Taz 4 Conversion - print quality, z axis has banding

Does anyone know of a conversion from the Taz to ANY other platform. This z wobble is completely unacceptable for such a highly priced 3D printer. I am not impressed with the print quality. I appreciate all the “fixes” that people have come up with, but at this point, for how much this printer costs, no one should have to print a fix for anything that countless other, cheaper manufacturers have managed to avoid.

I don’t know what you mean by “conversion”. To convert a TAZ to a Prusa I3 MK3S you just spend approximately $749 and throw out or sell all the TAZ parts you don’t use.

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Haha. Thanks @b-morgan. I was talking about potentially using the aluminum extrusions, steppers, controller, bed, and hot end. Then using a z axis design that actually works without translating its movements into all of the other axes causing these awful z banding issues.

Also, there are people that buy trash? Haha, I don’t mean to be a total a$$, but I’d rather rebuild an entire custom printer than attempt to ressurect a printer that clearly has issues. I havent seen anyone post a respectable print on these forums after having “fixed” the z axis issues.


Specifically which TAZ model do you own?

@TheVirtualTim - The Taz 4

The Taz 4 5 and 6 are all plagued by the same issue. The Z-axis only has one rod on each side of the printer. Due to this, the lead screw is supporting the X-axis in the x, y, and z directions. Ideally, the lead screw should be floating in x and y.

Possible solutions:
-Convert to a belted Z-axis like the Taz Pro or Mini 2
-Redesign the Z-axis to incorporate two rods on each side

I am currently working on the latter solution and will make a complete guide when it is complete.

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There’s a 3D printing YouTube’r who goes by the name “CHEP” and refers to “magic values” on the Z-axis.

Due to the nature of the way the stepper motors work in conjunction with the helical lead-screws on most printers, he explains that there are whole-step increments that the printer can easily handle. If you use fractional values then the printer tries to do a less-reliable fractional step of the motor … but it leads to poor quality in the Z-axis. So the natural “whole” increments of what the stepper can handle are what he calls “magic numbers”. I don’t know the “magic numbers” for the TAZ 6 and previous printers.

The current series (Mini 2, TAZ Workhorse, & TAZ Pro) all use belt-driven Z-axis with a resolution of .05mm … which makes it lot easier. My friends who own helical lead-screw driven Z-axis typically need to make sure their layer heights are multiples of a step of their Z-Axis stepper motors (e.g. multiples of 0.12 or 0.18, etc.). If they use anything other than an even multiple of these numbers (depending on the printer) then they get reduced quality on that axis.

Here’s a link to the video: https://youtu.be/WIkT8asT90A

Again… I don’t know what the “magic number” is for your printer (my printers have belts on the z-axis) but he describes why Z-axis quality varies based on layer height due to the way the helical lead-screws work. You’d need some info on the number of steps in a complete rotation of the motor combined with knowing the thread-pitch of your lead screws to work out what the “magic number” is for your printer.

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I was thinking the same thing and turning my old TAZ 4 into a Hypercube Evolution. reusing as much of the parts as possible

The screw pitch is 2mm therefore multiples of 0.01mm are whole steps. So any layer height entered in cura le that has no more than two decimal places would be a whole step.

This magic number only works if the steppers are being inaccurate; however, due to the helical nature of the layer variations shown in the picture, this is not the case. In the video :[https://youtu.be/WIkT8asT90A ] the layer variation with the non-magic layer print was very irregular, not regular or repetitive like those shown in @jimjamurprint photos.

@George I took a look after @TheVirtualTim said something because I do own an Ender 3 as well and I do use the magic numbers on that printer.

Using the Prusa optimal layer height calculator you can see that just about any layer height is just fine:

Prusa Calculator

Also for anyone wondering the specifications on the lead screw:

LulzBot TAZ 6 Lead Screw

Needless to say, changing the layer height didn’t produce better prints. - @ZRG_3D was correct.

My next move is dumbing down the acceleration values to more reasonable numbers to see if that helps. Does anyone actually print with these insane acceleration values that Lulzbot sends these printers out with? 9000?? is that a joke? Ill try with 500 and post back some results.

So, I also have a taz4. I do use the default settings, with pretty good results. The only things I see when using a standard hot end are ringing from the printer stiffness, and a bit of extra material around the edges of holes, other then that it’s pretty clean. With the large format head I’ll see occasional layer translations, and layer starts and stops. The only time I recall seeing banding like in your photo was when I had the original budaschozzle, and it’s resistive heater started disintegrating into dust (I don’t think anything similar is going on here)

Thanks for your feedback, I’m glad someone is getting good results. Do you use Cura LE or Slic3r?

I use Cura le, currently 3.6.20

Since I’m nearly ready to trash this printer, I decided to take some cheap measures to see what I could get out of it. I took the z-axis lead screw bearings out so the lead screws could freely wobble. While I had the axes taken apart I also cleaned the lead screws and re-lubed them. I also loosened the z-nut-mount from the z-nut. This seems to allows the z axis to wobble like hell and the x axis remain unaffected.

For the longest time I thought my bed was warped, but as I have been lurking around the forums it has come to my attention that the “warp” is really the x-axis smooth rods bending because of this behemoth of a direct drive setup. I’m planning on building a new 3D printer, if it happens to be this TAZ being fixed or an entirely new setup doesn’t matter all that much to me. Either way, I wanted it to be a bowden setup. So I ordered an E3D clone, a real E3D throat and set off on a design to lighten up the x carriage. This is what I have accomplished so far:

  • I moved the extruder stepper to the left x-axis plate so it is “flying”.
  • I 3D printed some linear bearings. The old Igus ones on the x axis are shot (temporary).
  • Custom X-Carriage to hold the E3D clone.
  • New cooling fan, mount, and nozzle.
  • A real E3D hot end cartridge (replaced the crappy resistor from the hexagon)
  • Custom spool holder to lower the spool down closer to the bowden extruder.

I have tried to design everything with the thought that it can be used on a different printer if need be. The only part that is not reusable is the mount for the flying bowden.

My “bed warp” is gone :slight_smile:, I’m fairly certain my x-carriage is less than half the weight of the original because the extruder stepper is no longer being slung around.

I rebuilt Marlin 2.0, that was interesting. These RAMBO boards are fun. I like the digi pots.

Anyways, I moved to stock Cura, trying to get a decent profile built for the new hot end. Here are the results of a Benchy print. Z-axis banding is mostly gone, but ringing is still prevalent. My extruder needs more tuning as far as steps are concerned, I have a fair bit of under extrusion. After this print I did tune the retraction a bit more, so near the top of the benchy when a lot of retractions are happening should look better the next time I go to print one.

Any thoughts on getting rid of the z-seam zits / blobs in the cura profile?
What about the ringing?
Other thoughts?

Thanks!

New setup:

Benchy:

For ringing: https://itworks3d.com/product/taz-frame-reinforcement-kit/