2-3-4-5-Owl - Ridged Y Carriage for Mendel and Prusa

thingiverse

UPDATED belt holder (see below) This is a precise y carriage for mendel and prusa printers that features some advantages over the original frog design. It utilizes all 5 mounting holes of the heatbed to achieve maximum stiffness for the heatbed. It utilizes 4 linear bearings to improve accuracy. The owl shape y carriage uses 3 point bed leveling, which is more precise than 4 point leveling. This is because 4 point leveling can only work if the construction is flimsy enough. Two guiding rods are used to eliminate rocking in the leveling screws. No need to sacrifice flexibility of the print bed to gain accuracy. The distance between the two bearings on one smooth rod can be extended by 36mm to achieve more precise guiding of the y carriage. SC8UU bearings can be used, even LM8UU bearings can be locked in the bearing holders to prevent them from slipping out. The bearing blocks are shorter and the mounting screws are narrower than in the original design, reducing the force on the bearings in case of misalignment. The carriage can be removed without disassembling the y frame by pushing the bearings out of the holders. The belt is held a bit lower to eliminate triangular deformation of the belt path, which reduces wobble in the belt tension. Explanation on Youtube (in German) UPDATE: I3 Y Belt Holder with Tensioner I added two versions of cable support brackets to guide the wires of the print bed. See also my other Prusa i3 reworks in my Collection. This Part is also used in my Prusa i3 master reworks. Print Settings: Printer: Sintron Prusa i3 Rafts: No Leveling screws and springs are installed as usual. The belt clamp is just screwed under the owl using 4 M3x20 screws driven directly into the plastic. The holes in the carriage can also take a standard belt clamp with 45mm hole distance. Mounting the carriage into the y frame: Make sure that your rods are exactly parallel by checking the distance on both ends and in the middle with a caliper. Also check the vertical distance to the desktop. All these distances should be equal. If you don't have access to precision measurement instruments, install the y assembly as usual but don't tighten the nuts yet. Also the screws that are holding the block of the linear bearings should be loose. Push the y carriage back and forth to feel the resistance of the friction and hear the noise of the bearings. Some rattling will help to align the rods properly. Place a rolling object on top of the carriage, put shims under the legs of the printer to level the rods. The rolling object should not roll to the left or to the right. Neither if the carriage is pulled to the front nor if it is pushed to the back. Tighten the screws and nuts while continuing checking sound and friction of the movement. This procedure is necessary to work around some design flaws of the mendel and prusher design. Removing the carriage is quite easy, just push the bearings out of the holders and lift the carriage from the frame. Mounting the print bed: Find the side of the heated bed where are the solder pads for the wiring and the 3 holes. Insert M3x20 screws in the two holes on the edges and lock them with two nuts. The second nut is only to provide some distance. You can use washers instead. Lay down the print bed onto the carriage and align the two just installed screws with the holes in the guide rods (gfk/FR4 fins). Use two washers and a nut on each edge to connect the print bed to the guide rods. Then install the 3 leveling screws and springs into the remaining holes as usual. I generally recommend to use medium size washers on any surface where a screw is mounted to an plastic part to distribute the force and reduce wear.