Hello everyone! I’m back again with another question, as after hours of attempted research myself I feel it is faster to ask all the experts here for help. Recently I purchased two Prusa I3 style printer kits made of acrylic out of China (ontop of the one I already had) and am really looking to find a way to upgrade them to auto bed levelling. Being that I’m mass producing a lot of products it’s really becoming the only way to go for me. They all have a melzi board. Primarily I use cura as a slicing software, and recently I’ve started using 3D Printer OS to control and monitor my printers whilst I am away. I was hoping there was some way of integrating auto bed leveling into the mix with some ease, being that I have almost no knowledge of that subject I haven’t the faintest clue. And so I come to you! Sincerely thanks again though to any and all input! It’s much appreciated.
The best and easiest way of implementing auto leveling is by using an inductive proximity sensor, such as the kind Printrbot uses on their printers. Servos are a bit tricky to implement and Lulzbot’s “run a current through the nozzle and board” is almost impossible without custom hardware.
Thomas Sanmladerer has a great video on it here.
Knowing the acrylic kits, I’m guessing the main hurdle you would need to overcome is the bed. Most Chinese i3 kits I’ve seen come with either an MK2 PCB heatbed or no heatbed at all, just a sheet of flat acrylic. You’d need some kind of aluminum sheet to have the inductive sensor work, like an MK3 heatbed. (Aluminum foil is too thin.) If that’s not an option, you’d have to resort to a microswitch mounted on a servo.
Thanks so much for the reply! Sorry I never got back to you, I never got the notification of a response. So I actually do have a heated bed, as well as the exact sensor noted in Tom’s guide, my issue is mostly on the firmware side of things. As well, I was wondering if anybody had further info on the wiring of the sensor, I have two printers, one of which the end stop switches only have two wires normally rather than three. I’d assume one of the wires from the sensor would just run to the printers main power supply’s ground, but do not know for sure.
I’ll post pictures tomorrow when I’m back out in my garage again and can take some
Sorry for the lack of response! (For the record, I wrote this post out 3 times now but the site refuses to post it, and then just refreshes and undoes all of my typing…) I’ve made some headway on this topic and wanted to get back to you all, as well as ask for more advice.
So I’ve actually managed to mount the inductive sensor onto my printer, as well as wired it up and have it working as a z end stop switch now, but still have a couple problems.
Problem 1: Whenever I home all axis, or at the beginning of the print when the print tells it to, the X axis as well as the Y axis home, but this leaves the Z end stop switch, or rather the induction sensor, above mid air. This is a real problem as now the sensor has nothing to tell it to stop moving with and if I dont stop it manually it would just go down until the point where it broke my printer. I’ve tried looking into changing the firmware or the EEPROM and many other solutions but to no prevail.
I’m currently using Repetier host as my slicing software instead of cura which I normally use (I’m just using the cura engine in repetier) As this seems to actually be capable of connecting with my printer.
Picture of my printer with the induction sensor:
I bought it off ebay for 2$, seems to do the trick.
Problem #2: I actually can’t seem to get it to do the auto bed leveling. I know I found some setting in repetier yesterday what was labelled “Auto Level” and had two possible values, 0 for inactive and 1 for active. So I switched it to active but it doesn’t seem to have had an impact. I know some people online say change the start gcode to adding lines like 29 or 32 or whatever they are, but none of them have worked thus far.
My Motherboard:
Melzi board V3.0 with the default firmware on it (Sorry for the blurry picture)
Please, if anybody has any information about what I may possibly be able to do for this, let me know! I plan to make a tutorial video when I go to do this to my other printer that way the next person to upgrade this exact printer won’t have to go through what I did!
My Inductive sensor:
