I'm trying everything now to improve the quality, but I don't have the time to get some new rods, so I'll just keep using these. I'm now going to print the corner braces tanephar mentioned and hope that'll make a noticeable difference.
I also tried updating to a newer version of cura, because I was still using 15.04.6. Can anyone maybe share their settings for cura 3.0.4?
If the project in the end turns out to be a success, I would also like to share it with you guys
I promised to let you guys know about the project if it turned out to be a success. It did, so here is the post I made: