces.

Here the original which is public grab the parts you want, radically redesign it and share if you want

[www.tinkercad.com]

Edited to hopefully make it work

Edited 1 time(s). Last edit at 07/03/2017 05:17PM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Must be in a newer version than mine (1.1.0) only got Calculate Volume, Element statistics and Mesh Reduction

Thanks Guys Appreciated

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Suggy
Must be in a newer version than mine (1.1.0) only got Calculate Volume, Element statistics and Mesh Reduction

Yeah. I would say mine is a bit newer. 3.1.1. You just need to upgrade yours is all. The purchase price includes updates (unless that changed from 1.1.0).

I have that version I use for 1 machine, 3.1.0 on 2nd machine and 3.1.1 on the 3rd.
Find it easer to keep them all separate and there on 3 different pc's