Wed Nov 18, 2020 5:11 pm by huxleypig
To address the OP - the circular part, if not used right will result in no openings, ever! It slides back and forth and exists in order to move all of the wafers up to their most extreme positions. The tool is reset (zeroed) and inserted with the shim (round part) pushed all the way forward. Then, when fully inserted into the lock (the correct way up, this bit is crucial), it is retracted so that the self impressioning part can work. Once picked (or not), the shim (round part) is pushed forwards again so that the tool can be extracted otherwise the tool will be stuck inside the lock.
HU66 is the easiest auto lock to open on the planet (of the more recent ones anyway, the last 20 years or so). They can be easily picked, raked, self impressioned, decoded, overlifted. Either by hand, using hand picks, or using one of the many, many dedicated tools out there.
It has more opening tools for it than any other auto lock. It has a propensity to rake very easily, especially in the locked direction; then you use a plug spinner to get it to unlocked. Lishi have (at least) 3 generations of tools for the HU66 and from my experience they all work well. You have to make sure it is in the right way up.
There is an "inner groove pick" which is basically a sprung rake; that works really well too (locked direction easier again). They overlift easily too.
HU66 is the lock that every beginner in auto locks starts with.