Anet A8 Z Endstop Fine Tuner by klownius

Last crawled date: 3 years ago

This is an amalgamation of several different mods that I used to create the Z Finely Adjustable Endstop that I needed. Basically, I purchased an autolevel sensor, but I didn't want to mess up my printer updating the firmware to get the sensor to work. I have heard good stories and horror stories.
With this mod, I really don't need an autolevel. I adjusted all four bed screws using A4 paper to get it level initially (one time). Before every print, I just make sure both carriages on the Z threaded rod are at the same height, and then I adjust the nozzle height with this mod using an A4 paper in the middle to check its height. Turn the dial to raise or lower, and home the Z Axis. Do this until the A4 paper has some resistance but not a lot of resistance. When I mess with the bed to install a mod or something, I have to re-do the four bed screws, but that is it.
I printed the barrel fatty part with the hole side up. I printed the top endstop part with supports.
This mod does go over a chain mod, this one specifically:
http://www.thingiverse.com/thing:1905344
If using a different one, please check to make sure this will fit over it. Also, you might need some spacers/washers behind the bottom part depending on your mod situation.
Hardware needed extra (reuse the endstop switch screws and the bolts and nuts the standard Z endstop uses):
4 x M3 Nuts
3 x M3 Washer
1 x M3 Lock Washer
1 x 40mm long (or longer) M3 Screw (any type head)
2 x M3 Screw (longer screws to fit through this mod, the chain, the carriage, and into the motor)
? x Washer/Spacers (as need be)
Need to know how to melt a nut into PLA/ABS. Screw an M3 nut to the very end of a long M3 screw. Use a lighter to heat up the nut for about 22 to 30 seconds (in the BLUE part of the flame - it can get a black coating if using the orange part). Line the nut up over the plastic part, and using the nut into the PLA/ABS with the hole centered. Push until the nut is all the way in, and it is flat (not tilted). Carefully unscrew the bolt, and let it cool in there.
Construction:
Print one of each of the parts. Melt a nut into the bottom of the thumb wheel (side without numbers). Melt another nut into the fatty endstop cap (the side with the hole).
Slide a nut into the Z endstop top part (the little slot there). Screw the 40mm or longer bolt almost all the way in to that nut on the Z endstop top part (look at the picture to see orientation).
Screw an M3 nut onto the 40mm or longer bolt, followed by a lock washer, followed by a regular washer. Screw on the thumb wheel so the numbers are facing the Z endstop top, and do it ways up the bolt. Finally screw on the end cap fatty part all the way onto the bolt so that it is tight without moving (hand tightening is good enough).
Now, screw the thumbwheel down towards the fatty endcap until it is solidly against it, pretty tight (hand tightening is good enough). Push the washer and lock washer down on top of the thumb wheel. Finally, screw the M3 screw all the way down until it is down solid (use a wrench to tighten, but not over tighten).
Now, you should be able to turn the thumbwheel clockwise or counterclockwise so that the screw head near the slotty nut goes up or down. It should turn fairly easily. Vibration doesn't really change it, and I level it between prints, anyway, so there is no real need to lock it down.
Unlike the other mod this was based off of, do NOT remove the switch arm - it provides a necessary function. When the nozzle head is too close to the bed, you turn the dial so that it pushes the switch arm down a little more (it will bend slightly, and that's fine). When the Z axis is homed, the nozzle will now be raised slight higher. Without the arm, it's not possible to screw it down any more to raise the nozzle - not so good.
Install the top part of the mod as seen in the picture. Install the bottom part of the mod by replacing the current Z endstop and brackets. Be sure that the fatty top part hits the bottom switch end square on. Adjust or use washers/spacers on the bottom part until it does so.
Make sure the carriage isn't over the heated bed when you try leveling initially. Move the thumb wheel until there is about the same amount of bolt space above and below the slotty nut. Set the bottom part to pretty much the bottom. Try homing the Z axis only (again, not over the bed) until it looks like the nozzle is at least 1mm above the bed. THEN and only THEN, try leveling over the bed using an A4 piece of paper.
There it is!
I would like to thank alexan9er and cd1701 for their awesome mods. Without people like them, this mod would not have been possible!