This table shows the voltages I am using for my FLSun QQS-Pro printer that is using tmc2208 stepper drivers:
| Stepper | Voltage |
| X | 0.82 |
| Y | 0.81 |
| Z | 0.81 |
| Extruder | 0.85 |
Naturally the X, Y, and Z values should be the same, but I just couldn’t get the X stepper adjuster to show 0.81. So Either 0.81 or 0.82 should be fine. The extruder likes a slightly higher value since it has to both push the filament through the Bowden tube and hotend, and also pull the filament hard enough to turn the filament spool.
How did I determine these values?
When I upgraded my printer to the new HISPeed motherboard it came with the 4 tmc2208 stepper driver chips (steppers) not installed on the board. The steppers were packaged with small heat sinks that stick on the top of each stepper. So I installed the steppers and the heat sinks on the board with no problem. The new mother board booted up fine the first time, so I loaded up the proper firmware for it and started my first print.
The part I chose to print was large – it had an estimated total print time of 52 hours. I’ve printed large parts like this before with my previous printer, so I wasn’t very concerned about the lengthy printing time.
To make a long story short, I had 2 failures. Both were the same type – missed steps with the X. Y, and Z steppers. The first one happened after about 4 hours of printing, and the second one after about 11 hours. So I posted photos in the FLSun QQS Facebook forum and got quite a few replies.
The most helpful ones said that the tmc2208 steppers are quite sensitive to their voltage settings and can overheat if they are set too high. The recommended settings were 0.80 – 0.85. Overheating will result in missed steps, so it is important not to”over drive” the steppers with a voltage that is too high.
When I checked the voltages of my steppers I discovered that they were all in the range of 1.3 – 1.5. So I tweaked them to the values shown in the table at the top of this page. Then I restarted my long print.
I noticed right away that the printer was printing A-OK, and it was even a bit quieter than it had been with the original factory settings. But the printed results were great, so I have kept these settings.
Last Update: 16 Sep 2020