Z - Offset in S3D - not zero for some parts

[Alan555]

I'm sure this has been answered before in the forum but as I am not even sure how to describe it then searching has revealed nothing.

I was trying to add a separate process to a part so that the top of the part gets printed with better quality. I'm just feeling my way with this but have encountered a problem. I have double clicked on the part and got the position, scaling and rotation panel. My plan was to drop the part down and note the Z offset for where I want to start printing at the finer resolution.

Not sure if that is the best way to do it, but my query is this:

Some parts when I open them and bring up that panel show the Z Offset at Zero with the part on the bed, while others show it at very different heights i.e as my screenshots. Is there a way to set the Z offset for the part to Zero when it has been dropped on the bed? This would make it easier to visualise and note the height relative to the bed.

Screen Shot 2018-02-27 at 14.19.41.png (19.95 KiB) Viewed 2971 times

[wirlybird]

I think if you look on the print preview screen at the lower left you will get the actual layer height you are looking at. So, if you use the slider at the bottom to "slice" down through the part to the level you want it should show what that height is.

See if maybe that helps.

[Alan555]

Thanks,

I have used that before to get the height and it worked out not too badly but just wondered why some parts are at Zero on the bed plate and others not after you drop them on the bed?
Would be good to have a Zero point to work from each time.

[wirlybird]

Yea, I think it is relative to the parts orientation as it is loaded. Like if you have a box sitting at "0" on the Z in your CAD program vs. it is at "25mm" Z in the CAD program.

[Alan555]

Ah, never thought if that, so really it's where the part is placed on the design software planes when the stl is created. I have just tried that with a small part I created in Fusion 360 and it came out at Z zero in S3D

[Aha]

Part alignment numbers are really stupid from getting imported from other programs. No matter what plane I make them in in Solidworks, it never goes flat like it should!

[DarthRevan]

After you have dropped the part to the bed in S3D, you can use File > Export STL to have the new coordinates be applied. Import it back in and it should show the Z offset as 0.