How to set z-offset via Octoprint?

[halr9000]

Put my 3dp back on after a lot of CNC and wanted to get Octoprint fully setup like I have it going for my Ender 3. Only issue at this point is understanding when to set z-offset and where so that it persists between jobs and ideally, I don’t have to think about it when I print from different places. I can print great from Luban wifi or local, but jobs sent from Octoprint thus far are not adhering, and I’m pretty certain at this point it’s due to that z-offset not coming across.

I know how to send terminal commands from Octoprint, and have played with a couple, but have not seen a difference yet in results. Also thinking about adding to the start gcode, but I’m worried that it will be a cumulative effect.

Was looking at your post @brent113 and thinking G1029 is the best? You using Octoprint by chance?

How do you change/save updated Z offset without calibrating?

You’re not missing something obvious here, but there is a way to do this. Several ways in fact. I think you’re after item 1, but here’s everything I know just in case. Touchscreen Z offset M421 Q command M206 G1029 D which is a secret undocumented gcode Snapmaker added. Use the Z offset function in the touchscreen. I believe it’s saved between power cycles, and is great for quickly adjusting a z offset. It’s not as straightforward as you probably hope, but the machine stores the Z offse…

[stewl]

I use OctPrint all the time and detailed how I do Z leveling in this post.

Using the Z probe to set bed hight rather than just bed level

On a “standard printer” the Z probe is used every time you print to check ”where the bed is”, you add on the Z offset, the distance between the sensor and the nozzle from the M851 value to put the nozzle at exactly the same height every time you print. This is a very consistent process and takes into account any movement/slop or change in the printer frames or structure every time you print. Snapmaker bed position is measured by the user when they manually set the nozzle height during the final…

[halr9000]

Awesome, gonna hack my start codes!

[stewl]

Hope you have success with it. Been working very well for me since I set it up. I get very consistent first layer even after bed changes which I can watch being put down from my chair in the lounge via the OctoPrint camera

You do need to adjust the Z offset that you get from counting how far down you take the Z axis at the end of the standard manual calibration. Had to do it today after fixing leaking hot end (usual incorrect build). Needed to make the value about 0.3mm smaller. For the manual calibration I moved the Z axis down 0.9mm so I set the Z offset in OctoPrint to -1.2mm but go conservative!