[CallumRD]

Hello,

I'm looking for a control board recommendation for a new board for a simple 3 axis CNC mill. I've settled on Delta B3 servos, ideally the multi-turn absolute CA encoder versions, for the x, y, and z axes. These can be purchased with standard -L drives or etherCAT -E drives. I'm also running a servo with encoder for the spindle motor. I'll be using Mach4 to run everything. Ideally, I'd have a control board that supports the following features:

- rigid tapping (synchronized z and spindle using encoder outputs), mostly used with smaller taps (1/4"-20 / M6 and smaller)
- support for the B3's CA multi-turn absolute encoder for maintaining servo (and thus axis) positions through power on/off cycles
- connection to computer via ethernet or similar; I don't want to be using expansion cards

I haven't purchased the servo drives yet so I'm not locked into etherCAT or standard wiring configurations. Once I've found a control board that will work for me, I'll order the corresponding drives to work with it.

I appreciate any input anyone has on a control board for this build. My budget is not huge, but I'm willing to pay what's necessary to put together a robust, capable system. I just don't want to spend more than is necessary.

[cncmakers001]

Hello,

I'm looking for a control board recommendation for a new board for a simple 3 axis CNC mill. I've settled on Delta B3 servos, ideally the multi-turn absolute CA encoder versions, for the x, y, and z axes. These can be purchased with standard -L drives or etherCAT -E drives. I'm also running a servo with encoder for the spindle motor. I'll be using Mach4 to run everything. Ideally, I'd have a control board that supports the following features:

- rigid tapping (synchronized z and spindle using encoder outputs), mostly used with smaller taps (1/4"-20 / M6 and smaller)
- support for the B3's CA multi-turn absolute encoder for maintaining servo (and thus axis) positions through power on/off cycles
- connection to computer via ethernet or similar; I don't want to be using expansion cards

I haven't purchased the servo drives yet so I'm not locked into etherCAT or standard wiring configurations. Once I've found a control board that will work for me, I'll order the corresponding drives to work with it.

I appreciate any input anyone has on a control board for this build. My budget is not huge, but I'm willing to pay what's necessary to put together a robust, capable system. I just don't want to spend more than is necessary.

Have you ever considered an NC based controller?
They said NC based is more reliable than PC based control card.

[CallumRD]

Would an etherCAT controller like this one do what I want? I'm having trouble parsing the capabilities of these control boards from the minimal product descriptions.
https://www.automationtechnologiesin...ion-controller

[joeavaerage]

Hi,
Mach4 can be run as Ethercat.

There are two solutions:
1) Mach4 communicates with a motion control board that has Ethercat realtime comms, Vital Systems offer a board of this description. When all said and
done it is little improvement over Mach4 and a motion board....you still have a motion board its just Ethercat capable....so where is the advantage?
2) Kingstar Ethercat. Kingstar partnered with Interval Zero to get a genuine realtime core running in a multicore Windows PC. This means that a Windows PC can and does offer
genuine realtime Ethercat comms. This set-up is sold as a complete (probably re-purposed ex-lease PC) and everything is preinstalled. Costs about $2000USD, that includes a Mach4Hobby license,
Interval Zero runtime license and Kingstar runtime license on the aforementioned PC. To my way of thinking this is the genuine Ethercat thing....no motion board whatever.

The real question is why do you want Ethercat? Ethercat has huge advantages if you have an extensive machine, or several machines with conveyors between them...but for a simple three axis machine????....
what do you hope to gain? Its no more accurate, or faster or more powerful or more anything as far as I can make out. Don't get me wrong if I had the extra money at the time I built my machine I would have
got it.....but so I could brag!!! And bragging is about the only extra thing you get.

https://www.automationtechnologiesin...ntrol-computer

Craig

[pippin88]

Linuxcnc + ethercat works well.

Cheap too

$0 for linuxcnc. No motion control board needed, another $0.
Just need the ethercat servos.

[joeavaerage]

Hi pippin,
yes Ehtercat for free.......but what do you get with Ethercat? You still have to pay a premium for Ethercat servos but the what about non-servo IO? For that you need Ethercat IO modules.....and
again I ask what for? Its no faster or more accurate or anything than regular Step/Direction from a motion board.

Craig

[pippin88]

Hi pippin,
yes Ehtercat for free.......but what do you get with Ethercat? You still have to pay a premium for Ethercat servos but the what about non-servo IO? For that you need Ethercat IO modules.....and
again I ask what for? Its no faster or more accurate or anything than regular Step/Direction from a motion board.

Craig

For Delta, ethercat premium is about $50 per servo.

By not needing a hardware step generator (motion control board), I save that much.

So cost is neutral.

Wiring is less.
Feedback of information to controller is more (alarm states, power etc) and easier (no wiring)

Delta A3 ethercat has 7 digital inputs and 4 digital outputs per servo driver. Configurable (not fixed function).
That is plenty for my needs.

[joeavaerage]

Hi,
fine your limits and home switch, if you need one, go direct to the drive....but what about non-servo specific IO, say a probe input or inputs, or various pump outputs?

Delta A3 ethercat has 7 digital inputs and 4 digital outputs per servo driver. Configurable (not fixed function).
That is plenty for my needs.

Those inputs control certain specific functions of the servo only, likewise the outputs are selected from a number of servo drive states or status......not a probe input
or a pump output.

They are usually handled by an Ethercat IO module, and they aren't cheap, especially if you want good like Beckhoff.

Anyway, you've told me that you think Ethercat is cost neutral, which I disagree which is neither here nor there,....but still you have yet to come up with a good reason
to have Ethercat. What does it add to your machine? Does it actually do anything that a regular motion controller cannot?

Craig

[shineworld]

What is your budget price for a NC Board which support EtherCAT for Delta drivers ?

[arturod]

There are many options. We can help you, please contact us: https://cnc4pc.com/contact
EtherCAT is better for high-performance applications. You will need to put some effort on tuning the system once it is mounted and working with the workloads.

Arturo Duncan
https://cnc4pc.com

[automationtechinc]

We have a customer who used Linuxcnc with this Ethecat servo motors, He told me it works great
https://www.automationtechnologiesin...t-1000w-220vac

[joeavaerage]

Hi arturod,

EtherCAT is better for high-performance applications.

Why...what does it do that makes it better?

Craig

[joeavaerage]

Hi,
the only thing I am aware that Ethercat can do that my Ethernet Smooth Stepper (ESS) cannot; is the number of motors.

As you know Mach4 can have up to 12 motors, 6 coordinated and another 6 Out-of-Band (OB) axes.

My ESS has 6 motor output channels, say 4 coordinated and two OB say. An Ethercat could have all 12.....so that is an advantage. But OP is talking about a three axis machine....so lets assume
that he requires four servos (two being for a gantry) the he is still within the capability of an ESS without the extra the Ethercat offers.

The situation is actually somewhat worse than even that.

Mach4 has one output to control PWM for a spindle. Were you to use an ESS and BoB, then one ESS input is dedicated to converting that to an analoge output for a spindle.
Ethercat cannot do that natively. Ethercat is a realtime comm protocol, if you wsih to generate an analogue voltage then you need an Ethercat node that can generate it. Likewise
inputs, things like probes, door interlocks, coolant circulation interlocks, they would with an ESS/BoB be hooked to spare inputs. Ethercat cannot do that natively. That would require
a digital IO node.

Ethercat IO nodes are common, but none are particularly cheap. You would require at least one node with a minimum of one analogue output and half a dozen digital inputs. This is an example
of a fairly cheap Chinese made Ethercat IO module:

https://www.ebay.com/itm/37518344026...Bk9SR_7omrP5Yw

It has 16 digital inputs and 16 digital outputs but no analogue IO channels....for $136USD. Have not found any IO blocks that combine analogue and digital IO yet....I am sure there are some out there...and if you go
Ethercat you'll need one at least.

My ESS is set up to be 'input centric'. That is to say that I have 31 inputs and 20 outputs. Once I have assigned 12 outputs to the six axis motors, two outputs for the spindle (one for ON/OFF and the
other for PWM), one output for a machine wide Enable, one output for a machine wide Reset I have four outputs to spare. To date I have used 24 inputs, (limits, homes, individual axis alarms, Estop, probe
and wired pendant) and so have 6 to spare. In short the ESS is adequate, but I am approaching its capacity.

Ethercat on the other hand allows that you just plug in another Ethercat slave IO node. My understanding is that you can have up to 100 Ethercat slaves, where an IO node or an Ethercat servo both count a an Ethercat slave.
Effectively Ethercat can be expanded to have as much IO as you could ever require.

The question is does OP need it? As I have described I have sufficient inputs and outputs (with my humble ESS) for a five axis mill, and that is without compromise or forced IO economy. So I do not need extra IO....so is
Ethercat offering something that I could really use or need....no......it is not.

Just because Ethercat is available and appealing does not necessarily mean that it will do a hobbyist any good. If you had a large installation with multiple machines running in a coordinated manufacturing operation....
the yes Ethercat is perfect.....but for a three axis mill or even a five axis mill?

Craig

[pippin88]

Hi,
fine your limits and home switch, if you need one, go direct to the drive....but what about non-servo specific IO, say a probe input or inputs, or various pump outputs?



Those inputs control certain specific functions of the servo only, likewise the outputs are selected from a number of servo drive states or status......not a probe input
or a pump output.

They are usually handled by an Ethercat IO module, and they aren't cheap, especially if you want good like Beckhoff.

Anyway, you've told me that you think Ethercat is cost neutral, which I disagree which is neither here nor there,....but still you have yet to come up with a good reason
to have Ethercat. What does it add to your machine? Does it actually do anything that a regular motion controller cannot?

Craig

Wrong. Read the manual.
Delta digital inputs and outputs (on the ethercat drives) can be configured as general purpose inputs and outputs.

[joeavaerage]

Hi pippin,
I certainly will read the manual.

You still have not answered the question.......what is it that Ethercat brings to the party that a regular motion board does not?

Craig

[joeavaerage]

Hi pipppin,
you are 100% correct. I am very familiar with the B2 manual which definitely does not have general purpose inputs. The A2 and the A3 have four transition sensitive Event pins, and also have
up to 16 digital output pins driven bitwise from a data register. Neither are hugely convenient to use, by comparison to a regular Ethercat IO block,but none-the less could be if you wished.

That would work for most ancilliary digital IO but does not solve analogue output. I still think you'd need an Ethercat IO block for PWM output at the very least. This is an entry level
Beckhoff 4 channel analogue output block:

https://www.tme.com/nz/en/details/el...ff-automation/

What I cant work out is whether this block needs be paired with an Ethercat slave block, I rather think it does....but I'm not sure.

Craig

PS: Yes it does require an Ethercat Coupler. So Beckhoff IO modules require a Coupler. This is the most basic example:

https://www.tme.com/nz/en/details/ek...ff-automation/

There is a Bus End Terminal, which is a plastic shield that covers the right hand most end of the electrical bus, they are only $4.00:

https://www.tme.com/nz/en/details/el...ff-automation/

The point being that by the time you buy the coupler, then the IO block and end termination you've spent a few bucks!

[pippin88]

I have already listed some of the benefits.

1. Wiring is super easy - just ethernet cable. Reduced interference issues compared to bunch of wires running from motion control card to servo drives

2. Information feedback to controller - encoder position, motor power / current, fault status/information.
Yes a motion control card may be able to accept encoder input, but most are limited. Many do not accept 4+ high speed encoders.
Axis load is useful information. That's why real CNC controllers all have this.

I don't need analog or PWM. It should not be assumed that everyone does.

My VFDs happily accept modbus input. USB to modbus adaptors are cheap and work fine with LinuxCNC.

So what is the advantage of Windows ($) plus Mach4 ($) plus ESS ($)
Vs
LinuxCNC (free) plus Ethercat servos (small price premium).
?

There are affordable ethercat IO modules with PWM and modbus available on aliexpress for about $100. Simple GPIO 16 in 16 out.more.like $70.

[joeavaerage]

Hi,
the connection from my breakout board to each servo drive is a nine core flex cable (6mm diameter) less than 600mm long....Ethercat is saving me very little. For a modest three four or five
axis machine you save very little. If you had a whole string of machines then it might save some cabling grief....but remember OP is talking about a three axis machine,
and if I understand correctly a PWM driven spindle. Further OP said he is using Mach4. These are the questions that OP asked...not what you or I might like....what he wants.

Axis load is useful information. That's why real CNC controllers all have this.

BS. I had a ammeter for each servo driven by the analogue output of the drive for this exact purpose. The ammeter showed near zero current 99.9% of the time and then a brief blip up, then back to bugger all.
Complete waste of time. Save your time and energy for something useful.

There are affordable ethercat IO modules with PWM and modbus available on aliexpress for about $100. Simple GPIO 16 in 16 out.more.like $70.

Now try and find analogue IO. Cheap Chinese...pretty questionable.

And still you've not told me one thing that Ethercat CAN DO the a decent motion board CANNOT DO.

None of the perceived or real advantages that Ethercat offers are applicable to a modest hobby machine of three four or five axes.

So, how many axis is your Ethercat machine?

Craig

[shineworld]

Why...what does it do that makes it better?

I have been working on an NC board project with Ethercat, so I feel I can list the advantages and disadvantages of this motor control system.


- Ethercat is particularly good for 5-axis systems because it allows you to use absolute, driver-managed encoders, such as the Delta E-series, and so at least for rotaries you do mechanized zero once and no more Homing. In the case of CNC shutdown being able to rely on the position of the rotaries, even better if the liners as well, and avoid having to do a Homing allows the tool to be easily removed from the workpiece without worrying about possible collisions. It also reduces the machining startup time at machine startup.


- Ethercat is easy to wire especially for manufacturers. Bringing a single LAN cable from CNC to driver and from driver to driver is a quick operation, the connections are secure, and there is high immunity to noise compared to other systems. In contrast, the hobbyist making a single machine will face the stumbling block of having to learn the rudiments of a more complex system than classic 4 wires per axis.


- Ethercat brings the actual positions to the CNC while STEP/DIR-based systems rarely bring the encoder even to the same and merely close the loop in the driver.


- With Ethercat Delta there are models that handle both an Encoder (resolver) in the motor, to manage the speed loop, and the scale on the axis to compensate for mechanical problems directly in the driver.


- Ethercat permette un'ottima gestione degli allarmi, stati e edventuali I/O extra presenti nel driver.

- In contrast, an Ethercat-based system has a slight price premium, but for a CNC builder this is usually offset by lower costs of implementation and construction of the power panel.

- As a rule, resolvers (encoders) in an Ethercat driver, such as the Deltas, have high resolutions, about 140,000 pulses per motor revolution, which gives great possibility for position control.

I could add more details that are too technical for the moment

[joeavaerage]

Hi Callum,
I looked very closely at a Mach4 Ethercat solution 3.5 years ago when I was building my mill. At that time the Kingstar package (PC+Kingstar Ethercat license+RTX64 runtime license+Mach4Hobby license)
was $1600USD. To compare apples with apples I came to $1000USD for the same PC + Ethernet SmoothStepper + breakout board + Mach4Hobby. The difference as $600USD, then there is the premium for the Ethercat servos (five of them)
plus whatever Ethercat IO modules I might require. I came to the conclusion that Ethercat was goping to cost about $1000USD more overall.

Today the same Kingstar package is $2000USD and I would guess the same PC/ESS/BoB package is about $1200USD. Difference of $800USD. Then there is the premium for Ethercat servos plus any IO modules you
might require. All up I guess Ethercat still costs about $1000 more than Mach4 and a motion board.

As Pippin points out that LinuxCNC is free then the price is damn near neutral, maybe within the exception of an IO module or so. For Mach4 there is a distinct premium for Ethercat, less so or non existent in LinuxCNC.

When I was deliberating the choice, I came to the realization that my machine would be no better with Ethercat. That is to say the ESS and breakout board offer the same performance as Ethercat....so when it comes
to making parts you'd never tell the difference. Were my machine be very complex with many more motors etc and/or conveyors or robot arms, then Ethercat is highly desirable but for a hobby five axis machine
Ethercat offers nothing than I cannot get with Mach4/ESS/BoB.

It really comes down to what you want. If you would like the newest and developing tech then yes, Ethercat will spin your wheels. If however, your dream is to make decently accurate and finished parts in tough materials
the Ethercat offers nothing extra. That same $1000USD could however upgrade your spindle or coolant system or ATC or....the list goes on.

I came down on the side of pragmatism. Sure, I'd like to have Ethercat to explore....but that will not make any extra parts for me. I now use my machine daily for business. In fact, as I left work
I set the machine up to make four circuit boards, total runtime abut 2 hours. Got it set up, set it to run and stuck around to confirm it was behaving....and then left for home. I'll need those boards for customers in the morning.
What matter Ethercat or Mach4/ESS/BoB.....its the circuit boards I need.

Craig