Help! First start and homing issues
October 05, 2014 03:08AM
Dear experienced forum members,

may I kindly ask for some help getting my newly assembled Ormerod 1 up and running. I a complete newbie into the 3D business, and just completed the assembling, plugged power, USB and networks in, and all this works. With Arduino, Pronterware or the web interface I can move the head in all directions, and the extruder works. I have firmware updated to 0.78c. The proximity sensor seem to work properly, however the value between 600-700 I do only get at about 3 mm above the bed, not 1.8mm. Is that a problem? The micro switch for the Y end works. I have put rectangle pieces of white paper (25x25mm) on the glass and used Kapton tape on them to fix on the bed (all over). Each paper is about 5 mm away from each edge.

And now I am coming to the issues. I tried hard to follow the manual, but I can't make it. Might be a combination of not my native language (I am german) and some overcomplicated or inconsistend descriptions in the manual, and there seem to be some gaps as well?

First of all, for my understanding. Shouldn't the printer move the bed and the head into its home position as soon as power is ON ? My printer does not. And so it can happen that the bed clashes at the right end of the axis (opposite side of the stepper motor).

Another understanding problem: where should the home position be? I would think, the home position should be somewhere on the left rear corner of the bed, about Y=20 mm frome edge and X=20 mm.

Yes? I think it could not be X0 Y0, because what about those paperclips, which holding the glas bed? The printer head clashes with them in these extreme positions.

When I am pressing Home Y in the Webui, then - depending on where the bed is in this moment, it moves to the right and clashes at the end, and the motor makes loud noise, so I have to switch power off to rescue it.

I tried this Z-homing guide from Ian (http://forums.reprap.org/read.php?340,413271) but then I got error messages "you must homing X and Y before Z". And in the original guide (https://reprappro.com/documentation/ormerod/commissioning/#Test_the_proximity_sensor and [reprappro.com]) I didn't found anything about homing X and Y.

Might be a newbie problem, and a general understanding problem, but I can't crack it at the moment. I am doing circles.

Conclusion: could someone here help me to make a successful start into my first print?

I think I need to understand better how the printer starts up after power on, and how to program homing for X, Y and Z into which config files.

Any useful help would be awesome, and many thanks right upfront!

Cheers
Wolfgang
Re: Help! First start and homing issues
October 05, 2014 03:46AM
Hi Wolfgang, welcome to the forum.

The printer is not supposed to home automatically when power is applied.

The foldback clips do get in the way sometimes, and I recommend replacing them with photo frame clips, See this thread [forums.reprap.org].

You should home X, then Y, then Z in that order. When homing each axis is working properly, the Home All button will home them in that order. But until you are sure that it is all working, home them individually.

When you home the X axis, the head should move up (about 5mm I think), then move towards the X motor, but stop before the head hits anything. Is the head moving the right way? If it is moving away from the X motor instead, then you need to plug the X motor connector the other way round on the Duet, so that the colours are in the same order as for the other motor looms. This changed between firmware versions 0.78 and 0.78a, so you may have wired it up according to the old instructions and then upgraded to more recent firmware.

When you have X homing working, we can look at the other axes.



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].
Re: Help! First start and homing issues
October 05, 2014 05:23AM
Thank you dc42,

That is very helpful. And at which position is the "correct" home position? How many millimeters away from the corner? And how to home correctly? With that Gxx X0 command, after I moved the head into the right position? Do i need to do that each time after power on? Or does the duet remember the last position after power on?

Edit. I think I found the answer. it resets current head position each time after power as the new "home" position. So my conclusion is: it i put the head more or less in the rear left corner, and my print object is not full size (200x200mm) it should not give any problems. Is that assumption right?

And I am coming across two other points:

1) X homing works now well, at all times the head moves close to the X motor, and is stopped by the proximity sensor.

However, pressing "Y Home" let the bed always clash badly at the far Y end, only exception is, if I move it beforehand to the left until it touches the microswitch. Though, even then, when moving 200 mm in one pass, it happens most times, that the bed clashes the other end for half a second, maybe half millimeter too short way.

Do I need to fix this and if, how?

2) And using "Z-Home" button in the Web UI drop the nozzle always so much down, until it lays on the bed and the motor axis is lifting a bit (so virtually something like -2 or -5). This happens regardless of having the command "G31 Z2.8 P680" in the config.g file (and the file is read at startup, I can proof this all the time with IP address setting).

How do I stop this and fix it?

Thanks again so much!

Edited 3 time(s). Last edit at 10/05/2014 06:42AM by WolfgangA.
Re: Help! First start and homing issues
October 05, 2014 06:52AM
Quote
WolfgangA
I think I found the answer. it resets current head position each time after power as the new "home" position. So my conclusion is: it i put the head more or less in the rear left corner, and my print object is not full size (200x200mm) it should not give any problems. Is that assumption right?

Yes, it assumes the head position is (0,0,0) after power up or reset. You should always home the axes before printing.

Quote
WolfgangA
However, pressing "Y Home" let the bed always clash badly at the far Y end, only exception is, if I move it beforehand to the left until it touches the microswitch. Though, even then, when moving 200 mm in one pass, it happens most times, that the bed clashes the other end for half a second, maybe half millimeter too short way.

Do I need to fix this and if, how?

On the Ormerod 1, the bed should move towards the Y motor until the microswitch is triggered, then 200mm the other way. If the bed does not move towards the Y motor initially, then you have the Y microswitch not connected, or connected to the wrong terminals on the Duet, or the loom connected to the wrong tags on the microswitch. You should be using the two outer connections on the microswitch, not the centre one.

Let's sort this one out before we look at Z homing.



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].
Re: Help! First start and homing issues
October 05, 2014 06:58AM
Quote
dc42
then you have the Y microswitch not connected, or connected to the wrong terminals on the Duet, or the loom connected to the wrong tags on the microswitch. You should be using the two outer connections on the microswitch, not the centre one.

Thanks again. I have all this positive. Only that my impression is, that the total way of the bed is probably 1 mm too short! It stops always properly at the microswitch. If I then let it move towards the other end, and I am doing this in small steps, it stops at 200 without clash. If I do it in a single fast move, than a little clash happens.

I would think I should adjust the microswitch a little millimeter away from the frame. However, no clue if that works, there are no longholes for its screws...?
Re: Help! First start and homing issues
October 05, 2014 10:59AM
Your machine should have a full 200mm of travel in the Y direction. If it is triggering the microswitch too early (so that it could in principle travel a few mm further furst), than you could file down the protrusion on the Y rib that triggers the microswitch.



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].
Re: Help! First start and homing issues
October 05, 2014 11:52AM
I'll add that if the Y bed is moving further on a fast move than when you move it in small steps, your belt may be too loose. It is not easy to get the Y belt tight with the original hardware, but once you have it tight enough to print, you could print one of the modified Y belt clamps that make it much easier to get the belt to the correct tension. As an easy way to get a bit more tension on the belt, look at this:- [www.youtube.com]

Dave
Re: Help! First start and homing issues
October 05, 2014 01:29PM
Thank you both, I will check that.

I have a new, more serious issue now.

The Y end stop at the motor side seems to be ignored by the board, this is new. This morning it was fine. If I click 2 or 3 times Y+100 for moving the bed towards the Y axis motor, then it does not stop at the micro switch anymore. The motor makes lot noise when it clashes with the micro switch and aims to move on.

I have double-checked the switch with a multimeter, and also, when powered on, there is a red LED shining, which goes off, when I click the micro switch manually. So it seems to me the switch is still ok.

What I have noticed, is that, for one time today the loom slipped off the board plug, while I was not making anything on the electronics, however, I think it might be related to adding the filament roll on the housing axis, and sorting the cable looms at the backside a bit. And then this loom slipped off without noticing it. However, I remember that it stopped properly only for a single time after putting the loom back into the plug on the board. And since then, I have the non-stopping problem described above.

Could it be that something in the electronics broke when I moved the Y motor to its end while the loom was off?

What shall I do to fix the problem?
Re: Help! First start and homing issues
October 05, 2014 03:13PM
Quote
WolfgangA
Thank you both, I will check that.

I have a new, more serious issue now.

The Y end stop at the motor side seems to be ignored by the board, this is new. This morning it was fine. If I click 2 or 3 times Y+100 for moving the bed towards the Y axis motor, then it does not stop at the micro switch anymore. The motor makes lot noise when it clashes with the micro switch and aims to move on.

That is normal behaviour until you have homed the axis. The endstop switches are not checked in normal moves, only in homing moves. The important thing is that when you try to home the Y axis, the bed moves towards the Y motor and stops when the microswitch is reached.

Even when you have homed the axis, there are ways of overriding the axis limits.



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].
Re: Help! First start and homing issues
October 05, 2014 04:56PM
Quote
dc42
Quote
WolfgangA
, the bed moves towards the Y motor and stops when the microswitch is reached..

Not sure, if you understood me. Exactly that does not work any more. The bed moves beyond the micro switch. Or tries to, the switch does not stop it.
Re: Help! First start and homing issues
October 05, 2014 06:10PM
Check the operation of the microswitch. There is a red LED on the Duet board, just above the 3rd cylindrical capacitor in the row of 4 near the bottom of the board, counting from the left. It should be lit if the microswitch is connected correctly but not pressed. If the microswitch is disconnected, or if it is connected but you press the button on it (and you should hear it click), then the LED should go out.



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].
Re: Help! First start and homing issues
October 05, 2014 10:47PM
Quote
dc42
It should be lit if the microswitch is connected correctly but not pressed. If the microswitch is disconnected, or if it is connected but you press the button on it (and you should hear it click), then the LED should go out.

According to your description the micro-switch works. The LED lit and go out accordingly. However, the bed ignores it and that is my problem. What can I do?
Re: Help! First start and homing issues
October 06, 2014 02:45AM
Wolfgang, I'm not clear about what the problem is. When you try to home the Y axis, does it stop at the microswitch, or not?



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].
Re: Help! First start and homing issues
October 06, 2014 02:53AM
Try moving the Y axis by had into the endstop. does the LED on the duet board goes out when you hear the click from the microswitch? are you sure you connected to the correct terminals on the duet? he duet does come with additional micro switch terminals for X and Z axis that are not connected.

If that does work try the Command M119 while having the Y axis at the endstop. You should get the current sate of your endstops as seen from the firmware.
Re: Help! First start and homing issues
October 06, 2014 02:57AM
Quote
dc42
Wolfgang, I'm not clear about what the problem is. When you try to home the Y axis, does it stop at the microswitch, or not?

It does not anymore.
Re: Help! First start and homing issues
October 06, 2014 03:03AM
Quote
DasBasti
Try moving the Y axis by had into the endstop. does the LED on the duet board goes out when you hear the click from the microswitch?


Yes it does

Quote
DasBasti
are you sure you connected to the correct terminals on the duet?

Yes, because it worked before.


Quote
DasBasti
If that does work try the Command M119 while having the Y axis at the endstop. You should get the current sate of your endstops as seen from the firmware.

Will try that.
Re: Help! First start and homing issues
October 06, 2014 03:24AM
OK, here is another test to do:

Power off the Ormerod

Move the head to about the centre of the x axis, and the bed to about the centre of the Y axis

Turn the Z threaded rod until the head is at least 10mm above the bed

Power the Ormerod on

Check that the z probe reading is less the the threshold you have set in the G31 command in config.g

Check that the Y endstop LED is lit

Send this command:

G1 Y200 S1

The S1 is very important, it is what tells the firmware to check the endstop during the move. The bed should move towards the Y motor and stop when the microswitch is reached, at which point the red LED should go out. If it doesn't stop, check whether the LED is lit or not.



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].
Re: Help! First start and homing issues
October 06, 2014 03:36AM
Thanks dc42, will try this too. As I am abroad on business trip it will take until the weekend before I can answer.

Wolfgang
Re: Help! First start and homing issues
October 07, 2014 11:23AM
Wolfgang email me. Here's my usual advice, in addition to the testing suggested by dc42:

The endstop only works when you 'Home' the axis, not when you move it manually; it is only during 'homing' movements that it looks for the endstop. If you move an axis by hand, it loses it's position; this is called 'open loop' control. 'Closed loop' control, where the position is monitored all the time, is much more expensive!

If the Y homing is not working correctly, first check the wiring (wiring diagram: [reprappro.com] ). Make sure that the endstop wire is connected to the pins next to the Y axis (it is easy to connect them to the Z or X by mistake, and is the most likely error), and that the wiring loom is connected to the OUTER two pins of endstop. Test the endstop by moving the Y carriage by hand, so it touches the endstop. You should hear a little 'click' as it engages, and the red LED on the Duet (next to the Y axis motor stepper driver) should turn off. If the light does not go off, make sure that endstop is correctly orientated and secured, with the button of the microswitch fitting through the hole in the y-axis-plate, and the tab on the y-carriage is connecting with the button.

Ian
RepRapPro tech support
Re: Help! First start and homing issues
October 08, 2014 11:54PM
Quote
dc42
OK, here is another test to do:
Power off the Ormerod
Move the head to about the centre of the x axis, and the bed to about the centre of the Y axis
Turn the Z threaded rod until the head is at least 10mm above the bed
Power the Ormerod on
Check that the z probe reading is less the the threshold you have set in the G31 command in config.g
Check that the Y endstop LED is lit
Send this command:

G1 Y200 S1

The S1 is very important, it is what tells the firmware to check the endstop during the move. The bed should move towards the Y motor and stop when the microswitch is reached, at which point the red LED should go out. If it doesn't stop, check whether the LED is lit or not.

This check is successful. So that is a good sign, I assume.

Edited 1 time(s). Last edit at 10/09/2014 12:06AM by WolfgangA.
Re: Help! First start and homing issues
October 09, 2014 04:37AM
If that test works then Y homing should also, provided that if you are using the standard RepRapPro firmware (not my fork) then the Z probe reading at the time must be below the threshold you set in your G31 command in config.g. So try Y homing again.



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].
Re: Help! First start and homing issues
October 11, 2014 12:36PM
Thank you all for your help. Finally I made it. And I can't even really say, what the reason was. I think mostly I struggled with some gaps and flaws in the online build manual, which I think is written by a professional and not reviewed by a newbie ;-)))

My printer works now, and I am happy! Have a first few success things :-)

thumbs upspinning smiley sticking its tongue out
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