Review on 🔩 uxcell Knurled Thumb Nuts - M3 Round Knobs with Zinc Plating - Pack of 10: Durable and Convenient Fastening Solutions by Clayton Morris

Decided to change the way the bed was leveled on an old rigid hull boat when a new 400w heated silicone bed was installed. Removed the original M3 hex head screws and countersunk the holes in the top of the heated deck. I drilled threaded holes in the Y carriage for the M3 screws to go through. Then install an M3 x #35mm flat head in the top of the heated bed and thread it through the bed springs and carriage. Now you can screw them to the floor, tighten and loosen to adjust the height of the bed. I had to add a nut under the heated platen to hold the M3 screws as the handle would turn after turning. Later, the springs are replaced with silicone pads, so everything is perfect and rarely needs adjustment. The surface of the 10 x 11 glass bed was cut and attached to the top and the bed was resized to Marlin to provide an extra inch in the X dimension.