Messages

1961

Mach4 General Discussion / Re: Galil vs Vital

« on: November 04, 2019, 10:16:10 AM »

Hi,

When I asked about dedicated control panels I was thinking about the lower end offerings at around $1000 which o/p step and direction data.  Would those signals feed directly into the new servo drives or is an Ethernet SmoothStepper and a MB03 breakout board still required?

The only dedicated controller I have seen in that price range was a POS Chinese controller fitted to a customers plasma table.
Between the controller and the stand-alone THC unit they were the Achilles heel of the whole setup. I convinced them to ditch
the Chinese crap and get Mach4 and a Hicon, as at that time the Hicon only had THC among the Mach4 motion controllers.

It must be said that the Chinese controller produced step/direction pulses directly to the Mitsibishi servo drives fitted to the
table.

The ESS (or the Hicon come to that) are specifically for Mach (3 or 4) loaded PCs. Ergo they are not required nor would work
with ANY other control software. The MB03 is a breakout board designed to work specifically with an ESS and will only
EVER be partnered with an ESS.

The cheapest quality controller I've seen advertised is a Siemens 803 (three axis) at around $3500 USD (new).

Don't be duped by the Chinese rip-off Siemens look-a-likes......you MUST establish it is the genuine thing BEFORE
parting with a cent.

Craig

1962

Mach4 General Discussion / Re: Galil vs Vital

« on: November 04, 2019, 07:10:18 AM »

Hi,
there are quite a few questions in your post.

If I need to feed these new controllers with +/- 10 V surely I would still need something like the Galil card to supply that.

You are correct you would need a Gallil or something like it IF you persist in feeding the servo amps with an analogue signal.
The AC servos I'm recommending are step/direction, not analogue at all. You can thereby avoid the need for a feedback capable
controller.

So if the position loop is closed in the controller how does it know where to stop, if it is not sent a position signal.

That's what the linear scales are about. They not only drive the DROs but also supply the controller with the current actual
machine position and the controller will compare that to the commanded position and cause the motors to drive in a direction
and speed to match the commanded position exactly.

The AC servos I'm recommending don't need  linear scales because it has a built in encoder. Thus if the position is commanded
to move 10mm to the right and the machine has a 5mm pitch ballscrew the ballscrew must rotate two times. If the encoder
has a 10,000 count per rev encoder (entry level these days) then the trajectory planner/motion controller will issue 20,000
pluses and the servo drive will follow that command and monitor the encoder so that the commanded position is achieved
exactly. In this instance its the servo drive which 'closes the loop' rather than the controller.

Modern servo drives do a very VERY VERY good job of closing the loop, easily as good and in many cases better than
Gallil simply because the manufacturer is making a drive for his servo and he knows them both extremely well. Galil on the other
hand have to accommodate such a wide variety of motors and can't be great at all of them.

If I replace the motors and drivers, as you suggest, then is a PC based system the best way to control them?

This is a bit of a loaded question. I think it has less to do with whether you replace the servos or not but rather is  'PC the right
way to control a CNC machine?'. The shortest answer is NO. The best way is with a dedicated hardware controller like
a late model Fanuc or Seimens 840. These controllers are worth $20,000 plus. The question is whether you have the budget
to buy a dedicated controller or you can afford a much more humble PC.

A suitable but low powered PC for Mach4, an Ethernet SmoothStepper and a MB03 breakout board, and a Mac4Hobby
license would  cost under $2000 new. That leaves quite a bit of budget for controller panels and pendants etc.
I run my mill on a Mini-ITX dual core Atom board without a graphics card, as the saying goes, 'it couldn't pull the
skin off a rice pudding' but it runs Mach fine. Its 32 bit by the way, Mach4 runs on either 32 or 64 bit without demur.

If you have budget for a dedicated controller like Fanuc or Siemens and a motion controller like Gallil then why mess about
Mach4 or in fact any PC based solution? That you are on the forum suggests that you don't have that sort of budget.
Mach4 is one of the Windows PC based software solutions that can achieve good, surprisingly good, performance relative
to dedicated hardware controllers worth ten and more times as much.

Craig

1963

Mach4 General Discussion / Re: System recommendation for newbie

« on: November 04, 2019, 06:19:37 AM »

Hi,

Does this indicate what type of servo it is?

Your description of the measurements you have made and the testing you have done confirm the motor you have as
common garden variety stepper motors. They are not servos.

A servo is an electric motor, it could be a synchronous motor (aka an AC servo), it might be a brushed DC motor, or
it could be a variable reluctance motor, of which a stepper motor is a particular example, coupled and mounted
with an encoder/resolver to indicate angular position. A controller, be it Mach4 in combination with an analogue motion
controller like the Hicon or a dedicated servo drive will drive the motor in direction and speed such that it angular
position (encoder) is exactly the same as is commanded by the trajectory planner (Mach4).

The controller/drive is said to 'close the feedback loop' and it gives a very crisp and accurate response to commanded position.

A stepper motor and its associated drive just steps a certain number of steps in a given direction. If the load is such that it
'misses or can't make a step' then the controller has no way to detect that fact. Thus if a two phase (normal) step motor is
commanded to rotate one revolution by the application of 200 pulses but it makes only 198 steps because it didn't have
the torque to make those last two steps it will end up at 356.4 degrees not 360 degrees as intended. Because a stepper is
'open loop' this inaccuracy will not be corrected.

This might sound like a disaster, but really its not. Provided your steppers are adequately sized and you do not ask more of them
than they are capable they will never miss a step and be accurate all day long. This is how the majority of hobby CNCs work.

There are a number of Chinese manufacturers making 'closed loop steppers' by incorporating an encoder onto a stepper motor
and a smart stepper drive. They claim they are as good as servos.....they're bull*********ting, they are good but still not a patch
on a real feedback servo. They do a good job of selling to  hobby CNCers who are paranoid about losing steps.

What drivers, if any, do you have for your stepper motors?

If you don't have any the US company Gecko make superb and robust drivers, all their leading models are 80V capable.
They aren't cheap. Leadshine AM822s are 80V capable up to 8.2A and are more reasonably priced. In order to make your
stepper go fast use the highest voltage your driver can handle. The Gecko and Leadshine 80V drivers will make any stepper
sing.

Craig

1964

Third party software and hardware support forums. / Re: XHC USB Motion Controller Speed Input

« on: November 03, 2019, 07:10:18 PM »

Hi,

If not, it means that XHC is a very weak device.

Sorry to say, but on the basis of manufacturer support, XHC is not just 'weak', its absolute rubbish. I feel sorry
for those people who buy them, I just wished they had asked or even spent a couple of hours reading on the forum
before they bought.

Do yourself a favour and look to US and European manufacturers that support their products:

ESS by Warp9TD
UC100,UC400,UC300 by CNCDrive
57CNC,57CNCdb25 by PoKeys.

Craig

1965

Mach4 General Discussion / Re: Galil vs Vital

« on: November 03, 2019, 07:00:04 PM »

Hi,
modern AC servos are (programably) multi-mode. So, yes,  you could use analogue (+/- 10V) control them,either speed or torque modes
but also you can use position mode using the built in encoder.

I suspect if you were to retrofit that position mode is the one you would consider. Note that it renders the glass linear scales redundant.
That may be an issue to you in that linear scales 'enclose' backlash within the feedback loop whereas the rotational encoders on a AC
servo do not. If your ballscrews have no backlash then there is no real difference between the two. If there is backlash then the scales
enclosed in the loop are probably a feature that you would not want to miss on.

Note that you could use the linear scales with AC servos but it would still require an analogue capable controller and any savings you
hoped to make vanish. For instance even, the cheaper of your two options, the Hicon with the required analogue activations is $1200 whereas
a step/direction motion controller like an Ethernet SmoothStepper is $180. Thus the cost saving would pay for two Delta 750W B2 series servos AND drives.
It makes no sense to buy new servos only to then have to use an expensive controller.

The current trend in servos, and has been for twenty plus years, is ever smarter servo drives. In  the early days servo amps were just that 'amplifiers'.
In the very earliest of days there was no tacho feedback.....then came tacho feedback, the came step/direction control with the servo mounted encoders
being monitored by the drive and closing the loop. Gecko 320's are an example of these, brushed DC motors but with the feedback loop completed
by the drive NOT the motion controller. Nowadays with field oriented control has given rise to brushless servos.

More recently still with Ethercat, Profibus, CANOpen and the likes the servo drive assumes responsibility for the motion control of its own servo, this
is called 'distributed motion control'. Its coming whether you like it or not. I say 'go mad now and beat the rush'.

You may have noted on the NFS Forum video banner a Matsuura VMC machining a part. What may not be evident is that its Ethercat controlled. Interval Zero
have contributed a real-time core and plugin to a basic Windows PC and Kingstar have written an Ethercat module for Mach4.

I'm not suggesting that you leap quite that far yet, Ethercat is at the leading edge of development for Mach4 even if it is well established in industrial applications.
None the less, I am suggesting that you move to a natively step/direction controller and AC servos. If you absolutely require linear scales to be included in the feedback
loop then its not an economic proposition.

Craig

1966

Mach4 General Discussion / Re: Galil vs Vital

« on: November 03, 2019, 02:44:42 PM »

Hi,
just as a matter of interest what would it cost to replace the existing servos with modern AC servos?

I have recently bought three Delta 750W B2 series (17 bit incremental encoder) for approx $500 each. They are superb.
I suspect they would be cheaper than a new Galill......

Craig

1967

General Mach Discussion / Re: mach3 download and setup

« on: November 02, 2019, 02:52:49 PM »

Hi,
if you have a 32 bit Windows7 or 32 bit WindowsXP PC then you could use a parallel port. If the PC has one built into the mother board
they usually work pretty well. Other than that you can buy a parallel port card. Note that not all, in fact not many work well
with Mach. PMDX has selected and supply a parallel port card that does work well:

https://www.pmdx.com/1PARPCI

The parallel port works OK but has its limitations. For instance it does not work well on most laptops and is very sensitive to
other software installed on the PC. If you try to run other programs at the same time as Machs parallel port it will often
stutter or stall wrecking your CNC job. You can in fact run two parallel ports which greatly relieves the shortage of input
pins, the common complaint if you use just one port. The upside of parallel port/ports is that they are cheap.

Note that you'd need a genuine parallel port, any USB-to-parallel gadget will not work.

If you want an Ethernet or USB connected motion controller there are some very good ones out there if you avoid
Chinese. They make rip-off copies that don't work well, peddle pirate copies of Mach (NVUM is a prime example),
have absolutely no product back up. The only thing to recommend them is that they are cheap.......although how cheap is
it to buy something that doesn't work only to later have to throw it out in favor of something that does?
 
There are two examples of a USB input motion controller that has the equivalent of one 'parallel ports' worth of IO:

UC100 by CNCDrive (don't buy a Chinese rip-off, buy direct from CNCDrive or their nominated distributor)
57CNCdb25 by PoKeys

Both of these motion controllers are around $120 for a genuine example. Note that because they only have one 'ports'
worth of IO you may run out of inputs. You can only run one motion controller at a time so the lack of inputs is restrictive.
Note also that these are genuine motion controllers and while they appear to be a USB-to-parallel gadget, these devices
are in fact a great deal more than that, they both have a sophisticated FPGA inside.

I would recommend motion controllers with more IO:

Ethernet SmoothStepper by Warp9TD, approx $180, 51 IOs.
UC400 by CNCDrive, approx. $150,34 IOs.
UC300 by CNC drive, approx. $160, 85 IOs.
57CNC by PoKeys, approx. $160, 57 IOs.

There are others, more expensive, and sometimes much more expensive, and maybe required if you want to run analogue
servos:

Hicon Integra by Vital Systems, approx. $600 for the base model and up to $1200 with analogue activations
CSMIO/P by CSLabs, approx. 600Euro
CSMIO/A by CSLabs,approx 600 Euro, required for analogue servos.
Gallil, various models, starting at $2000 for three axis.

I personally favor the ESS (Ethernet SmoothStepper) as it has a very complete Mach4 plugin, at this time it enjoys a market leading
Mach4 plugin, certainly in the 'value' end of the market. It performs very creditably with Mach3 and has done so for many years.
Warp9TD have their own website and forum for support and a full-time support man.

https://warp9td.com/

Craig

1968

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

« on: October 31, 2019, 11:55:44 PM »

Hi,

So now I have a license file that is no good.    Can I simple open up that text file and add in the correct PC ID from Mach 4.   Or am I am I stuck waiting for Mach to answer my groveling emails to allow me to restart this long, painful process.

Mach4 is licensed differently to Mach3, with Mach4 EACH individual PC (called PCID) on which Mach4 is to run must be licensed to avoid the Demo restrictions. The good news is that
with Mach4Hobby you can have up to five PCs licensed with the one purchase. Further you can 'release' the license on the laptop and then use that 'slot' on another PC. You are
allowed up to seven such transactions in a two year period.

If you buy the Mach4 license direct from NewFangled Solutions (online) you create an account that you can manage your own licenses without the need for NFS personell being
involved, more or less instantaneously. In your case you may have to rely on AVID or whomever you bought the license to manage it on your behalf.
You might try to ask AVID if you can have the username and password such that you can mange the NFS Mach4 license page yourself.

Craig

1969

General Mach Discussion / Re: Servio motor Delta adas b2 Software and electronic gear ratio

« on: October 30, 2019, 01:34:23 PM »

Hi,

Last servo is capable of 2500 ppr so with 5mm pitch we can get 2um accuracy

Re-reading this and I don't think you are correct.

The 2500ppr (lines) encoders used on cheap Chinese servos are all Tamagawa encoders or a Chinese made copy of a
Tamagawa. They are pretty damn good, especially for the money, such encoders ten to twenty years ago would have been
considered 'state of the art' and very expensive.

2500 ppr with quadrature becomes 10000 cpr. Thus a servo equipped with such an encoder has an angular resolution of:

angular resolution= 360 / 10000
                          =0.036 degrees
                          =2.16 minutes of arc

If such a servo is direct coupled to a single start 5mm pitch ballscrew like mine then its linear resolution is:

linear resolution= 5 / 10000
                       =0.0005mm
                       =0.5um

So.....yes, the current entry level 2500 ppr (10,000 cpr) encoders offer very good resolution at affordable prices. It is not
really necessary in my opinion to have even greater resolution in an encoder but ALL the leading servo makers are going that
way.

For instance the latest Delta A3 series servos are equipped with 24 bit absolute multiturn encoders with battery backup.
This means for example that you could use 16 bits (65536 cpr) of resolution for the angle within any given turn and 8 bits
(+128,-128 turns) to keep track of the number of complete turns from the nominal 'home' of the servo. Additionally the encoder
is absolute reading, that is as soon as it is powered up it knows where it is whereas the cheaper previous generation incremental
encoders (like mine.....sigh) require an initialization procedure before that are effective in determining servo angular position.
With a battery backup when you turn your machine off and the servo does not lose home reference, when you turn your machine
back on you don't need to home it as is common practice. Pretty 'groovy'.....but as nice as those features are I don't really
need them and don't want to pay the extra to get them. Maybe you do....if you do be sure to tell us all about how they work.

Craig

1970

General Mach Discussion / Re: Servio motor Delta adas b2 Software and electronic gear ratio

« on: October 30, 2019, 01:04:09 PM »

Hi,
Delta is not the cheapest servo out there but it is the cheapest 'quality' servo.

I considered DMM (Canadian brand manufactured in China) and Delta (Taiwanese brand manufactured in China) and
ruled out the even cheaper Chinese brands.

I have good results with Delta VFDs.....and they have been in business for a long time whereas the cheapest Chinese brands are
newcomers to the market.

There is always a manufacturer somewhere who will make an item cheaper but of lesser quality. People who buy
on price alone are that manufacturers legitimate prey.

I tend to buy the best I can afford....often the cheapest IS the best I can afford but in the case of servos I wanted
better than the cheapest Chinese servos....there are quite a few posts on the forum about them, by no means all bad but often
there are shortcomings with them. One of the worst complaints is the atrocious 'Chinglish' used in the scanty user manuals.
Secondly many of the cheapest servos can only be programmed by button pushing on the drive whereas Delta (and DMM)
have software that resides on a PC and can be used to program the drive. You will see that in my previous post I now regard
that feature as essential. Modern servos have that many parameters, tuning options an modeling parameters that button
pushing is increasingly unrealistic.

I bought the ballscrews off Ebay from DYGlobal in Korea. He has become a favoured supplier having provided linear guides
and ballscrews for this new build and linear guides and various Vexta stepper motors/drives for my previous build mini-mill.

https://www.ebay.com/itm/THK-Double-nut-ground-Ball-Scr-BNFN3205-5-638mm-FK25-Precision-Z-axis-CNC-Router/201960959809?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160727114228%26meid%3Dd16a24a45f9b46f5a5d6059dc4911ec3%26pid%3D100290%26rk%3D1%26rkt%3D4%26sd%3D201960959809%26itm%3D201960959809%26pmt%3D1%26noa%3D1%26pg%3D2060778&_trksid=p2060778.c100290.m3507

Craig