Hi people,
I was happy to buy an Ultimaker 3 Extended last week, with the 0.4 mm print heads. I also bought a 750 g spool of transparent Ultimaker Nylon. I use the latest Cura 3.2.1 (which is super slow on Windows 10, by the way), and also updated the printer's firmware. But since then I run into a number of issues. Firstly, I tried printing the Ultibot design that came with the provided USB stick (so, default parameters), using the supplied PLA and PVA. PVA was extruding well from the BB head, but PLA was not from the AA head. Then, I switched to nylon. This worked well with PVA. So, I decided to print a custom design of a cylinder that has an internal structure. I sliced a small part of this (40 mm height) in Cura with the default parameters for Nylon and PVA. I was surprised to see how bad the result was. While the outer wall printed well, the internal structure did not look right, with nylon and PVA mixed randomly. At the end, after having it submerged in water for a few days, the whole internal structure just melted away. As indicated by others, the print became bendy as well after being in water for days. Assuming the structure was too thin to be printed properly, I changed the design by thickening the internal walls to 0.8 mm, and changed several Cura parameters. Specifically, I reduced line widths to 0.35 mm and the print speed to 30 mm/s or less, I increased the infill density of Nylon to 100% and the support density to 15%. Everything else was just the default. According to some online posts, these are sufficient to improve the quality of the print, while not spending loads of PVA. So I went for the full design (156 mm height). After almost 3 days, this stopped close to the end (not sure when exactly) and the printer showed an error: "The X or Y axis is stuck or the limit switch is broken". So, I discovered that the X axis switch is broken and needs replacement. But let's forget about this for now... The print stopped ~1-2 mm before finalizing. The prime tower fall at probably the middle of the print, and the cylinder was obviously missing a lot of support on the sides. After melting the PVA in water for a few hours, a big chunk (4-5 cm) from the top was... not there! So for the last several hours it was only printing with PVA. There is still plenty of Nylon on the spool.
Honestly, I am quickly losing my faith to the printer, or this technology in general. Does anybody have any suggestions to solve the printing quality issues, at least? What would be the best approach for Nylon and PVA? Maybe use a different material?
Thanks.