Month: July 2016

Bridge Building Contest!

Okay guys, a lot of people had said that a bridge design contest would be fun, so here we go! If you are interested, please fill out this form in the comments below:Reddit Username:Nickname (if none, Reddit name will be used):Are you a professional Engineer?What design software are you using?The design limitations are as follows:Bridges must fit into a 4-inch x 6-inch x 4-inch area, with solid beams across the 4-inch edges, so that the bridge can rest on blocks over a gap. Also, please make sure that you have a beam on the bottom of your bridge, near the center, to hang the weights off of.Bridges must be able to be “functional,” meaning that they must have a 2-inch wide section straight across for “cars” to move across, and it cannot have a solid top, but beams are allowed. You do not need a solid surface for the “cars,” but this rule is just there to stop people from making solid beams.All bridges will be printed on the same printer at the same settings using the same materials. Pieces will be printed out of PETG at 100% infill. If your design is over 50 grams, it will be disqualified or the infill will be reduced until it is at 50 grams (support material will not count).Designs must be submitted by the deadline: August 15, 2016.1st place in both of the two categories (professional engineer and amateur) will receive a roll of Atomic Filament PETG, and 2 rolls of Atomic Filament will be donated to a local high school engineering program in their name. If anyone else would like to add items to the prize pool, let me know!If we have received more than 50 entries, we will judge them in virtual destruction to choose the strongest 50.If there is a lack of interest, we will cancel the contest and return any items added to the prize pool.The winner will be selected based on what bridge can support the most weight on its load-bearing beam. Weight will be measured using Vernier laboratory equipment.Let me know if you have any questions, or if you have suggestions. http://ift.tt/2a13WJP

Linear Magnetic Encoder Modules – Print Error Correction

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