Offsets & Print Preview

[greybeard]

I recently upgraded my ‘Hictop 3DP i3’ printers with V6 hot-ends.

The V6/Nozzle at home position (set by the limit switches) is 10mm and 5mmm off the bed X/Y respectively.

I iterated on various settings and ended up with prints that are properly centered on the bed.

Everything is perfect and prints great

However, the Print-Preview representation in Simplify is not how it gets printed nor the same as shown before Print-Preview.

Because of the V6 offset and clips holding the glass, the maximum print area is 192x226. Thus, I set the Bed size to 192x226.

To compensate for the 10mm/5mm V6 offset, I set the Origin Offset as shown. I could/should adjust the X-axis another 2.5mm, but, it’s good enough.

The problem is the Y-offset with respect to Print-Preview

Why? What needs to change?

[mroek]

You have a global G-code offset of 36 mm in the Y-axis, why is that? That's what (correctly) offsets the part in the preview, the odd thing is that this is not actually how it prints.

[greybeard]

36mm puts the actual center of the part correctly in the center of the print zone. Without it, the part prints 36mm lower on the bed.
It prints where I want it (center of print zone).
It works great in Slic3r - both print and print preview.

The problem is only with s3d print Preview.

[mroek]

I don't get this. You have intentionally added a global G-code offset, and when S3D correctly applies this offset and shows it to you in the preview, you complain that it offsets the part?

When you choose "Center and arrange", S3D will geometrically center (and arrange) your parts on the bed, ignoring both global G-code offsets and origin offsets (which it should). The X and Y settings for "Build volume" dictates the size of your bed, and parts will be centered in this area. Origin offset tells S3D where the nozzle is in the homed position (related to the bed), so that it can print onto the bed as shown in the preview.

For the preview, it will apply the global G-code offsets to show you where the parts will actually be printed. If the parts do not print as shown in the preview, something else is wrong. I would argue that you should not need any global G-code offset here.

Try this: Set both the global G-code offsets and origin offsets to 0, and load up a test cube or some other small simple part, and slice and print a couple of layers of it (no need to print the whole part). Then measure where it is on the bed, and compensate using only origin offsets. The offsets to enter are the measured distances (in X and Y) between the actual center of the part and the actual center of the bed.

[S3D-Jake]

Use the origin offsets to correctly position the origin in relation to your build area. This will make the grid for your printable area have the correct size and models will be positioned properly.

If it helps you can also make a quick simple model for your print bed and import it using tools > options > machine > add.

[greybeard]

I readily admit I can be confused so, perhaps the best way to resolve this would be for you to fill-in the values to accomplish this. The two panels needing the values are the Pref’s>Machine and the Gcode:

Origin Offset
Toolhead Offsets
Global G-code Offsets

(Refer to the attached and previous attachments - the filled-in panels for offsets are shown in my post on the General Discussion page)

Physical Nozzle is off the bed (10mm to left and 5mm above bottom edge of bed)

The printable area is 192x226 and is 36mm above the bottom edge of bed.

I want both the Centered/Arranged view, Print Preview and actual Print to be in the center of the print area.

[greybeard]

Following up on "Mroek" comments

Origin offset tells S3D where the nozzle is in the homed position (related to the bed), so that it can print onto the bed as shown in the preview.

If you looked at my posted values, you’d see the X-Y Origin Offsets are set a -10 and 5. This is the Homed Nozzle position. It is correct.

Try this: Set both the global G-code offsets and origin offsets to 0,

If I do not set the Y-axis Global Offset to 36, printing is 36mm below the center of the print area.

The offsets to enter are the measured distances (in X and Y) between the actual center of the part and the actual center of the bed.

My Bed is larger than the Print Area

[mroek]

Following up on "Mroek" comments

Origin offset tells S3D where the nozzle is in the homed position (related to the bed), so that it can print onto the bed as shown in the preview.

If you looked at my posted values, you’d see the X-Y Origin Offsets are set a -10 and 5. This is the Homed Nozzle position. It is correct.

No, it is not. You need to include those 36 millimeters in the origin offset calculation. The origin offset should be the offset in relation to the origin of the printable area. And global G-code offsets should be 0.

[greybeard]

You need to include those 36 millimeters in the origin offset calculation. The origin offset should be the offset in relation to the origin of the printable area. And global G-code offsets should be 0.

Thank you! I seemed to have made a mountain out of a Mole Hill. Sort of...

Indeed, setting Global Offset's to 0 and X-Y Origin Offset to-13.5 and -36.0 took care of it. With the exception that it shows the origin those distances off of the Bed. I can live with that but, what I wanted was to show them off the Bed by only -10 and 5 (and off the Print Area off by 36).

I'll leave it where it is now and Thank You (all) for the help

[mroek]

Indeed, setting Global Offset's to 0 and X-Y Origin Offset to-13.5 and -36.0 took care of it. With the exception that it shows the origin those distances off of the Bed. I can live with that but, what I wanted was to show them off the Bed by only -10 and 5 (and off the Print Area off by 36).

I get that you wanted the visible zero to be at the corner of the printable area, but that would in fact be misleading. You have intentionally made your print area be smaller and offset from the real zero, so in my opinion what S3D does is exactly right. It shows you where the nozzle is homed to, and that can be pretty useful at times. For instance, in the print preview you can enable travel moves and see exactly how the nozzle will travel into the print area.

Anyways, glad I could be of help.