Automatic Bed Leveling, Fact or Fiction?
Update: January 19th 2014
Today printrbot released videos and information on their own auto leveling setup. It looks very promising but, as pb said it still needs work. One of the main obstacles is making a setup that can be adopted onto the majority or all of the Printrbot’s that have been built. Another issue is pin availability on the Printrboard. I think that this can be solved using a magnet to deploy and retract the z probe. I like the idea of running two homing switches in parallel as the stock probe serves as a fail safe against the head crashing into the bed. Since the homing switches are wired NC, this is very easy to do.
I plan on testing out a few different setups to try and solve the issue of deployment and retract of the z probe. More than likely I will use a different switch as I believe that the setup wide be more effective using a momentary switch much like the ones used as homing switches on the Enventorbot build. I will update this post as I go with more details on the z probe setup.
The post below here is the original post primarily documenting matterhackers approach at auto-leveling
I’ve recently decided that I wanted to figure out a method for automatic bed leveling and running across some tweets about it was all I needed to get started. There seems to be several different methods for automatic bed leveling. Some of those include an automatic lever that drops down and is put away via firmware commands as well as a manual version where the user is required to drop the endstop. Matter Hackers has come up with software that aids in auto leveling but, this is done a little bit differently than others via software. Matter Hackers setup works best with a z axis homing switch on the top but, they have recently done it on a Printrbot Simple which has its switch on the bottom.
I have yet to test out matter hackers version but I will be very soon. First I wanted to see what I can come up with. I searched around my prototyping space to see what scrap parts I have laying around. I managed to find a few pieces of aluminum and angle brackets that I used to fashion an endstop holder. As of right now it is a manual version you have to flip it up or down for calibration. Once I get the manual version figured out I will be making an automatic folding version. Currently this is gorilla prototyping at its best. I had a few ideas when trying to figure out what would work the best.
One of those ideas was to use a laser like the ones found in laser rangefinders to determine distance with the combination of a camera. The laser beam would be spread to skim across the print surface which would show which parts are and are not level. That would be seen by the camera or cameras and adjusted through software. There has to be an easier way and that’s why we are currently looking into similar setups as matter hackers. It’s a lot more feesable.
The restraint needed when designing an auto-leveling is fair. We could solve this problem with a complicated setup that would require people to modify, buy special parts and reset up their printers. I think a better solution is found in a setup that can easily added on to repraps everywhere for a minimal amount of time, money and parts.
Hopefully by tonight or tomorrow early I will have my newly upgraded Printrbot Plus fully calibrated and ready to test out matter hackers software development. I will definitely update as I go so others can eventually say goodbye to the bed leveling headache.
Posted from RepRap Squad HQ