Wavy vertical surfaces


When I print the vertical walls of the object are wavy.

like this:


Where each “|” represents a layer.

This happens uniformly over the entire object on inner and outer walls and on all sides.

Anybody have any ideas how I might solve or trouble shoot this?


That’s likely either the phenominon known as Z-wobble, or possibly Z ribbing caused by you using a layer height that happens to be the same as the thread widht of the the threaded rod. The latter one is easy to check for. Try changing your Z layer step height to a matching value for your machine using the Z axis layer height calculator here: http://calculator.josefprusa.cz/ and then adjust to that layer in slic3r. if that doesn’t have any effect on the issue at all, you’re likely looking at a z-wobble, which is mechanical in nature and can be the bane of a 3d printer’s existance to figure out.

First off, what specific type of machine are we dealing with here, a TAz, or an AO-10x? the motion systems are similar, but there aredifferences in threaded rod thickness, mechanicals, etc that make troubleshooting the one a completely different process than the other. Let us know what type of machine this is and we can give you some things to try.

Yes, after I posted I did more googling and found it probably is z-wobble.

I will try the layer thickness.

This is a AO-101, stock.

There is no noticeable play in the left Z, but the right Z has obvious +/- Z play. it appears to be slop between the nut and threaded rod, not the nut and the carrier.

(Side question: How do others adjust the nut/rod left/right to level?)

Well, the good news is that there are a couple Ao-10x specific upgrade projects in existance that may help with some of that.


Adjusting the nut and threaded rod can be done a couple of ways. if one side is just off slightly too high or two low on Z axis, with the machine unpluged you can turn the threaded rod itslef until it is level. If it’s too far in or out from the machine, the adjustment for that is moving the z motor on the right or left side in or out slightly to compensate. front to back offset would be moving the entire motor mount itself.

The +/- Z play in the threaded rod and the nut may just be wear, or it may be a slightly out of specification nut. The Ao-taz modification fixes that issue by adding a second nut with a spring putting tension between them, so one nut is always in contact with the upper side of the thread on the threaded rod, and the other is always in contact with the lower.

Hmm…I suppose the linear rails would be nice. Even better if I happen to have a set kicking around in the parts bins in the dungeon…but alas, no. :smiley:

The loaded nut seems like the right way to go, I actually have some precision lead screws with loaded nuts in the dungeon collecting dust, I’ll have to see how/if I could adapt them. :bulb:

I don’t think wear is an issue, I doubt I have more than 10 hours of print time on this machine.

I’m working on a lead screw mount. You can see the progress so far in the development forum section. Just need to finish the upper mount now.

So one thing I’ve not searched yet: If I change the lead screw I’ll end up with a different thread. What/where do I change the settings for that?

In the firmware steps section.

Umm…that firmware section would in which of the several thousand files on my PC?

None of them. It’s the firmware on your controller itself. You would need to download the latest a 101 firmware and arduino edit the local firmware steps section in the main marlin release then flash the firmware back. Same procedure you use for see she’s 10 mm height increase mod.

Hmm…so it has to be a specific windows version of the Arduino IDE?

What does one do in Linux?


Arduno has a Linux variant for the bios loader. I know nothing about how it works or operates though. The firmware files themselves are the same though.

Which specific variant of the AO-101 do you have. Is it the one with the fully enclosed RAMBO controller, or one of the AO-100’s that was upgraded to an Ao-101 but still has the open a-frame mounted RAMPS controller? If it’s the latter, I have the firmware updated to the latest version for that. You would either need to go with the 160mm height increase at that point, or revert that portion of the firmware, and the e-steps for my extruder may not match what yours utilizes, but aside from that it would be a direct update if you need it. No idea if it would work on a RAMBO controller though.

I have the later A101-1 with the controller fully enclosed.

I’m familiar with the arduino and it’s use.

Other than searching the forum, is there a instruction write up some where that details the process of updating the firmware?

And, is the code for uploading the firmaware part of the firmware download? Or is it just a typical arduino programming process from the arduino gui?


We have several guides on reflashing the firmware, but most of them are writtend for and point to the TAZ 3D printer. You can use the same firmware versions but simply download the OS specific build for your local operating system of choice. The more general instructions can be found here: https://www.lulzbot.com/support/re-flashing-your-3d-printers-firmware If you’d like more specific help you can contact support at Support@LulzBot.com for more guidance and answers to your specific questions.

Ok, so I have Arduino installed and tested with a stock Arduino Mega.

And, I’ve loaded the MArlin.ino and compiled it successfully.

I did not attempt to upload it to my A101-1, because there is nothing to gain since, as yet, I’ve changed nothing.

Assuming I change from a 3/8-12 rod to a 10 TPI leadscrew is the following line the only place I need to change:

In Configuration.h:

#define DEFAULT_AXIS_STEPS_PER_UNIT {50.25,50.25,756,408} // default steps per unit for AO-101

I’m guessing {X,Y,Z,E} ???

So how do I calculate the right value for the Z change. At 10TPI that’s 2.54mm/rev.

I tried the ReRap calculator with the 3/8-12 and didn’t find any combination that matched the 756 above.
So I’m thinking the 314.96 that it calculates for 2.54mm/rev is not right.