It’s an odd question but hear me out…I want to cut a spindle shaft, retap it, and drill a hole through the flat of the er11 head…hear me out I said
So awhile back I blew up my nomad3 spindle. I bought a replacement and have been sitting on the old one ever since.
Recently I’ve gotten into gem cutting (if you thought cnc was an expensive hobby…) and I’ve found myself wanting to modify the dops that hold a gem for cutting.
These dops are fairly well machined brass with a 1/4” shank.
To modify the head of the dop, I need to hold it rock solid and as perpendicular to the head of the nomad as possible.
Enter the old spindle assembly! I figure I can cut the bulk of the shank off, retap it for m6, and cut a holding fixture on the nomad. That should give me the best alignment I can ask for.
That’s all cool, but why do I want to drill a hole through the flat?? Well the dops often have a 45 degree flat put on the bottom for orientation. If a can put a small dowel through the bottom of the er11 head, I can ensure repeatable rotation if I ever need to recut. It’s not strictly necessary but it’d be mighty convenient if possible.
Is this a dumb idea? Am I better off just milling a jig to hold the dops and skipping the whole er11 reuse? How hard is the shaft? Can I tap it with a standard tool or is something special required?
Many unknowns here but it sounds fun. Happy to hear any/all opinions so me know what you think!
Ha! I love this dumb little machine
Cut dry with one of the super cheap coated corn cob roughers. (The uxcell titanium coated ones that come in a 10 pack for $20)
1/8” shank, 2mm diameter cutting end, 24,000rpm, 0.1mm step down, 200mm feed rate. Suuuuper conservative because I’d rather burn up a $2 tool than wreck another spindle bearing but hey…it got the job done with no fuss in less than 5 minutes. I call that a win
My spindles are also piling up. Number 6 is currently on its last legs… Number 1-3 was sent back to C3D for diagnostics but no fault was found.
But anyways. Partially unrelated to the topic itself; have you found a solution to the bearings dying?
No solution to the bearing issues unfortunately, I’m just more careful than I used to be when putting side loads on them…not sure if that does anything to help but it makes me feel better about it so I’ve got that going for me
Per the topic, next step is to bring the 8mm shaft down to a quarter inch to match the dop shank.
That should let me chuck it up in the faceting machine without needing modifications to the machine itself.
I figure this will weaken the collet assembly quite a bit but that should be fine given the relatively low forces involved in lapidary work.
The trick will be to make sure the shaft stays concentric to the collet taper. Seems like I could just chuck up a piece of precision rod in the lathe, dial it in, and then mount the collet assembly to start cutting…let me know if this sounds stupid
I’ve got some next steps planned assuming that all goes well but we’ll get to them in due time
) and I’ve found myself wanting to modify the dops that hold a gem for cutting.
