I had an enormous amount of ringing/ghosting with my flash. After making sure all belts were tight, the TMC2100's where on 1.05V and there were no other loose parts, I didn't know what to do.
The best solution so far: Tighten the roller wheels so that the bed and extruder aren't moving freely anymore (but a lot of wear on the wheels...), so it dampens the ringing a little bit. Also the acceleration is reduced to 1000mm/s and the jerk to 5.
I print at 30mm/s by the way, so not even that fast. The ringing is no "somewhat" under control. Here is a picture of the ringing before the reduced acceleration.
Anyone who has the same problem?
When you order the new TEVO Flash from Banggood, you can pick "European Direct Mail". This route makes sure you won't get charged afterwards with taxes. In my case this means I don't have to pay the 21% tax and 4% import, almost €90.
One REALLY important note: Banggood claims this shipping method takes 7-20 days, this isn't always the case. There are reports from shipping times up to 30 or 40 days. But hey, you don't have to pay taxes!
You can find the printer here: https://www.banggood.com/TEVO-Flash-98-Prebuilt-3D-Printer-Kit-235235250-Printing-Size-p-1311319.html?p=TC11053751477201602P