AM882 strange sensorless stall detection issue

[istvan58]

Hello,
I'm new on MYCNCUK, just joined.
Let me please share my experiences with AM882 and 4Nm motors from cnc4you.co.uk.
I bought AM882 from Ebay china, and got 2 version, two was V1.1 other 1.0. (the last digits in serial number is MS11x, or MS10x, x=with one letter, in my case is K and C.)
Based on my testings version 1.0 have stall detection working exactly upper 300RPM, but for V1.1 stall detection started to work at 180RPM.
But when tried with the 4Nm motor from cnc4you after auto tune the stall detection isn't work when set current above 2.5A. Tried with other motor worked well.
I got really confused but I found a work around to solve the issue on this way:
After auto tuning I saved the configuration file with pro tuner and the motor coil resistance was as I remember about 1.1....1.2Ohm, which is real.
Opened the config file with notepad I edited the resistance value to 2 Ohms, and uploaded to the driver and saved in eeprom. Now the stall detection is working very well with nema 23 4Nm motors from cnc4you with current set to 3.5.....4A.