Messages

1201

Mach4 General Discussion / Re: Rtx64

« on: April 09, 2021, 05:04:52 AM »

Hi,
if you think that going the Ethercat route is cheap....then I think you are in for a rude awakening. If you think you can buy cheap
Chinese stuff and get it to work I think you are going to waste some serious money.

The whole point of Ethercat is a QUALITY CNC solution....and you don't achieve a QUALITY result by using cheap junky servos and IO modules.
You'd be better off sticking to PoKeys and Leasdshine.

one thing i forget ask ,is this plugin its also for hobby or only industrial

I'm not 100% sure but I think either.

Ethercat is a realtime bus communication protocol....it does not have any 'affinity' with any given software. Kingstar is the provider of the
Ethercat/Mach4 plugin. The question is best posed to them.

My understanding is that you buy a Kingstar license and that includes the Interval Zero runtime license. Smurph has previously recommended
that it be installed on a capable PC, probably an i5 or i7 with generous RAM etc.

Ethercat can have up to 100 slave devices. This makes it very attractive in manufacturing situations where you may have several machines
with conveyors and/or robots between each. All the wiring and cabling reduces to a pair of ethernet cables between slave devices.
There was a time when it was not legally permissable to run safety data (things like Estops, door interlocks etc) over an Ethercat bus, or
in fact any bus. Thus all that safety cabling had to be run manually which rather detracted from the lean and elegant Ethercat cabling scenario.
My understanding is that Ethercat has matured to the point that government safety regulators permit safety data be transmitted over
Ethercat. There are Ethercat slave devices which are designed and approved for use as safety devices....you'll recognise them by virtue of costing
five times as much!

Ethercat was always intended to be used in industrial situations where the bus communication and distributed motion control strategy represents
a distinct advantage which overcomes the cost premium. For a standalone machine of two/three/four/five axes and spindle only the Ethercat
is an costly solution compared to a centralised motion control board like a PoKeys ad standard servos.

You really need to do some serious research and establish a business case for Ethercat......its going to cost more than usual.....how much more
is the question.

Craig

1202

Mach4 General Discussion / Re: Rtx64

« on: April 08, 2021, 03:17:46 AM »

Hi,

You mean Delta already had been test ,and can buy and use

Yes, Delta make srvos and drives which are Ethercat compliant. Look for a '-E' appending the drive
model.

About i,o do i must use Ethercat also?
Or i can continue use pokeys as i/o?

No, you must use Ethercat compliant IO modules. There is no place to hook a PoKeys in an Ethercat setup. You don't need or even
want a PoKeys in an Ethercat setup.

As Steve has pointed out there is a Ethernet cable plugged into you PC which connects to the first slave, be it a servo or IO module, and
another Ethernet cable to the next Ethercat slave in a daisy chain until the last Ethercat slave in the queue is connected back to the PC
with yet another Ethernet cable. All of the slave devices (servos, IO modules or your own home brew Ethercat slave) are in a ethernet ring.
No room for a PoKeys device in such a ring!

There is a great deal of information about Ethercat out there....you need to read it. Ethercat is great, and in certain industrial situations
has many advantages......but could be a costly excerise if you don't do your homework.

Craig

1203

Mach4 General Discussion / Re: Rtx64

« on: April 08, 2021, 02:58:32 AM »

Hi,
you need to be  a bit wary of Ethercat. The Ethercat specification and properties are public documents and manufacturers and
users alike are encouraged to adopt it. There are in effect no license fees, it is built into the cost of the half dozen or so
Ethercat slave ICs. You buy the IC....and make a new Ethercat gizmo with it and you're golden.

Various manufacturers have implemented Ethercat in slightly different ways.....and while that is not supposed to happen; it does.
Yaskawa have been in the business of Ethercat servos for years, and they along with Beckhoff are the accepted industry standard
types for servos and IO modules respectively.

You need to select suppliers of Ethercat slaves with care, some may not operate as you hoped.

There is an organisation, I forget its name, but as a commercial service it offers to test out any Ethercat device for compliance to the
published standard. The cost of doing so is not cheap, but not prohibitive either, maybe 10k. As a consequence all the good manufacturers
of Ethercat slave devices have had their devices certified by this organisation and can market their devices as 'compliant'. You should look for that
compliance.

As a side note ProfiBus and  closely related ProfiNet which are broadly speaking similar to Ethercat but will prohibit you from selling any device
without being strictly compliant......and guess who does that compliance testing....they do. Their preferred method of getting the fees is to have you pull
your trousers down and bend over while they extract the funds with cruel instruments! The cost of ProfiBus and ProfiNet products tends to be
much higher than Ethercat.

I use Delta servos, Taiwanese brand made in China, good quality, performance, backup and tuning software at a reasonable price.
Their Ethercat model servo drives are compliant with the standard.

I've seen secondhand Beckhoff IO modules on Ebay at very reasonable costs....so to my way of thinking there really is no need to buy cheaper
or lesser brands when you can have the real thing.

Craig

1204

Mach4 General Discussion / Re: mach4 uninstall problem

« on: April 04, 2021, 03:43:27 AM »

Hi,
good on you Tweakie.

I've heard you and your missus are real animal lovers and secretly send the Easter Bunny food parcels between Easter gigs.
I've also heard that he flats with the Tooth Fairy, they longue around smoking weed and bonking all the girls. I'm sure the food
parcels keep up heir strength.

Craig

1205

Mach4 General Discussion / Re: mach4 uninstall problem

« on: April 03, 2021, 04:25:06 PM »

Hi,
this post belongs in the Mach4 General discussion board. No doubt Tweakie will shift it there when he recovers from
Easter Egg bingeing.

I suspect that what happens is that the edits and modifications you made to various macros meant that they were saved, internally at least,
as individualized files. When you delete Mach4 those files will remain...they are no longer on Mach's list of install files.

When a new install of Mach comes along it just gets written into the same directories and thus your edited macros survive the re-install.

If you need to 'wipe the slate clean' then you need to delete the entire Mach4 directory, and that should take those pesky files with them.

There may be a better method however. If you have macros and/or other small chunks of code scattered throughout an otherwise standard
Mach install....when those files compile they will fault. Mach compiles ALL Lua chunks, both standard install AND individualized chunks into one
master file for runtime. If that file fails to compile there will be compile errors reported, and in particular a location in the file where the fault
occurs. If you open ScreenScript.lua you will find the entirety of the all the combined chunks. Scan down untill you find the line or lines
which are in error. Note that you cannot edit this file directly....you need to go back and edit the macro (or other lua chunk) at its source.

While it might be OK to 'wipe the slate clean' and start again when you are first starting out with Mach4 it becomes very VERY tedious once
you start making you own customizations in Mach. Often the fault is one line, and maybe just a misspelling or miss-click you don't want to have to start
all over again for such a small fault.

Craig

1206

Mach4 General Discussion / Re: Does anyone have experience with KFLOP motion controllers?

« on: March 31, 2021, 08:02:39 PM »

Hi,

Starting from scratch now, I'd buy AC Servos that do the job, but it's not economical for me to do that now.

Yes, I understand, I have no intention of replacing my servos with later model ones either.

I very much doubt that you'll achieve lost motion of better than 20mictrons with your system.

I do better than that with my mini-mill and my new mill is 10 times the rigidity. The manufacturers (THK) spec
of the screw stiffness is 1100N/um. Naturally the overall machine will be much less but I'll be disappointed if I get much less than
FEA predicts, that is 45N/um in all axes.

I think I'll just design my own compensation board when I get a bit of time. I've already schemed out a strategy that ought to work with my existing drives and the ESS. You can buy development boards for less than £100 which ought to be more than capable of doing the job. It doesn't need that high processing speed and you don't need many pins.

I understand that sentiment and have done similar things in the past just because it was interesting and a good hobby project. I'd have a hard time trying to
justify the investment in time to my boss however.

I think one reason why servo manufacturers are leaning towards smarter systems with auxiliary feedback is because they can finally do it ecomonically. Once one does it, the others have to follow.

Yes, than can do it economically, and because the design paradigm is shifting ever towards distributed motion control servo drives now, effectively, have to have this feature for the increased
accuracy demanded of them.

That's much easier to do from inside the Servo Amplifier than outside.

This I very much agree with. I would add that a manufacturer of a servo motor is the BEST placed to design a feedback control system to best exploit his devices performance.
General purpose feedback controllers are always up against the fact that they are general purpose....and can never be as focussed as a servo manufacturer.
As an example, I have a second hand 1.8kW Allen Bradley servo I use as a spindle motor. Amongst the parameters built into the drive is a piecewise linear approximation
of the magnetic saturation curve of the servo. Have you ever come across a motion controller that attempts to model the magnetic non-linearity of a servo?

Craig

1207

Mach4 General Discussion / Re: Does anyone have experience with KFLOP motion controllers?

« on: March 31, 2021, 07:13:03 AM »

Hi,

really cost effective to change them to accommodate a deficiency in the motion controller.

I don't regard the motion controller, in your case the ESS as deficient. The trend is with motion controllers is that they are becoming simpler
and simpler, so much so that with Ethercat, and similar distributed motion control protocols, the central motion controller disappears altogether.
Servos, or rather servo drives, are becoming ever smarter and are responsible for their own motion control.

Why do you suppose that all the leading servo manufacturers have, in their top models only, these secondary encoder channels? It's not because they
expect OEM machine builders to use deficient motion controllers.

It's a pity that the ESS doesn't implement closed look control.

Personally I'm damn glad that it does not, as the complexity and cost go through the roof. The Hicon is $1200, the CSMIO/A is 600Euro and the Galill
about $2000 for three axis. Verses an ESS for $180. You do the maths.

Thus you could buy three Delta A2 servos and drives for about the same as a Galill. When I bought my 750w B2 series a year ago, the 750W A2 series
servos were $530USD, and I'm confident I could find them still at this price if I searched around which would make three servos and drives cost competitive
with a Hicon (including the activations required for closed loop servos).

They were very expensive and do a superb job though

At the time I bought my B2 series I did not understand the advantage that the A2 series had, namely the secondary encoder channel, and so did not
consider the extra as justified. It was only later that I realized the advantage, yet I have no intention of replacing by B2's, they do a superb job
as is, just as you have found with your servos. I do not have linear scales, nor do I intend on getting them. I use 32mm diameter double-nut
C5 grade BNFN THK ballscrews and I anticipate vanishingly small flexure with either the ballscrews or the hundreds of kilos of cast iron into
which they are mounted.

If you want to close the position loop around your linear scales to accommodate lost motion then the most cost effective solution is load sensing
servo/drives such as the Delta A2 series. I have no doubt you could still sell your existing servos for a pretty penny and defray at least half the cost.

Craig

1208

Mach4 General Discussion / Re: Does anyone have experience with KFLOP motion controllers?

« on: March 31, 2021, 12:40:52 AM »

Hi,
to my knowledge KFlop does not have a Mach4 plugin.

The Mach4 controllers that can 'close the loop' are the Hicon Integra (with suitable but costly activations) and the CSMIO/A which
has a buggy Mach4 plugin. Note that both of these are analogue output. You would need analogue servo amps/servos or analogue input servo
drives with encoder rotary feedback, typically DC servos.

There is a third alternative. Most of the better AC servo manufacturers produce models of servos and drives that in addition to the rotary encoder
required to enact 'Field Oriented Control' have an additional encoder input about which you can close a position loop, with say a linear scale.

I'm using B2 series Delta servos for my new build mill. They have a 160,000cpr encoder. The later model and slightly more expensive A2 series
have a 1,280,000 cpr rotary encoder AND  a second encoder input channel for closing the position loop.

With A2 series servos you could carry on using the ESS but actually close the position about your linear scales without any additional hardware other than
the servos and drives.

https://www.fasttobuy.com/delta-750w-075kw-a2-series-servo-system-drive-motor-asda20721f-ecmac10807ps-new_p27765.html

Revise my earlier estimate. I was sure that when I bought my 750W B2 series servos/drvive/cable they were $460USD per kit and the A2 series were another $50USD each.
The link prices 750W A2 kits at $725USD, rather more than they were a year or so ago. I note also that the 750W B2 series are listed at $438USD....so they have come down
a little.

https://www.fasttobuy.com/flange-80mm-239nm-ac-motor-driver-kits-with-3m-cable-220v-075kw-cnc-servo-motor-for-cnc-router_p28084.html


Craig

1209

Mach4 General Discussion / Re: How to Create a Simple Dialog Box

« on: March 30, 2021, 03:12:42 AM »

Hi,
of all of the features of Lua I find wx.Lua the hardest to get my head around.

There is very good reference material, for geeks, by geeks and in geekese!

I found the first few faltering steps were when I copied and pasted some of the dialogues in LuaExamples. In particular I found
the file dialogue useful. I experimented with it until  understood each of the parameters and their syntax. It was slow but I got several
very useful macros which I now use daily.

At smurphs suggestion I did experiment with wxFormBuilder. I have spent about six hours on it so far, but probably need to spend
a lot more to become familiar with it. The adavantage is that you can see wxWidget code, which in conjunction with the reference material,
you can start to de-mystify it all.

raig

1210

Mach4 General Discussion / Re: New people welcome !! Come in here and introduce your self!

« on: March 27, 2021, 09:30:25 PM »

Hi josh,
best place your question on the Mach4 General Discussion board.

1. The ESS or Mach seems to be rounding off some of the corners of my carves and it doesn't make sense.  I generate toolpaths with VCarve Pro and have a lot of experience on our other machines, none of those seem to do this so it seems the ESS is the likely culprit, but I'd love suggestions.

There are two different questions to be answered here.

Firstly its not uncommon for Mach to display a toolpath which seems to take shortcuts to get around corners but the machine does not in fact take
those shortcuts. My understanding is the the toolpath display may have a different 'resolution' than the actual toolpath. This seems to happen when the
feed rate is high and you zoom in on a particular part of the toolpath display. I see this quite a bit when making PCBs. I regard it as a quirk of
Machs display as it does not get reflected in the finished result.

The second question is when the toolpath IS being 'blended' and indeed the toolpath does take shortcuts around corners. Mach is the trajectory planner
and it decides how the toolpath has to be to met its objectives. The ESS just carries out the trajectory. If a stepper cannot keep up with the ESS generated moves,
which are in turn specified by Machs trajectory, then the stepper either misses steps or stalls.

There are a number of influences on when and by how much a toolpath will be blended. Obviously if you select 'ExactStop' mode then NO toolpath blending will
occur. If, as 99% of users do, you use 'Constant Velocity' mode then blending does happen. In that circumstance there are some tuning parameters that you can tweak
but by far and away the most important fact is max machine acceleration. The faster the machine can accelerate the better it will follow a toolpath, any toolpath.
High acceleration is more important than high axis speed and often times is actually more important to overall cycle time than max velocity.

I suggest tune your machine to its highest reliable acceleration....even at modest expense of axis speed. Mach uses the max acceleration (in the motor tuning page)
to determine its CV strategy.

Craig