I recently added an Ender 3V3 to my bench. Great little devil! Ultra-fast and accurate. So far, I have encountered only 3 cons: one, the Bowden tube that feeds the filament from the runout sensor to the print head gets bent rather sharply when the gantry reaches its top position (If that would only happen at the tallest prints I wouldn’t have cared too much. But this is happening on every print start as part of the homing/calibrating routine) so I figured I had to do something. The second issue is the location of the filament runout sensor location behind the gantry, which makes feeding the filament into it somewhat awkward. The third issue is the location of the spool which sometimes interferes with the movement of the print head wire loom coming down from the sensor position.

So, here is my solution for all three issues. I designed a bracket that basically locates the filament runout sensor in front of the gantry. This way the Bowden tube to the print head doesn’t get bent at the Z-home position, feeding the filament into the sensor is easier and straight forward and by reversing the spool hub on its arm, the spool is now away from the moving print head loom.

There are several items that you would need in addition to the printed bracket.
1x 8 cm JST-XH 2S extension cable for the filament runout sensor: https://he.aliexpress.com/item/1005004113756212.html?spm=a2g0o.order_list.order_list_main.10.7aa2586aZgDdF1&gatewayAdapt=glo2isr
2x m3/22mm CS bolts
2x m3/16mm bolts
2x m3/12mm bolts
4x m3 nuts

The modification is simple, straight forward and reversible (if needed) Simply remove the items from their original location (remove also the sub-plate that holds the sensor and the tube fitting – this will not be used) insert the four m3 nuts into their cutouts and attach the printed bracket instead of the sub plate using the two m3/12mm bolts. Now re install the sensor and tube fitting at the new locations. Attach the printhead loom to the holder ‘hook’ on the bracket and re connect the sensor using the extension cable.

I printed the bracket with PETG with 30% infill.
Happy printing.

p.s. You may also like my complementary rotating spool arm: https://www.thingiverse.com/thing:6993122