Partial Answer Z-axis offset, adjusting.

Having issues with getting PETG CF, to stick to bed. Did get one good print, several hours long.

But, it took several tries. Since I recently changed the nozzle to hardened steel and re-leveled the bed, one of the things I want to experiment with is Z-axis offset, but it is not clear to me what adjustment should be entered as.

I'm guessing there is a "stock" distance above the bed that is produced at "home" and that any adjustments made in the software (MC in this case) would be from that point? So - adjustments would reduce that distance and a + setting would increase it?

What is the proper way to adjust this? At least for testing purposes. Macro in this case? The existing Macro's are all positive numbers.

 

How do I know which version I have? LCD says "RoBo3DR1AUTOV4". Arduino say "Auto_Level_7_17_516inch" on the first tab.

All the macros show positive numbers. Is this as "offset" from whatever the physical distance is upon completion of "home"? So if I want it closer to the bed I would enter some negative value in a Macro, or via gcode in terminal?

 

Thanks for trying to get me going. I cannot find that test print for the first layer, that I think I had at one time.

As mentioned earlier all the Macros contain the M565 code and all of them are positive values. That is my main issue as all I have read seems to say this will attempt to drive the extruder into the bed and the value should only, ever, be negative.

 

Interestingly, does not matter what I enter in the Macro command, what I see on terminal is always a positive, or at least a number without a sign, such as M565 Z0.5 no matter if I put Z-0.5 or Z0.5 in the macro.

 

Oi! Current custpom gcode has G29 as the last in the start sequence. As is then, if issue a macro, then start a print, the macro offset is ignored?

How then can I effectively run any valid tests, other than perhaps exporting some small print and inserting the offset code after a G29?

Which leads me to asking again about the skirt test print referenced earlier.

 

I got it, despite my babbling. I guess this means I have to put the offset code in the start G-Code block and change it each time I want to run a test Which I suppose is not all that inconvenient.

 

Further questions on M565. and Z homing.

Wrong. The sign DOES carry though. I did not have the - sign in the macro I tested. It was a bad day all around, I guess. I did 3 macros and only tested one. I had even knew I should check the others, or at least check my editing, but, was too (insert pejorative of choice) to do so.

 

Further to this sad tale, I have more questions about Z homing.

After home, what should the physical clearance be between bed and nozzle tip? I find virtually ZERO. I have to raise Z about 1.1 mm to fit a .004 inch piece of paper under it.

 

That link shows how to get the the custom gcode place in MC but only shows a G28 command.and some grayed out codes.

One thing that will help me to resolve my questions is how the Z offset, as seen in MC, Settings, Printer, Print Area, affects things. Is this the Global Offset you referred to?

Is this the distance the Z axis will be lifted once the Z limit switches (one or both?) are activated? Seems to me the distance may vary quite a bit from machine to machine due to manufacturing tolerances and user mods, such as lead screw upgrades.

 

And what does the M565 code actually do? This is something I ran across "M565: Set Z probe offset Example: M565 X3 Y4.5 Z-2.37 Set the offset from the extruder tip to the probe position." What does that mean "probe position"? There is no "probe". Does that refer to the position determined by the limit switch actuation?

 

I seem to be finding that neither the Z offset as set in MC nor the M565 affect the nozzle position after a home. The measured clearance appears to be pretty much zero after a home. That troubled me and caused me to drive my frustration level up significantly by experimenting and dealing with test prints that refused to stick to the bed.

I was expecting the distance from nozzle to bed to increase or decrease after a home, each time I changed it. Apparently this is not the case.

Also noticed that the Z axis doe not "lift" before moving X and Y during a Home all. I was pretty sure I read somewhere, maybe in configuration.h that raising Z prior to certain moves was a desired "safety feature". I can see the value in that and wonder if the what I see is normal.

 

I get the M565 has no effect on the Z home position. Did not mean to imply I thought is should, just saying it did not. I'll try to be more precise.

'm srill puzzled by the un-measurable clearance, if any, between the nozzle and bed after a home. Changing Z offset, in MC, as noted earlier, does not seem to affect that. Is there some setting that does affects it?

Also, should I bother to investigate raising Z prior to doing a home? I can look at the source code to see if it is an easy thing to do I guess.