Upgrade your Vertex Delta brass bushings with LM10UU linear bearings, for smoother operation and faster break-in of the printer.
The linear bearings are a larger diameter than the brass bushings, so this modification will reduce the maximum build radius of the printer by about 3mm. In return, I was able to increase the height by about 5mm. The automatic calibration procedure will compensate for the change in geometry, so no firmware changes are required to support this enhancement.
These carriages are designed to print without any supports. The small endstop actuator tab is meant to be inserted into the slot on the back of the carriage. You will need six LM10UU linear bearings and three of these carriages.
I have also provided the STL file for the small endstop tab extenders that I used on an early version of this enhancement. The tabstop extenders can be used with the stock K8800 carriages to switch to LM10UU linear bearings. These will print more quickly than the full carriages, but you will lose more like 5mm from the build radius.
UPDATE: I have added a .STL of a carriage that incorporates printable bushings. I haven't tried these out yet, but I suspect they'll need a few drops of mineral oil, or graphite, or some other light lubrication. Let me know how these work for you.
Full write-up: https://forum.vellemanprojects.eu/t/the-solution-for-all-your-delta-woes/29088
Velleman Vertex Delta K8800
These can be printed without supports.