What is this? Z Wobble? Software issue?

I am getting really good prints. I am not trying to be OCD about quality or anything. That being said I am getting really irritated by these two issues.

The part I am talking about is z-anti wobble, the one on the left. ((I bought the printed parts for the printer.))

First issue is the ripples in the outer surface of the print. Its like none of the layers are lining up perfectly. I know they are not that off, but I see prints all the time that look perfect from other Prusa I3s.

The second issue is illustrated in the second pic. Nozzle drag. I have calibrated and calibrated and calibrated. Adjusted flow rate, z-height, bed leveling, etc...I still get that line through the top surface of ever print.

Thanks in advance guys and girls.

First Pic
Second Pic

That does not look like Z wobble to me. It looks more like the wavyness you get when your machine is moving faster than it can handle and wobbles a bit. Try slowing it down say 25% and see how it looks.

The extruder on most machines is heavy and making that go back and forth fast means it will stretch the belts a little and possible other parts of the machine then wobble a bit as they release the energy stored up from stretching. You can slow down to lessen this or lighten the weight of the extruder. It's really not that bad in your example. I would suggest just running it like it is for most prints (structural parts) and slow it down when you need them to look a bit better.

So switching to a bowden setup would help with the weight issue. I had a feeling it was due to all the weight on the x-carriage. I have a normal Wades Extruder, a 50mm fan for the hotend, and two squirrle cage blowers for the print.

I will post the results of that same part with it slowed down. I printed those at 45mm/s I think. I will drop the speed to 30mm/s and see what it does.

45mm/s is not that fast. I see that type of thing at 80mm/s and up and I don't if I drop to 50-60mm/s but that is my printer and yours may be different.

Other things to check are that the belts (X & Y) are nice and tight (mine make a ping sound if I flick them), check your linear bearings to see how much slop there is. And overall just see if the machine is solid, can you easily flex the main body?, does it sit nice and level (solid on table with no gaps under legs).

Yes a Bowden extruder was designed just for the purpose of removing weight to allow faster prints but as in life nothing is perfect, because there can be a slight delay in a Bowden due to the length of the filament some people struggle with blobs from retraction issues. It's still a good system but pickier about settings. There is a reason that not everybody is jumping to replace say a Wade's with a Bowden.

the weight doesnt necessarily loosens your belt. it causes inertia meaning that the weight wants to go past the center due to motion changes, and if thats picture of a part holding the m5 threaded bar to the 8mm smooth bar throw them in the bin, reason for it m5 threaded bar isn't truly straight, so it makes your z follow the threaded bar instead of the 8mm rod, only proper lead screws can be captive in that way

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