CR-10S, S4, S5 Dual Z Threaded Rod Sync

thingiverse

The CR-10S (all sizes) have a design flaw. When you power down, the steppers lose power and the left and right threaded rods can move and affect the squareness of the gantry. This is especially a problem on the S5 with its large bed. You can take a few minutes to realign them before every print, but I wanted a way to link the two rods so they would never become different heights. This is a simple, inexpensive and very effective method that I thought I would share with the community. What you'll need: (1) Dual Z Idler Bracket (attached file) (2) Idlers (6mm height, 5mm bore). I used these: https://www.amazon.com/gp/product/B07CCMQ8T7/ref=oh_aui_detailpage_o03_s01?ie=UTF8&psc=1 (2) GT2 Timing Pulleys. I used these: https://www.amazon.com/gp/product/B077P8PQHK/ref=oh_aui_detailpage_o05_s01?ie=UTF8&psc=1 (3) M5 Screws (1) T-Nut (1) Closed Loop GT2 belt (length to be determined based on CR10 model) I have the S5 and I used this one: https://www.amazon.com/gp/product/B018HMU9NU/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 Start by loosening the threaded rod on each stepper to get some extra slack above the bracket at the top. Loosely attach the pulleys so they will still move a little on the rods. Add the idler bracket (printed earlier), then attach the idlers as shown in photos. Feed belt around pulleys and idlers as shown and slide to the left or right until it begins to tighten. (Don't over tighten or it can bind or bend the rods) Next, align the height of the gantry so it is perfectly level and square. I did this with calipers, but it can be a little tricky especially if one side likes to hang lower than the other. Tighten the grub screws on the pulleys to finalize the linkage. Enjoy! As an added benefit, when the steppers are powered down, you can grab the belt at the top and drag left or right to quick move the z-axis up and down :)