I didn’t have screws, but super glue works perfectly. I printed in PTG hoping it would help smooth the movement. All parts went together perfectly (when I assembled them in the right order, LOL). I lubricated the screw and ran the sled all the way up and down (that takes a little bit, since the thread pitch is set to make it that way so it works). I am far more impressed with how well this works than I anticipated! Thank you! (the attached photos show one photograph from the session vs 91 taken at each 1/4 turn of the knob, stacked in Affinity Photo 2 on iPad, then cropped and edited in Lightroom on iPad.) edit: I was able to press fit a tripod adapter as an insert with a lighter, and it mounts perfectly on my tripod!