65mm Spindle Height

Hey pwsusi,

Many reported to use one (see here) but some of them switched to a 80 mm spindle later.

yes, with the original 65 mm mount the spindle does not clear the stepper. That is why you have to slide the spindle much downwards into the mount in order to not bump the Z axis stepper, like shown here:

– Image appears by courtesy of @curtisreidart

This however does not prevent many users using a 65 mm spindle. The disadvantage is because the spindle has to protrude the 65 mm mount that much, the leverage force that acts over the spindle on spindle mount, Z bushings and subsequently on X rails while milling is greater than it was if spindle was clamped closer to the axle end.

But it should be noted that this disadvantage is by design, the Makita trim router for which the Onefinity CNC was designed does not clear the stepper either and has to be slid that far into the mount the same way. It is a design issue.

As Bill also stated the other day:

But back to spindle. If you want the leverage force exerted on the spindle and subsequently on the mechanics of the cnc machine to be reduced by not sliding the spindle that much into the mount, you have three possibilites:

  1. You do not slide it that much into the mount, but then you loose some amount of Z travel (and Z motor will do stall homing against spindle back (not recommended))
  2. you raise the stepper by using taller stepper mounting blocks and extending stepper axle with another coupler
  3. you install the optional 80 mm mount which was designed to respond to the demand for the ability to mount 80 mm spindles. With this mount, the spindle clears the stepper so you do not have a limitation on spindle length or Z travel:

– Thanks for shooting this photo to @MikeH!

Further Reading