no, I was interested in the size of the leadscrew dia, length, pitch (e.g. 16mm, 800mm long, 5mm pitch) so to see if you were getting any effects from the screw inertia exceeding you motor capability at the acceleration you had programmed. Sounds like you were hitting some issues due to excessive endloading due to the screw being too long and this translated to a binding effect which may have been limiting your top speed by preventing your rig accelerating without loosing steps.