Upgraded the Anet AM8 to a removable magnetic bed from Here. Went to a 24v power supply for the heatbed only, running through the Mosfet. Spring steel sheet shown is from the stack of heatbeds for the Prusa printers.
Removable Magnetic Bed
Author: kris
2018 lurches to a close
Happy holidays, best New Years Song I know.
http://nervousmetaphor.com:4040/share/Gmpii
Anet AM8 – Hallon Auto-bed-leveling – Octoprint – Marlin 1.1.8
This project took way longer than it really should have. It starts with the Hallon ABL upgrade. I have been putting off upgrading the infamous Anet H-plate far too long, and finally committed to that upgrade.
- H- Plate Upgrade – I ordered this one. The plate itself is well made, and fits the standard hardware. I tapped the holes for the y-axis belt holder to m4. This seems to be working, though if my belt gets loose with some printing I will drill them out, and remount the bed with M5 screws and M5 lock nuts.
- Solid mount heatbed – Printed this spacer in ABS plastic. Printed all close together with a joined brim. ABS tends to shrink in a not perfect manner, so I then used calipers and a file to bring them all down to within .03mm of each other.
- Leveling of the X-carriage – I used a set of 3x2x1 blocks I had laying around to level the left and right sides of the x-carriage to the bed, which i think is more accurate than leveling to the top of the frame.
- Octoprint with ABL expert – Link to plugin repository It is easiest to find in the plugin manager. I set it to bilinear correction.
- AM8 modifications: ABL trigger mod (found this in the comments, haven’t tried it, made my own thing in freecad, though this looks much better than mine, so I am linking it)
- Frame extension: I made a simple spacer, though I saw a full height one somewhere, and will link it when I find it again.
To find roughly your offset, use this procedure:
- G28 – home position (which should show Z-10, safe nozzle position)
- G1 Z0 – this puts it at 0 to the bed, this should be right where paper grabs
- Once you have your offset determined, M851 Z-16.06
- The -16.06 above is specific to my setup, and yours will be different
- M500 to save eeprom
Initial Auto bed level controls added to machine settings in cura
G28 ;Home
G29 ; ABL hallon
Printing with Octoprint, I use the ABL expert plugin. I found the Z correction I found via the procedure to need some tweaking. Always Preheat at least the bed before ABL, not going to have a useful result any other way. Running .1 lower Z compared to paper to get good 1st layer. Expect to have some trial and error here, printing some first layer tests. I think it is a part of letting octoprint do the level correction.
Carpenter bee gets faster.
