Messages

1731

General Mach Discussion / Re: I can Jog Fine but everything stutters when running GCode or even calibrating.

« on: February 02, 2020, 09:10:53 PM »

Hi,

It will be off about 1/16 - 1/8 of an inch.  I continue to do the same and always enter 10" and it continues to get off more each time.

Sounds like your steppers are missing steps. Try tuning them to half their current speed and acceleration and try again.

I am playing with the backlash settings but have not been able to resolve the issue yet.

Disable and/or set the backlash settings to zero and leave them there. They are just confusing you. You need to be able to
MDI 10 inches the the left and then 10 inches to the right and come back to the same location within the bcaklash of the machine,
which should be minimal.

If the backlash of your machine is 1/16 to 1/8 inch then fix your machine. Expecting software to overcome that sort of lash is a fools dream.

Craig

1732

Mach3 under Vista / Re: Initial Setup - No movement please help!

« on: February 02, 2020, 01:31:04 AM »

Hi,
if the driver test is giving bad results then Mach will not work....at all.

I was unaware that anyone was still using Vista, it was always problematic with Machs parallel port.

Note that there are two distinct parts to Mach, Mach3, the Windows application which is a GUI, a Gcode interpreter and trajectory
planner. The trajectory planner produces numeric PVT (Position & Velocity over Time) data in 1ms slices. The second part is the motion controller,
in this case Machs parallel port is the motion controller, converts that numeric data to pulse streams which are in turn communicated
to the outside world via the parallel printer port.

What most people fail to realise that the 'parallel port' is much MUCH MUCH more than just the parallel printer port.
The code must time pulse streams (using interrupts) very accurately at pulse repetition rates of shorter than 40us. Windows operating systems all but make
that impossible as Windows uses the interrupt system extensively for it own purposes thereby precluding Machs pulse engine access to the interrupt
system.

If you are dead set on using Machs parallel port I would suggest winding back to 32 bit XP or 32 bit Windows 7.

An even better alternative would be to use an external motion controller like an Ethernet SmoothStepper (ESS) or a UC300. Avoid the temptation to buy
cheap Chinese motion controllers, they don't work as they're supposed to and you won't get any help from them. Stick to the well known and respected
European and US manufacturers.

An ESS or UC300 relieves the PC of the necessity to generate pulse streams and therefore is no longer restricted to 32 bit Windows 7 or earlier
nor is it restricted to desktop PC's. With an external controller you can use just about any PC you like, Mach, the Windows app part, is not a difficult
program to run, Machs parallel port engine is.

Craig

1733

General Mach Discussion / Re: Arrggghhh!! Mach3, Win XP, ESS, and MB3 Spindle RPMs erratic

« on: February 01, 2020, 07:04:06 PM »

Hi,
it seems like you have a few things going on and creating a lot of confusion.

May I suggest strip the problem down to its component parts and diagnose each individually.

In the first instance use a separate DC supply to provide a constant voltage to the VFD and therefore a constant
spindle speed. You have already established that with constant voltage the rpm is stable, ie the VFD is OK.
You have also established with a scope that the 24V index signal going INTO the MB3 is good.
Now probe the index output of the MB3 TO the ESS, it should be a clean square wave but now 0-5V.

This would prove that the index input circuit of the MB3 is correctly wired and operating and that the index signal is
being correctly translated to the ESS input. You should be able to sweep the DC input to the VFD and therefore sweep
the index pulse rate through its full range. The full range of pulse frequency should be displayed in Machs spindle speed DRO.
If the spindle speed is correctly displayed you have established that the ESS is correctly reading the 0-5V index signal
input from the MB3 and signalling Mach the actual (measured) speed.

In ESS plugin DISABLE the spindle PID. Now with MDI test the PWM output of the ESS (0-5V) and then the PWM DC
oputput of the MB3. Given that the spindle PID has been disabled the speed should be close to the Snnn command given in
the MDI line.
You might expect:
M3 S1000 result in a approximately 1/5 PWM output of 2V, assuming 0-10V full-scale.
You might expect:
M3 S2500 result in 1/2 PWM output of 5V assuming 0-10V full-scale.
You might expect:
M3 S5000 result in 100% PWM output of 10V assuming 0-10 full-scale.

Assuming a positive outcome of this test you have proved that Mach3 can signal the ESS to produce a given percentage PWM output
and that the MB3 can convert that duty cycle to a varying DC voltage necessary to drive the VFD.

If both these experiments have conclude successfully THEN try spindle PID. I suspect from your description that this is the fault.
That is, I would anticipate that the two experimental procedures to be successful and that the PID loop is unstable. GET USED TO IT,
PID loops are HARD TO TUNE, especially loops like this that have very restricted input bandwidth. By input bandwidth I mean the rate at
which the ESS signals to Mach the actual (measured) speed. Mach compares the actual speed with the commanded speed and produces an
error signal with which to alter its PWM output to reduce the error. The number of times per second Mach gets updated about actual speed
is quite low, approx. 40 updates per second. Consequently the rate at which it can correct an rpm error is also quite low, and if Mach
attempts a too greater correction the loop becomes unstable. This fits your description.

If the PID loop is unstable....what to do about it?

First question to be answered is ….do you need spindle PID at all? My experience is that if you command a spindle speed in Mach, either
MDI or Gcode, a good motion controller and breakout board will provide a DC voltage within a few percent accuracy WITHOUT a closed loop.
If the rpm is within a few percent and it does not drop to badly under load....who cares about spindle PID?. For years and years
I've used manual lathes and mills WITHOUT spindle PID, in fact only discrete (gear/pulley) spindle speed settings....and work turns out fine
on manual machines. Is it strictly necessary to have precise speed control just because its a CNC machine? I don't think so.
One area where a closer control of spindle speed is required is single point lathe threading. Is this your purpose/requirement?

If you  require spindle PID then you'll have to tune it. Tuning PID loops is a whole subject on its own. As a starting point increase the P(proportional)
component of gain and set the I(integral) and D(differential) to zero. Once you have established a maximum P gain back off by 25% and try a smidgen of
I gain. If you keep the I gain low you may not need any D gain. Increase I gain until you achieve your steady state error specification and then tweak
the D gain for best dynamic performance.

One of the limitations of Spindle PID in Mach3 is that the input signal refresh rate is determined by the index signal which is by definition one
pulse per rev. In Mach4 you can use an encoder and therefore have multiple inputs per rev thereby increasing the bandwidth by a factor of ten
to one hundred. The increased bandwidth allows a MUCH easier to tune and stable PID loop.This is a quantum leap forward in spindle PID, and
should be considered VERY favourably by anyone wanting to do single point lathe threading, ESPECIALLY with a marginally powered/inertia spindle.

Craig

1734

General Mach Discussion / Re: Mach 3 / Mach 4 support for ISEL UPMV 4/12 cards

« on: January 31, 2020, 06:32:00 PM »

Hi,
to my knowledge neither Mach3 nor Mach4 will drive the ISEL UPMV 4/12 motion controller.

Mach3/4 are Gcode interpreters and trajectory planners. The trajectory planner produces PVT (Position,Veloctiy over Time)
numeric data in 1ms time slices. The motion controller, and for this discussion Mach3's parallel port engine is a motion controller,
takes that numeric data and converts it to pulse streams for various motors etc.

If the manufacturer of the ISEL card produces a plugin that converts Machs PVT data to trajectory input acceptable to
the ISEL then it would work. Does ISEL have such a plugin? I suspect not. Its not that Mach COULDN'T drive the ISEL
but rather ISEL has provided no means to adapt their product to Machs trajectory planner.

Craig

1735

Mach4 General Discussion / Re: Create elements in Mach 4

« on: January 31, 2020, 05:11:17 PM »

Hi,
now you are wondering how you set the filepath right? I'm soooo glad you asked 

https://docs.wxwidgets.org/3.0/classwx_file_dialog.html

This is jut one of hundreds of different classes in wxWidgets, but is a commonly used one in Mach because we often
need to navigate to a file either to read, write or append.

I have attached a pic of an excerpt of the public member functions for this class, namely the SetPath function.

I am not really familiar how to use this particular function but that's where wxFormBuilder comes to your rescue.

Craig

1736

Mach4 General Discussion / Re: Create elements in Mach 4

« on: January 31, 2020, 04:57:24 PM »

Hi,
now consider the two items that you want automated or otherwise built in to your screen set.

You have a directory or repository on your PC which holds all your Gcode?

If you click <Load Gcode> on the standard Mach4 screen what happens? In my installation it opens a file dialogue window
by which you navigate to the desired folder and then to the desired Gcode file. Typically the file dialogue window opens at
the last directory that you used. When you first start Mach that could be anywhere but once you navigate to your
Gcode repository thereafter each time you click <Load Gcode> the file dialogue will open in the repository directory.

In Windows the location of a file is made up of two parts, the filepath and the filename. In wxWidgets the default path is the last
used filepath but you CAN specify a path other than the default. You are in effect using a subset of what Mach (in actual fact wxLua)
does already.

In a similar manner if you require a Gcode file on a USB thumbdrive provide you navigate to the USB drive and indentify the file
it will load.

May I suggest that you confirm that the standard <Load Gcode> button behaves that way, namely opening at the last used filepath.
Assuming that you are happy with that experiment a solution is now in sight.

Replace the one <Load Gcode> button with two others but with a specified filepath rather than the default.

Craig

1737

Mach4 General Discussion / Re: Create elements in Mach 4

« on: January 31, 2020, 04:34:51 PM »

Hi native34,
I'm glad to hear that you are prepared to dig in.

I just wish there was better documentation and examples like there were when is was programming VB. They had pretty clear and concise examples and how you could implements them.

But there is SUPERB documentation about wxWidgets and its Lua wrapper, its just the documentation is written by geeks, for
geeks and in geekese! I don't know about you but my head spins. In this regard wxFormBuilder is a great tutor, have wxFormBuilder
generate some code and then compare that code to the documentation and viola you have gleaned a wee bit of geekese.

https://docs.wxwidgets.org/3.0/

You may recall:

NFS has no part in determining the style and development of wxWidgets.

Its up to you to learn about wxWidgets, its not NFS's responsibility to teach you. It certainly is NFS's responsibility to document Mach4,
Mach4 being their core product, whereas wxWidgets is publicly available and documented software tool/suite that is used in the
creation of Mach4, but NOT NFS's core product.

Craig

1738

General Mach Discussion / Re: recommend a simple pendant? mach 3

« on: January 31, 2020, 03:56:02 PM »

Hi,
I use a VistaCNC P1A and have done for years, both Mach3 and more recently Mach4.

Craig

1739

Mach4 General Discussion / Re: movement very slow and also there other instance of mach on background

« on: January 30, 2020, 06:23:35 PM »

Hi,

and because the second instance its run very slow?

To my knowledge Mach WILL NOT OPEN if  there is ALREADY a current instance running.

Craig

1740

General Mach Discussion / Re: Need help getting my stepper motors to run smoothly

« on: January 30, 2020, 06:19:28 PM »

Hi,
some PC's just don't run Machs parallel port at all well whereas another PC does, without any real
difference between the PCs.

It sounds like you have another process/service/application starting up that is robbing Machs parallel port the
quasi-continuous CPU service it requires. Maybe with the Task Manager you might identify competing processes/services.

The other alternative is to use an external motion controller like an Ethernet SmoothStepper or UC300. Such a device relieves
the PC CPU from realtime operation for which PC's are most definitely not suited. Don't be tempted by cheap Chinese made controllers,
they don't work properly and you won't get any help from them. Stick to the well known and respected European and US manufacturers.

Another advantage of an external controller is now just about any PC will work well, including laptops, 64 bit OS's like Windows 10.

Craig