Thread: CNC Mini lathe

firstly my old lathe, would cost a fortune to cnc this girl

Step 1

Need a bench to store the lathe on, and to create some more room in my workshop, so here Ive welded up a bench thats on wheels so I can roll it up to the wall, I have also made it a bit larger than required so that way it can also house my wood lathe as you can see already on the bench, this allows me to throw away the crappy legs that came with the wood unit, it also allows me to store consumables underneath in the internal cavity of the bench. Ive simply cladded the steel frame with 6mm mdf sheeting. I also had a hydraulic press that was taking up floor space, so Ive fitted this to the end of the workbench as well.

Next I will pick up the lathe

What lathe are getting for the CNC conversion?

I was looking at quite a few, but decided to go with the hare and forbes hafco al-50ag. its a small lathe for 995, for a few more hundred dollars they step up into some really nice lathes, but I decided I only want the smaller version becuase I have a large lathe already and convenience wise this will be more than ample for what I need

On top of this, rod who is a member on this board does a kit for the motor mounting, so instead of re-inventing the wheel, Ill give his kit a go, and let people see how it works etc.

But first I pick the lathe up tommorrow, it arrived today, Ive been waiting a few weeks for new stocks to come in, currently cant pick it up today due to work commitments but will squeeze it into tommorrows lunch break and pick it up

Originally Posted by simso

But first I pick the lathe up tommorrow, it arrived today, Ive been waiting a few weeks for new stocks to come in, currently cant pick it up today due to work commitments but will squeeze it into tommorrows lunch break and pick it up

Well where's the NEW piccy?

Ask and yee shall recieve, isnt it just purty

My first task is to get rid of the old toolpost and fit a quick change unit, I grabbed the 100 series from hare and forbes while I was there, there small, nothing wrong with the old toolpost but quick change units make life easy, I have one on my large lathe and I would be lost without it, it also will allow for easy tool manipulation when doing different profile cuts on the cnc, heres the old toolpost

Now that I have the lathe at home, I can measure up and place an order for the ballscrews and nuts, Im even tempted to do a trial run with the ariginal acme threads that come with the lathe, just so I can do a comparison check at completion

Okay quick change toolpost is fitted, was a bit more of a drama than I thought it was going to be, to fit the item, I basically removed the old toolpost and threaded the top of the vise to accept the new toopost thread, unfortunatley these vises are cast, and when I tightened the bolt up it stripped the threads out of the vise, so I ended up milling the underside of the vise and mounted a nut inside the casting and then simply bolted the quick change toolpost from above, this will make life very easy when having to do toolchanges during the cnc operations

Im ordering the ballscrews and nuts this weekend for the movement of the two axis's, but that being said I will be running the unit as well for a while with the original acme threads, as I am curious how much accuracy is in fact gained with ballscrews. Okay next step is to make an area for mounting the computer and cnc driver board and power supplies, Ive shown a picture of the back of the lathe and this is where I am going to box up and install these items

Hi Steve,
Lathe looks good.
Are you going to retain the tool slide in the conversion? If so you might want to make the 4 bolt tool plate to make sure the tool post is rigid. I can give you links for this if you need them.
If you are going to do threading you might want to consider a DC motor and tacho or a 3 phase motor and VFD. Just suggesting this now so you can leave room when you make the driver control box.

Thanks rod, Ill take any links you have mate. Now that Im starting the process, its all starting to make sense again, yes I intend to be able to do threading, but like my cnc router and the fourth axis, threading is something I will attack after its all up and running.

The current toolpost/cross slide clamping system is rubbish, they use a circular ring to pull down around a round collar to hold the toolpost/slide solid, and gee surprise surpise it moves, not a little but a lot, under hand pressure you can deflect the toolpost a good 9-10mm.

Tommorrow Im starting on the computer cavity, hopefully Ill have that finished by the weekend

Hi Steve,
Here is the link for the 4 bolt clamp. Don't worry about yours as it is a common problem for this lathe.
Here
He has full instructions on how to make it and I made mine using his details. I have some steel the right size so don't go buying a length to do the job.
This fellow is a guru in the 9X20 lathe circles so spend some time looking over his other projects on the lathe.

The other Rod was over tonight for a workout in the shed and I talked to him about CNC threading. Apparently it is easy and all you need is a tachometer on the standard motor set up so I led you astray a bit on my last post. It only needs a single pick up (one count per revolution) on the spindle and Rod has worked all this out to feed back to Mach3. I probably have made it sound difficult because I don't fully understand this mumbo jumbo electronics.

Oh yeah you will laugh as umongst other things we mounted a QCPT to his cross slide tonight.

I am currently ordering ballscrews from that new link in China and will let you know how it goes. So far not as cheap as expected but still less that our previous supplier in USA. I still have to have freight costs confirmed so that might change things a bit. Will let you know how it goes.

I'll keep watching this thread with interest as I will do my lathe conversion one of these days. Before I start that I have two machines on the drawing board as well as one under construction so I might start a thread on that one.

Okay well I got the Computer / Cnc driver cavity made up today, for those that dont know its important to set something up that is easy to access when in use, allows fine tuning of the circuitry and also allows easy changing of parts if necessary.

Here I have carved a hole in the back of the workbench behind the lathe, boxed it in, created an access hole and then wired a computers motherboard in, it all works fine, I hooked up a monitor and remote keyboard mouse and it works a treat. Now Ive just got to put the cnc driver board in "which is sitting on my desk here at home" and a power supply for the driver board and then its into motor mounting.

Hey Steve its a wed one dat must be weely fast , why not triton orange it rods favourite colour