If there’s one task that has been most frustrating in operating a 3D printer, it has to be leveling the bed. Like any other task that involves making multiple adjustments, this one was tedious and time-consuming. Get one corner “Just right”, and another corner goes just a little out of adjustment, and you’re making another round. When I first built my Makerfarm Prusa i3, there was no method available to adjust the Y-axis, so all I could do was adjust the X-axis and hope for the best. This got a little better when a simple manual bed leveling arrangement occurred to me (apparently just after it occurred to Colin at Makerfarm).
The manual bed leveling helped, but added to the time and effort required to get the bed actually dead level.
Luckily, as often happens in the RepRap community, someone brilliant got it sorted.
In the interest of full disclosure, it’s worth noting that this mod does not actually level the bed. Rather, it probes the bed at three locations, and from that data calculates the plane that the print bed actually sits on. The print is then adjusted so that it prints perpendicular to the bed. Here’s an example of what this looks like from Alex Borro.
Here’s how I implemented this on my Makerfarm Prusa i3: There may be better ways, but this is how I did it.
What you will need:
I remixed one of Alex’s parts, and designed another one. You’ll need to print one of each. I suggest printing these in ABS, since they will be near the hotend and will probably be experiencing some heat.
You’ll also need a small, 9g servo. Here’s one:
You will also need (2) M2.5 x 12mm bolts and (2) M2.5 nuts
The Z-axis endstop will actually be moved onto the end of the servo arm. You can wire in a secondary endstop in series if desired. I found the stock microswitch with the flag attached to be less accurate than a microswitch without the flag. Here is the one I used:
Once you have all the parts, assembly and installation are pretty straight forward. Here’s a video:
Next up: Configuring Marlin to work with the Auto bed-leveling mods: