Messages

241

Mach4 General Discussion / Re: Rotary Axes in Radians vs Degrees?

« on: February 19, 2023, 08:20:21 PM »

Hi Katz,
I'm using a rotary toolpath to make parts, in most cases the Gcode is ex Fusion. Some simple and specific tool paths I write by hand, but mostly CAM.

Mach4 Toolpath Window does a rubbish job of four axis display. I have seen on the forum a guy whom had written 'four axis kinematics', not that his interpretation
is what I'd describe as kinematics, but none the less he had a very credible tool path display to show for his efforts.

I'm already working on a fifth axis, I have the gear reducer already, the servo is ordered and paid for and on its way from Hong Kong as we speak, and I'm waiting on my local
steel supplier to cut a piece of 150mm 4140 steel shaft for me to make the C axis platter. A wee windfall on the income front will also mean that I can order the laser cut steel parts
I need for the trunnion table, I was going to have to wait until next week after I've been paid!

I'm thinking that once I get into five axis then even a decent four axis toolpath display is going to be of limited use.

Craig

242

Mach4 General Discussion / Re: Rotary Axes in Radians vs Degrees?

« on: February 19, 2023, 08:08:21 PM »

Hi Steve,
yeah that makes sense. I'm limited to what Fusion can do, namely Radians or Degrees....unless I hand code everything!

At the current time I don't use roll-over anyway, so whether its keyed to 360 or not may not matter.

I will have to give a bit more thought into the consequences of a non-rational angular unit. Its usually the case that I'm the irrational unit! 

Craig

243

General Mach Discussion / Re: tips for getting started with 2 axis plasma cutter

« on: February 19, 2023, 07:20:07 PM »

Hi,
depending on the material you are cutting and the output current of your plasma you may require very high cutting speeds.

I had a customer, some years ago now, whom had a 65A plasma but would on occasion cut 1.5mm sheet. The cut speed was in excess of 8m/min
to maintain a good cut profile. The steppers kept blowing up....they really struggle to go that fast. We fitted servos to X an Y (two required), and problem
solved. Those same servos are still working after 8 years.....and this outfit uses the plasma table almost continuously 8 hours a day, 5 days a week.

If you require high cut speeds then servos are probably the only realistic choice. If however you have a plasma of low output and are cutting 3mm sheet or
more then you may not need high speeds and therefore steppers will be adequate.

Note that while you can dial down a plasma the torch usually has an optimum current below which the cut quality drops off a cliff.

HF start plasmas are exceptionally electrically noisy and ALL electronics are going to struggle. Contact ignition like Hypertherm is less noisy and therefore much preferred.
Plasma is by definition a 'contained continuous lightning strike' and is still electrically noisy....so take any advantage you can get.

Craig

244

Mach4 General Discussion / Re: Keyboard short cuts & editing current Gcode

« on: February 19, 2023, 07:01:57 PM »

Hi,
I've just tried wxRouter.set and wxPlasma.set and both have the <EditGcode> button.

Typically wx4.set and wx6.set are the 'all inclusive' screen sets. You would take one of those as a basis and delete those things that you don't need for your machine.
Other screensets like wxRouter.set tend to be a subset of the 'full house' but with perhaps one or two features added specifically for that type of machine.

Take a copy of whatever screenset most closely matches your machine and give it a unique name. Then you edit/add whatever you detremine you want.

Craig

245

Mach4 General Discussion / Re: Rotary Axes in Radians vs Degrees?

« on: February 19, 2023, 04:03:26 PM »

Hi,
I've just noted a typo in my post.

150rpm is 54000 degrees/min....not 5400 per my post.

It just goes to show that degrees are numerically unwieldy, and mistakes happen.

Craig

246

Mach4 General Discussion / Re: Keyboard short cuts & editing current Gcode

« on: February 19, 2023, 03:57:54 PM »

Hi,
I just tried loading wxMach.set....and it does not list the screen set in use at the lower right-hand corner as do wx4.set and others.

Can you post a screen shot of your screen......I suspect it will be wxMach, but a screen shot will confirm it.

Craig

247

Mach4 General Discussion / Re: Keyboard short cuts & editing current Gcode

« on: February 19, 2023, 03:51:02 PM »

Hi,
So what screen set are you using? Look at the very lowest right-hand conrner and the current screen set is listed.

The only thing I can think of is that you are using wxMach....which is a very stripped down screen set used for testing, and only ever in the early days at that.
If that is the case may I ask if you are using a XHC motion controller?. If I'm not mistaken XHC motion controllers do not support Machs standard screens (with built-in
GUI editor) and must perforce use wxMach.

Craig

248

Mach4 General Discussion / Re: Keyboard short cuts & editing current Gcode

« on: February 19, 2023, 03:44:14 PM »

Hi,
Steve is right, this is a standard wx4.set from build 4839, but that button has been in every standard screen set for the last eight years
I've been using Mach4.

Craig

249

Mach4 General Discussion / Rotary Axes in Radians vs Degrees?

« on: February 19, 2023, 03:35:55 PM »

Hi,
I fairly recently started using continous four axis toolpaths and find the the A axis units (in degrees) is a pain.

For instance if I wanted to put a thread on a shaft I might do so like this:

g1 a3600 x-15 f5400

the a 3600 means rotate 10 times ie 3600 degrees, the x-15 means the pitch is 15/10=1.5mm, and f5400 means that the cut speed is 5400 degrees per minute, being
150rpm, the max speed of my fourth axis.

Note that might also mean that any of the linear axes are under the current Feed Rate of 5400 mm/min, which is ludicrously fast for a linear axis to cut, in metals anyway.
The linear axes are coordinated so the max speed of the A axis effectively 'throttles' the linear axes, but given that F is modal any successive linear moves could conceivably
take off at 5400mm/min and crash.

Lets imagine the units for a rotary axis were in Radians then the Gcode would become:

g1 a68.82 x-15 f942.3

where 68.82 is ten revolutions in  radians (10 x 2.PI) and 942.3 is 150 rpm ( 150 x 2.PI)

Should a subsequent linear move be attempted at the prevailing Feed Rate it would be 942.3mm/min, which is a far more acceptable rate for a metal cutting machine.

I use Fusion which can post either radians OR degrees so I could very easily have all my rotary axis Gcode in radians if only Mach4 would recognise radians
as a rotational unit. If Smurph or Brian or Goomba is listening.....can this be done easily?

Craig

250

Mach4 General Discussion / Re: Keyboard short cuts & editing current Gcode

« on: February 19, 2023, 03:10:10 PM »

Hi,
I'm not quite sure what you mean. If I want to edit the Gcode which is already loaded into Mach4 I use the <EditGcode> button.
The Gcode file is opened in the editor of your choice, as programmed in Machs General settings, do the required edit, then close the editor
and the edited Gcode is now in Machs Gcode window per normal.

Craig