FreeABL - the ultra cheap (free) ABL for Ender 3 Optimized

prusaprinters

I wanted to use a cheap ABL as i'm very bad at leveling my bed manually... So i found the FreeABL by stevohen.However i had some microswitches left and didn't want to use the original one (also as kind of safety-backup) so i used a microswitch with a roll on the lever and removed the lever to achieve higher accuracy.(e.g. this one: https://www.amazon.de/gp/product/B086396MXJ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 )It worked just fine for one week, but then i have seen that even if the both parts do fit very tight, the force on the switch will lift up the switch a bit caused by the L-shape of the original design.(The L-design is having the microswitch in front of the mount in the y-axis direction. So in that direction basically you get a 20 mm lever with only having 3 mm of mounting)From mechanical engineering perspective the original design is not good, so i remixed it again.The main changes:The switch is positioned directly below the mounting, so there are no unwanted forces and the results are more exact plus there is less waste of the partsThe mounting plate offers a spare position to park the switch plate without blocking venting holes (as seen in other remixes)The switch plate offers a cable tie mountI used an extra micro switch (< 1€) and removed the leverYou find all my files here and also the project file for Fusion 360. Please feel free to modify again for your switch.I also recommend to search for another switch which has lower resistance, as the switch pushes down my printing bed at the left and the right side. You can see the effect at the bed level picture attached. I can work with this, but you should be aware of this effect.Please use the manual of the original part.My Offsets in marlin are as follows:"#define NOZZLE_TO_PROBE_OFFSET { -37, -12, -6 }"My real Z-Offset is -6.85 mm, but this may vary for you.As i often forgot the printer when heating up or after bed leveling finished i added a M300 P300 S100 Line to my slicer, so my printer beeps when i have to insert the switch and also when i have to remove it.I printed it with 1.6 mm layer hight. It will fit very tight in the beginning, i manually reworked it a bit to fit perfectly.Scale with 10 %.In the end i have to say that always putting in and removing the switch is grinding my gears and now i purchased a capacitive sensor. However i managed to print PETG with this ABL without additional adhesion stuff and it helped me a lot for some weeks. If you like my work and want to support it you can do it here: https://paypal.me/sebastiandruckt  Print SettingsPrinter Brand:CrealityPrinter: Ender 3Rafts:NoSupports: NoResolution:0.16Infill: 20Filament: Tecbears PLA Black   Category: 3D Printer Parts