Question Is it possible to print a 400mm x 400mm object on my 400mm x 400mm build plate using Cura? How? (Unable-to-slice/Can't find Location...)

[cnd 2]

My Anycubic Chiron can print XY 400mm x 400mm on its glass 410mm x 430mm build plate - however - CURA won't let me slice anything that's the same size as what my printer can do, and it can't even work out how to place it on the build plate...

 

What am I doing wrong?  Can we ask the developers to fix the placement bug?

 

Adhesion and supports are off.

 

 

I can see an infuriating grey line around the outside of my build plate which smells like the problem - if I turn on adhesion or mess with it, the grey line grows wider, however, I've got no idea why it will never go away entirely.  What's this unwanted boundary I can't get rid of?

 

Model is precisely 400.00000 mm:-

 

perl -e 'print 6.63669e+01+3.336331e+02'

 

(see STL)

 

Body10.stl

[cnd 2]

P.S.  No - I cannot go diagonal, and yes, I absolutely do need that very last millimeter (it's for a laptop HEPA filter holder, and I need to put a silicone sock on this to make an air-tight seal below my laptop, which is (grr) precisely 400mm...)

[GregValiant 1,260]

"My Anycubic Chiron can print XY 400mm x 400mm on its glass 410mm x 430mm build plate."

The physical size of the build plate, and the actual Printable Area are two different things.  Since your model is line-to-line to the limit of the Printable Area in the Cura Machine Settings - Cura won't slice.

Anycubic has provided a 5mm safety area on the left and right, and a 15mm safety area along the front and rear.

If you go into Manage Printers and then Machine Settings and change the build plate size to 405 x 405 the model will slice and it will fit your build plate.

 

There are really several settings involved in this (Home Offsets, software end stops, etc.) but for a single model the above should work and should print properly.

[cnd 2]

Thanks Greg (I mentioned the build plate size to remind everyone that the 400mm size "limit" is the actual real printable output size that gcode is guaranteed to work for)

 

Any chance someone on the dev team could be asked to find and fix this bug?  " Since your model is line-to-line to the limit of the Printable Area in the Cura Machine Settings - Cura won't slice." - that's logically wrong, of course - the only time Cura should refuse to slice is when it is *over* the limit...  (I'd go as far as to say that allowing even more than the actual "limit" when any extra amount is not going to result in gcode exceeding the limit should also be allowed - e.g. 400.00005 should still be just fine (and is plausible, since floating-point-rounding...) - in fact - the build area should really be logically extended by the nozzle width as well, since we get an additional half-a-nozzle-width worth of plastic coming out on all of the sides at all times of course)

 

I'll try the 405 idea - but I'm not convinced that Cura is going to slice correctly still - it already refuses to do 400mm, so my guess is that it's going to output gcode that goes from 1mm to 401mm if I let it use 405mm, and I'm not sure what the Chiron firmware is going to do with that past-the-limit 401mm when it gets there...

 

Those grey lines around the border of my build plate suggest to me some kind of logical region that something in Cura has been told not to print in - which means Cura is *never* going to be able to print at (0,0) until we work out what those are and how to get rid of them?

 

Through a pile of trial-and-error, I worked out that the unprintable amount is somewhere between 1.3mm (cannot print) and 1.3001mm (slices fine) so a model that is 398.6999mm wide outputs this GCODE (which has 398.31mm extents using a 0.4mm nozzle, which looks correct):

 

;MINX:0.845
;MINY:199.805
;MINZ:0.2
;MAXX:399.155
;MAXY:200.195

...

G1 X399.155 Y199.805 E12.94194
G1 X0.845 Y199.805 E25.85859

...

But it proves my point - 0.845 is the smallest it can go - so something is wasting that much all around the edges.

 

I checked all the settings - there's no "(Home Offsets, software end stops, etc.) " (where "etc" is everything mentioning any of those things or parts of them or synonyms) - Chiron settings don't have those (not in cura, and not in firmware), and it's irrelevant since I'm looking at the gcode first.

[GregValiant 1,260]

I wonder if that gray area is a "Disallowed Area" described in your printer definition file?  I don't get that area with a Chiron active in Cura and it appears that you have Build Plate Adhesion set to None.   What version of Cura are you working with?

I apologize is some of this is basic or things you already know.  

I'm surprised that Home Offsets isn't a menu option on your LCD.  I am NOT surprised that "Disable Endstops" isn't available.  With the Endstops disabled the print head can crash into things that are just off the build plate.  Not good.

Is your Auto-Home location the same as the printer 0,0,0?  After Auto-Homing the XYZ locations shown on the LCD reflect the current location of the nozzle relative to the Home Offset 0,0,0.  They are in fact the Home Offset numbers.

 

"how the printer firmware will react" is a point well taken.  You can fool Cura because it doesn't care how big you make your build plate.  You can't fool the printer though.

My guess would be that the printer will indeed take a location like X400 Y400 and be capable of getting there.

 

The printer will put the origin of the gcode file at it's 0,0,0.  On my printer that would be the Home Offset location since I have designated the point I want to be 0,0,0.  If there is no Home Offset designation then the gcode origin will be placed at the Auto-Home location as that is the 0,0,0 of the printer.

 

Here is how a Chiron loads in my 5.1 install.  No gray area around the border.  I know the Ender 3 definition has disallowed areas for the bed clips whereas the Ender 3 Pro definition does not.  I don't know why my definition would be different than the one you are using.

 

 

 

 

 

 

 

 

[MariMakes 198]

Hey @cnd,

 

Not sure if it helps but I often doublecheck to this list of settings if I want to utilize my full buildvolume:


https://support.ultimaker.com/hc/en-us/articles/360013799339-How-to-print-the-maximum-build-volume-in-Ultimaker-Cura

Maybe it helps. Good luck! 💪

[cnd 2]

The grey area appears to be related to print options, like skirts and brims and so forth - and somewhere in that mess of code there's an "out by 1" error, or someone accidentally put ">0" when they mean ">=0" or whatever, causing the full build volume to be unavailable.

 

Changing the size of the build area in the printer profile to make it larger than it really is, ended up working OK.  Lucky for me, the firmware seems happy to let me print past the maximum extents allowed - so I guess as long as the print head doesn't hit an end-stop, that's your *real* printable size... on the chiron.