I3 Z Limit Chock Block

thingiverse

One less thing - That's great. My favorite Forrest Gump quote! This block helps to lock-in your Z-limit switch height. This eliminates a critical variable which is the second most likely cause of needing frequent bed re-leveling. (read on for the primary cause and solution). The block is an irregular ten-sided polyhedron with unique properties: opposing faces are different dimensions. In this case, five sets of opposing faces provide spacing of 22, 23, 24, 25, and 26 mm. Just turn the block to the size closest to what you need, and slide it under the Z limit switch. Then re-tighten while pressing the switch against the block. Use bed screws to fine tune the level. If different sizes are needed, simply scale this in your slicer before printing. What is the actual primary cause of frequently needing to re-level the bed? The cause is: Loss of Z rod synchronization. This happens when one Z rod turns while the other does not. This often occurs when changing filament, due to a large amount of downward force needed to compress the extruder spring. It can also happen if one Z stepper skips and the other does not. The fix: Turn off the printer or disable the steppers. Use a real level to verify that X carriage rods are perfectly level (or even better - match the level of the table the printer is on!). Manually turn the Z rod collars until perfect. Make small marks on the very front of each Z-screw collar. (see second photo) Perform a normal bed leveling. During this process, make sure the marks on the collars stay in sync. (relative to each other). Take time to be precise because this one should last a while. From this point forward, all you need to do is ensure the marks are in the same clock position before starting a print. You can also just turn them both to 6 o'clock. It's best to turn Z rods while the printer is off or the steppers are disabled. It's especially important to re-sync the Z rods after changing filament. During brim or skirt printing, observe the bead. If you need to raise or drop the bed, turn all four bed screws by the exact same amount. I use a screwdriver with an easy-to-see mark on the handle to keep track of fractional turns. By using both techniques, I have been able to bypass the complexity of adding an auto-bed leveling system. P.S. If you found this useful, then please check out my new product "OFFi" Auto-off switch for ANET A8 at: http://www.ebay.com/sch/i.html?_nkw=jimb15122 Thanks, JimB15122 Inventor of the original "Stiffi" X-axis bracing system.http://www.thingiverse.com/thing:1985444 "Try to solve the real problem, in the simplest way possible." Print Settings Printer: Anet A8 Rafts: No Supports: No Resolution: any Infill: 10% Notes: Walls, top, bottom - 1mm How I Designed This Is this something new? I thought of it myself, but I'm pretty sure a shape like this isn't really new. If any geometry buffs out there can provide some background or a formal name, please comment. Thanks