I’ve been able to fine tuning my tool chain and Tantillus printer to the point that parts come off the printer looking almost perfect. The dimensions are close to spot-on, though my first layer is still a bit squashed. The surface finish when I print PLA with 150 micron layers looks almost like satin.
Therein lies the problem. The surface finish is so good that any defect is immediately noticeable. And I’m getting what I call ‘zits’ on the surface at some locations during the print. The ‘zits’ are small protrusions of extra plastic that stick out from the surface. My best guess is that it’s a retraction problem that occurs at z-axis transitions and other spots where the extruder has to quickly retract the filament.
Of course the same zits must be occurring within the part, but since I can’t see them they don’t bother me. And, as long as the parts are fairly simple – like cubes, cylinders, and the like, the zits don’t show up very much. However, as soon as the part gets a little complex, especially when I use infill, the zits pop up like a high school student addicted to chocolate bars and quarts of ice cream.
Going back to the Slic3r initial settings that were developed for Tantillus doesn’t eliminate or minimise the problem. Researching the problem online has helped a bit, and convinced me that it is a retract related problem. But, since Tantillus is a Bowden based system, unlike most of the RepRap printers out there, the retract settings have to be considerably different.
So, to try and debug the problem, I’ve started to print multiple copies of the same part – initially a simple ring, while varying the retract settings. Hopefully I’ll be able to see which setting(s) make the problem better (or worse), and home in on a solution.
- The Right Tool for the Job
- New 3-Way Extruder Design Yields Multi-color 3D Printed Parts
- Shrinking the Design Process Using 3D Printing/RepRap
- WebCam Mount for the Tantillus RepRap 3D Printer
- Adding Focused Lighting to a Tantillus RepRap Printer