Firmware 2.03 Z-Adjust weirdness
Note that I recently installed a Zebra Plate on my Atom2 and, as the instructions stated, had to readjust my Z offset because the Zebra Plate is VERY sensitive to the 1st layer's extruder height. After a number of experiments with printing test parts I finally ended up with this statement in my GCode header: G29 Z+0.525 ;auto level
This value of 0.525 resulted in good first layer adhesion and layer depth and I printed a number of parts A-OK. After printing my first good test part I put a ; in front of the above statement since the offset is stored in the motherboard EEPROM.
Then I saw that firmware 2.03 was available; since I was running 2.01 I figured it would be a good idea to catch up and I installed 2.03 with no problems. I looked at the Z-Adjust video and decided to try it since I had never done the paper test procedure before.
My initial trial value was Z+0.3 and that was too tight; I could not move the paper at all after Goto Zero. Next I tried Z+0.4 and that was better, but there was still a fair amount of pressure on the paper when it moved. So I tried Z+0.45 and that seemed right on - the paper moved pretty easily but still maintained contact with the bottom of the hot end.
I figured I was good to go so I tried printing a real part. But the first layer did not extrude at all - it was clear the hot end was too close to the Zebra Plate. So I went back to the Z-adjust procedure and increased it to Z+0.5. This seemed too loose when I did the paper test but I left it anyway. My next print was only slightly better - the 1st layer was barely visible .
At this point I decided to go back to the old way and ran a test part with G29 Z+0.525 ;auto level in the GCode header. This worked well and that's where I am now - of course with that statement commented out.
I'm not sure what conclusion to draw from all this. Perhaps it means the paper test simply doesn't work with Zebra Plates. Perhaps I made some mistake somewhere or left out a key step. At any rate my printer is printing fine; I'll have some more interesting posts tomorrow or the next day.
翻譯年糕
Clarence Lee
2015-11-20 07:45:13
Is it possible to z adjust 0.525? Or 0.52 0.53
Birk Binnard
2015-11-20 13:25:44
If I remember correctly I did try 0.520 and 0.530, but 0.525 was a better choice. I do understand that the steppers may not be capable of making a move as small as 0.005mm; all I can say is 0.525 seemed to work best in my situation.
Clarence Lee
2015-11-20 13:28:16
It’s possible. My branch of the revision might implemented the support of the 0.001mm z offset runtime adjustment.
Clarence Lee
2015-11-20 14:37:51
err, after review code, current via lcd most small scale is 0.01mm. It's possible to add function to implement it.
What is your first layer height?
Birk Binnard
2015-11-20 23:09:21
Well I just had an interesting experience!
When I started to print a new part I turned on the printer, did Auto Home, and began printing. The GCode for the part to print had the G29 Z+0.525 statement commented out. But when the printhead reached the
build plate it crashed into the plate and disconnected 4 magnetic arms.
Needless to say I stopped the printer, re-sliced the part with the comment removed from the G28 line, and now the part is printing OK.
This makes me think the results of the G29 command, when executed from a print, is not being stored in the EEPROM. But is this possible? And how to find out? Is there a way to display the vaues stored in the EEPROM?
Clarence Lee
2015-11-21 00:06:01
use pronterface, when connet or M503 displayed the saved array
Birk Binnard
2015-11-21 01:14:16
Thanks Clarence - I don't have Pronterface anymore but I can use SImplify3D to do the M503. I'll post results back here probably tomorrow.
Clarence Lee
2015-11-21 09:03:21
8.184 M500: Store parameters in EEPROM
8.185 M501: Read parameters from EEPROM
8.186 M502: Revert to the default "factory settings."
8.187 M503: Print settings
ref:
http://reprap.org/wiki/G-code
Birk Binnard
2015-11-23 01:30:55
First layer height is 0.250mm; normal layer height is 0.200 mm.
