Call it Z-banding or Z-Axis wobble, it's something that can easily be reduced. The contributors to the effect is mis-alignment of the drive nut on the two Z-Axis with the Z-Axis motors. These two planes have to be in perfect alignment, something that can't be expected on a $200 printer! The contributors to the error are many;
1. Not 'true' threaded drive shaft
2. Couplers that don't run true.
3. Mounting hardware not in perfect alighment.
Number 3 can for the most part be ignored, most of the Acrylic and Aluminum frames are laser cut and quite accurate.
Number 2 is a problem, on my printer one unit was perfect the other was a wobbly gobblin
Number 1 can be a problem but like checking the roundness of a drum stick, just roll the rod on a flat surface and you can verify if they are out of round (mine were perfect).
I didn't think the coupler would be a problem since the design is to isolate these imperfections, but what I found was far from isolation. My prints were fine but then I reviewed this mod on thingiverse:
http://www.thingiverse.com/thing:1782670
I was skeptical, but printed these and installed on my printer. The results are great. A big improvement over stock configuration. I hope to post my findings onto youtube so you can really see the amount of wobble this minor mod isolates.
Improve z-banding on I3 Pro B
Re: Improve z-banding on I3 Pro B
Thank you for your experience sharing. 
-Keep your mind and try to test it. 
-Everything will be fun！-Support all Getech printer.
-You can ask me the questions and I will kindly reply.
-Respect others is the best way you can get help!
-Everything will be fun！-Support all Getech printer.
-You can ask me the questions and I will kindly reply.
-Respect others is the best way you can get help!
-
mannymiller
- Posts: 14
- Joined: Mon Feb 27, 2017 4:27 am
Re: Improve z-banding on I3 Pro B
Thanks for the links etc..
i have had issues with z banding.. and i think in the early stages anyone thats new to 3d printing will come across it. i have seen lots of videos and posts on thingiverse but i have yet to see a proper before and after video / picture. The ones i have seen reduced it, but did not fix it. My fix would be.. make sure your threaded rods are straight. my set were, but i ordered a new set anyway. The geeetech smooth rods are not very good, one was loose in the bearing, the other too tight. which failed after a couple of prints. so would suggest new smooth rods. ( a problem which will still arise even with the z wobble fix ). Poor belt tensioner bearings / pullys, replace these with good a toothed variety. Then many people do not understand how to install a coupling correctly. yes the supplied ones are not the best. but install them correctly and they work just fine.
I have seen some amazing prints come from this machine without all the mods and addons. yes a nozzle cooler is recommended. but other than that if built correctly you will not need the rest.
i have had issues with z banding.. and i think in the early stages anyone thats new to 3d printing will come across it. i have seen lots of videos and posts on thingiverse but i have yet to see a proper before and after video / picture. The ones i have seen reduced it, but did not fix it. My fix would be.. make sure your threaded rods are straight. my set were, but i ordered a new set anyway. The geeetech smooth rods are not very good, one was loose in the bearing, the other too tight. which failed after a couple of prints. so would suggest new smooth rods. ( a problem which will still arise even with the z wobble fix ). Poor belt tensioner bearings / pullys, replace these with good a toothed variety. Then many people do not understand how to install a coupling correctly. yes the supplied ones are not the best. but install them correctly and they work just fine.
I have seen some amazing prints come from this machine without all the mods and addons. yes a nozzle cooler is recommended. but other than that if built correctly you will not need the rest.