If you have a Precision Piezo Z-Probe and want to connect it to your duet wifi/ethernet board here's how to do it. Tuning and other aspects of the probe's operation are dealt with in the manuals at http://www.precisionpiezo.co.uk/documents

Electrical connection:
The Piezo20 module or Universal Z-Probe Kit PCB comes with a standard DuPont 3 pin endstop cable attached with correct wiring at the piezo pcb. The other end has three wires red (VCC), black (GND) and green/blue (SIG/TRG). A 4 pin DuPont connector housing is supplied.

Insert the red wire at one end of this housing, ensure the crimp is inserted so the spring clip retains it in the housing. Leave a gap of one pin, then connect black, then green/blue. Insert the plug into the duet z probe connector with the red wire end facing toward the long expansion socket and the green/blue SIG wire facing towards the end of the duet board with the LEDs and sd card slot.

Config.g

You need to define a probe there are two options:
Analogue:
This enables you to adjust the fine sensitivity of the probe on the fly, the coarse sensitivity is adjusted from the pcb. If using a Piezo20 module the signal must be NO (active high) and therefore use the I0 parameter. If using universal kit PCB you can set up the PCB with a NO - active high (I0) or NC - active low (I1) signal. It's your choice but NC -active low offers failsafe operation.

Add
M558 P1 I0(or I1) R0.4 F300 X0 Y0 Z0
(analogue mode, NO/NC, delay, speed, not used as axis endstop)

And

G31 X0 Y0 Z-0.1 P600
(X, Y, Z offsets, sensitivity/threshold)

To reduce mechanical noise from the frame or axis vibration, the R parameter is the delay before probing in seconds, set a longer delay if the probe triggers before contacting the bed.

Probing speed F parameter (in mm/min). A value from 300-420 is recommended. Slower can give more accuracy but too slow may not trigger, as the probe generates a signal on a change (compression or flexing in the piezo disc.

The z probe analogue value is from 0 to 1000. If you get a lot of false triggering increase this value, a firmer bed contact will be needed to trigger. This value can be seen on Duet Web Control in the "z-probe" box. It is normal for this value to bounce around during head movement and printing moves, its only required for it to be stable just before and during probing dives.

Digital:
which is simpler and works as it would on an 8 bit board.

Add
M558 P5 I0( or I1) R0. 4 F300 X0 Y0 Z0
(digital mode, NO/NC, delay, speed, not used as axis endstop)

and
G31 X0 Y0 Z-0.1 P100
(X, Y, Z offsets, debounce interval)

The debounce interval in ms smoothes the signal.

Please note as of RRF version 1.20 you can use M558 P8 instead (other parameters are the same) which is a digital probe but without filtering or smoothing of the signal. This increases accuracy, as it takes less time to react to a trigger.

The Z offset accounts for the compliance in the sensor and is usually -0.1mm as effectively the trigger point is just below the bed (this is opposite with inductive/IR sensors which trigger above the bed). If you have to babystep your first layer lower by 0.1mm, for example, then reverse the sign and add it to your G31 offset or vice versa if you have to babystep higher subtract the value from G31. Example, G31 Z-0.1 is set in config.g, probe/level/home/calibrate then print, if you babystep up 0.1mm then subtract 0.1mm from G31 Z change the value in config.g, power cycle/reset the machine, when your print finishes and you are ready for consistent first layers from now on.

Okay so forget about colours of wires when wiring stepper motors. Every different brand of motor has different colour wiring there is no standard.

This is about understanding how they work. Once you do it will seem simple. They have two sets of coils inside (that's why they're called bipolar). Two of the wires go to one coil, the other two wires go to the other coil.

On most printer controllers, and duet wifi is the same the motor plug has 4 pins. The two pins on one side pins 1,2 go to one coil, the other two pins 3,4 go to the other coil. What you need to do is determine which of your 4 wires from your motor are a coil pair. So get multimeter on ohms/resistance and measure between the motor wires. Two wires will have some resistance between them, they are one pair, the other two wires are the other pair. Now you know how to wire it one pair to pins 1,2 and the other to pins 3,4.

Write down the colours which form the pairs as you might have more of the same brand motors and they can all be wired the same way.

Motor might turn in the wrong direction when you ask motor to move, but its an easy fix if the motor goes the wrong way, TURN THE POWER OFF, then turn the motor plug the other way around, this swaps the pairs over and now the motor turns the other way. You can change the motor direction in firmware, but never unplug or work on motor plugs or wiring with power on, it can destroy the motor driver chips, which is an especially irritating and expensive mistake to make on duetwifi as you can't just plug new ones in.

Yep those are the things. If you have a 1 PSU system and your bed is below the 18A suggested limit, then they are probably an extra bit of kit you don't need. But a 2 PSU system is easily setup using one of these. Plus you get the highest current part of the system off the duet board - not a bad idea really.

Those smaller ones will work for most application they do make an even larger one

But I did buy one of these, they are massive could probably handle 50A+

I have these big red emergency off switches on all my printers.

http://m.ebay.co.uk/itm/Emergency-stop-button-station-twist-to-release-CE-1-N-C-contact-PT-A1-/231146690965?nav=SEARCH

They are only single pole so for mains heat beds in an error state caution is still advised.

I also with a bit of help from David and a few other on reprap came up with a simple smoke power shutoff.

http://forums.reprap.org/read.php?392,578686

It's not been extensively tested to determine if it will shut off the power before a fire begins, but it does latch in an off state when smoke is detected and requires manually resetting once the fault has been cleared, I expect it would work best in an enclosure. No false triggers yet after over a year in use, no genuine one either thankfully. It's obviously independent of the controller, and fairly simple.

What I have started using on my new printer is a plug-in rcd (ground fault device) right next to the machine. I can hit the test button as an emergency stop or general off switch, it should protect me against a mains heat bed problem and its double pole so shuts off the power to the device completely.

@Agniusm:

@DjDemonD:

Plasticmetal- hmm yes i don't know why I posted that, must have been tired and looking at the wrong message. Show us a photo of your setup especially where the piezo is mounted. First thing to try is reversing the polarity of the piezo disc by flipping the plug around at the piezo pcb.

Agniusm - make sure the red led is on by tuning vr2 (or the single pot if its a later revision), then use I1 in M558 (which is active low, the default mode for the latest piezo boards). It should be - red LED on until the piezo is bent/squeezed then it changes to blue for 0.25 seconds. There's nothing wrong with using Z1 (although it's technically deprecated after 1.19) but if homing with a piezo probe you are better off homing x and y then using G30. You might need to change threshold in G31 P…. or consider using M558 P5 mode or P8 mode which I find less difficult to work with.

I have red light and when i touch the nozzle blue comes on without any force. When i home Z it digs into the bed, and stays there. It should just touch it and back off as i understand which is not happening.

I now tried M558 P1, P5 and P8
P8 brings manual leveling dialog in web interface and P1 and P5 acts the same.
I have more recent board with 1 pot and if i adjust it to sensitive it triggers on the start with error message

Okay so on your duet web control, when you tap the sensor and the light changes from red to blue with light force, what does the z-probe box say? It should say 0 (if on p5/p8) then 1000 when triggered, or if on P1 it might read something around 200-300 open and then rise to 700+ triggered.

P8 bringing up the manual levelling dialogue in DWC suggests a software or config problem as that should not happen. Are you using the z-probe connector on the duet? and have you verified the wiring is correct?

Please also do this polarity verification test "push up on the (cold) nozzle (not tap) see what happens, then release the pressure. If it triggers on push it's correct if it triggers on release the polarity is reversed of the piezo disc.

Yes by using a 24v to 12v buck converter. Or by buying 24v heater cartridges.

A 12v cartridge run at 24v produces 4 times the power. That's why you can't achieve this by setting PWM to 50% (as that's not actually 50% lower power) or even PWM 25% which is 50% lower power output because you're forcing the cartridge to run at 120w (when it was 30w at 12v) which is not good from a safety point of view.

As a real ghetto workaround you could run two 12v cartridges in series, but you need to do something with the second one - maybe there is something else that needs usefully heating? More likely to just be a fire risk, having a hot thing flapping about doing nothing.

Initially I used a buck converter as I had 12v fans and heaters, but now I stock 24v ones so I use 24v ones its much easier.

I can understand why different methods of estimating print time remaining all have their individual validity, but given that they all change/converge as the print progresses and are viewed, certainly by me, as fairly much rough guesses anyway, why not just average the three methods and display one print time remaining saving screen real-estate and potential confusion?

Okay so were always answering questions about fans and voltages, buck converters and PWM.

Not a big problem but would it be possible in future revisions of the board to have fans independently powered by the voltage choice of the user. I appreciate having a jumper block for 5v, 12v (and a reg) and Vin (often 24v) would be quite cumbersome, but how about some sort of fan control IC which would allow fans voltage to be set from software?

It would allow the use of the varied fans that people have lying around (also bear in mind not all fans are easily available in all voltages), think Noctua (very popular), but not easy to get in 24v. Might also mean less space taken up on the board if there exists some chip that can do 5v, 12 and Vin rails and PWM multiple fan outputs.

Thoughts?

My experience with this has been to measure temp at the nozzle with an accurate device like a K type thermocouple. If it's correct then it's a mechanical problem. Check extruder gear isn't clogged.

If it's tough to push filament through by hand the nozzle may be partially blocked. Cleaning with microdrills, burning it out with a blowtorch for a good long while these work. But nozzles are often cheap swap it out. Make sure when you tighten the new nozzle to the heatbreak you do it as hot as your setup allows 270 degC or so any loose fit between nozzle and heatbreak will cause problems.

Make sure the heatbreak is clean and be careful not to scratch the inside surface with any tools. Quality all metal heat breaks only work if highly polished or coated in some way. Ptfe lined ones are more tolerant, but make sure the ptfe isn't old and degraded which it does become even at 250 deg C max over long periods.

Also I'd recommend using heatsink compound between heatbreak and heatsink, nothing between heatbreak and heater block and copper grease between the nozzle and heater block.

Just to say the corexy has now been dismantled and the parts are available separately:
https://www.ebay.co.uk/sch/therealdjdemond/m.html

Okay so I'm going travelling and won't be doing any 3D printing for a while, there's not much point in storing these machines as they might be fairly out of date by the time I get back.

I've listed them on ebay so here are the links:
https://www.ebay.co.uk/itm/202386854013
https://www.ebay.co.uk/itm/202386853581

Both Duetwifi powered, the kossel XL has a lot of decent parts on it.
Working capable, machines but a great source of parts as well if you were looking to build something yourself.

I'm in the UK, you would need to collect from Bristol.

I have to agree with David. H300 will instruct the machine to try to begin 300mm above the probing point, which is unnecessary, might be impossible given the z height available and will be time consuming. Sure setting it to 50 (or 20) might make sense if you've just changed something which affects the max Z height, such as slid in a new bed of differing thickness or changed delta arms etc... and this will ensure head crashes are less likely. Also probing from 300mm above relies on your machine to be extremely accurate and repeatable over that 300mm.

Also consider changing G31 P1000 to P100 this is for digital probes a debounce interval and it need not be as long as that.
Many are getting better results with M558 P8 which removes the debounce filtering altogether.

I have found using the latest builds, the multitouch probing options offer a greater sense of accuracy, in that it will throw an error and abandon calibration if multiple probes of each point are not consistent. This prevents a problem such as a loose probe or wobbly bed, generating a nonsense calibration and the resulting craziness that can ensue.

M558 P5 I1 R0.4 F1000 X0 Y0 Z0 H7 A5 S0.02 B1

F1000 - 1000 mm/min travel speed between probing points
H7 - dive height 7mm, enough if things basically stay the same between probing sessions
A5 - probe each point 5 times at most
S0.02 - Tolerance so if probe 2 is within 0.02 of probe 1 then the firmware moves to the next probing point, otherwise it tries again up to 5 times (A5)
B1 - turn off bed heater when probing. Seems to make a difference for some - I haven't made my mind up yet.

On the reprap forum you said that removing the deploy and retract files made the problem worse, this is very illogical since these files are only needed when a probe needs to be deployed or stowed, one feature of piezo probes is that they are permanently mounted and do not require any deployment ot stowing. Did this change help or not?

When deploy/retract was first introduced into RRF my printer did some odd moves, until I deleted these files. Then it probed normally. Post your M558 and G31 as you have them now please.

Hi have you read this?

https://forum.duet3d.com/topic/2671/precision-piezo-z-probes-guide-for-duet-users-reference/99

Just double check the wiring into the duet, as the Orion and latest products come with standard endstop wiring, i.e. +,-,sig so as long as these connections on the duet z probe connector are correct the config should be fine.

Remember its an active low switch so it triggers when the voltage drops, use switch I1 in M558, other than that just set it up as per the guide above ( see the 1st post there).

HiCraig, please see www.precisionpiezo.co.uk or contact us via https://www.precisionpiezo.co.uk/contact

My colleague Idris Nowell now runs the company and can provide support.

That flat cable looks great.

Network cables are problematic they do work harden and the insulation fails, probably in my case exacerbated by having slightly too tight a bend at one point in the cable, but a short from hotend heater (was using 6 cores for heater) and 5v fan kills 2 duetwifi and 2 paneldue boards. Second one shouldn't have gone, but I presumed the first one was a dropped nut which caused the short and installed a second board. That'll learn me.

I can answer some of this as I have upped the voltage on my CR10 to 13.8v.

I'm not sure I can answer your questions exactly as you've put them so,

Your heated bed has a fixed resistance, so a voltage increase will increase its wattage (output), and the gains are fairly impressive.

If you take a 12v 1ohm bed - 144w output
13.8v and 1 ohm bed - 190watts output

and I can confirm on my cr10 before doing this I could not get past 90 deg C on the bed, now I can hit 110.

Peak power demand - when heating up the machine before printing will be 2-3 times greater than the demand maintaining temperature. So you need to cover bed at max, hotend at max and all motors running at maximum speed, when determining what wattage PSU to buy, fans and LEDs can be factored in but unless they are massive don't use much power.

Adequate cooling (extra never harms the electronics - might offend your ears though), is a good idea.

The other issue is that the voltage regulators on your electronics will have to work a bit harder if your PSU is outputting more than 12v. On duet with many machines running on 24v and no issues there - it will make no difference if you go from 12v to 15v. On lesser controllers like arduino/ramps the 5v reg was notorious for failing.

EDIT- what I don't know is whether the total wattage of your PSU will increase or remain the same.

Hi yes, so its all on our website www.precisionpiezo.co.uk and on our reprap thread https://reprap.org/forum/read.php?1,767998 it a fully open source project so its not a secret.

If you connect a piezo disc to an arduino and ask it to monitor the voltage on an analogue pin, you will see that they are incredibly sensitive, any slight vibration or certainly any deformation of the disc will generate a large voltage. Hit one with a hammer and you'll see 50v! (don't do this with your 5v arduino analogue pin please). This is how electronic lighters work, by striking a piezo hard and generating an arc.

In the hotend sensor systems, the piezo disc is deformed when the nozzle contacts the bed. It only needs to be around 0.1m (which is repeatable so you can set this as a z offset) to give a signal, and can be very gentle when correctly tuned.

There is no electrical contact between the Precision Piezo sensor and the hotend, this would be very undesirable as a short or wiring failure would create damage to Piezo PCB or 3d printer controller board.

Autotune won't affect heat up times.

You can check your mosfet board, just connect the bed directly to the PSU, start a timer, and measure the temp, don't leave it unattended when it hits whatever temp your aiming for disconnect it. It should heat up just as fast with the mosfet.

WHat bed (amps or watts) and PSU (24v yeah? what amps or watts) are you using?