ANET A8 relocating the Z probe to the right... by aeropic

Last crawled date: 3 years ago

After playing around with my ANET and a z-probe located as 90% of people do id est to the left of the fan, I came to the conclusion this location is not optimal...
The ANET stock X axis is quite flimsy and presents a huge overhang for the motor and the extruder. When located in front of the extruder, the Z-probe has an offset of around 40mm with the noozle and around 70mm with the X-axis. A small rotation of the X axis induces a huge translation of the z-probe. The X axis rods are at a distance of 5 cm, if your rods are slightly bent, let's say a differential bending in Y of 0.1mm (which is very commun after a crash on the bed), you get a motion of 0.1 x 7/5 = 0,14 mm at the level of the z-probe and only 0.1x3/5 = 0.06 mm at the level of the nozzle. Which means your first layer is false by 0,08 mm...
The only solution to get rid of this is to locate the z-probe in line with the nozzle with a 0 Y-offset.
It is difficult to locate it close to the nozzle at the left, I then tried to place it at the right.
I get the following offsets :

define X_PROBE_OFFSET_FROM_EXTRUDER 60 // X offset: -left +right [of the nozzle]


define Y_PROBE_OFFSET_FROM_EXTRUDER 0 // Y offset: -front +behind [the nozzle]

Even if located to the right, it does not interfere with the right Z screw and carriage (see the picture). The bed is fully accessible.
Only drawback is that the probe cannot sense lower than 30 mm on the left. 1 or 2 cm might be recovered moving the X-end stop to the left. there is some room which is lost ...
Please see the provided "configuration.h" for MARLIN 1.1.5.
see it running here: https://youtu.be/62fMU7dB4yk
Most inductive z-probe supports use the z-probe nuts to hold the probe. They are quite big and not really accurate especially when screwed on a thin support. Which means the probe may rotate a bit...
I designed this support to be stuck to the back of the motor (with double sided tape) and screwed in posiiton. The support is a long 18 mm tube with 2 M3 screws which will secure in place the probe: it is very rigid !
Hope you will like!