5 Attachment(s)
Carriage lead nut bracket
The first pic shows the bracket for the leadnut and the second shows a gusset that I added just for the heck of it. I'm sure it would have been plenty stong without it.
In the last pic you can't actually see the leadnut but you can see theends of the machine screws that hold it on. You will also notice that I drilled a 5/16" hole just below the leadscrew for a 1/4" rod to pass through. I made HDPE support followers for the leadscrew. I threaded the ends of some harware store steel rod to screw into the followers and used jamb nuts to keep them tight and indexed. You can see the jamb nut in the last pic.
All I had was 3/4" HDPE so I cut a 1" wide piece for the bottom and cut a 1/4" deep tenon to ride in the slot on the extrusion. I used a 1/2" ball mill to cut the groove in the top and bolted the two pieces together with machine screws. The followers are captured between the extrusion and the leadscrew. The leadnut bracket will hit one of the followers and drag the whole assembly with it allowing the other follower to support the leadscrew. The followers are short enough that they don't reduce the axis travel.
EDIT: I added a pic that shows the follower a little better.