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
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.
