LinuxCNC for lathe, what to buy...?

[DR]

I have a CNC lathe, actually an Accuslide two axis slide on a Hardinge chucker bed. The monitor went out on the Fagor 8025(?) control. The Fagor control is a little off the beaten path anyway so I'd like something else.

Machine has DC servos, Servo Dynamics drives, limit switches, VFD for spindle control and spindle encoder for threading.

A friend who lives and breathes Linux is going to help. But he isn't familiar with LinuxCNC.

So what and where to buy the things I need other than a PC? And does the PC need anything special in terms of capability?

[Sparky_NY]

The pc does not have to be anything special, that is a benefit of Linux. I use older dual core pc's and they work just fine. I prefer the small form factor size being so compact.

For hardware, MESA boards are what most use to interface with the machine. They make the task pretty easy. Mesa has a huge variety of interface boards.

Here is one of the most popular ones for interfacing projects like you have in mind. http://store.mesanet.com/index.php?r...earch=ethernet

[Doc Nickel]

If the drives can accept standard step/direction signals, another option is the Centroid Acorn. I'm quite happy with my setup, and a very nice, professional interface.

Doc.

[elf]

I have a CNC lathe, actually an Accuslide two axis slide on a Hardinge chucker bed. The monitor went out on the Fagor 8025(?) control. The Fagor control is a little off the beaten path anyway so I'd like something else.

Machine has DC servos, Servo Dynamics drives, limit switches, VFD for spindle control and spindle encoder for threading.

A friend who lives and breathes Linux is going to help. But he isn't familiar with LinuxCNC.

So what and where to buy the things I need other than a PC? And does the PC need anything special in terms of capability?

The main thing with a computer for LinuxCNC is latency. I'm using a NUC clone, but it was a bitch to install Debian 2.8. Ethernet connection is better than a parallel port connection. I used a mesa 7i76e for my conversion of a new mill, but the 7i97 sounds like a better fit for yours. In any case the 7i76e is out of stock.

[Black Forest]

That Mesa 7i97 sounds like a great board. Not much you couldn't do with it.

[Sparky_NY]

The main thing with a computer for LinuxCNC is latency. I'm using a NUC clone, but it was a bitch to install Debian 2.8. Ethernet connection is better than a parallel port connection. I used a mesa 7i76e for my conversion of a new mill, but the 7i97 sounds like a better fit for yours. In any case the 7i76e is out of stock.

7i76 is step direction control, he has servo dynamics drives which are industry standard type drives that take 0-10V control voltage.

[Sparky_NY]

That Mesa 7i97 sounds like a great board. Not much you couldn't do with it.

Yes, Mesa interface boards are pretty amazing. They have expansion boards that can be connected to the 7i97 to expand capabilities out to hundreds of I/O pins and other interfaces. Take the Mesa hardware along with Linuxcnc and the sky is the limit as to what you can control.

[Sparky_NY]

I have a CNC lathe, actually an Accuslide two axis slide on a Hardinge chucker bed. The monitor went out on the Fagor 8025(?) control. The Fagor control is a little off the beaten path anyway so I'd like something else.

Machine has DC servos, Servo Dynamics drives, limit switches, VFD for spindle control and spindle encoder for threading

A friend who lives and breathes Linux is going to help. But he isn't familiar with LinuxCNC.

So what and where to buy the things I need other than a PC? And does the PC need anything special in terms of capability?

Worth noting that being a pro with Linux is not going to help a lot with a linuxcnc retrofit. Its the Linuxcnc software that one needs to learn or be familiar with not the operating system.
There is a definite learning curve getting into Linuxcnc but it is well worth the effort. The HAL (hardware abstraction layer) of Linuxcnc is where most of the pain of learning occurs.

Fortunately, there is a huge pool of knowledge and help available on the linuxcnc forum.

When you get things started I have the configuration files for my American Way lathe which is extremely close to what you have and would provide a excellent starting point or sample.

[RB211]

We recently discussed this over on the Digital Machinist sub forum. I picked up a Mesa USB interface that a cheap parallel port breakout board plugs into.

[Baz]

Although this drifted into 'buy an interface board' the original idea of Linux CNC was to run a cheap old computer using the parallel port. That got screwed up when it became normal for motherboards to be 'all inclusive' with the video handled on board stealing cpu power and putting glitches in the steps and slowing down latency too. So you either need a separate video card or the interface board. You might find an old gaming computer (like only a couple of years old as gamers are nuts for speed) that already has a the video board since they also want that for super graphics. I thought I hit pay dirt a few years ago when the Company was tossing old desktops but that's when I found out about the video problem and kind of put it aside with all the other half projects for retirement.

[Sparky_NY]

Although this drifted into 'buy an interface board' the original idea of Linux CNC was to run a cheap old computer using the parallel port. That got screwed up when it became normal for motherboards to be 'all inclusive' with the video handled on board stealing cpu power and putting glitches in the steps and slowing down latency too. So you either need a separate video card or the interface board. You might find an old gaming computer (like only a couple of years old as gamers are nuts for speed) that already has a the video board since they also want that for super graphics. I thought I hit pay dirt a few years ago when the Company was tossing old desktops but that's when I found out about the video problem and kind of put it aside with all the other half projects for retirement.

All of my Linuxcnc retrofits use cheap dual core computers with the on-board video, more than adequate. The reasons for the mesa board use are 1) it is extremely rare to find a computer with a parallel port any more 2) A parallel port can't run fast enough for a servo machine with a reasonably high count encoder, the pulses per second required exceed the parallel port speed capability by a large factor 3) On anything but a very simple build there are more I/O pins needed than you can get from a parallel port or even two of them not to mention parallel ports cannot do analog I/O signals.

Something like a simple two axis lathe with stepper motors is where the parallel port still can be used provided you can find a computer that has one !

[DR]

Thanks for all the replies.

Looking briefly at the MESA board suggested by Sparky, it looks scary with all the options I know nothing about. There is a time in my life I would have welcomed the learning challenge. No more though, Now I just want things to work. I will check the linuxCNC forum though. If there was someone locally who could advise me on the conversion I'd gladly pay him/her a couple thousand bucks.

The reason I didn't immediately go with the Centroid Acorn is my machine has existing servos. Acorn supports step-direction so I could go with Cearpath by replacing the servos and drives. Plus, I am currently getting into a mill conversion with Acorn + Clearpath. Acorn just seems much simpler.