Messages

411

Mach4 General Discussion / Re: Thinking of doing a lathe build and need some basic questions answered.

« on: December 12, 2022, 05:12:07 PM »

Hi.
lathe threading is a realtime process and it largely enacted by the motion controller, not Mach4 at all.

Mach4 provides the numeric parameters to the motion controller, and the motion controller handles it from there. Mach4 is at best a supervisor.

There are a couple of variations of the one theme, but the idea remains the same. If the spindle is rotating at some fairly slow but known and constant speed
then its index pulse is used to start the thread. This allows multiple passes as you cut one thread....so your spindle must produce a single index pulse per spindle
revolution. In addition you can use either an index pulse or, depending on the motion controller, an encoder to measure the exact speed of the spindle.

Ideally the spindle speed would be constant, but as the  cutting starts it will slow a little. The controller needs to know the reduction in speed so it can slow the Z axis advance
to have the thread retain the programmed or desired pitch. For example if the spindle is rotating at 600rpm, or 10 revs/second and you wish to cut a 1mm pitch thread
then the Z axis must advance 1mm per rev or 10mm/second. If as a result of the cutting the spindle slows to 550rpm the Z axis advance needs to be slowed to 9.166mm/second
in order to maintain the same pitch. Clearly a absolutely constant and rock steady spindle speed is very VERY desirable for threading.

Some motion controllers use the spindle speed as feedback to try to maintain the spindle speed constant.

I'm not familiar enough with the Hicon to be definitive but believe it has this feature. The ESS with which I am familiar definitely has this feature, that is to say that it can use
either an index pulse or an encoder pulse to slightly alter the PWM to the spindle drive to secure constant spindle speed for threading. This feedback feature may help with
underpowered spindles, but still there is the HIGHEST possible advantage to a powerful spindle of significant rotational inertia for lathe threading.

Craig

412

SmoothStepper USB / Re: probe won't retract

« on: December 12, 2022, 02:26:41 PM »

Hi,
this is an excerpt from a probing routine that I use:

Code: [Select]

M40 (Begins a probe log file, when the window appears, enter a name for the log file such as "RawProbeLog.txt")
G0 Z2
G1 X-0.589 Y1.5875 F1000
G31 Z-1 F100
G0 Z2
G1 X10.50726 Y1.5875 F1000
G31 Z-1 F100
G0 Z2
G1 X21.60352 Y1.5875 F1000
G31 Z-1 F100
G0 Z2
G1 X32.69978 Y1.5875 F1000
G31 Z-1 F100
G0 Z2
G1 X43.79604 Y1.5875 F1000
G31 Z-1 F100
G0 Z2
G1 X54.8923 Y1.5875 F1000
G31 Z-1 F100
G0 Z2
G1 X54.8923 Y11.67083 F1000
G31 Z-1 F100
G0 Z2
G1 X43.79604 Y11.67083 F1000
G31 Z-1 F100
G0 Z2
G1 X32.69978 Y11.67083 F1000
G31 Z-1 F100
G0 Z2
G1 X21.60352 Y11.67083 F1000
G31 Z-1 F100
G0 Z2
G1 X10.50726 Y11.67083 F1000
G31 Z-1 F100
G0 Z2
G1 X-0.589 Y11.67083 F1000
It works perfectly and dozens of other probing routines almost identical to it and has done for eight years. You need to look at your code.
What motion controller are you using? If its an ESS then you need to save a log file. I suspect that the probe data is not being sent to Mach
and therefore the G31 move never completes, and cannot progress to the following G0 retract move.

Craig

413

SmoothStepper USB / Re: probe won't retract

« on: December 11, 2022, 03:49:14 PM »

Hi,
can you show us the code?

A G31 probing move requires two Gcode moves, namely the G31, which is dynamically the same as a G1 move, ie linear interpolation at the prevailing feed rate,
followed by a G0 which is to retract the tool.

Unlike a home switch Mach does not automatically retract the tool from a probe event, you have to code it specifically.

Craig

414

Mach4 General Discussion / Re: Installing update to Mach 4 Hobby

« on: December 11, 2022, 02:34:36 PM »

Hi,
this post belongs on the Mah4 General Discussion board, no doubt Tweakie will shift it there.

Just download and install the later build, and it essentially overwrite what is already there, you don't need to do anything.
If there is a profile and/or a screen set that you wish to retain then they must have a unique name.

For instance if you have used wx4.set as your screenset, and have over a period of months added various tweaks and edits then when you up-date the wx4.set will
be overwritten by the new incoming wx4.set, and all your edits and tweaks will be lost. If however you name your screenset Mywx4.set for example them it will
not be overwritten on up-date.

The simplest explanation is that if you want something to survive an update unaltered then it must have a unique name, be it a profile or a screenset.

Craig

415

Mach4 General Discussion / Re: Mac4 VFD Spindle Speed Control Issue

« on: December 09, 2022, 04:44:31 PM »

Hi,
many people, myself included, have fallen into the trap of wiring up multiple components expecting a certain result....only to find
it doesn't work. Very disappointing.

I have gotten better over the years when designing  a circuit or control system about planning how I'm going to test each subsection.
For example I designed and built my own breakout board, well in fact I've built several, but the latest one seems to 'tick all the boxes'
and don't anticipate having to make another. I was adamant that all inputs and outputs have an LED so that I could see the status
of that pin. Note that this is, if you like, between the motion controller (ESS) and the breakout board. It meant that I did not have to dive in with a
multimeter probe to diagnose a fault, the LED tells me what I need to know. More often than not IF you dive in with a multimeter probe you will
probe the wrong circuit, or worse slip and bridge two circuits. If there was not a fault before.....now there is a fault....you just caused it!

At the output of the breakout board are pluggable screw terminations. This allows you to probe without risk of slip[ping and causing yet another fault.

In your case you had to break the problem down, and you did. First you established that there was a fault in the VFD programming and was able to correct
that. Then you tackled the problem of the UC100 settings and the G540 wiring.

Imagine if the UC100 had LEDs on all its outputs. Then you could have seen the PWM signal as a varying intensity LED....would that have made it easier?

Craig

416

General Mach Discussion / Re: Inventor not generating m3 in gcode

« on: December 08, 2022, 10:28:16 PM »

Hi,
that is a fault, or more likely an incorrect setting within the post.

Any CAM software that cannot generate m3's, m4's etc is just plain junk, or at least only appropriate for the lowest level hobby machines,
and that is certainly not the description of Inventor.

Craig

417

Mach4 Toolbox / Re: M6 again nothing fancy.

« on: December 08, 2022, 02:29:52 PM »

Hi,

I can Jog the gantry to whatever position I like.

Thats the bit that make it difficult. There is a thread which covers some of the ideas:

https://www.machsupport.com/forum/index.php?topic=46728.0

Craig

418

Mach4 General Discussion / Mach4Expert, can instances be sequenced or synchronised

« on: December 06, 2022, 05:33:20 PM »

Hi All,
hoping that someone out there is already using Mach4Expert with multiple instances.

As the title of my post suggests I'm interested in whether separate instances may be sequenced or even synchronised.

I've seen a couple of APIs in Mach4Hobby which look promising:

LUA Syntax:
rc = mc.mcCntlStopMotionDev(
      number mInst);

Description:
Stop the selected motion device.

LUA Syntax:
rc = mc.mcCntlStartMotionDev(
      number mInst)

Description:
Starts the selected motion device.

Are there more of this sort of thing in Expert?

Craig

419

Mach4 General Discussion / Re: force screen label to refresh

« on: December 06, 2022, 02:12:23 PM »

Hi,
GcodeExecuteWait works to ensure that one block of Gcode is executed BEFORE a second block is queued up.......but this is within one chunk, namely Machs core.
It does not work to separate the GUI chunk from the Main chunk.

As I posted earlier Lua co-routines are cooperative not preemptive. There is no way, to my knowledge, to force one chunk to yield to the other.

gcodeexecutewait(g04 p1.0) commands to force a machine pause condition.

I can see why you might think this is a good idea, but it won't work. 'g04p1.0' is still a Gcode instruction. Machs Main chunk will interpret this instruction and execute it, it does not mean
that the Main chunk becomes idle....after all it is doing something, namely waiting for the current instruction to complete.

Craig

420

Mach4 General Discussion / Re: force screen label to refresh

« on: December 06, 2022, 01:27:55 AM »

Hi,

LUA Syntax:
rc = mc.mcCntlGcodeExecuteWait(
      number mInst,
      string commands)

Description:
Execute G code as a unit of work and wait until it is complete.


Craig