@Gareth Owen Thanks. I saw the holes for the screws but apparently I was trying to over-engineer your solution. I was thinking you used something like a nut on either side of the fixed piece. Thanks again for posting your work on making this a better printer. I'll be printing those guides out tonight and hopefully installing them and testing a couple different ideas this week. I want to try combining your z steadying arm and creating a full length guide instead of the adjustable guides and them being separate pieces.

@Michael G Thanks for the reply. I wasn't sure because I couldn't find any documentation on the thread pitch so I wasn't sure.

When you implemented the new leadscrew/brass nut did you need to change the steps for the z axis?

Would you mind posting a picture or how you attached the adjustable z guide that you made? I looked at it and I can't make heads or tails on how the adjustable portion stays connected/gets adjusted from the static piece that's connected to the gantry from the few images that are on thingiverse. I was planning on designing something like this since I didn't like how wobbly the guides seemed originally and I saw yours.