ORMEROD 2 Beginners guide... Z-Cal

Hi All you 3d print beginners out there
I would like to share some of my build experiences/frustrations that I experienced during my RRP O.R.2 ----- I`m by no means an expert this is a BEGINNERS opinion !!
I battled through some setup stuff that wasn`t clearly explained in my opinion...
The biggest battle to get the OR2 printing was the fact that the nozzle/Head (mounted on the X-Axis) and Z-Axis up/down was not set-up correctly
I misunderstood a few things, SLIC3R settings !!
More later
Z-Cal it turns out to be the most crucial setting, here is how I do/did it...
In Pronterface (PF) I did the following
1- Switch the AC off so that the steppers are free to move
2- Push the table all the way right until you hear/feel the micro-switch click then pull it back about 10mm
3- Then switch the AC on
4- Click the all home button the PF
5- The X axis will pull back to the edge, and the IR sensor will detect the X home poss, then it will do some other stuff and stop
6- Now I clicked the Z Home button, the head moves forward and the IR detects the white paper on the bed, it then dropped down to "a" height it can be anything
7- Now use the Z up bar to lift the bar up to around 10mm, then send a G31 command, you will see the count in the PF window...
8- Drop the head by 1mm and send G31 again, until you get a reading around 550 or so, click the Get Positions button, you see Z has a value...any value, doesn`t matter
9- Now send the G92 Z0 command, check the Pos again, it will now be zero
10- Now send the G31 Zx.x P550 where the x.x will be the height above the bed -0.1mm here you must measure, with something ACCURATE...say a vernier or something
11- Then enter that command, G31 Z2.3 P550, 2.3mm in my case
12- Click the Z home button again, you will now see that the head drops to just above the bed, if you check the Pos again, Z will be zero
13- Click the All Home button and you will see the head pull back do some tricks and then drop to just above, I would suggest 0.1mm above the bed
This is not an exact science to do it a couple of times to get the hang of it,

*Layer height, I thought it was 0.1mm, not correct, if the nozzle is 0.5mm and you set slic3r to 0.1mm it turns out a mess... I started at 0.5mm and got some results
*Nozzle hole size, it is 0.5mm not 0.1mm.... if you set this wrong in SLIC3R you will either get to much or to little material.
*Print perimeters, are very important, you can let the printer do a couple of loops so that the head it nice and hot and the material is flowing freely....then you can start with the part
Hope this helps someone out there
I will post more as I go along and discover things the "hard way"
Tx Ben

Quote
BenBB
*Layer height, I thought it was 0.1mm, not correct, if the nozzle is 0.5mm and you set slic3r to 0.1mm it turns out a mess... I started at 0.5mm and got some results
*Nozzle hole size, it is 0.5mm not 0.1mm.... if you set this wrong in SLIC3R you will either get to much or to little material.
*Print perimeters, are very important, you can let the printer do a couple of loops so that the head it nice and hot and the material is flowing freely....then you can start with the part
Hope this helps someone out there
I will post more as I go along and discover things the "hard way"
Tx Ben

I usually use a layer height of either 0.2 or 0.25mm It is possible to print with a layer height of 0.1, but prints will take a long time. It is best to set the 1st layer height higher - the thicker the first layer (within reason) the more forgiving it is of an inaccurate Z zero height or inaccurate bed compensation. Personally I set the first layer height to 0.25 (i.e. same thickness) if printing 0.25mm layers, but 0.4mm if printing at 0.2mm layer height.

The nozzle diameter does not directly affect the amount of plastic Slic3r will extrude, but will affect the default extrusion width (which can also be set manually and indirectly affects extrusion rate but the print should still be OK)

The skirt's main purpose is indeed used to get the plastic flowing. You can set the number of loops to 1, but also set the minimum extrusion length to 15mm or so. That way a large print will have only one loop (which will be enough to get the plastic flowing), but a small print will have extra loops in order to extrude the minimum amount set so that it also gets the plastic flowing.

Dave

Hi Dave
Tx. I Will try those settings. The heat of the lpa I see is Very important as well, I tried cold and hot 180 to 220. Higher seems to cause the part to warp more than colder and one cannot print fine details it start to warp very bad.
what can you comment on the actual nozzel height from the bed.. initial printing. 0.1mm?? It seems to squash the material quite a bit
has anyone printed the ctrlv_3d_test.stl from thingiverse... mine turned out on a scale of 1-10 around a 6 its not very good. Stringy on the bridges and it seems to extrude too much material. How can I get it to extrude a but less material.
I also find that one must set slic3r to extract material with every layer change. Otherwise blobs appears. But how much... I started with 2 mm extraction it helps quite a bit.
BEN

Quote
BenBB
..what can you comment on the actual nozzel height from the bed.. initial printing. 0.1mm?? It seems to squash the material quite a bit...

You should alway zero you nozzle at the surface of the bed, thats what you slicer program expect, e.g. if you set your first layer hight at 0.25 the nozzle will start the first layer those 0.25mm over the surface

if on the other hand you "zero" the nozzle at 0.1 the first layer will be 0.35mm

Erik

Retract length of 4mm works well with the Ormerod. Set the Z zero height manually for best results. Heat the bed (but not the nozzle). Make sure the nozzle is clean (no plastic drips). Put a sheet of ordinary copier paper under the nozzle and lower it 0.05mm at a time while sliding the paper around until you can feel the nozzle gripping the paper (you will feel the fan vibration through the paper) but you can still move the paper. Set that as 0 by entering the command G92 Z0 Make sure you are not pressing down on the bed when sliding the paper around.

Use a similar method for setting the bed compensation, but instead of zeroing the Z height, read the height at the 4 (or 5) points you have selected for bed compensation.

Dave

Mnnn.. a bit different to other methods, yours make sense no comp needed But what about that G31 compensation setting; the guys claim the ir is not good at 950 so they lift the head to around 550 then zero z and then add the extra offset with G31 Zx.x 550 or whatever the ir reads
I can see it works. But yes it's impossible to judge the exact height the head must drop unless you have an accurate caliper to check z when the IR reads 550 ...
so I need to remove the G31 comp from the config file as there is already one in there and will contradict the Z zeroing.
My version of code only allow for a 4 point cal. can I simply add the command M557 P4 X100 Y100.... or will I need new firmware. I use 0.78c
To recap; set the z axis with the paper method and the zend a G92 Z0. The software will now remember this. I think I will zero the z axis there where it always starts to print 100x100... it just makes more sens, why zero at 0x0 ???

Tx Ben

Edited 2 time(s). Last edit at 03/17/2015 02:06AM by BenBB.

To calibrate the G31 height, position the head so the sensor is over one of the white squares. Lower the head until it just grips a sheet of paper. Then send G92 Z0. Then raise the head until you get a zprobe reading of about 600. Read off the Z height on the web interface, or send M114 from Pronterface to get it.

---

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].

To set bed compensation completely manually (I found the original IR sensor far too inaccurate so stopped using it for Z height), set the Z zero height at one corner using the paper and G92 Z0 as described. Then raise Z to 5mm, move to the next corner and lower 0.05mm at a time until it grips the paper as before, but this time instead of zeroing the Z height, read the Z height reported from the web interface or by sending M114. Do the same with the remaining 2 corners. Then enter the figures you read in your compensation command (the first corner will be 0, the other 3 corners will be the values you read).

If you are not going to use bed compensation (which is better), then set the bed to be mechanically as level as you can get it. The less level you were able to set the bed, the thicker you should print the first layer (Slic3r first layer settings - don't go thicker than 0.5mm, and set the Z zero height at the lowest part of the bed within the area of the design you are about to print).

I have found that DC42's improved IR sensor board is accurate enough to use for reliable automatic Z homing and bed compensation.

Dave

Quote
Dave
Then enter the figures you read in your compensation command (the first corner will be 0, the other 3 corners will be the values you read)

OK here I`m a bit lost here, where do I enter these comp. values once I get them,
which command do I use
and do I do it manually in Pronterface,
or in the CONFIG.G file on the SD card ?

(I do find the IR quite repeatable, it always shows close to the 554 to 556 count when I cal the Z, around 2.3mm from the bed... )

Ben

Edited 1 time(s). Last edit at 03/17/2015 03:13PM by BenBB.

I've updated the Ormerod 2 instructions with a 'quick' version of setting the Z-probe: [reprappro.com]

Ben: "Copy the G31 Z[zzz] P[ppp] command you have derived into the config.g file on the SD card."

Ian
RepRapPro tech support

Quote
BenBB

Quote
Dave
Then enter the figures you read in your compensation command (the first corner will be 0, the other 3 corners will be the values you read)

OK here I`m a bit lost here, where do I enter these comp. values once I get them,
which command do I use
and do I do it manually in Pronterface,
or in the CONFIG.G file on the SD card ?
Ben

It is the G30 command that sets the height of each corner and initiates manual bed compensation. You send a separate G30 command for each point (corner) with the last command having an "S" parameter to cause it to execute e.g.

M561
G30 P0 X60 Y30 Z0.00
G30 P1 X60 Y170 Z1.10
G30 P2 X150 Y170 Z2.00
G30 P3 X150 Y30 Z-0.9 S

The "M561" command removes bed compensation so we start with a clean slate.
The "P" parameter is the designator for the point, from 0 to 3 (for 4 points). I believe these points should be ordered in a clockwise direction.
The "X" and "Y" parameters give the position of each place you measured - usually close to each corner but clear of the clips.
The "Z" parameter is the height of the bed you measured at that point. These can be relative to anywhere (e.g. the bed center), but with my method they are relative to the first corner (which is thus always zero). It will have the same result whatever the case.
The "S" parameter is present at the end of the command for the last point only and results in the compensation being computed and executed.

You can enter these commands by hand (to test), and once you are happy with the compensation they can be put into config.g or at the end of a homing file if your bed is very stable.

The heights can however change from print to print if the bed is not too stable, so what I used to do before upgrading to a sturdier bed was to have a separate G file that I created with a text editor that I called "SetBed.g" (the example commands is a copy of that file). I loaded this file into a text editor and changed the Z readings to suit my measurements as I took them prior to printing, and then saved the file and sent it to the printer as a normal print file. The compensation should only be carried out after the bed has reached its set temperature because it can change as the bed heats up.

If your IR probe gives good, repeatable results you are lucky and can use the automatic method described in the commissioning section, though once you become adept you can carry out the manual method almost as fast.

Dave

Revised Z-Cal
I would like to share some of my build experiences/frustrations that I experienced during my RRP O.R.2 -----
I`m by no means an expert this is a BEGINNERS opinion!!
I battled through some setup stuff that wasn`t clearly explained in my opinion...
The biggest battle to get the OR2 printing was the fact that the nozzle/Head (mounted on the X-Axis) and Z-Axis up/down was not set-up correctly
I misunderstood a few things, SLIC3R settings !!
Before you begin make sure that your 3d bed is as level as possible, go through the Ormerod setup procedure and GET IT RIGHT! If your bed is mechanically level with the head then the rest of the cal will be much more accurate and straight forward. Get the G31 IR values as close as possible to one another and in the order of 550 to 600..
(Revised Z Cal)
Z-Cal it turns out to be the most crucial setting, here is how I do/did it...
In Pronterface (PF) I did the following
1- Switch the AC off so that the steppers are free to move
2- Push the table all the way right until you hear/feel the micro-switch click then pull it back about 10mm
3- Then switch the AC on
4- Click the all home button the PF
5- The X axis will pull back to the edge, and the IR sensor will detect the X home pos. then it will do some other stuff and stop
6- Now I clicked the Z Home button, the head moves forward and the IR detects the white paper on the bed, it then dropped down to "a" height it can be anything
7- Now use the Z up bar to lift the bar up to around 10mm, then send a G31 command, you will see the count in the PF window...
8- Drop the head by 0.1mm and send G31 again, until you get a reading around 550 or so, make a note of this value! You will use it later
9- The do the G92 Z0 command
10- Now place a standard 80gram white A4 paper under the nozzle, you only need the corner of the A4…
11- Drop the head in PF with the Z down button, by 0.1mm at a time, moving the A4 back and forth until you feel the A4 paper touch the nozzle, you will feel the fan vibrations as you drop the head
12- Now do a “Get Position” command, note the Z value, say it shows around 2.3mm…
13- Now lift the Z axis until it reads Z0.0 and do a G31 again, just to confirm the IR val is still as before… or close…
14- Do a G92 Z0 just in case…then enter the G31 Zz.z Pppp where z.z = 2.3mm in my case and ppp = the IR value…
15- Now click the Z-Home button, put the A4 corner under the nozzle, as it drops down you will feel it grip the A4 corner, BUT it must still be able to move once it stops, you can feel the fan vibrate through the paper
16- Switch off the AC and repeat step 2
17- The press the home button and all with return to pos. X0, Y0, Z0

I found that this method was the only one accurate enough to make proper prints
This is not an exact science to do it a couple of times to get the hang of it,

*Layer height, All I can say is that you need to experiment with layer height 0.25 is a good place to start
*Nozzle hole size, it is 0.5mm not 0.1mm.... if you set this wrong in SLIC3R you will either get to much or too little material.
*Print perimeters, are very important, you can let the printer do a couple of loops so that the head it nice and hot and the material is flowing freely....then you can start with the part
Hope this helps someone out there
I will post more as I go along and discover things the "hard way"
Tx Ben