UM2+ with Bondtech DDG Feeder - issues loading filament

[brunbjoern 0]

I today installed the Bondtech DDG Feeder in my Ultimaker 2+, installed the firmware provided on their webseite and did a factory reset afterwards.
If I load a filament through Ultimaker's menu, it gets fast forwarded in the bowden tube but it ends before entering the print head.
From there on the filaments proceeds in the bowden tube with the print speed until it finally reaches the nozzle and gets extracted. Unloading the filament causes the filament not to fully unload!
With the original feeder/firmware everything was ok. I have been using the most recent orignal Ultimaker firmware and the original factory installed bowden tube. The bowden tube is fully inserted on both ends. I have checked that.

 

I gave both firmware versions on the bondtech website a try, Ultimaker2_DDG_Firmware_20171023.hex and Ultimaker2_DDG_Firmware_20171117.hex as well as Tinker-MarlinUltimaker2plus-17.10.1.hex. I always did a factory reset afterwards.

In TinkerI've set the E-step to 311 and Loading speed to 50 mm/sec as described by Bondtech.

 

No Luck!. Filament stops far before entering the printhead, about 5-7 mm with the Bondtech Firmware, a bit more with Tinker.

I couldn't find any settings in Tinker to define the bowden length. I am not ready yet to shorten an otherwise perfect-length bowden tube.

 

Any ideas what might be wrong here and how to fix it?

 

Many thanks

Matthias

 

Edited February 19 by brunbjoern