Hi everyone!Earlier this year I posted a video of an error-correction system I was working on, and there seemed to be some interest in this sort of thing.I’ve spent my time since then working on the encoder modules I was using, and getting them – and a fork of Marlin with the error-correction functionality – ready to go.It’s taken a bit longer than I expected – some of the parts I was using were discontinued, and I had to revise the design a tad – but I’ve now got a batch of these encoder modules ready to go for anyone interested in playing with them.I’ve written up a post on the Aus3D blog with a bunch more information – there are some photos / a video there, and they probably work better than me writing stuff does.As a quick summary, these modules are basically magnetic linear encoders that communicate over an I2C bus. They do all the heavy lifting of tracking their own position, so they don’t bog down the main control board constantly polling or generating interrupts as a raw encoder would. They’re compatible with most any control board – RAMPS is plug-and-play – and give the printer’s firmware the ability to know the exact position of the axis at any given time.The control board can use that data to do a lot of stuff. Most importantly, it lets the printer check that the axis is where it’s supposed to be, and fix things if it isn’t – so this means that skipped steps ‘heal’ pretty much straight away, instead of resulting in permanent layer-shifting.Here (Imgur) are two sample prints I did earlier, with the X-axis stepper-driver massively overheating. The one on the left has the error-correction system enabled, right has it disabled – everything else is otherwise unchanged. Obviously you wouldn’t normally run a printer with a stepper driver that far out of whack, but it shows what the system can do to turn a completely failed print into one that’s not too bad.This data can also be used to automatically calibrate steps / mm settings for the axis – this is set up in my fork of Marlin, and I’ve been seeing some really great results. The limit of what can be done really rests with the printer’s firmware, and I’m hopeful that people are keen to play around and try new ideas with these modules.At this point, these modules are pretty much plug-and-play electronically and firmware-wise – though on the printer firmware front I plan to keep making improvements, and I hope anyone else interested joins in. The hardest part right now is in mounting the encoder and the magnetic strip – you’d want to be comfortable designing parts for your printer to make things work, but I’m hopeful most in this subreddit can figure something out there.I’m interested in hearing people’s thoughts and feedback, and I’ll gladly answer any questions I get!I’d also like to apologise for the massive wall of text – I’m so sorry!Relevant links:Blog postDocumentationStore Page http://ift.tt/29Zr2GT