I'm struggling to get the "tight grip" on the pillar rails that its tight enough to not have a wobble but loose enough for the gantry to move up and down freely when turning the lead screw by hand (stage 6, step 11). It would move up fine but moving it down, it would get stuck for half a turn before the coupler brings in down. I've tried the following with no avails: -lubricant -checked that my lead screw is straight -tried using the stepper motor to drive with but still can't get it to come down smoothly Been adjusting it for 3 days now. I was also one of those with the extra eccentric guide instead of the fixed one, thought that might have been the issue and printed a fixed guide from an SLS printer but that still didn't solve the issue.