Topics

1

General Mach Discussion / Can other software be causing Mach3 cutting 'lag' issues?

« on: February 26, 2016, 02:09:29 PM »

I wonder if anyone can shed any light on this please:  Is it possible for other software running to cause a sort of 'lag' for Mach3 issuing commands to the drivers?

I'm running the Mach3 2010 screenset on Windows XP out via Parallel to a BOB with drivers etc attached.  Everything has been running fine and then today whilst jogging the Z down (via keyboard), the Z continued going and dug the cutter into the bed after I'd let my finger off.  The spindle wasn't running so fortunately the stepper stalled otherwise I would have been in a world of hurt!  I figured it was just maybe a USB keyboard glitch but then whilst cutting (which was going fine) it seemed to make a grinding noise, didn't move very far (it wasn't jammed, it was still cutting:  it appeared to be being 'commanded' to make the move) and then continued cutting a nice smooth curve as if nothing had happened!  In fact it was cutting a fresh offset curve (because it had lost it's position) with a much deeper DOC (16mm vs the 6mm I usually cut at!).

I was wondering if Mach3 sent the commands and they got somehow delayed, or lost, before getting to the drivers?  Could another program (I had Chrome open on the computer!) be causing Windows to lag somehow and lose commands?

2

General Mach Discussion / A Puzzler: Is the Parallel Pin connected to the GND side or the PIN# side?

« on: February 11, 2014, 12:43:17 PM »

Hi,

I've got a bit of a puzzle that I've spent a few days on and can't for the life of me solve...  I can't work out wither the Parallel Pin is connected to the GND side or the PIN# side of the BoB for any particular pin - it seems to be connected to both (sort of).  Here's what I mean:

I've got the zeroing on my machine working.  I've wired the XYZ homing-plates into the GND terminals on the BoB for each pin.  I use a common wire for the crocodile clip (that attaches to the cutter) that goes to the PIN# terminal of Z.  It works...

However I was under the impression the PIN# terminal (which is at +5V relative to connection marked GND making me believe it's held high) should also work - i.e. the reverse of the above, but it doesn't.  Mach3 seems to auto-set the pin numbers correctly and sets them as active high (I think the ZP5A BoB might be inverting the signals?) but when I run the same auto zero code it doesn't work.

I just can't understand what is happening - whether the Pin is held high (and is connected to the terminal connection marked PIN#) or whether the Pin is held to ground and is actually connected to the GND terminal.  Because Mach3 auto-sets the same either way, but just doesn't work via the auto-zero command I'm well and truly at a loss!

I've attached a (badly drawn!) diagram in the hope this helps me explain!  (The G is GND and the P is the appropriate PIN# terminal at +5VDC relative to the GND)

Oh, and I also understand the theory behind active low/high for both NC and NO but with this BoB Mach3 doesn't set as the theory suggests.  For example the Estop is connected NC directly through the PIN# and GND terminals of a pin but when the switch is opened Mach3 see's it as active low.  I was of the belief that it should be active high (so the pin is held low whilst switch is closed and then goes high when the switch is opened).

3

General Mach Discussion / Is "GND" in the manual Common and +5v on the ZP5A-INT breakout board? (please!)

« on: February 06, 2014, 02:48:38 PM »

Can anyone help me understand the Chinglish in the manual?

In terms of the inputs on the ZP5A-INT board one terminal (of a pair) is labelled as GND and the other is labelled with the pin number.  It seemed fine until I wanted to zero the tool - I had to swap the X, Y and Z plate leads from (whats labelled in the manual as) the pin terminal to the GND terminal for each of the inputs - which didn't make sense.  The 'pin' terminal appears to be at +5v relative to the GND terminal but I'm not sure if the board is holding it as such.  I think that my lack of understanding on what each of the terminals represents has meant that getting this far (with the zeroing and estop) has been more down to trial and error/luck and the auto-switch-set feature in Mach3!

I would find it easier if I there was a +5V, a GND and a lead to the parallel pin because I'd be able to install my own resistors and switches to allow me to make it active low/active high.  As it stands (and as the boards screwed down to the base) I'm struggling to understand what's going off.

I'd be really grateful if anyone could shed some light on this as I (hope and!) think this is my last hurdle before I can have a trial run.

Regards,

Matthew

4

G-Code, CAD, and CAM discussions / Best Practice for Zeroing and Tool Changing on CNC Router?

« on: February 03, 2014, 02:55:24 PM »

Hi,

I'm quite new to CNC Routering - I've built my own machine but I'm now trying to get a handle on the use of it.  Could anyone shed some light on the best practice for zeroing and then tool changing on a CNC Router please?

To zero XYZ initially I was planning on using a script and some metal plates connected through the breakout board - I first found Mr Cockrums macro but since then I've found and added to airnocker's auto tool zero macro.  My version of the code first asks the user for the diameter of the probe/cutting tool and then uses the radius of this probe/tool to calculate the offset for zero (I've not tried it yet!).  I thought it sounded fine in principle...

But then I'm wondering... say I use an end mill to machine a flat shaped area into which I want to then V-Carve (for example to make a sign)...  If I zero XYZ using the mill (which as a cylinder should be fine), then cut, then want to swap the tool for the V-Carve cutter I just swap it out and zero the Z axis again (because the centre of the tool will be the same) - is my theory.  The assumption I'm making is that XY shouldn't need re-zeroing, but is this bad-form considering I've just been un-tightening/tightening the spindle in-situ - am I safe to assume it won't have moved?  If not, how would you zero a V-Carve cutter with only 2 straight flutes?

I've tried looking up information on tool tables (which I don't think would work because the cutter height won't always be the same in the spindle if she shanks aren't long enough to stop at the end of the collet) and offsets in Mach3 but I'm still not understanding something - I think I might be over-complicating it all!

Regards,

Matthew