Duet initializations issues

If the E0 endstop light illuminates when the sensor is triggered and off otherwise, then your wiring is correct.

Next thing to check is that the firmware correctly registers the Z probe as being triggered or not. Use the M119 command to do this, or alternatively look at the Z Probe field in the web interface.

You will need the following command in config.g to tell the firmware that your Z probe produces an inverted (i.e. active low) output:

M574 E0 S0

Set the Z probe threshold (P parameter n the G31 command) to 500.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
If the E0 endstop light illuminates when the sensor is triggered and off otherwise, then your wiring is correct.

Next thing to check is that the firmware correctly registers the Z probe as being triggered or not. Use the M119 command to do this, or alternatively look at the Z Probe field in the web interface.

You will need the following command in config.g to tell the firmware that your Z probe produces an inverted (i.e. active low) output:

M574 E0 S0

Set the Z probe threshold (P parameter n the G31 command) to 500.

P parameter in the G31 code was set to 500.

M119 is not reporting that the Z probe is triggered even though the LED is illuminating (both on the sensor and on the Duet)

I entered the following into the code:

Quote

; Axis and motor configuration
M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S1 ; Drive 1 goes forwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M569 P4 S1 ; Drive 4 goes forwards
M574 X2 Y2 Z2 S1 ; set endstop configuration (all endstops at high end, active high) OLD -M574 X2 Y2 Z2 S1
M574 E0 S0

;*** The homed height is deliberately set too high in the following - you will adjust it during calibration

The head still slowly drives itself into the bed. I can watch the E0 endstop LED light up and it just keeps on going.

I had initially tried to remove the original "M574 X2 Y2 Z2 S1" command, but the printer didn't like that at all. It tried to just go "up" from wherever it was so I ended up adding the second "M574 E0 S0" line.

What M558 command do you have at present?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
What M558 command do you have at present?

M558 P4 X0 Y0 Z0

Can you confirm that you have the Z parameter the G31 command in config.g set to sensible (and positive) trigger height?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Here's my G31 line:

G31 X0 Y0 Z.70 P500

This one has me puzzled - it looks to me that you've done everything right. The only thing left that I can think of is maybe the sensor isn't pulling the E0 endstop input down hard enough, or maybe the negative power connection to the sensor is at a higher potential than the E0 ground. Please try shorting the outer 2 pins of the 3-pin E0 endstop connector together, just like a switch would, and then see whether M119 reports the Z probe as triggered.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I shorted the two pins on the E0 Endstop as shown below, illuminating the E0 endstop LED, and M119 via pronterface reports the z-probe "at min stop".

OK, so it works if you short the pins, but not if you connect the diode anode to the STP pin even though the LED illuminates (I guess not at full brightness) when the probe is triggered. It means that the probe+diode is not sinking enough current to pull the STP pin to a low enough voltage for the Duet to see it as a logic Low..

Where did you connect the negative power wire for the probe (the black lead I think) to ground? The best place is probably the Gnd pin on the E0 endstop connector.

You could remove the diode and connect the sensor output directly to the STP pin, but if you do that and the ground connection fails, you could end up feeding 12V into the endstop input depending on the design of the sensor. You could try using a Schottky diode instead of the 1N4148, because that will have a lower voltage drop.

Edited 1 time(s). Last edit at 06/16/2016 09:27AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

You are correct about the illumination difference of the LED, it's not as bright as when I shorted the two pins.

I connected the -12V (the wire is actually blue) into the terminal block where the 12V power comes into the Duet. I switched it to the ground pin on the E0 endstop but it's still reading as not triggered when the endstop LED is illuminated.

I have a couple of Schottky diodes available to me. Will either of these work?

DIODE SCHOTTKY RB531S-30TE61 SOD-523
DIODE SCHOTTKY 45V 0.75A SC79-2

Either of those Schottky diodes should be OK in that position, but the first one is preferable because it probably has lower leakage current.

Edited 1 time(s). Last edit at 06/16/2016 02:52PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

OK, so I finally got an IR prox sensor and wired it as such:

3v (VCC) to 3.3v
GND to GND
OUT to PC10

I switched the line:
M558 P4 X0 Y0 Z0

to read:
M558 P1 X0 Y0 Z0

The LED on the IR prox sensor lights up correctly. however I am only getting two flashes when powering up.
M119 indicates "z probe: at min stop" always, no matter if the LED is lit or not.

When I trigger the bed leveling, the printer homes and then then does a nice (hex?) pattern above the bed and then moves up.

What else do I need to change to get it to actually probe the bed?

Hi Legrand,

Can you confirm that it is one of my mini IR sensors that you have connected to your Duet?

If so, then the wiring is described at [duet3d.com] for all versions of the Duet. On that page you can see that the OUT pin of the sensor should be connected to pin AD12 on the Duet 0.8.5 Z probe connector or the Duet 0.6 expansion connector. Pin PC10 is used for the modulation input on the RepRapPro simple modulated IR sensor, and is ont used by my IR sensor.

HTH David

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hello David,


I can confirm it is one of your mini IR sensors and that's the page/info I was looking for. Thank you.

The only problem I will have to get around now though is that they (Filastruder) sent a 3 pin to 3 pin connector and it's a 4 pin header on the duet. This wouldn't be an issue if the three pins required to be used on the duet were side by side, but they're not. it's 3.3, PC10, GND, AD12 which is why I thought that PC10 was part of the mix.

Questions: Is there a code I have to put in my gcode to trigger the bed leveling for each print (like G29?) or do I do it manually before the print?

Also, when the machine is done with the leveling process, it moves up a set distance in Z and when it stops, it moves really quickly, and offsets the head a little to one side, making a very "nasty-ish" sound (the motors are making the sound). Is that normal?

EDIT: I've been playing around with the auto-leveling feature and after several "deployments" it appears as though sometimes when it finishes, it does so smoothly and I can attempt (more on that in a second) to print, however when it makes the more rough, noisy parking of the head, the z-height is incorrect and any attempt to print will basically ram the head into the bed.

Regarding the "attempt" to print after a "successful" bed leveling, it appears as though my Z-zero height has changed. I have changed my z-offset in the slicing program to -1.4mm and I'm still too far away from the bed for the first layer to be successfully laid down. Is it normal for the Z-zero height to change so dramatically with the bed leveling?

Edited 2 time(s). Last edit at 08/16/2016 07:31AM by Legrand.

Quote
Legrand
Questions: Is there a code I have to put in my gcode to trigger the bed leveling for each print (like G29?) or do I do it manually before the print?

Yes, it's G32.

Quote
Legrand
Also, when the machine is done with the leveling process, it moves up a set distance in Z and when it stops, it moves really quickly, and offsets the head a little to one side, making a very "nasty-ish" sound (the motors are making the sound). Is that normal?

No. Is that what happens when you run G32 manually? If so then it's probably caused by something in your bed.g file, so please show us that file. Also, which firmware version are you running?

Quote
Legrand
Regarding the "attempt" to print after a "successful" bed leveling, it appears as though my Z-zero height has changed. I have changed my z-offset in the slicing program to -1.4mm and I'm still too far away from the bed for the first layer to be successfully laid down. Is it normal for the Z-zero height to change so dramatically with the bed leveling?

Running G32 will reset the Z=0 height according to the heights that the probe detects. Have you measured the sensor trigger height, and used that height (in mm) as the parameter in the G31 command in config.g?

Edited 1 time(s). Last edit at 08/16/2016 08:24AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

OK, I think I got it. The issue with the weird noise was that the feed rate in the bed.g file for the z-retract was set at 15000 which was clearly much too fast for my printer. It must have been skipping. I slowed it down to 5000 and I haven't seen any issues since.

I set the z-height in G31 (following IR Setup) and added a G32 to my files and am now successfully am printing again.

I guess the only other questions I have would be:
Do I need (or can I set) some sort of offset from the IR probe to the nozzle tip?
Can I set any other points to probe at or are they permanently pre-set? I upgraded this printer to a 12" bed (like yours) and it seems like it could be probing out further on the bed.

Quote
Legrand
Do I need (or can I set) some sort of offset from the IR probe to the nozzle tip?

Yes you could (in the G31 X and Y parameters); but you don't need to do that when using a Z probe to auto calibrate a delta, because what matters is the nozzle position at each probe point, not the sensor position. So the X and Y offsets should be left at zero.

Quote
Legrand
Can I set any other points to probe at or are they permanently pre-set? I upgraded this printer to a 12" bed (like yours) and it seems like it could be probing out further on the bed.

The points are defined in the bed.g file. You can use whatever points you like, as long as the head can move to those points and the sensor is over the bed at all of them. Here [escher3d.com] is a bed.g file generator that you may find helpful.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thank you very much David. Hopefully I'm good for quite some time (or until I install these magnetic arms I'm building).

I had some fundamental build issues with this large delta printer that I needed to correct. When I had built it I had bastardized a FolgerTech 2020, replacing the all of the legs and the bed to make it bigger. One thing that I didn't notice was that the aluminum extrusions from FT were not particularly high quality. They were cut in such a way as to cause the upright legs to bow outward in the middle by about 1/8" when the printer was fully assembled and the screws were tightened down. As you can imagine this caused all sorts of printing issues.

Over the last week I've replaced those corner extrusions from FT with a different version and this time I checked for squareness, skewnwss, parallelism, etc. and I'm much happier with the build quality now. When I use the Duet auto-level function, it looks like the head is travelling in a much more "square" fashion to the bed. The IR sensor seems like it's always about the same distance away from the bed, it's not closer on one side, and farther away on the other.

After reassembling the printer and resetting my z-height, I've tried to print a few times now but the head keeps ramming into the bed. I have checked my z-height and have actually decreased my build volume by 2mm from where it should be but it doesn't seem to make a difference. If I send the head to "Z 0.0", it's a couple of mm above the bed but if I print, the head just drags across the bed, scraping the surface. All I can think is that the auto level is doing something that I don't understand and it's setting the head distance such that it's grinding into the bed.

I know that my bed is high in the center, probably by 2mm or so. I don't know if that's the issue or not. I'm considering going to a 1/4" piece of aluminum that's Blanchard ground to make sure the bed is flat, but then I have to wait for another heater to come from China and I'm under a little pressure to get this thing up and running.

Any ideas what might be happening here?

Thanks.

Never mind, I figured it out with the prodding of someone else. There was a Z value in my G31 gode that was causing the issues. I zeroed this value out and then ran the auto level sequence and determined how far the nozzle was from the bed at "Z0". I have to make a couple more minor adjustments, but it looks like that was the issue.

Edited 1 time(s). Last edit at 10/20/2016 08:53AM by Legrand.