Topics

1

FAQs / Incomplete path OR maybe XY motion starting before Z motion is complete.

« on: April 23, 2022, 07:26:55 PM »

I am using Mach3 (licensed, for sure) with a T-Tech PCB milling machine and a homebrew controller.

The T-Tech is basically a 12" x 12" x 1" milling machine, with steppers and ball screws.  VERY precise, certainly capable of milling within .001".

I create my PCB in the editor, export the geometry as Gerber files, then convert the Gerber to GCode using FlatCAM.  I mount a piece of PCB with double-sided tape, install a .015" endmill and start "isolating" traces.

The whole setup has worked fine for years; I've made dozens and dozens of little (and not so little) circuit boards.   Worked fine until recently, that is, when it's started to do something weird.

It's most obvious when asked to mill a circular path, say, for a mounting hole.  Rather than milling the whole 360 degrees, it only mills about 350 degrees.  In fact, just about every path ends a wee bit short.

The fix is to place the "finished" board under a microscope with a sharp knife and scratch out the last few thou of copper from just about every trace.  Crazy.

It seems worse when doing arcs, although this could be my imagination; just about every outline has an arc in it, and FlatCAM always starts on a curve.

And FlatCAM doesn't actually do arcs (G02/G03)  Rather, it does zillions of short segments.
 
Attached is a bit of GCode created by FlatCAM to cut (outline) a single circle. 

This code seems to simulate properly, and just looking at the code, circles do end where they start.

And I don't think it's missing steps, because the boards always come out fine, save for these uncut bits here and there.

My best guess is that the machine is starting the horizontal motion before cutter is fully down, before the vertical motion is complete.

Is it POSSIBLE that there's something weird going on in Mach3?  Some setting I've inadvertently changed?

Thanks for any thoughts.



Alan

2

General Mach Discussion / Keyboard only screenset

« on: April 07, 2022, 08:02:50 PM »

I'm still using the original 1024 screenset that came with Mach3; it works, I know how to do what I need to do and (until now), that's all that's important to me.

However, I'm finding it increasingly difficult to use a mouse, and there's just SO MANY functions on the default screenset that require a mouse.

Has someone created a screenset that uses the keyboard for just about everything?

3

VB and the development of wizards / Surface grinder programming (aka, just getting started).

« on: April 13, 2017, 09:25:21 PM »

I have a small, entirely manual surface grinder.  It's a delightful thing to have, but a person can sure spend a lot of time standing there turning cranks.  As a CNC kinda guy, this seems nuts.

So I mounted some steppers on the Y and Z axis, and a small servo on the X.  I built a stand alone controller using a PIC microcontroller, a four line LCD and a bunch of pushbuttons to set the various parameters; y distance, y increment, z distance, z increment, x distance, x passes before y change and so on.

It works ok .. but barely.  A whole lot more programming work will probably (maybe .. hopefully) get it working well.

I also have Mach3 installed on a couple of milling machines, and started thinking that it sure would be nice to use Mach3 to move things on my surface grinder, rather than my little PIC.  (The motion portion is what needs the most work.)

So I started to think about writing a G code generator, treating the grinder like another milling machine.  That would be better than what I have now, but still sub-optimal.  For example, it would be nice add a "spark watcher", so that once the grinding is no longer making sparks, the program can go on to the next stripe or next height (depth).

That calls for programming, and it surely SEEMS as if Mach3 can do this.

But I'm not quite sure where to start!  I'm fluent in a couple of languages and have certainly written some VB code over the years.

But I don't see how VB interfaces with Mach3.

Is there a good thread or site about just getting started?

Thanks in advance for any thoughts.

Alan

4

General Mach Discussion / Turning wizard problem - "FilletRadius is too big"

« on: May 08, 2010, 05:43:15 PM »

For the record, I'm a new user to Mach3, using it in demo mode to try to get the hang of it.

I used the OD Turning wizard today to reduce some stock.  It worked fine as a test, leaving lots of material to finish the job.  

I manually ran a turning pass (i.e., used the handwheels), moved everything back, mic'd carefully and reset X and Z to 0.000  

I then reran the wizard with my now careful measurements, ran the program and found that the part was still too big.  Unexpected, but I decided to look into this later; for now, I just wanted the part.

So I went back to the wizard again and filled in some new values, clicked "Post Code" and got the message

"FilletRadius is too big"

and now that's all I get, no matter what I type in for values.  Typing 0 into the Fillet Radius field or -1 or 1 or anything at all results in the same message.  Quitting the program and restarting does not fix it.

Basically, this wizard is no longer useful!

Am I missing something?

Thanks for any thoughts.

Alan

5

General Mach Discussion / "Generic" screenset with buttons to control an output pin - is there one?

« on: December 06, 2009, 06:38:44 PM »

I'm trying to get up and running with Mach3 after years of using CNCPro for DOS.

My machine is used manually on occasion (usually for initial positioning) and to facilitate this, I devote three PPort output pins to enable or disable an individual axis in the controller box.  With CNCPro, controlling these outputs is easy, as is labeling them appropriately.

From my reading, it looks like I can create my own screenset to do this in Mach3 (I have no need to computer-control the coolant or the spindle).  Frankly, though, I want to get started USING Mach3, not trying to learn how to create screensets for a program I don't know how to use in the first place.

Is there a generic screenset with buttons like Output1, Output2 and so on?


Thanks.


Alan

6

General Mach Discussion / Keyboard only use of Mach3 - possible?

« on: December 06, 2009, 06:28:06 PM »

I'm just getting started with Mach3 after years of using the DOS based CNCPro.

One thing I like about CNCPro is the ability to do everything with the keyboard.  Given the extreme lack of space in the shop, not having to find room for a mouse is a BIG win.

Is it possible to run Mach3 pretty much entirely with the keyboard?

Thanks.


Alan

7

General Mach Discussion / Broken Limit Switch code ?

« on: October 06, 2007, 11:38:44 PM »

New user.  Just downloaded and installed rev 2.48 of Mach3 on a WinXP box and also onto a fresh Win2k install on another box.

Connected it up to my existing controller driving my PCB milling machine.

Tweaked the motor pins and motor config and the motors run great.

Next step was to define the limit switches.  These are just conventional microswitches, connected to a parallel port pin and Ground, closing when the table wipes past the switch.  That is, they are open most of the time, closing at "the limit".

With the switch open, I read 4.15 volts between pin 12 and pin 25 (ground).  Closing the switch, I read 0v.  This is exactly as expected (as it all worked with my DOS software).

I started by defining Y++ as   Enabled   Port 1   Pin 12   Active Low  (Not Emulated  Hotkey 0).  This is the ONLY input pin defined.
 
I then went to the diagnostics and saw the green "LEDs" on.  Manually closing the switch, one green "LED" went out and a yellow LED labelled M2++Lim comes on.  Open close open close results in off on off on. Clearly, the PC is seeing the switch closing, and the logic (active low) works as intuition suggests.

I then went Alt-2 MDI to jog the motor onto the switch to see what happens, pressed the big red Reset switch and IMMEDIATELY got the message "Limit Switch Triggered".

Hmm, maybe the logic is not as appears.  OK, back to pin config and "uncheck" Active Low.  Back to diagnostics, and I see the opposite.  With the switch open, a green LED and a yellow LED beside M2++Lim are both on.  Close the switch and both LEDs go out.  The logic has reversed, as expected.

Back to Alt-2 MDI, clear Reset and EXACTLY the same thing happens; a message reading "Limit Switch Triggered".

OK, maybe not a strong enough pullup (although Diagnostics WAS able to read it), so I added a 1k pullup to a source of +5.  Open switch, the port now reads 4.8 volts, closed is still 0 (of course).

But ALL else remains the same, the message "Limit Switch Triggered" within a second (or less) of "pressing" Reset.

It seems that if I define a Limit switch, Mach3 thinks that a limit has been reached, no matter how I define it.

This can't be right, but I'm 6 hours into muttering and swearing and reading forum posts and exactly the same thing happens on two different machines.  I've got to be missing something, but I surely can't figure out what.

Any help gratefully gratefully appreciated.

Alan