Which vfd is best for linux cnc?

devxpy wrote: @gmouer Can you please provide me with a link to example?

Here is some good basic info on spindle setup. It gives a good intro to the signals needed to control a vfd with linuxcnc.

linuxcnc.org/docs/html/examples/spindle.html

I know you said that you wanted a quality VFD, but I am actually (so far) rather happy with my HuanYang one, and it is very easy to integrate with LinuxCNC and the dedicated driver + USB modbus dongle.

As i said, It's a lathe meant for an industry, so i don't have an option to use a chinese vfd. Plus, i dont think there are any dealers for HuanYang vfd here in India

If if is a large industrial production machine, what hardware are you using to interface with Linuxcnc? (surely not just a parallel port.)

Most of the better interface hardware available for Linuxcnc have provisions for a standard analog controled VFD.

I was using a mach3 interface board through parallel port because the director of the industry had one lying around.
(Think because it was cheap and we were testing out if linuxcnc was a suitable setup)

If you say it will be easier to use a vfd with some other hardware,
PLEASE suggest better hardware, i will switch over immediately

What kind of motors does the lathe have, servo or stepper?

i have stepper motors for the axes and the spindle is a 3 phase AC induction motor.

don't need atc now because of the multi-function tool..

For a stepper machine, it is hard to beat one of the 7i76 options from Mesa. Either one of their DB25 FPGA cards (5i25, 7i92, or 6i25) with a 7i76 daughter card, or a 7i76e which is a stand alone card that connects to the Linuxcnc PC using an Ethernet connection.
store.mesanet.com/index.php?route=produc...83_87&product_id=119
It has up to 5 axis differential step/dir outputs, analog and encoder interface for spindle VFD, and additional isolated I/O 32 inputs and 16 outputs.
The step generators and encoder reader are capable of writing and reading pulses at MHz rates. (Fast enough they should never be a limitation.)

The 7i76 looks sick. So with that i wouldn't have to manually configure a vfd through MODBUS?

I will try to stay away from the ethernet versions since they don't have perfect integration in linuxcnc.

Also, another question - I have a parallel port in my pc so a 7i76 daughter card would be enough right?
I wouldn't have to buy a 5I25 Superport FPGA based PCI Anything I/O card, right?

Yes, direct analog control of the VFD (plus some digital I/O for start/stop, fwd/rev...) standard connections pretty much all VFDs have.

The Ethernet support for Mesa cards has come a long ways, about a year ago that may have been true, but today I don't think there are too many surprises left. They do take a little more to configure, because you have to set up the Ethernet connection (which is really an outside of Linuxcnc affair) but other wise I don't think it is much different from any other Mesa cards.