BLTouch on Anycubic I3 Mega (Version 2 with ultrabase) - Needs to be 8 bit version
This is designed to work with minimal modification from stock for BLTouch integration into the Anycubic I3 Mega
If you haven't already, I highly suggest you upgrade to TMC2208 drivers. Much much quieter, e.g. link below for 5 of them. You only really need X and Y axis drivers i.e 2, but they're so cheap getting 5 is not a bad idea.
What you need is a BLTouch probe (Affiliate link, consider buying from here if you want to give some support to this: http://s.click.aliexpress.com/e/Qr72FaY) - Cheapest price I could find, and was the one I used to code the firmware with.
Make this mount in ABS/High heat tolerant filament, and install it as per his instructions (as far away as possible from hotend) using m3 screws and nuts
Credit to Petrzmax
Download the PDF for clear instructions and images on how to install the BLTouch to the anycubic I3 Mega
Link to firmware using Marlin 1.1.8 with ABL enabled. Firmware also uses Z-endstop for G28 command to level bed, and G29 uses BLTouch to measure bed surface.
Flash this firmware: https://www.dropbox.com/sh/igl7ny8afryajq1/AADOUzbKtO8QfU5q04TysJdna?dl=0
It will use BLTouch 5 x 5 point grid
Original firmware based off derhopp and beaving - uses latest marlin build
And usual disclaimer do this at your own risk, but works well for me
PDF of instructions attached to this group
Link to facebook discussion group:
For those of you who want to play with the firmware, the uncompiled version is here:
Note: If after creating this and using the G29 command, you find the right side thickness of extrusion is much less than left side i.e. right side 1st layer is very thin, while left side 1st layer is much thicker, then you have a problem with the X carriage as I found out.
Print the following Bowden X carriage mount and Carriage converter which is designed to fit the Anycubic I3 Mega. It is an excellent design, fits perfectly, but you will need to buy a new 6mm timing belt, as the one with the stock anycubic I3 mega is too short to reach for the new x carriage. The firmware is slightly different due to different probe height and x/y axis position relative to the extruder, so download from my files section in the link above (Dropobx) the Bowden X-Carriage version of the file.
X carriage - https://www.thingiverse.com/thing:2023947
I found that using 2 bearings for the upper and lower poles of the converter to help with stability, so you need minimum 4 in total like below
You can also print out linear bearings if you wish, but I find these are pretty good
And you'll need 6mm timing belt like below
No more issues with inconsistent bed levelling with the BLTouch. So likely it was the stock carriage and poor x axis alignment with it from design caused the carriage to change its angle as it moved along the x axis , throwing off the calibration values and hence the right side of the print on first later was much closer than the left, something a few people have noted across a few different printers
I'll be updating this with more mods I've performed on my printer, and what I've found has worked, and what hasn't.