@chanders Hmmmm... Makes me want to check whether I could fit the lower half of a soda can into my printer...

Happy new year everyone,

over the holidays I've managed to do some CNC work and I realized I was missing a feature on my Duet-controlled Shapeoko-clone. My usual routine is

• home the machine
• jog to the desired stock origin in XY and set the WCS XY origin
• probe the Z height, set WCS Z origin
• (missing step here, see below)
• start the program
• realize that some of the cutting parameters were wrong

If I then use DWC to interrupt the program, everything is fine - I can correct the program, reupload and try again. If, however, things go south so rapidly that I have to hit the emergency shutdown, I lose the offsets of the WCS in relation to the machine coordinate system. That's where the missing step comes in - I should probably write down the coordinate system offsets every time, but in reality, I don't. This is what started me thinking:

Would it be possible to have a command / macro file that reads the current WCS offsets and stores them in a file on the SD card - preferably as a set of G-Codes so that executing that file re-establishes the coordinate system offsets?

Going through the list of supported G-Codes, I have not found anything to achieve this functionality... yet

Thanks
Volker

It's been 30 years or so that I've last tried to make something out of clay - but I remember very clearly being warned about trapped air bubbles, since they expand in the oven and may cause the hardened part to shatter (and damage parts around it). You appear to be using infill structures similar to "regular" 3D printing - how do you deal with that?

Try

M550 PSteam

then run the assistant twice, followed by

M117 Hey Hey-ey Goodbye

(SCNR)

I'm using the HEATER3 (pin 8 on the extension connector) to drive a CNC motor controller via PWM, and so far, it works. I need to use this pin (or a similar pin) instead of the heater or fan connectors on the board because I need a PWM signal relative to GND.

One slight issue: During startup, the pin goes briefly to HIGH, which makes the spindle turn on for a moment. I've already managed to fling my Z probe connector across the room in this fashion and decided I didn't like that... Is there a way to prevent this, or is there another pin available that I could use that does not default to HIGH during startup?

Thanks everyone - I've managed to run a few simple test cuts after using my "cheapishaw" probe, and I'll try a more complex part tomorrow. So far it's looking very promising.

Thanks, @EasyTarget, that confirms part of what I've already figured out. The rule of thumb appears to be: Don't mess with the machine coordinate system after homing, set the approproiate WCS origin instead - right?
However, I'm still unsure about several things:
What does DWC display - always machine coordinates, or does it adjust to the WCS selected?
What about the tool length offset - is that a change in the coordinate system, or is it just an offset that is applied to the G0/G1 movement commands? The offset changes the coordinates displayed by DWC, so that's got me a bit confused.
I'm using a PCB with a known thickness to probe the tool height, so I need to adjust the offset by the thickness of the PCB

After having (quite literally) blown up my el-cheapo CNC control board, I've replaced it with a Duet Wifi. I've got most of the stuff working so far, but now I'm stuck - at a point that probably has little to do with Duet specifics. I'm using M585 to probe the tool height, and while that works electromechanically, I'm having a hard time wrapping my head around the different coordinate systems, tool offsets and so on. I understand that a lot of stuff is possible, but what is the setup I should be working towards if I want to be able to get my CNC to process programs generated by Fusion 360? My machine homes to the back right top corner of its working area, so towards the X/Y/Z positive endstops, is that correct - or rather, is that sensible? I've adjusted the homing scripts so that the front left corner of the working area is equal to X0 Y0 after homing. I know the Z axis can move down roughly 90 mm until the chuck touches the working surface, so after probing with a tool of say 35 mm length, what should the offsets and positions look like? What coordinate systems would I be working with, and how should they be setup? Sorry if I sound a bit confused - I am...

I've recently switched to Prusa Slicer from S3D, and while I am generally satisfied with the print quality, I'm having trouble with the print time / progress display. For example, in the DWC status display, the jobs are always shown as "100% (0 of n layers)". I'm pretty sure I just forgot to change a setting in the slicer somewhere - which settings influence this behaviour?

Hi all,

I'm apparently facing some kind of mental blockage here... I have the situation that my part cooling fan only works if it is set to 100%. From what I've read so far, that is most likely a PWM frequency issue (can't try that at the moment because I don't want to disturb a long-running print). From https://duet3d.dozuki.com/Wiki/Gcode#Section_M106_Fan_On, I understand that the PWM frequency is set when turning the fan on. Do i need to run my generated G-Code file from the slicer through a post-processing script to have the F parameter added to each and every M106 command or is there a way to preconfigure the PWM frequency once during system startup?

Thanks
Volker

@aidar Thanks - my Google sub-system might still be asleep...