Z calibration, endless SD Printing message and failed first print

Hi
I'm trying to make my first print, so I know nothing. Here are a few questions I didn't find solved in the forum (probably haven't looked deep enough).

1) In the instructions for calibrating the Z-sensor, the example is a reading of 650 ish at 1.8mm over the bed. How to I measure the distance (1.8mm in the example)? I have a vernier and a micrometer, but nothing that can fit under the gubbins (technical term).

2) I've printed circle.g. While printing it pulses the message "SD printing" about every 4 seconds. Afterward it spams "not SD printing" continually, until I reset the machine. This sounds like an obvious thing I've missed.

3) After bed compendsation, the instructions says to print the axis structure. This is the first thing I've ever printed, so I don't know how, and it doesn't over any advice on how to print. . . eg how to get filament in the right position (if there is one) in the hot end. When I first tried to print the axes, it wafted away 1 cm above the bed until I killed it (despite following instructions for bed compensation and setting Z=0 while almost touching the bed. The two following attempts had the axes zero themselves, it deposit a spot of PLA on the bed, them home itself and lock (and stream "SD printing"). Can you stop a print in mid flow. I am guessing de-powering to re-set is bad because filament might set inside the hot end?

4) Trying to use the automatic Z sensing, the positions to have the z sensor over my squares include y=-5. Is this okay? Also trying to get the X axis far enough makes it grunt right at the far end of the travel. Although there's a few mm left to move before the bearing hits the end, it refuses to go further, so I cannot get the Z sensor over the square. Do I just need much bigger squares?

I realise part of building a reprap is the journey, and I feel if I can get it working imperfectly then I'll start learning. Any advise most welcome.

Jack

Hi jacqov, welcome to the forum. In brief:

1. Put a standard sheet of 80gsm copier paper on the bed. Make sure there is no extruded filament stuck to the bottom of the nozzle (if there is, heat the hot end to about 160C to melt it). Lower the nozzle on to the paper until the nozzle just grips the paper. Then send command G92 Z0, which defines that point as Z=0. Then raise the nozzle in small steps, watching the G31 reading, until you get a reading of about 650. Then read off the Z height. This is easier to do with the web interface than with Pronterface, because it gives you a continuous z-probe readout.

2. I presume you are using Pronterface to control the printer, and I guess Pronterface is continuing to ask the printer for its status. Again, the web interface is better.

3. I advise against printing the axis compensation piece until you have gained some experience. Print something small instead, e.g. the snowman, then the coat hook. If you use the web interface, then you can stop a print in mid stream using the Pause and Reset buttons. If you install bed-levelling screws and you set the Z axis accurately at 90 degrees to the Y axis, then you don't need to use axis compensation at all.

4. Once you have homed the axes, you can't move to negative offsets unless you override the axis limits by sending M564 S0. So it's not OK to have -5mm as a prove point. I've redefined the upper limit of my Y axis as +210mm so that the lower limit is at 0. Alternatively, my fork of the firmware (described in other threads) allows you to define the lower limits of axis travel too, so you can define the lower limit as -10mm (or whatever) and then a move to -5mm is OK. However, this facility is really intended for the X axis, so that you can define X=0 to be the edge of the bed.

Edited 2 time(s). Last edit at 06/10/2014 12:09PM 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].

Maby some one with a still stock printer could make an instructional video of stuff like changing filements and manualy setting the z hight. Also i wonder if some threds could be made stikey such as latest firmwear mods and frequently asked questions.

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JMC
Also i wonder if some threds could be made stikey such as latest firmwear mods and frequently asked questions.

I think the wiki page for the Ormerod is a better place for it (more stable over time and easier to search for), and that is linked to in the forum description. Then again, none of us frequent posters here are very good at writing stuff for the wiki...

Okay - I've done the paper grip thing. Upon printing the snowman (can I suggest you put this in the build instructions because it does read as the first thing to print are those axes) it still zeroes the Y and X, then grinds the nozzle into the plate again; goes home and locks pronterface.

I'm taking your suggestion about using the web interface. After 3 hours I've had no luck getting the interface to appear in Chrome. I am trusting instructions, changing the IP on config.g to be 10 different from that shown in ipconfig (see images). I've tested the cable, I have green and orange LEDs in the Duet and laptop, and I don't have to wait a minute before the Duet talks to Pronterface.

What have I got wrong?

Jack

Hi jaqcov,

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it still zeroes the Y and X, then grinds the nozzle into the plate again"

I suggest you edit the snowman.g file to remove the G92 homing command near the start. You can edit it with any text editor, e.g. if you are running Windows then Notepad or Notepad++. Then home XY and set Z using the paper before you print.

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I'm taking your suggestion about using the web interface. After 3 hours I've had no luck getting the interface to appear in Chrome. I am trusting instructions, changing the IP on config.g to be 10 different from that shown in ipconfig (see images). I've tested the cable, I have green and orange LEDs in the Duet and laptop, and I don't have to wait a minute before the Duet talks to Pronterface.

First thing to do is to get to the point where you can ping the Duet. From the command shell, use this command:

ping 192.168.1.80

replacing 192.168.1.80 by whatever IP address you have configured the Duet as. If it reports no response:

1. Check that you have the correct M552 command in config.g, no spelling errors.

2. How do you have the PC, Duet and your router connected? Here are two ways that work:

(a) Connect the Duet direct to the router.

(b) If you have connected the Duet direct to the PC, and the PC is connected to the router via another port (e.g. wireless), then you need to bridge the network connections. In Windows, go to Control Panel->Network and Sharing Centre->Change adapter settings. Highlight both network adapters, then right-click and select Bridge.

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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].

Hi Thanks for the ideas.

Notepad can't find G92 in Snowman. It's a pain because notepad isn't respecting the linefeeds in the .g files but a search yielded nothing. I'll look into better editors.

The bridging worked. I have web controller - hurrah! I didn't see that in the set up guide - it would be great to include it.

Many thanks. Its so nice to see progress.

Jack

Sorry jaqcov, I made a mistake. The homing command you need to remove is G28 (not G92), and it's around line 24.

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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].

Thanks for all the support. I have my first snowman.

One issue was windows notepad didn't recognise the line breaks so I had an unreadable block of text. Notepad++ let me see it was waiting for bed and hot end to warm up (I had done this manually), and before I had interpreted that wait as a crash.

Thanks

Jack

Just for the record. The endless messages of SD printing is due to checking the [ ] Watch in pronterface.