Help appreciated

Terradive

I have an ender 6 with duet wifi mother board. I've been having issues with VFA horizontal lines at.1 layer height since installing the duet 2. I'd like to try a run with TMC2209 stepper motor drivers. What is going to be the easiest/cheapest way of doing this? When you buy a duet 3 you have to install stepper drivers? Are there potentially better stepper drivers out there? My goal is to print as quickly as possible at low layer heights. Any thoughts ideas are helpful.

droftarts

@Terradive I see you posted in this thread: https://forum.duet3d.com/post/309070
Did you follow any of the advice to work out the cause of the VFAs? Specifically, watch these three YouTube videos, print the parts, and check them to isolate problems in X/Y motion, or extrusion:
https://youtu.be/dL6u0UwPJOQ
https://youtu.be/32dTLRNIYmw
https://youtu.be/UWuSsYKI-YM

Ian

Terradive

@droftarts yeah I did that. I’m not seeing the wood grain pattern. I’m seeing vertical lines packed closely together. The videos don’t talk about that much

droftarts

@Terradive Okay, if a tapering object doesn't produce a woodgrain pattern, and the vfas are still vertical, the problem is in the motion system. If you've gone through and checked bearings, belts and the rest of the machine mechanically, you're left with drivers and motors. If you want to try a different driver, there are a number of ways to add them to a Duet 2. See https://docs.duet3d.com/User_manual/Connecting_hardware/Motors_connecting_external

However, I'd also look at your motors. Mid-band resonance is an issue with all stepper motors, and it is often a problem when printing in the 60mm/s range, but depends on machine setup, steps per mm etc. Older Prusa i3 printers had this problem, where the 'quality' setting exhibited more vfas than 'draft' mode, because the draft speed was higher. Try printing really slow, eg 20mm/s, and then faster than normal, or do a print where the speed starts slow and increases every few mm. Better quality motors may help, or changing from 1.8 degree motors to 0.9 degree, though this often just hides the problem by doubling the vfa frequency.

There has been some talk in the Klipper forums about setting the stepper driver settings to better suit particular motors, which may also help with vfas, but I can't find the information on that at the moment.

Ian

Terradive

@droftarts thanks for your help. Here’s pics. I have .9 motors on the x and y axis. Lgx lite withe the steel gears upgrade. Hi win Linear rails on x y z.