Monoprice v2.1 Y Bar Alignment Jig i3 Maker Select Wanhao

thingiverse

Bed level is a huge issue, and it's largely influenced by how things are aligned. Let's face reality here: most 3D printers are slapped together at the factory without much care for precision. So, getting everything perfectly straight is what we need to do. Nobody wants to spend their time using calipers to get every detail just right. Holding calipers, holding the frame, holding the rods, tightening bolts - it's a real pain in the neck! You need an extra set of hands to get it done, but who has that kind of time? I'm lazy, and I like things simple. This is version 2.0 of my solution: first print two jigs, then place your printer on a nice flat surface. Remove the gantry (just like you'd find it when it's shipped to you). Take out the heated bed, and check that the springs are evenly spaced - if one is way off, it can put too much tension on the lower plate. Remove the lower plate, and if it's warped, just flatten it back out. Most likely, it was warped from the factory anyway. Loosen the rod bolts and grub screws (if you don't have grub screws yet, get them - otherwise, your rods won't be completely stationary). Place the frame on your surface, and all four corners should make contact if they're perfectly aligned. These jigs were originally designed to go under the belts so that all four corners would be at equal heights. However, there's only 0.5-1mm of play in the bolt holes, and a thick coating applied to the printer's frame throws off distances. Ideally, you want your Y rods level with your base because your Z motors are sitting on that same surface. So, shim each corner with paper or just flip the jigs as shown - I had minimal height variances by sitting them on top due to the coating. Tighten the grub screws first, then slowly and evenly tighten the rest of the rod bolts. When placing your lower plate on the bars, make sure it's flat, and pressing each corner will help you detect if any other corner pops up - if it does, either your rods are not perfect or your lower plate is warped. Adjust as needed. Attach the lower plate loosely, and feel how it moves - front/back. Grab each block, and again, evenly and slowly tighten the screws for the bearing blocks. If you just tighten one screw at a time, the block will twist and cause drag. Then reassemble the rest of the printer. Now, you should notice that your four springs have almost equal compression to them, which will result in far less bed relevels - even with the stock thumb wheels (which I still use).