Not worried about fire risk - a few people have reported electronics being upset by static - an earthed piece of metal in contact with the plastic pipe will drain any static build up - may not be a problem, but aluminium cyclone dust separator is same price as plastic one.
Alex.

 

PS - I once had a job in a furniture factory where the dust extraction system exploded - it was blamed on static but personally I think the guy operating the belt sander saw the foreman coming and threw his cigarette end in it!
Alex.

 

In machine co-ordinates do exactly what you would do with a probe - jog the machine until the bit just touches on Y axis - make a note of Y coordinate (minus 1/2 diameter of bit). Repeat for ☓ axis. Find Z zero in the usual way. Jog the machine to the coordinates you worked out. Switch to workplace coordinates. Set workplace zero.
Alex.

 

You only need to change the bit, and jog it to the correct Z home height (or use a probe if you have one). Not sure about setting Workplace coordinates manually, looks like the Duet has some special control GUI; I have a G92 in the program that automatically does this, so I can't forget to do it or make a mistake. Geoff

 

Could be anywhere on each axis, but easier in the corner - then you haven't got far to jog for the next one.
Alex.
PS @GeoffH is talking about after tool change you need to reset Z zero without resetting Y and ☓.

 

No, and don't jog X or Y at the Tool-change, only Z. Geoff

 

You are setting work zero at the centre of the tool. So to change tool return to work zero, raise Z axis, change tool, lower Z axis to workpiece, set work co-ordinates - ☓ and Y have not changed - only Z.
Alex.

 

Yes, and the grbl(mm) post-processor for Cut2d / Vcarve always returns to the Home position (Work zero), so no need to do that. Geoff

 

Didn't know that @GeoffH - when you say "home =work zero" do you mean front left of machine? MACHINE CO-ORDINATES zero is front left with Duet, HOME where the limit switches are is back right.
Alex.

 

In Vcarve you can set the Workpiece Coordinates zero to any position but normally you might choose one of the corners or centre of the Workpiece. The Machine zero isn't defined or known in Vcarve, only the Workpiece. This is at the end of post-processing

begin FOOTER

"M5"
"G0[ZH]"
"G0[XH][YH]"
"M30"

So this stops the Spindle, Rapids in Z to ZH(Home), then Rapids in X Y to XH YH (Home), End of Program. The Home is Workpiece coordinates, not Machine. Geoff

 

Thanks @GeoffH - I wanted to check that what I had said fitted how vectric software works - it gets very confusing when "home" can mean two different places.
Alex.

 

By the way, I don't have any limit switches on my Machine, so I have no concept of Machine coordinates. Maybe this is a difference between 3d printing and Subtractive Machining operation, in the latter we have to know exactly where the workpiece is, in 3d printing it's not so important, as long as it's on the bed. So I think for 3d printing you would normally start the process from a Machine zero, whereas for subtractive machining from a Workpiece zero. Geoff

 

My only previous experience of nc maching was over 30 years ago when the school where I was head of the technology department acquired a Denford mill programmed in g code (text editor) in absolute machine co-ordinates. My 3d printer starts from machine zero and moves to the position on the bed where the "workpiece" is - I haven't looked at the gcode but suspect it uses machine zero as its reference point. I haven't fully explored how the workbee and duet work together, but things do get very confusing if you don't "home" the machine on power up - the machine has no idea where it is or where its edges are.
Alex

 

Hi Alex and Colin, I'm just hoping that I haven't confused you both. The Duet and Oooznest comes from a 3d Printing background, so I understand why it may be the way it is?? I'm assuming that at some stage you must manually tell Duet where the Workpiece is on the bed, because the first thing in the grbl gcode program is a rapid move to the Workpiece Home position. In my situation I clamp the workpiece to the bed, jog the tool to the Workpiece Home position (lower left of the workpiece is my favourite), set the tool Z height, then all I have to do is to run the Program. Geoff

 

Yes, clamp workpiece, jog machine to chosen origin, set workplace coordinates zero.
Alex.

 

That sounds the same Alex, except "set workplace coordinates zero" is in my gcode program with G92. Sorry to both for any confusion I may have introduced.Geoff

 

What I don't know is whether @Colin Mccourt's software also puts that G92 code in. Either way I think he has to set his work coordinates before he runs his Gcode.
Alex.
PS the Duet betrays its printer origins when you run gcode it asks if you want to print it.

 

I think Colin is running the standard grbl(mm) post-processor which doesn't have a G92. It has a Rapid Move to the Workpiece Home Position, so unless he has set the workplace coordinates zero in the Control, it could move anywhere. Geoff

 

Sounds good Colin, so if you have set Z10 for example as the Home Z in Cut2D


the first move in your program should be a Rapid(G0) to Z10 - then everything will be as expected, so forget I even mentioned G92 Geoff

 

Home all axes first (I think that's what you are saying anyway). I don't know vectric software, but I assume you set an origin when you do the cam which is where you set your workplace coordinates zero.
Alex.
PS I think I should drop out of this conversation as I don't know the vectric stuff and risk causing confusion - take more notice of @GeoffH @Colin Mccourt (and post a pic of the football shield when it's finished.
Alex.