Advice on new setup please

Hi All
I'm building a new CNC mill and looking to change the setup. Currently I run Leadshine MX3660 and steppers and am thinking to change to Mesa and possibly servos. I just wanted to pick peoples brains about what setup is better and why it's better and what I need.

System will be 4 axis, maybe 5 later. I would like spindle feedback, spindle control, ATC, and enough inputs and outputs for home, limit, coolant, spindle change etc.

Is there any benefit of using servos?
Is there any benefit of closed loop?
What's the benefit of Mesa over Leadshine?

I'm looking at low end professional use for the system so want to have something that is accurate and repeatable when cutting large diameter circles and arcs. The mechanicals are going to be linear rails and C5 spec ball screws so would like the electronics to be on par.

All advice appreciated.

Jools

My choice :
Mesa, servos, loop closed in Linuxcnc, always.

With servo's they seem to have far lower torque ratings than steppers. Do they need less or should I get something comparable to the steppers rating?

The main difference is :
Steppers - high torque at low speed, very low torque at anything above 200 to 500 RPM.
Servos - lower torque for the same size, can spin much faster at rated torque, can do short high torque bursts.
My above comment was for a mill, due to forces and weight etc, loop closed in Linuxcnc so any issue or error or missed position would stop the machine and alert about what went wrong.
For plasma machines i mostly use steppers, less prone to interference, not much weight to move and no cutting forces.

Servos do have lower torque for the same size and noticably less holding torque at stand still.
Look at peak torque value.
Gear down the servo maybe 3:1, then you get the torque you need and a usable speed range,

A closed-loop stepper can be an alternative. They add torque at higher revs.

Hakan wrote:
A closed-loop stepper can be an alternative. They add torque at higher revs.

Yup that is also a nice idea and the price is not that high.

So on this what's the difference between the 7i76e and the normal 7i76?

Quite a bit, the 7i76 is a daughter card that needs to be connected to a Mesa FPGA DB-25 card such as a 5i25, 6i25, 7i92, 7i80... The 7i76e is an all in one Ethernet card probably most analogous to having a 7i92 and a 7i76 rolled into one card. It has the FPGA built in and all the same outputs and inputs as a plain 7i76, plus a couple of DB-25 headers for further expansion by attaching other Mesa daughter cards.

Todd Zuercher wrote: Quite a bit, the 7i76 is a daughter card that needs to be connected to a Mesa FPGA DB-25 card such as a 5i25, 6i25, 7i92, 7i80... The 7i76e is an all in one Ethernet card probably most analogous to having a 7i92 and a 7i76 rolled into one card. It has the FPGA built in and all the same outputs and inputs as a plain 7i76, plus a couple of DB-25 headers for further expansion by attaching other Mesa daughter cards.

So pardon my bluntness but what's the point in havinig two cards that are for all intense purposes the same? Does the 5i25 add something extra?

In many cases you may not need all the I/O that a 7I76 provides
For example a 5I25/6I25/7I92/etc can connect directly to a Leadshine MX3660/4660
or Gecko G540, and that may provide all the I/O you need.
You can also use the 25 pin FPGA cards with inexpensive generic
parallel port breakout boards.