In blade lift testing, we discovered damage to our test blades indicating that they were swinging back and striking parts of the rotor head when rotational speed was suddenly increased. This led to designing blade locks which would keep the blades from swinging too far and cushion them from impacts due to sudden accelerations. This is a quick video showing testing of the original blade lock design on HLQ. The design ultimately failed for 2 reasons. First, we decided to try 3-d printed parts which ultimately delaminated on initial engine start-up resulting in catastrophic failure. Second, the ABS plastic was hard enough still that it cause indentation in the blades where they touched. An alternate solution was implemented and successfully tested that will allow us to proceed with our sequences of pre-flight testing. A video of that test will be available shortly.