Choosing the correct MESA board

Hi guys,

I want to build 5 axis milling machine, wood, and aluminum. Lately, I have gathered a lot of information, so the machine will run with five or six motors, NEMA 34 8.5N.m closed loop with HBS86H stepper driver (60/72v).
Currently, the spindle will be 2.2kw water-cooled with a VFD but, I want an option for ATC in the future. 
As for the computer hardware I guess a Raspberry Pi 4 model B will be fine (or you can recommend something else, I'm open minded).

My question is, which MESA board should I choose? 7I96S or 7I76E? maybe something else due to RPI 4? Budget range is up to 400~500$ if needed.

Thanks!!!

I recommend choosing the available one...

7i92S and 7i76E provide 5 step and direction signals only (without the addition of extra cards or interfaces).
store.mesanet.com/index.php?route=produc...oduct&product_id=374

store.mesanet.com/index.php?route=produc...69_62&product_id=290

Both boards ONLY provide 1 high speed encoder input (generally used for the spindle encoder or Phasma Voltage input (via a Voltage > Frequency card))

The HBS86H is a SERVO driver and NOT a STEPPER driver
www.ebay.co.uk/itm/374072008990?chn=ps&_...vv22RMMaAiS3EALw_wcB

Although they are closed loop...... they are not REALLY acting as closed loop can be done in linuxcnc where linuxcnc closes the loop via an encoder input.

The 7i76E has a lot more I/O's that the 7i76S, and more IO's in my opinion is always better as you will more than likley need them later.

You can always add 2 x 26PIN cards to the 7i76E where as the 7i96S will only accept one and then you rely on modbus.

If you really want a lot of IO's then consider the 7i95T
store.mesanet.com/index.php?route=produc...69_62&product_id=383
As that will drive 6x axis + have proper closed loop encoder feedback (so you can buy cheaper drives that are NOT closed loop servo / stepper drives)

Thanks for the informative reply!
I'll wait until the 7i95T is restocked.

About the motors, I found this as a kit and, I thought is a good one (probably not now...):
www.aliexpress.com/item/1005001345394148.html

I want to dig deeper on the things you have mentioned, where can I find more information about it? (Specially about the last two rows you wrote)

Thanks.

robertspark wrote:

... The HBS86H is a SERVO driver and NOT a STEPPER driver ....

 

I agree with everything you wrote except that... The HBS86H is in fact a STEPPER driver as it is to be used with stepper motors, not servo motors. From the manual: The HBS86H hybrid stepper servo drive system integrates the servo control technology into the digital stepper drive perfectly.

They are mentioning 'servo drive' only because of the feedback loop from encoders but this driver is definitively made for stepper motor with 4 wires, 2 phases.  Here is a link to the manual: hardware-cnc.nl/images/PDF/ACT/HBS86H_English_Manuel.pdf

not bothered if it's a stepper or servo they are treated the same in linuxcnc

it said servo on the eBay link I searched for and not stepper..... it says servo on the pictures of the drive

up to you to sort out what it is.

there is no way I would EVER buy a hybrid drive with linuxcnc as would let linuxcnc do the closed loop and not the drive

but each to their own, good luck

_____________________________


maybe some info in here on open and closed loop with linuxcnc

Chose the avaiable one