Linear bed bearing replacement for Anet A8 or A6 printers

prusaprinters

<p>One of these linear bearing replaces two LM8UU bearings for the Anet A6 or Anet A8 bed. It is intended to primarily remove noise, mechanical play and weight. It is made of only two parts: a housing and a snap in spiral bushing. Self threaded M4 holes to fasten the bearing with the original screws. The bushing is printed using vase or spiral mode to get it really even without abrupt layer changes.</p> <p>It is made using the "free" Fusion 360, and is fully parametric/customizable. You can find the CAD-file in the files section.</p> <p>There are many linear bearings variants here on thingiverse, and to give due credit I've copied the idea for the bushing from <a href="https://www.thingiverse.com/thing:2537701">https://www.thingiverse.com/thing:2537701</a></p> <p>Unfortunately I couldn't get the scad customizer to work there and made a Fusion 360 variant instead.</p> <h3>Print Settings</h3> <p><strong>Printer:</strong></p> <p>Anet A8</p> <p><strong>Rafts:</strong></p> <p>Yes</p> <p><strong>Supports:</strong></p> <p>No</p> <p><strong>Resolution:</strong></p> <p>0.20mm</p> <p><strong>Infill:</strong></p> <p>30% triangle</p> <p><strong>Notes:</strong></p> <p>Use a raft (approx 5 mm high + 5 mm outer) to limit the slight dimension change of the face sticking to the hot bed, mind these are long upright parts so this also gives it a good bed adhesion. If possible print on a cold bed to avoid any uneven shrinkage (unfortunately I'm unable to get a good stick to a cold bed)</p> <p>I'm using lower speed to get even surfaces (40mm/s) also forced nozzle width of 0.4 mm.</p> <p>Triangle (0, 60, -60 deg) infill gives good strength without adding to much weight.</p> <p>The bushing is printed using vase or spiral mode one by one for the spiral mode to work. Again a raft is probably needed since it have a very small surface area facing the bed.</p> <h3>Post-Printing</h3> <p><strong>Adjustment and mounting</strong></p> <p>Clean up and remove the raft and force the bushing all the way into the housing until is snaps firmly in place. Insert the metal rod and test the friction. Hold the bearing vertically then the metal rod should fall by its own weight. Switch over and hold the rod instead and now the bearing should not move by it's own weight.</p> <p>Due to the need of a really good fit for the house and bushing onto the rod you probably have to make fine adjustment of the bushing in Fusion 360 and reprint the bushing part and try again. Each printer/filament makes slight dimension errors during printing. But this is a rather small part so you can adjust and print some versions until you get a accurate fit with some slight friction.</p> <p>There are some options if the bushing does not fit perfectly:</p> <ol> <li>If the part is too lose:</li> </ol> <p>Slightly decrease the bushing inner diameter in Fusion 360 and reprint the bushing part. 2. Too much friction, the fast way:</p> <p>Heat one end of the metal rod in boiling water, and fast slide the bearing (bushing and housing together) onto the hot end and leave it there for a few seconds, then fast slide it back to the cold end. This will slightly soften the bushing and make a good fit onto the rod, but it can have the disadvantage of the bushing might get too lose in the housing. 3. Too much friction, the slow way:</p> <p>Leave it on the rod for a day or two :)</p> <p>That will slowly level the plastic in place and remove the high friction points. This only works if it is slightly too much friction... well, unless you would like to wait for weeks or more ;)</p> <p>Remove the bed and belt, unscrew original LM8UU bearings and mount the new ones. Now you probably need to adjust some things since there is no, or at least very little play. Just tiny misalignment of the rails rods and/or the bearings makes unnecessary friction. I found out the hard way that the H formed bed holder was not properly aligned from the factory and I needed to loosen all the screws on it to make it nice and square.</p> <p>Soo, hope you also can enjoy a play free bed... (umm, that sounded a tad bit boring though ;)</p> <p>Now I'm onto the rest of the linear bearings... and the ACME nut... Arrgh!</p> Category: 3D Printer Parts