Because I've been taught to define acronyms: I.D. = Inner Diameter O.D. = Outer Diameter This is a spacer needed to install standard 14mm O.D. X 8mm I.D. Bronze Bushings onto the FlashForge Creator. The stock LM8UU Linear Bearings have an outer diameter of 15mm. Standard Bronze Bushings do not come in a 15mm outer diameter size (I haven't found any at least). After doing this upgrade my printer runs MUCH smoother and quieter. It also feels much stiffer than it did with the stock linear bearings. Printer runs like butter now. Bronze Bushing Part Number (from sdp-si): A7B4MP081416 Print out the spacers. I printed out a few extra (sixteen total) just in case. You'll noticed that the spacer I.D. is a little bigger than 14mm. I designed it like this so they can be pressed in easily but still fit snug (they fit perfectly). The uploaded .x3g file was generated in Makerware (my Simplify3D doesn't like thin walls) but feel free to slice the stl however you like. Press the spacers (carefully!) onto the bronze bushings. Remove your extruder head. Disconnect the connector going to the X-axis motor and the connector going to the X-axis switch. Carefully move them out of the way. Disassemble the Y-axis Rods. Slide the bearing holders (plastic pieces) off of the Y-axis rods. Slide the extruder carriage off of the X-axis rods. Remove the the old bearings from the Y-axis holders and the extruder carriage (total of eight bearings at this point). I used an Allen key to help pry them out. Be carefully doing this so you don't crack your plastic. Remove your build-plate arms and carefully pry out the old linear bearings. At this point all twelve of your old linear bearings should be removed. Press the new Bronze Bushings w/ the 1mm Spacers (installed in step 3) into all locations where linear bearings were. Total of 12. Notes: I noticed that the bushings and X/Y axis rods were binding just a little when I tried sliding the extruder carriage in the X and Y directions. This was probably from the bushings not being installed perfectly inline. This however made no difference and the printer runs like butter. I found it impossible to install the belt spring-clips once the belts were already installed onto the pulleys. Instead I put the spring clips onto the belts first and then installed the belts. I made sure to "tension" the belts enough so the spring clips were engaging.