Messages

7391

General Mach Discussion / Re: Does this product exist?

« on: September 26, 2016, 06:33:59 AM »

Hi rcaffin,
yes that is exactly what I'm using.
I considered using a soft nickel-iron but eddy loss limits frequency which requires
multi thousand turn coils in VERY fine wire which I deemed to be beyond reasonable
means at home.
Ferrites on the other hand while being lower permabilty behave well loss-wise in the
100's of kHz and I can wind multi hundred turn coils in 0.2mm wire without undue
difficulty.
The current example offers 38mV/mm/Vexcitation and best measurement to date with
passive de-mod a noise floor of 200uV at 4.5V excitation for resolution of 1.2um.
If I can shrink future examples to 50mm overall height I might end up with something
useful at a fraction of the cost of existing commercial designs.

Craig

7392

General Mach Discussion / Re: Help Please: Computer upgrade causes no communication with controller

« on: September 26, 2016, 02:01:46 AM »

Hi guys,
the explanation makes sense, some chips can't match the functionality required.

I know at least one of the current MOSCHIP IC's work as I bought one and got it to work
I seem to recall amongst the different posts I've read at least one ROCKWELL chip also
works.
In the advertising for PCI cards few state what chip their product is based on and it seems
a few CNC'ers have been caught with nonoperable cards. Tweakies advice of buying from
a known CNC supplier makes good sense.

If I can retrieve the info for the card I bought and perhaps more importantly the chip it uses
I will post it. As I said above I think I just lucked into a usable card.

Craig

7393

General Mach Discussion / Re: Help Please: Computer upgrade causes no communication with controller

« on: September 25, 2016, 03:47:19 AM »

Hi Preso,
that's great news.
I bought a PCI card and I think I lucked out, it is based on a MOSCHIP device. It didn't
work straight up but after fooling around for a while and trying quite a few different
drivers I got it to work.
Can't really say that I understood exactly what was going on but it been working for me
eversince.

Craig

7394

General Mach Discussion / Re: Help Please: Computer upgrade causes no communication with controller

« on: September 24, 2016, 07:13:02 AM »

Hi Preso,
sorry didn't mean to come over highhanded but giving up is the third and least desirable option.

The first test should be to check if the pulse engine is running, aka 'the driver test'

Set it running, as admin if you have to, and observe the results.
If the kernel speed is 25kHz, the default, the timer will issue an interrupt every 40us.
The driver test measures what variation in time delay the PC requires before servicing the interrupt.
A well configured/managed PC will have a variation of 3 or 4us and an occasional peak delay of 12 to
15us. The line of the graph give a visual representation of the data. The raw data is displayed in
text boxes below the graphics screen.

Once you've run an digested the info for the kernel at 25khz, close it and reconfigure Mach3 on the
ports and pins page to run at 45kHz say. You will need to close Mach and then restart Mach for the
change to be seen. Rerun the driver test, you may need to check the new kernel speed and observe
the results as before.

Would expect the absolute 'jitter' to be similar but to represent a larger percentage jitter but with any luck
the driver test should issue an 'excellent' rating. If this is the case there is reasonable assurance that it will
run at slower speeds with some margin. My old XP machine would run pretty well at 45khz poorly at
60kHz and crash at 100kHz. The new dual core Atom platform I use now while technically less powerful
than the XP it replaces runs sweet as a nut at 100kHz, go figure!

I run my machine at 25kHz and there is no advantage in running faster unless you need it.

My guess is your real problem is the communication between the pulse engine and the parallel port.
A lot of PCI cards don't work. A lot of them 'emulate' a PP with some creative conversion from serial
to parallel, they don't work. Have a read of the documentation that came with the card, sometimes the language used
will give you a hint that the manufacturer has used this technique. Post the details and maybe I can help.

Craig

7395

General Mach Discussion / Re: Help Please: Computer upgrade causes no communication with controller

« on: September 24, 2016, 04:48:15 AM »

Hi Preso,
I've been running Windows7 Embedded for several years now. It works better than
my XP machine ever did. Better still it ran pretty much perfectly from the time I
installed it.

Mach3 is not brittle!  The parallel port, also known as the pulse engine, can be fickle.
Depending on the exact hardware arrangement and/or competeing OS software it
may or may not work on some machines. The fundamental fact is that "A WINDOWS
PC IS NOT A GOOD CHOICE FOR A REALTIME CONTROLLER". How would you feel
about Boeing using a PC to fly their fly-by-wire Dreamliner! Try some searches for
realtime operating systems, they are out there, and even some Windows derived
systems which are 'deterministic' in the realtime engineers jargon. I couldn't get
any of the manufacturers to commit to paper a price for a one off licence for RTS
but was informed by my local distributor in Melbourne that I would pay $16000US
to get started!
The pulse engine of Mach3 is a VERY VERY clever bit of software coding. Art Fenerty who
wrote it made possible CNC using Windows PCs. To my knowledge no one has ever
matched it much less exceeded it. I'm glad Art used his talent to write it because if
he'd used his cunning to hack defence systems for instance the world would not be safe!

As to your specific situation its time to buckle down to the task of getting your pulse engine
to run on your platform and have it communicate to the PP. Confusing and sometimes
difficult but usually achieveable.

The other alternative is to use an external motion controller, there are plenty reasonably
priced examples. Without the 'trick pulse engine code' just about any PC can run Mach.

'When the going gets tuff the tuff get going...whimps throw in the towel'

Craig

7396

General Mach Discussion / Re: Stepper issues

« on: September 24, 2016, 03:25:24 AM »

Hi,
don't think you can get Window10 in 32bit.

As far as I'm aware if you wish to use a parallel port then 32bit Windows7 or earlier FULLSTOP.
No exceptions or workarounds.

Craig

7397

General Mach Discussion / Re: Cutting smaller

« on: September 24, 2016, 03:16:47 AM »

Hi Bill I,
when you calibrated the axes who did you go about it?. When I did mine I did the
calculation, the number of stepper pulses/rev times gear reduction time pitch. It worked
fine and have never had need to go back.

Imagine the situation where I had 6mm pitch ballscrews but are in fact 1/4" ie 6.35mm pitch.
The calculation would be persistently and consistantly wrong.
Could your problem be of the same type ie one factor in your steps/unit calculation be slightly
adrift of the actual?

Craig

7398

Mach4 General Discussion / Re: input as a dro display (not closed loop),

« on: September 23, 2016, 02:40:55 AM »

Hi All,
your posts have been most informative and I have a much clearer understanding
of what to do to achieve the result.

Thanks
Craig

7399

Mach4 General Discussion / Re: input as a dro display (not closed loop),

« on: September 22, 2016, 05:04:53 AM »

Hi,
really interested by Bob_at_pmdx post.

One of the reasons that I bought Mach4 was that I was struggling to achieve the functionality
I wanted from an encoder, amongst other things not being able to reset the raw count.

In the Mach4 configuration screen there is an MPG tab which I assumed I could use as an
encoder input. Bobs comment suggests that the motion plug confers this ability. Can either
be used and what are the logical differences between them?

Craig

7400

General Mach Discussion / Re: My machine stop while running a program

« on: September 22, 2016, 04:47:24 AM »

Hi there,
just a quick question is your software licenced, in Demo mode it will stop after 500 lines of code.
The name of the licencee is right at the very top of the screen.

Craig