Just an FYI for folks building an LR3 or LR4:
I disassembled my LR3 today in preparation for building the LR4 and found that nearly every single screw that attached a stepper motor to the mount was loose - some had nearly worked their way completely out; others were barely finger tight.
Planning to use some lock-tite on those screws when I assemble the LR4. And very glad I didn’t have a bigger mess while using the LR3 – it wouldn’t have taken much for one of the steppers to come loose and cause all kinds of damage…