Messages

3361

Mach4 General Discussion / Re: Non Linear Spindle Speed?

« on: December 17, 2018, 12:44:44 AM »

Hi,
Mach can read spindle speed very accurately if it is supplied an index pulse from the spindle motor. Plenty of Mach users have made
one by gluing a magnet onto the rotor and mounting a small Hall sensor adjacent to it. Mach measures the time between
pluses and calculates the spindle speed very accurately indeed.

I'm not sure about the Hicon but I would guess its similar to my ESS and the ESS has a PID feature, fairly new feature at that, that would ensure that the
spindle is under closed loop control. That would solve your problem.

Craig

3362

Mach4 General Discussion / Re: jogging increments.

« on: December 16, 2018, 04:17:34 AM »

Hi,
some changes that you make in either the Control plugin and/or your motion plugin are effective immediately where others
require the .ini file to be updated and then re-read by Mach before becoming effective. That means either Mach shutdown
and then restart or a 'Flush' command that flushes updated data to the .ini file.

Smurph did explain the difference on an occasion some while ago....I can't find the post at the moment.

Craig

3363

General Mach Discussion / Re: Lots of Questions- ac servo spindle, macros, and tool changing

« on: December 15, 2018, 08:56:42 PM »

Hi,
I haven't used Mach3 for nearly three years having migrated to Mach4. Having said that the similarities between the two should
be sufficient for you to implement a strategy in Mach3.

The first consideration is whether you require your spindle to be capable of  coordinated motion. This would be required for
rigid tapping. Coordinated motion requires not only velocity control but position control. Position control can be achieved with analogue
controllers as I posted earlier....but at some extra cost and complexity.

Given that your motor is a servo it can of course be operated in step/direction mode to achieve position control. This would mean that you don't
require one of the more expensive analogue controllers. I am unsure of the exact details of how you implement step/direction control for a spindle in Mach3.
I am more familiar with the idea in Mach4. The trick here is that a free running spindle, which is its normal mode of operation would require a step
signal accumulator of infinite size so the spindle can keep rotating without numerical overflow. A position controlled spindle for rigid tapping might only
rotate 20 turns in one direction and then unwind the same 20 turns in the other direction. I have got my high torque spindle to do this, its an Allen Bradley
1.8kW servo motor.

It took considerable effort to get both modes of operation to work, namely the free running spindle mode and the 'C axis' mode. Guess what....I don't
really use it. Because it was possible I thought I would do it only to find it was pretty much a waste of time. Sound familiar? It happens to me quite a bit.
99.999% of the time all I require is a free running spindle. This is much simpler and I would recommend it as a first step in your spindle control
evolution.

In Mach4 there is the possibility to have a free running spindle running in step/direction mode. No extra hardware required. Just fill in the required settings
and  away it goes. If memory serves Mach3 can do the same, see the attached pic.

Another choice that achieves the same result is to use the servo in analogue mode. Just about all AC servos allow the possibility to use a +10V to -10V
analogue voltage to control the speed of the servo. In which case you can use an AC servo in a manner very similar to a VFD controlled induction motor.

Thus you have two choices to control a free running spindle with an AC servo:
1) Free running step/direction mode as provided by Mach
2) Analogue voltage control using Mach and your BoB to produce the control voltage  and program your drive to be analogue velocity controlled.

If you require either an indexing spindle or a coordinated motion spindle that's a whole bunch harder. Would recommend you stay away from this until
you have had some experience controlling your spindle in free running mode....then maybe think about it!

Craig

3364

CS-Lab / Re: Index Homing

« on: December 15, 2018, 07:21:11 PM »

Hi,

is it likely that one channel could go down, or would it more likely be a cabling fault?

It could be either. The index signal must hook up to the CSMIO/A and that is where I would probe the input. If the signal is present
then the index homing fault is due to the CSMIO/A or Mach, if the signal is not present then either the encoder or cabling is faulty.

The advance of application specific digital technology has resulted in some very cheap scopes becoming available. Being able to use one
to advantage and interpreting the results still requires all the old skills however. By all means get a cheap scope, this might be your first foray
into that experience, just don't expect a scope to magically solve all your problems, intelligent application is still required.

Craig

3365

CS-Lab / Re: Index Homing

« on: December 15, 2018, 06:49:53 PM »

Hi,
I presume your encoder is differential?

If that is the case you will have an A channel, a B channel as the two quadrature signals but you should also have an index signal,
commonly called I or Z. Your quadrature signals are working as evidenced by your test of manually turning the servo but that does
not test the presence of the index signal.

You'll have to devise a test for the index signal. The index signal is so brief that measuring with a multimeter is likely to miss it and you
might conclude that the encoder is faulty when it is not. Observing the signal with a scope is the correct procedure.

Craig

3366

Mach4 General Discussion / Re: jogging increments.

« on: December 15, 2018, 06:37:23 PM »

Hi,
the jog increments are in machine setup units.
I assume therefore that your machine is set up in inches. Sorry can't tell you hat the difference is between 'machine setup units'
and 'units mode'. Note that my machine is setup in metric and I have made them consistent.

The biggest jog increment programmed into my machine is 1 (mm). If I code a G20, ie displaying inch mode, my DROs do indeed display
inches but they increment 0.039 inch per max jog step.

Craig

3367

General Mach Discussion / Re: AC DRIVE ISSUES.

« on: December 15, 2018, 03:04:17 PM »

Hi Mick,
no I don't think so.....the wiring you have posted complies with pg 117 of the manual.

Craig

3368

General Mach Discussion / Re: Help please! Work is way outside of table.

« on: December 14, 2018, 11:58:03 PM »

Hi,
that's starting to sound like either Mastercam or the post is adding a specific point to the tooplath.

May I suggest looking at the machine definition in Mastercam. If memory serves you can specify axis travels. I'm wondering
if the 250,250,250 is not Mastercam producing a line of Gcode that goes to the machine extents, despite the actual extents
being somewhat less than 250,250,250.

Craig

3369

General Mach Discussion / Re: Help please! Work is way outside of table.

« on: December 14, 2018, 11:16:09 PM »

Hi,
Mastercam has a reputation for being hard to learn, I certainly had trouble with translating the toolpath relative to the WCS origin when
I encountered the exact same problem you are having.

Regrettably I no longer have access to Mastercam, despite its somewhat thorny user interface I liked its completeness. Shame I would have to take out another
mortgage to buy a copy for myself. I'm sorry I can't recall how I did it......I do remember setting the XYZ translation distances manually to ensure my preferred
touch off feature landed on 0,0,0. I recall definitely translating my part TO the WCS, not trying to make a new WCS. I had great difficulty trying to do that
as well and found translating my work relative to the existing WCS much easier.

It does seem strange that the Gcode should call a move to 250,250,250 when it would appear your part or even your stock does not extend that far.
Is it possible that some point, maybe a drafting mark or center point of a radius has been inadvertently overlooked and retained in the MasterCam
drawing?

Craig

3370

General Mach Discussion / Re: Help please! Work is way outside of table.

« on: December 14, 2018, 10:30:24 PM »

Hi,
yes the gnomon is always at 0,0,0 but that means your part toolpath starts at x=250, y=250 and z=250 ie outside your boundaries.

You need to (in Mastercam) highlight the whole of the tooplath, stock and so on and translate it relative so the first corner of the part
is not 250,250,250 but 0,0,0.

This is a CAM issue, not Mach3 at all. You have drawn your part too far away from the WCS origin. Shift your drawing to be close if not
coincident with the WCS origin.

Craig