Messages

2351

General Mach Discussion / Re: Mach3 freezes constantly_little to no support from.....support.

« on: June 28, 2019, 10:38:46 PM »

Hi,
I have a dual core Atom mini-ITX board with on chip graphics to run my machine. It ran two parallel ports on Mach3
and then I went to an Ethernet SmoothStepper (ESS) on Mach4. The little (read damned whimpy!!!) PC has worked a treat.
I believe that your PC is more that adequate for Mach, its certainly several more times powerful that my machine PC.

Plasmas a ABSOLUTELY RENOWNED for producing electrical noise. Your description sounds like a noise issue.

Can  I ask a few questions and try to establish some parameters of the problem.
1) What controller are you using? Your description sounds like you are using a parallel port but that is totally in consistent
   with Windows 10. If that is the case then you must be using an external motion controller. If that controller is USB connected then
   you can expect noise issues and the problems you have described. An Ethernet connected motion controller is preferred.
  Make and model of the controller please?
2) What plasma machine are you using? HF start machines are just about impossible to tame. A pneumatic contact break start
    machine invented and popularized by Hypertherm is much much better. Make and model please?

There is an experiment that I want you to try. Set the machine running but with the plasma machine off, ie just above the material
but no arc. Does Mach complete the task? If so it rather suggests that the plasma is indeed producing electrical noise sufficient
to de-rail Mach.

Curing noise issues with a plasma table is likely to be a long winded affair. It is probable that more than one solution is reqired.
For instance if you replace a USB controller for an (non Chinese) Ethernet controller you may achieve a 60% gain in performance
but you need to combine other things like earthing, shielding, signal decoupling and line filtering to get to an acceptable solution.

Craig

2352

General Mach Discussion / Re: Send PWM signal from Geckodrive G540 to PC

« on: June 28, 2019, 10:14:29 PM »

Hi,

Another thing though, I just saw something online about how you can put multiple limit switches on one pin. That would free up an extra pin, and then (with two pins) I could have up to four states, which would be fine. Would you all recommend putting multiple switches on one pin? It seems very simple but I know I may be missing something.

I have always argued against linking all the switches to one, or a few pins. I'm a lone voice against this practice however.
Many people do it just exactly to free up another input for some other purpose. My concern is that when you link all your
limits and home switches to one pin then Mach loses the ability to distinguish between a limit event or a home event and cant
even distinguish which axis.

If however you use a second parallel port card now you could have one pin for each home switch, one pin for each limit switch,
a total of 9 input pins and still have inputs to spare.

If you were to use an Ethernet SmoothStepper (ESS) you could have up to 51 inputs and outputs, with a maximum of 31 inputs.
Is that enough? If not consider a UC300, now you have up to 85 inputs and outputs, which if I'm not mistaken, means you
can have up to 57 inputs.

As interesting as that is.....there maybe a solution for your EDM sinker problem.

With Plasma Tables a very important control strategy is THC (torch height control). If the torch height is too high the voltage
of the plasma arc increases beyond optimum. A voltage measuring device (THC unit) would signal Mach 'Torch Down' and
Mach will lower the torch.  This is usually done in realtime such that the torch voltage is controlled in a feedback loop.

You might be able to use the same strategy for your EDM machine. If you have a microcontroller that determines whether
the die needs to go up it could signal Mach to do so using THC_UP and THC_DOWN signals. If you do not have a up/down,
ie binary signal, you could make it by having a comparator and a reference voltage, a simple electronic circuit. It would
produce a signal up or down (binary).

I presume that you need the die to retract very quickly after detecting an impending short circuit event? If you need response
in the sub millisecond range then you must have a realtime controller. While not without its shortcomings Machs parallel port
is such a realtime controller and can support THC. Most of the external controllers like the ESS or UC300 also support
THC in Mach3.

Recently Mach4 has a script based THC feature added. It is done in software and is an order of magnitude slower than a realtime
THC solution, we anticipate in the range of several milliseconds. The advantage of that solution is that you can script your own
solution with all the processing power that Mach can bring to bear. The only question is.....'will millisecond response be
adequate to prevent my sinker die from shorting out?'

At the current time there are only two controllers that support realtime (read fast) THC support in Mach4, including the ESS.
Effectively Mach4 requires an external controller like the ESS. Mach4 does have a parallel port called Darwin ($25 licence fee applies)
but it does NOT nor will ever have realtime THC support.

The upshot is that if you wish to go for a Mach4 solution and thereby take advantage of the superior scripting flexibility that it brings
then you would require not only the purchase of Mach4 ($200) but an ESS ($190) also. I would guess therefore that you would
wish to stick with Mach3 and avoid the cost. I think you could use some workarounds to get Mach3 to perform as you wish
but you will have to code in VB, and good luck to you. There are plenty of VB masters on the forum but I'm not one of them.
In fact it was to avoid VB that I moved to Mach4 in the first place. If you want to do a Mach4 solution I'll back you but I'm
not going to 'bust a gut' over Mach3.

Craig

2353

Mach4 General Discussion / Re: Toolpath Display with 4 Axis

« on: June 28, 2019, 09:32:30 PM »

Hi Mauri,
kool.

In this case it was the work that you put in to establish a suspected clash with the two operations that was critical.
Thereafter writing a little code is a small matter.

I seem to recall a quote from some scientist, it may have even been Einstein, that 'Science is 10% inspiration and 90%
perspiration'.

Craig

2354

Mach4 General Discussion / Re: Toolpath Display with 4 Axis

« on: June 28, 2019, 09:26:39 PM »

Hi,
sorry forgot to attach a pic that I mentioned.

Craig

2355

Mach4 General Discussion / Re: Toolpath Display with 4 Axis

« on: June 28, 2019, 09:21:45 PM »

Hi Mauri,
may I suggest as an experiment try this little piece of code:

Code: [Select]

function m201()
local inst=mc.mcGetInstance()
local filename ='......Gcode File you wish to load.....'
mc.mcCntlLoadGcodeFile(inst,filename)
end
if (mc.mcInEditor()==1)then
m201()
end

Note that I have left the filename for your file to load. We can easily put a file dialogue in later should this idea prove workable.
For this experiment however just substitute the path and filename of a suitable test file.

What I am trying to establish here is whether mcCntlLoadGcodeFile() automatically also starts the toolpath generator
as well. What you would need to do is test this same piece of code (MDI m201) with in one instance with the
'Generate Toolpath On Load' checked and then again with it unchecked.

I suspect and hope that it does not automatically launch the generator. This will be critical if this idea is to work at all.

Craig

2356

Mach4 General Discussion / Re: Toolpath Display with 4 Axis

« on: June 28, 2019, 09:05:18 PM »

Hi Mauri,
I haven't given a great deal of thought to how to code it and if it would work if I did.

This is what I found (attached pic) behind the <Load Gcode> button of Mach (4125). Note that there is a stock action 'GcodeLoad'.
We can't see the nuts and bolts of the code behind it. Presumably it loads the Gcode file and if the 'Generate Toolpath onLoad'
box is checked it launches the toolpath generator.

What I propose is to substitute some Lua code in place of the stock action. You may wish to leave the stock button alone
and add a custom button for those occasions when you want to load a large file.

Additionally my idea was to compose the code as a series of macro calls. In part its because I am more familiar with
programming macros but it also allows you to use mc.CntlGcodeExecuteWait() type instructions which would specifically
wait for one operation (load Gcode) before trying to generate a toolpath.

Another plus of a the 'series of macros' approach is that you can test Machs state, if it is executing a macro it will have
a particular state which can be distinguished from MachState=idle, ie a macro has completed.

Both of these are the means to ensure sequenced operations, either or both might be required. I will give some more thought
as to how it can be coded over the course of the afternoon (local time).

Craig

2357

Mach4 General Discussion / Re: Toolpath Display with 4 Axis

« on: June 28, 2019, 08:23:22 PM »

Hi Mauri,
that's great that you have done all that research and posted the results.

I'm wondering if you find that loading Gcode without the toolpath display 'On Load' means that the Code loads
properly and can THEN the toolpath be generated and displayed means that with the two operations (load code and
toolpath generate) being so intensive cause a clash within the CPU. It sort of makes sense.

What happens if you load just a small subset of your code, 5000 lines say? If it loads and generates a correct toolpath it
would tend to suggest that a clash is occurring.

If you modified the <Load Gcode> button or alternately made a new custom button that loaded the Gcode file
using mc.mcCntlLoadGcodeFile() and then waited for Mach to complete before executing mc.mcToolPathGenerate().
Maybe that would automate the process.

Craig

2358

General Mach Discussion / Re: Motors not moving in Motor Tuning Menu

« on: June 28, 2019, 07:56:08 PM »

Hi,
I have borrowed liberally from the Leadshine website because they publish Torque/Speed curves for many of their stepper products.

I have taken two steppers (57CM26 and D57CM31) which are both 23 size and close to the same length (3.3 and 3.4 inch)
with similar holding torque (369 oz.in and 439 oz.in) but the D57CM31 has a much lower inductance (1.18mH) vs the 57CM26
(2mH). At 1000 rpm the low inductance motor retains a little over 50% of its torque at 1.6Nm whereas the higher inductance
motor retains scarcely 25% of its torque at 0.8NM. This shows the principle that low inductance is good for high speed stepper
operation.

To reinforce the idea I have included a third motor (57CM13) which while is still 23 size it is shorter (2.2 inch) and much less
torque (185 oz.in) but intermediate inductance (1.6mH). At 1000 rpm it retains 75% of its torque at 0.85Nm and actually has
more torque than its bigger brother (57CM26) because its bigger brother also has more inductance. This illustrates the principle
that sometimes a lower torque motor also being low inductance can outperform a higher output motor but with commensurately
high inductance.

Code: [Select]

Model: 57CM26
Frame Size: NEMA 23 
Phase: 2
Step Angle: 1.8° 
Accuracy: ±0.9°
Length: 84 mm (3.31 inch)
Number of Wires: 4
Holding Torque: 2.6N.m (369 oz-in)
Phase Current: 5 A/Phase
Voltage: 2.2 V
Resistance: 0.44 Ω
Inductance: 2 mH


Code: [Select]

Model:D57CM31
Frame Size: NEMA 23 
Phase: 2
Step Angle: 1.8° 
Accuracy: ±0.9°
Length: 88 mm (3.46 inch)
Number of Wires: 4
Holding Torque: 3.1N.m (439 oz-in)
Phase Current: 6 A/Phase
Voltage: 1.56 V
Resistance: 0.26 Ω
Inductance: 1.18 mH


Code: [Select]

Model: 57CM13
Frame Size: NEMA 23 
Phase: 2
Step Angle: 1.8° 
Accuracy: ±0.9°
Length: 55 mm (2.17 inch)
Number of Wires: 4
Holding Torque: 1.3N.m (185 oz-in)
Phase Current: 4 A/Phase
Voltage: 1.68 V
Resistance: 0.42 Ω
Inductance: 1.6 mH

I have looked at some of the advertising material for 23 sized steppers from Wantai and they publish inductance figures of
5mH and greater. If that is correct......avoid like the plague......these things might not have enough torque to do 1000rpm
unloaded let alone coupled to an axis.

Craig

2359

General Mach Discussion / Re: Newbie with a few questions

« on: June 28, 2019, 06:26:59 PM »

Hi Gerry,

V Carve Pro has the same 3D toolpaths that Aspire has. But it has no modeling tools, and limits 3D imports to a single model per file.

That's good news. I have watched Youtube videos on Aspire only. I have not downloaded Aspire and tried it out. I still have
some time on my Fusion 360 trial and feel that I sort of owe Autodesk a 'fair suck of the sav' as the Aussies so eloquently
put it.

Overall I think Fusion 360 is good and Autodesk is a manufacturer of real substance. I'm just less than happy
with the subscription model. It works out to about $1500 every three years. $1500 is about or similar to the price of
a number of the perpetual licence software packages like VisuallMill Std or Aspire. Note that I have not counted the optional
cost of yearly upgrades with VisualMill or Aspire. You might argue that I'm not comparing apples with apples....with some
justification, its really a reflection of my budget (or tight-fistedness).

For personal use I think Autodesks price of $1500 every three years is a bit too steep. If it were about $750 then I would
pay it. In fact I would guess they could put all their competition into the shade at that price.

I did watch some Mecsoft vids. There was one in particular (VisuallMill) that had some great toolpaths but when I investigated
further all the 'tricky dicky' toolpaths that really made the software appealing were restricted to the Pro ($5000) and Premium
($10000) versions rather than the Xpr ($600) or Standard ($1500) that are within my budget.

My advice to anyone reviewing the capabilities of various software solutions pay attention to what modules/capabilities are
in the package you are considering and can afford rather than some the headline expensive version that you cant afford.

Craig

2360

General Mach Discussion / Re: Send PWM signal from Geckodrive G540 to PC

« on: June 28, 2019, 05:57:24 PM »

Hi,

https://www.pmdx.com/1PARPCI

Craig