First remove the bottom drive belt cover, drive belts and Pulley from the Spindle.
At this point all you need to do is get a wooden dowel or block of wood and carefully tap/press against the bottom end of the spindle, shown here. It is a slight friction-fit with the bearings but will easily slide up through the bearings. If you are having difficulty a quick spray of WD40 may help.
Have an assistant holding the Platen and Spindle so that it doesn’t drop and damage itself or the machine.
Once the Spindle has moved up a bit, you can put the machine upright and grasp the platen on either side. Carefully pull it from the bearings having your assistant hold the Omni base steady. It will be much easier to tap the spindle free using a dowel however.
This is what the Spindle and Pulley look like when removed from the Spindle Housing. In this picture I have it resting on the machine base after I removed the Spindle Housing and Splash pan – which is not necessary to get the Spindle and Platen free.
Note that the Platen is a press-fit Aluminum plate on a steel spindle. You can also see punch marks between the black marker lines on the shaft. These punch marks are apparently to help the shaft fit more snugly into the bearings.
I sent this off to a machinist to have the Platen spun and levelled to try to eliminate the hop. I also asked the machinist to reduce the diameter of the Platen from the current 5.75″ to 4″. This will allow me to mount a 6″ saw blade on the platen to slice larger rough.
The results of the modifications can be seen here:
This is what the machine looks like without the Platen and Spindle in place.
Do you see a rather severe design flaw here? More detailed photos and discussion are on the Omni Design Flaws pages