It’s been quite some time since the first post announcing the arrival of our newest communal 3D printer here at ‘Berg. In the first few weeks of its arrival I put it through a series of tests to make sure calibration was accurate. While it crushed many of these, like the torture test that is Benchy, the experiments led to a fair share of struggles. Fixable struggles, but important lessons that I thought I would share with the community.
The problem: changing the filament.
To gear up for a new print, I needed to change the filament to a darker color. It seemed simple enough. Until some filament got left in the tube. And not a lot of filament. Just a tiny thread less than an inch long that we assumed would be pushed out by the new filament. Turns out this does not matter. The new filament will not push out the old and we were left with a mess. In order to clear it out, we went with the “Atomic Method” (Ultimaker’s terms, not ours). This involved disassembling the bowden tube, cutting a piece of filament to the approximate length of the tube, and manually pushing the remains out. Since this was our first time testing out this method, it took about an hour to change a roll of filament. But the good news is, it has been accomplished.
What did we learn? Tack on an extra 30 minutes to any project requesting a different color filament.
The problem: warping
I have to admit, this one surprised me. In hindsight I’m a little embarrassed by that fact. Making sure that prints stick to the build plate is always something I think about when looking at a model. There are many different ways to make this happen: use a glue stick, create supports like rafts, use an alternative surface (rubber mat) to print rather than the glass plate, etc…What I failed to realize, however, is that anything with a large surface area (e.g. more than 2 in x 2 in touching the build plate) would be more likely to warp. Why? Because larger surface areas cool faster than smaller surface areas. Once it warps even just a little, the nozzle, which dispenses the hot filament, catches and often times loses calibration and/or pries part of the print loose making it even more warped than it already was. As I said, embarrassing in hindsight because this makes complete sense!
Warping can also occur in taller prints, but has yet to be experienced in anything we have tried thus far.
What did we learn? Prints with more surface area touching the build plate are more likely to warp and require a higher build plate temp.
The problem: leveling the build plate
This actually isn’t a huge problem and should maybe be labeled a good practice. The printer sits on a table that could be sturdier. When people visit my office, they oftentimes lean on or bump against the table. Both of these things can throw off the calibration of the printer and cause distortion or failed adhesion in a print. Whenever a print starts to warp right off or won’t even stick to the build plate, it’s a good sign that the calibration is off. Luckily, the printer has an easy process for re-leveling the build plate. By aborting the print, letting everything cool, and following the simple instructions, it’s back on track.
What did we learn? Re-level the build plate! Simple and quick fix.
Where is most of this information coming from? The Ultimaker 2 Manual.
Next up on the blog list, a look at future training and events now that the Fall semester is here…