Messages

6601

FAQs / Re: How can I control ac servo motors using mach3? help!!

« on: September 22, 2017, 05:34:10 AM »

Hi,
yes servos can be controlled with Mach. Mach and its motion controller produce step/dir signals which are hooked to the Delta servo drive.
The drive and the servo form a feedback loop. Excepting fault conditions the servo will match Machs programmed position within fractions of
a degree over a wide range of speed/acceleration profiles.

Craig

6602

Third party software and hardware support forums. / Re: Need help -only some signals output on longs breakout board

« on: September 22, 2017, 04:26:15 AM »

Hi,
the only thing I can think of is that pins 2-9 can be either all outputs or all inputs. Usually port1 pins 2-9 are outputs, after all you must
have outputs to control your motors. Port 2 however you can configure. Is it possible that you have ports 1 and 2 confused?
You will see it on Config/Ports and Pins page.

Can you post a manual for your new board? Its not impossible that there is a setting on it to make 2-9 inputs which would have the same effect you
describe.

Craig

6603

General Mach Discussion / Re: Interference with axis motors

« on: September 22, 2017, 04:07:03 AM »

Hi,
glad you've got the interference problem sorted...it will probably recur but using fairly simple principles solves most issues.

I am intrigued that your Win10 machine can run what appears to be a parallel port and yet a 64 bit OS cannot support a parallel port, even
in deepest darkest Affwicka. As an experiment would you confirm the motion plugin Mach is running.

Ordinarily when Mach is fired up the first screen asks you to select a motion control plugin from those that are installed. Normally you select one
and that selection would be repeated at each startup, tedious and so you can hide the screen. You can view it again by Function Cfg's/Reset Device Sel...
and then restart Mach. Can you tell me which plugin is currently selected as your motion control plugin. While a parallel port plugin might be listed
I don't think it will work. Note any other plugins listed, one I suspect will relate to your motion control card which I believe must be the PCI card.

Maybe if you have access to the card you could take a pic or indentify the main ICs on the board, I would suspect one to be an FPGA or DSP or maybe
an industrial micro that would not be on a PCI to parallel card.

You might also try to run DriverTest.exe from the Mach3 folder, it tests the parallel port. I suspect it will fail as no parallel port can be installed on a 64 bit OS
machine.

As I say I'm intrigued, you may have seen the hundreds if not thousands of posts by people who are disgusted that Machs PP cannot be run under a 64 bit OS
and seem to imagine that Artsoft or maybe MS is involved in some conspiracy to prevent it.

Craig

6604

General Mach Discussion / Re: Moving settings to another computer

« on: September 22, 2017, 03:22:49 AM »

Hi,
good question, I've never had to delete the lot and start again. As far as I know there are no hidden files or quirks to trip you up.

Craig

6605

General Mach Discussion / Re: Servos progressing well, but question about index

« on: September 22, 2017, 02:59:24 AM »

Hi,
what you want is a closed loop control....Mach3 is not suitable.

Closed loop control occurs when an encoder/index pulse /tacho measues the current speed of a motor, some electronic device or computer compares the current
speed with the programmed speed and increases or decreases the voltage/current/frequency to the motor to  get it closer. While Mach3 can read an encoder
it can only stop and do the comparison and consequent correction about ten times a second, the macro pump rate. The Nyquist sampling theorem tells us that the
best control bandwidth is half that ie 5Hz. A control engineer would say that you'll get no/poor 'discrimination' at 5Hz, in fact it will still be pretty ragged at 1Hz.
Your control bandwidth is 1Hz at best, any variation in speed of your spindle due to load or whatever that occurs faster than once per second cannot be corrected
by Mach3, its just too damn slow.

Mach3 is primarily a Gcode interpretor and trajectory planner and does pretty well, as a closed loop motion control device it sucks.

Mach4 is much faster with the PLC script running every 10ms easily and faster if you wish to program it so. It can achieve a Nyquist rate of 50Hz  and pretty good
discrimination at 5Hz. Useful but hardly great, for a spindle I'd like about 5-10 times better and for an axis servo 100-500 times better. Yes axis servo bandwidths
are at least hundreds of Hz, 500Hz is a common number but 1kHz and more is not unheard of even if expensive.

There are a few Mach ready motion control devices that can close a control loop nicely, Galill, HICON, KFLOP and maybe others. All are reasonably pricey. In truth
most are best considered motion control devices that can optionally close a loop but is not their primary claim to fame.

The best device to close a servo loop is a matching servo drive. If you choose a servo and drive from the same manufacturer you can be pretty sure that 1) it
will work and 2) achieve best or near best performance capable of that servo.

With a suitable drive Mach can feed it with an analogue voltage say and the drive/servo loop will maintain its speed to within a small fraction of 1% depending
on the drive/servo pretty much irrespective of the load AND you don't have to do any fancy programming with Mach. Theres a reason control engineers are weird
antisocial chain smoking alcaholics....it comes from trying to program PID control loops on poor gear for an uncaring public..%$#)(*&&&!!! If you value your
health don't be too inclined to program feedback loops.

Craig

6606

General Mach Discussion / Re: Moving settings to another computer

« on: September 22, 2017, 02:22:43 AM »

Hi,
I would expect that if the problem is to be solved using this method the percentage change should be small.

If you have 10 buttons arranged vertically of 40 pixels width and another 40 pixels between each you would need 760 pixels vertical to display them without a
margin at top or bottom. If you then say the page is now 700 pixels high how are you going to fit all your buttons in? You could as you say go and scale
all of them but is very tedious. I think any changes made should be within 5% of the nominal number of pixels that the screen designer had in mind.

I can adjust the size of the screen to the extent that the last error text field is visible or not depending on the setting. I'm beginning to think that a small alteration may
be all that is possible this way. I have not encountered any other means either.

Craig

6607

General Mach Discussion / Re: Servos progressing well, but question about index

« on: September 22, 2017, 12:43:05 AM »

Hi,
how is the spindle servo driven? Does Mach3 send an analogue voltage or a step/dir signal?

Craig

6608

General Mach Discussion / Re: help whit signal step

« on: September 22, 2017, 12:39:26 AM »

Hi,
certainly the 2N2222 is required for gain but does it actually switch off? Any stray capacitance in the base circuit
might mean that they don't turn off when the PP input goes low.

You are correct the 33k pull-up is required given that the L297 input is active low. I didn't propose that you pull it
down but rather the the base of the 2N222s.

Craig

6609

General Mach Discussion / Re: Moving settings to another computer

« on: September 22, 2017, 12:07:12 AM »

Hi,
when you say it doesn't fix anything do any of the adjustments show up at all. I suspect that your changes
are not being seen for some reason. It works perfectly here, and I would say this is a 'one step fix' provided
you don't go overboard otherwise the combined size of your button and panels would be bigger than the screen
you allowed for them.

I like this way of dealing with it, I set the size and it stays that way...

Craig

6610

General Mach Discussion / Re: help whit signal step

« on: September 21, 2017, 11:52:07 PM »

Hi,
I dont think so, the CLOCK signal to the driver IC is active low, ie in inactive state its high. It s adequate as is.
What does puzzle me is that the base of the 2N2222s is not pulled to earth to ensure that leakage current doesn't
keep the tranistors conducting in absence of signal. I would be loading them to earth with 50k ohm or there abouts.

Craig