This holds the bike lock securely using water bottle mount holes. Unlike other designs that clamp on the frame it doesn't interfere with cables and stays completely inside the frame triangle. The lock pieces slide into the part and lock to keep themselves in place

I recommend using relatively thick walls when printing and installing it with washers (The slot is only 10 mm but relatively thick. Under the lock body fits a 3/16" washer) It's currently laid out to mount with a 44.3 mm frame tube but that radius can be adjusted.