6x6 Stewart (Parallel Kinematic Machine Tool)

ommar wrote:

1. Is my machine hardware suitable to control with Linuxcnc ?
Stepper motor
Stepper motor controller (dirver)

By default the drive is configured as a single-step step/dir/enable system. This is entirely conventional and well supported by LinuxCNC.

Motion Control Card

It might be possible to write a LinuxCNC driver for this card, but I think it would be much simpler to use something that is already well-supported by LinuxCNC. For example the Mesa 5i25 / 7i76 combo is well regarded and is conceptually similar to the ADLINK card.
store.mesanet.com/index.php?route=produc...83_84&product_id=215
It looks easier to wire than the SCSI connector on the ADLINK too.
The 7i76 only supports 5 axes, but the 5i25 supports two daughter-cards, so you can add another 4-axes with the (cheaper) 7i78 card.

2. Can i get help a control and configuring guide for parallel kinematic mechanisms with linuxcnc..

Yes, though you might also need to ask via the mailing list to find the ones who have already built them.

ommar wrote:

adlink motion control card price is approximately 2000 USD but mesa 7I78-5I25 PLUG-N-GO KIT is only 159 USD so are the motors synchronisation (contact speed like Ghz) difference from each other ? Clearer, what is the reason of this price case ?.

With that motor and drive combination the motor synchronisation is controlled by the drive. The drive simply receives a position command from the computer.

The reason for the price difference is that the Adlink card is a motion control system. And LinuxCNC is also a motion control system. You do not need two of them.
With LinuxCNC and the Adlink card you would have a situation where LinuxCNC as controlling the Adlink card in the simplest possible mode, and wasting a lot of the capability of the card.
With LinuxCNC and a Mesa card all that the interface card is doing is creating stable, precise step/dir signals as commanded by the LinuxCNC motion planner.

You would need 2 x 7i78 for a 6-axis machine as the 7i78 only supports 4 axes. It is probably worth buying 5i25 + 7i76 + 7i78 just to have the extra general-purpose IO channels and the spindle control lines of the 7i76.

Did you intend to use the encoder inputs of the Adlink card? That drive / motor combination seems to expect the motor encoder to connect to the drive, rather than the motion controller, but it is possible to share the signals.
I don't know what the Adlink card would _do_ with the encoder feedback, but LinuxCNC is Open and configurable and there are options that can be exploited with steppers + encoders.

If you _do_ want encoder feedback back into LinuxCNC then you could look at 2 x 7i85S + 5i25 (or 6i25). The 7i85S has a serial port to connect the Mesa "SmartSerial" cards if you need to add extra general-purpose IO.

ommar wrote:

If i want to work for Close loop (conntecting Encoders to drivers) can i read feedbacks from linuxcnc?

Those drives are closed-loop between the motor and the drive. I assume that they can signal a following-error to LinuxCNC.

You could also take the encoder feedback to LinuxCNC, but doing so does not make the control any more "closed loop".

One possible configuration is to connect the encoders to both the drive and to LinuxCNC. What you can then do is run two control loops, one in the drive and one in LinuxCNC. You run the step-generators in LinuxCNC in "velocity mode" and then the pulse stream to the drive is effectively a speed + direction signal. Whether this has any advantage would depend on many factors, but in theory moving the position controller into LinuxCNC means that you can use velocity-feedforward for better dynamic response.

That is a decision that could be made later, though.

ommar wrote:

For controlling six step motor, six encoder, a spindle;
7i76 (4 step motor driver and 1spindle connecion)
7i78 (2 Step motor driver connection )
5i25 or 6i25 (Connecting to linuxcnc) Which would you recommend? What's the difference ?

The 5i25 is for full-size PCI, the 6i25 is for PCIe. So which you use depends on what sort of PCI slot your motherboard has.

And lastly Do i need extra or special cables for connetcing 7i78 and 7i76 to 5i25 or 6i25 ?

The 7i76 plug-and-go comes with one cable. To use the 7i78 (or similar) requires a generic P-port breakout and another cable, but Mesa sell those too:
store.mesanet.com/index.php?route=produc...74_79&product_id=235 (bit shows out of stock, but it is one of these)
www.amazon.com/gp/offer-listing/B0002J1T...e=UTF8&condition=new
And a second DB25 cable:
store.mesanet.com/index.php?route=produc...74_79&product_id=239

ommar wrote:

i colud not see Mesa 6i25 in I/O control ports/boards. Must I install linuxcnc (2.6) on debian ?

The 6i25 looks _exactly_ like a 5i25 to the software. Configure it as a 5i25 throughout. (Even the HAL pins say "5i25")