It’s been a while since I have had some time to work on the site. During the past few weeks I’ve taken apart my Omni faceting head and photographed it. I will be posting photos of the process hopefully in the next couple of days.
I also have had a machinist look at the quill assembly to see if he could find what was the cause. His response was that there was a quality problem with the way the quill was made. It was not measured after machining as they assumed the lathe was cutting correctly. It was not, which explains why the others who have found this problem with their own Omni faceting machines have almost the identical runout amount and directionality.
The other issue with the quill is that it’s supposed to be friction-fit into a pair of bearings in the faceting head. However when I loosened the screw holding the quill into the bearings, the quill literally slid out of the bearing races under its own weight! With proper press-fitting of this part there is no way you should be able to pull it out of the bearings by hand, let alone have the part slide out on its own.
As a result of some discussions with the other owners, I am working with Mike to design a collet-based quill that will do away with the set screw. This should ensure that the dops are held perfectly centered in the quill despite any wear of the dops or quill that may occur over time.
The new quill will be made from stainless steel, which has better mechanical properties to ensure that the alignment will be maintained over the long-term.
Once I have the design finalized I will be buying a several of these collet-based quills which I will offer for sale to other Omni owners. It’s significantly cheaper per piece to buy several made at once rather than a single item.
*Note – I am no longer able to get these custom quills
Stay tuned!
-Allan