Creating your own 3D printed movable type printing press can cause some unexpected problems.
Even when everything is built to plan, exported correctly, and sent to the printer, there are still issues. For my project this manifested in printing the letter “l,” which often failed to print completely. Even with the successfully completed l’s there were still irregularities. While the print was functional, I was still curious as to what was going wrong, why the PLA was not adhering to the build plate and why the skirt (which is part of the build plate adhesion process) was intersecting the print. This issue has been a case study in how many ways a print job can fail.
The first issue which was part of build plate adhesion problem was a blob effect. According to Dremel FAQ’s:
“Why is the filament blobbing on the build platform?
This may be the result of a build failure or a poorly constructed file. The building process may have been interrupted by the computer disconnecting, or by removing the SD card/USB flash drive during the building process. Run the Dremel Test Print to verify that your printer is working correctly, allowing the print to finish completely before disconnecting it.”2
But even though there was a blob, it seemed to have started with an adhesion issue which is a common and reoccurring problem throughout this project. Research about this problem yielded many results, tips and tricks from different sources. According to Autodesk Instructables, poor adhesion could be due to the heat of the build plate which for PLA should be about 60 degrees Celsius.1 Suggestions to help adhesion include using painter’s tape, a layer of Elmer’s glue, and even hairspray!
Other suggestions even included ensuring the extrusion temperature was appropriate. It needs to be hot enough to push out enough plastic and cold enough to solidify and adhere to the build plate. But if it was too hot then it could not cool, not adhere, and ultimately be dragged around. For PLA this temperature should be around 200 degrees Celsius.1
In another source from 3D Printing – StackExchange, a thread titled Reasons for a PLA print not sticking to bed all the sudden? is answered by a user named Trish who mentions factors to keep in mind:
“Have a sufficient surface for the print to stick. A pyramid printed on the tip can’t print properly.
Check the leveling of your bed occasionally and relevel the bed. By removing prints, one can easily unlevel it over time without noticing it.
Clean your print bed from fingerprints and grease every so often. Fats are good separators between the print and the bed. Getting them off with Isopropyl alcohol or other solvents can restore print surfaces in an instant.”3
This is followed by an answer from another user JayCrossler who mentions a time when their printers all had a non-stick issue around the same time and it was “mostly around changes in temperature and humidity – the outside temperature changed inside AC settings/wind-flow, etc.”3
Any one of these were potential solutions to test; however, the next letter that was printed after the first two fails of the letter “l” came out with a new issue which was seemingly under- extrusion. The base printed fine and the letter was completed but there are tiny gaps within the print, leading me to believe it is a case of under extrusion, where the extrusion temperature was too cool making the layer not want to adhere to the previous layer. Or, another likely issue is that after the two failures, the nozzle was still a little clogged.
The next letter after printed better; however, there was a base issue where the skirt was printed into the print itself. Nothing in my settings had changed and I ensured the print was lying flat. Ultimately, I’m not quite sure what is wrong and why there are issues that seemingly come and go. All I can really think of is that it is a print failure that occurs and like other printers, it’s a typical moody printer.
Perhaps we will just have to take the “L.”
BradBuilds. Failed 3D Prints, and How to Fix Them. (n.d.). Autodesk Instructables. https://www.dremel.com/us/en/digilab/3d-printers-faq
Dremel. Frequently Asked Questions. (n.d.). https://www.dremel.com/us/en/digilab/3d-printers-faq
Reasons for a PLA print not sticking to bed all the sudden? (2019 September 6). 3D Printing – StackerExchange. https://3dprinting.stackexchange.com/questions/10980/reasons-for-a-pla-print-not-sticking-to-bed-all-the-sudden