I've printed similar objects with a different colored PLA, but I ran out of it and switched to this.
Is it possible that this could be influencing the outcome?
I have tried reducing the printing speed by 50%, but this did not seem to have a significant impact.
[SOLUTION] The problem was a loose screw. The offending part as well as the new result are pictured below. It's not perfect, which I guess is actually a part of the model this time, but it's good enough for my purposes and way better than what it was before.
I figured this out by twisting the Z-axis thingy manually all the way to the top to see if I could feel any issues. Towards the top, it would start to 'skip', where I would turn and pretty much nothing would happen. I assume this has to do with the lack of lube at the top because my prints rarely go that high. I checked to see if the screws were loose, and sure enough, the top one was. I tightened it up and now my printer is printing like the beast I remember!
A good design from an engineering prospective doesn't use 3d printing to print a pipe .... It implements already existing pipes and adapt the design ... It's the concept of this type of manufacturing that we are questioning Let's take as an example a standard plastic chair Yah you could 3d print it but they don't, Heck you could buy a solid 1*1m of plastic and machine it out but that's not done either, why? because stamping it in a mold is way cheaper way faster and way easier right ? The point is to find the manufacturing method that solves your problem the cheapest fastest and better way possible so if you want a straight plastic pipe for any reason you should just buy a pipe it's way cheaper than the filament it's water tight without imperfections stronger in any direction and if you want it to be close just print some caps .... 3d printing, taking in count the length of time to produce one item and the relatively high cost of production should be reserved for objects that you can't cheaply fabricate in any other way ...
I'm not saying you should throw away your already printed tube just keep in mind next time that if you need a big square plastic box maybe you should consider buying it instead of waiting 8 days to 3d print it .... (Unfortunately this is not a random example... A friend of mine insisted that I 3d printed a box for him ... )
I solved the issue; it was just a loose screw.