Hi Everyone,

I'm pretty new to CNC so I do apologize for the newbie questions! I just want to ensure I'm accounting for everything I need and not missing a key piece of hardware or barking up the wrong tree.

Some background on me first - I make custom fountain pens, generally out of wood, resin, and metal accents - sometimes delrin or ebonite as well. I may or may not start making metal pens, but if I did it would likely be brass/aluminum. I started last year, but my small business has taken off and I'd like to automate / open up some of the possibilities of what i can do. A lot of my tedious work involves drilling, threading (int + ext), rounded square blanks, and shaping my pens once they are done - I have a number of pens in different sizes which all have different curves/profiles. I'll also be making accent rings out of round stock.

My original plan was to buy a 10x22 metal lathe and outfit it with a DRO - my current process is that I do everything by hand on a wood lathe, and it gets quite tedious. Not only sizing tenons, threading, etc, but getting my pens down to the size for the model I'm making is a pain in the butt, and then i have to go to town with a file, and then sand the crap out of it to get rid of the file marks. Being able to dial in the diameter and kick on the auto-feed would be great, but we all know that full CNC control is the bees knees and if the DRO is gonna cost half of the CNC cost, I might as well go all the way!! My backup plan is a template system for profiling, but i sense that it's only marginally more work to do a CNC retrofit.

Since I "just make pens" I don't have a 3D printer or a mill - so my first thought is that I will use the lathe as it is, and drive everything with belts. My hope is that this will let me learn the ropes, get my feet wet, and get used to the CNC workflow. I'm a little shy about replacing the leadscrews with ballscrews right away because of the mods that would be required (milling out the cross slide which I can't do). I don't know the first thing about encoders but I get the sense that I need to encode the spindle somehow for multi-start threading. I'm in canada so there aren't any pre-made kits for the lathes that I can purchase, and pre-retrofit lathes from CNC Conversions Plus are out of my price range. My plan for now is to use Centroid Acorn because I should be able to hit the ground running.

So with all of that out of the way, what I'm wondering is -

1) With backlash compensation, will threading go OK, or should I assume that until I do a ballscrew replacement I'll need to keep using my taps and dies? if I can use CNC for tenons, shaping, and some drilling, that will be a huge help and I can always put off threading.
2) What kind of spindle encoder should I be looking for? I can't connect anything to a shaft, because the lathe spindle is a gigantic hole. Is there a simple approach and a readily available optical/magnet sensor that I can employ?
3) assuming I can create a reliable zero where i can start and end the CNC, is it reasonable to assume that I could do manual operations by removing the belts? or should I anticipate that i'll need to either (a) get good at Intercon or (b) do turning operations using the MPG? I've been told I "can't do manual turning using the MPG", but some folks are just biased. but maybe without using ball screws that's true?
4) As a worst-case scenario, is it safe to assume that if nothing else I could do profiling with a belt+leadscrew setup? That alone would be worth the effort for me. It takes me two hours to shape a pen, sometimes more.

I think I've got a list of all the hardware I need, so I might make a separate thread for that - I just want to make sure i'm on the right track. If I really need to be looking at a full retrofit I'll have to take a step or two back and probably wait a year.