Converting Lathe to CNC

Converting Lathe to CNC

Joined: 19 Nov 2017, 17:19

19 Nov 2017, 17:45 #1

I have an old belt driven Lathe that has NEVER even been turned on. It was a brand new Grizzly lathe (12" X 36") about 25 yrs ago, or so. Got a job of traveling and never home; so it just gathered dust.

I am itching to convert it to an all CNC machine now; because of the "state of the art" and the fact that I am now fully retired. I have the means.

Saw one on a YouTube video last night; by Centroid that looked pretty simple to do.

I live in "NE Atlanta". Specifically: City of "Berkeley Lake" (Duluth).

I need someone to get me started. That is all. I can do the rest. Learn easily and quickly, Praise Jesus.

Doc, could you email me if you are interested. If not I understand. I was given your name and website by the man that made the video above, after I emailed him last night.

Note: I also have a Grizzly Mill; bought at the same time brand new. NEVER been turned on-gathering dust. I want to convert it to a CNC also. Excited does not describe what I am feeling about this.


Joined: 01 Jan 1970, 00:00

19 Nov 2017, 19:25 #2

Okay, the first thing to remember is that there's no "right" way to convert your machine. There's lots of different ways, but in the end, all you need to do is mount a decent-quality ballscrew to your axes, and figure out a way to attach your motors to them.

Yes, some people have more... "elegant", for want of a better term, installs, while others are purely utilitarian- not as good-looking but they get the job done. Again, in the end, all that matters is does it work.

Google "home cnc lathe conversion" and click on "images", and you'll see a hundred different ways of mounting the steppers or servos. Again, none of them are the "correct" way, they're all just different ways of accomplishing the same task.

Look at several of them, see if you can find one that's close to your machine (the 12x36 is a common model from places like Jet, Grizzly and others) and look for a conversion that appears relatively simple.

And while I'm thinking about it, have you given thought to how you're going to make the parts? I mean, if you have the lathe torn apart to make a stepper mount, what do you do when you need a lathe-turned spacer or part?

I had a second, fully functional lathe as well as a mill, in order to make parts for my conversion. Will you have access to other machines, or a friend with machines, in order to make the parts?

Next up, you will be faced with a bewildering array of options for steppers and stepper drivers. (Skip over the servos for now- that's a whole 'nother can of worms, and you can always upgrade later.)

Again, there's really no "right" choice. Some choices are better than others, but virtually all of them will get the job done.

You might find one of the DIY CNC suppliers that has a "kit"- two motors, two drivers, the necessary power supplies, etc. That's almost certainly what I should have done, myself, but instead wound up with boxes full of brand-new parts I can't use or don't need. Trust me, you're going to do the same thing, so don't fret about it. You will undoubtedly run across plenty of guys online who will love to help you, but will have their own preferences for parts.

My particular combination is detailed over in the article Marty probably linked you to (Logan lathe conversion) but again, that's just one possible combination. I wound up buying mismatched, more or less random parts because I didn't know what I was after- and still kind of don't.

But mismatched or not, they still work, and do the job. (It's also worth keeping in mind that I'm shooting for short-run production work, not just hobby stuff.)