Toolhead offset shifts the print inside preview mode

[Martin Majewski]

Hello,

somehow the common way to add toolhead offsets does not reflect inside the resulting gcode - haven't found any hint for a offset command there.
So I added the M218 command as starting script manually. But unfortunately it seems that my Marlin FW revision ignores it.

I used slic3r for months before I switched to S3D (I switched to S3D because of the customizable supports) and had no problems with the tool offset setting there. So i digged into slic3r's gcode results and realized that slic3r calculates the offsets directly into the coordinates. So I activated the "Apply toolhead offsets to G-Code coordinates" option in S3D and got the desired results during print.

BUT: As soon a I hit "Prepare to print" I get a preview where all my objects are shifted by the offset. This can be "as designed" by you guys at S3D for sure, because the offsets are integrated into the coordinates, but this is not what one would expect - especially it only one toolhead is providing an offset

This topic is somewhere between a bug report and a feature request.

I think it would be convenient if one of the following options would be available:

1) An option to "turn off" offsets in preview mode aka. subtracting them again, or

2) to make S3D smart enough to distinguish between absolute and relative offset settings.

Absolute offset setting are offsets that I want to reflect directly on the spatial position of my objects on the print bed.
Relative offset settings are values that relates to mechanical characteristics of the printer and has to be provided to calibrate the printer's origins.

My MendelMax 3 dual extruder printer has its secondary extruder left to the primary (by design) and the secondary's offset it therefor -32,90mm - and therefor outside of the bed when at home-positon. So to get to the print bed's origin, I have to move the X-axis +32,90mm to the right, resulting in a relative x distance of 0mm from the bed's origin. S3D however shows my prints 32,90mm inside the print bed's x direction. So everything that I want to position at the right most position at 250mm is shown as outside of the print bed.


Sincerely,
Martin

[CompoundCarl]

Read this: viewtopic.php?f=9&t=3494&p=15311#p15311

You're using the third option from that post, which should only be used as a last resort. What version of Marlin are you using which doesn't support M218 commands? It was added all the way back in 2012, so if yours doesn't support it, you may want to update your firmware

Anyways, if you tell the software to actually offset the gcode coordinates, then it's going to look different in the preview. I don't see any way around that. For example, if you imported the gcode you made in slic3r, it would look the exact same way.

[bluecough]

I just purchased the software yesterday and finally got everything setup on my rig. I have a dual extruder and had to set the offset for T1 to be about Y:50mm.

When I print it comes out perfectly centered on my print bed however on the software, the preview is now offset by the amount described above. Is there a way to fix this?

Preview is offset

[CompoundCarl]

You need to fix the toolhead offsets in the firmware. That's how you are always supposed to do it. That will make the display correct.

[Oaken]

When I setup a job to print on my Raise3D 305x305x305 and press prepare to print the print shifts a good 25mm to the left.

[CompoundCarl]

Yes, that's because the Raise3D firmware was based on Marlin, but they chose to completely disable the ability to correctly set your toolhead offsets (even though it was already implemented in Marlin...)

So because of that, you have to literally shift every single XY coordinate in the gcode file to try to fool the printer into moving to the correct location. So that's why you see shifted positions in the gcode preview. It has to shift all of these coordinates to account for the misconfigured firmware.

You should ask the Raise3D people to just re-enable proper firmware offsets in their Marlin firmware and then you wouldn't have this problem. That's how pretty much every other printer and firmware out there works.

[Mike Welsh]

Hi,

I am having trouble getting the same results in the preview that I see in the main view.

My Steps to create the problem are:
1. Load my two STL files (body and light pipes).
2. Reset their positions so they line up.
3. Use the dual extrusion wizard and set each to the appropriate print head.
4. rotate the group by 270
5. click center on bed.
6. I can verify from any angle that the models are aligned and the correct color/material.
7. click prepare to print.
8. The process selection dialog I choose: select all, continuous print, and click ok

Upon completion it's immediately visible after processing that the objects aren't in the same positions as the main view.

Somehow the light pipes have moved.

I have attached screenshots that show the correct position in the main view and the wrong position of my light pipes in the preview.

Anything will help...

Thanks!
Mike Welsh

[brian442]

You probably have toolhead offsets enabled. What printer are you using?

[Mike Welsh]

I am using the default settings for the Raise3D N2 Plus.

[Mike Welsh]

So if I go to my 'Setting Dialog' and look on the 'G-Code' tab I see combo box labeled toolhead offsets.

I haven't changed them so the default settings are 'tool 0' x:0,y:0 and 'tool 1' is x:-25,y:0.

So we think this are wrong?