I was cutting aluminum today and all was going well until the very end. I hear a funny noise that sounds like the bit is going through the plastic end of the clamp set holding the aluminum down (I have done that enough to recognize that sound), but the bit was broken and the tip was in the aluminum at the last point in the carve. I put in a G30 command and noticed that the router moved to the right spot but the router did not rise. I saw the delrin nut on the ACME lead screw without the spindle carriage attached. Apparently the two bolts holding in carriage to the delrin nut had worked their way out. I fixed the issue by adding lock washers under the bolt heads - hopefully this will prevent this from happening again. I am reluctant to try locktite or something similar, as I do not know if it will work or if it will damage the delrin. I would recommend making sure that these bolts are secure during assembly of the machine because repairing it later is a hassle.
Loctite won’t damage it. Use it.
Yep, I’ve had that happen before early on. The router literally fell off the carriage and onto my workpiece.