The original mount on both mine and my father's FLsun Delta printers fit into its pivot very tightly and had to be forced and it would bind when trying to use the Z stop switch with the hot end for homing and calibration. One of us filed down the piece to allow it to pivot freely only to find that the hot end could now flop around as the hole for the M2.5 pivot bolt was over sized. This causes all kinds of other issues.
In addition to that, we noted that the M3 bolt that actuates the Z stop switch was not located optimally.
This part addresses both these issues.
1) The mount no longer pivots on the M2.5 bolt. Instead the bolt is simply a retainer and the part grips the fingers that originally caused the binding at the pivot. Instead, I have implemented a flexing action that cannot bind and increases the rigidity of the hot-end mount except in the exact direction that we want flex for improved precision when sensing the build plate.
2) I have relocated the M3 bolt that actuates the switch so that it is centered over the switch's button instead of further up the arm. This lowers hysteresis and further improves precision by requiring the minimum travel to trigger the switch.
Uses all the original hardware.
I am still gathering data, and intend to do comparative testing with the original part vs. my improved design. For now when running calibration G33 P10 on my printer, I am seeing Standard Deviation of 0.012 - 0.007 and lower regularly over repeated calibration runs, and my Z probe offset is currently at 0.3mm.
I also sent this to my father to try, and he reports instant improvements in print quality and calibration just feels and sounds more reliable.
Printed with 4 perimeters
Printed in PLA, but just about any rigid plastic will work.
Just use enough spring tension to ensure that the moving end of the hot end mount is pressed fully against its stop surface, and then tighten the spring screw by 1/2 turn more.
Then adjust the M3 actuating screw to just barely depress the Z-stop switch so that it clicks.
Press up on the hotend tip repeatedly listening and ensuring the switch clicks both when pressing up and when you release the hot end again.