Proposal for Automatic Sheet Detection
If submitting prints remotely (e.g. with Octoprint), you are not present when the print starts, and there may be a risk that you've forgotten to replace the steel or textured sheet.
If the heatbed were to have a hole or cut-out in it somewhere along the bottom edge, the PNDA probe could look for it when it does the bed level check. If the steel sheet is fitted, it won't find the hole (because it will be covered) and everything is fine. If the probe finds the hole, the print could abort with an error.
I am not clear as to whether the probe could actually detect a white or red painted spot - i.e. it may not be necessary to cut a hole, just painting the heatbed may suffice.
This method could be extended to differentiate between steel and textured sheets being fitted, and if the probe can detect goles or coloured spots. It may be possible to use a sticker on the bed to tell the difference between steel sheet 1 and steel sheet 2 - that way the sheet selection could be automatic.
Best Regards,
Steve
RE: Proposal for Automatic Sheet Detection
pinda cannot detect paint colour, or presence of paint...
Holes in the printbed / build plate would seriously restrict print area
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Proposal for Automatic Sheet Detection
@joantabb
Shame about the colour, but not really unexpected. I wasn't expecting large holes would be necessary - possibly slightly larger than the PNDA probe. And the holes could be along the bottom edge, outside the print area, say, just after the nozzle clean.
So my idea sounds to be not too practical for a sheet identifier, but could still work for a sheet presence detection.
If the steel sheet were installed, of course, the "sheet detect" hole would be covered.
Steve 🙂
Steve
RE: Proposal for Automatic Sheet Detection
[...] So my idea sounds to be not too practical for a sheet identifier, but could still work for a sheet presence detection.
Mesh bed leveling will fail with an error if the steel sheet is not present when starting a print. Is that what you're after?
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Proposal for Automatic Sheet Detection
Actually, I thought of something like this when I first got the textured sheet and was continuously forgetting to set the correct sheet type profile. My idea was to drill a third small hole in the textured sheet, outside the print area in line with those two existing holes, and mount a photosensor in the heat bed (something I've realized is a Bad Thing) to detect, by room light, which sheet is installed.
I did not pursue this, and simply got into the practice of setting the sheet profile whenever I grab a different sheet from the shelf above the printer.
RE: Proposal for Automatic Sheet Detection
@bobstro
Yes, that's what I was thinking of - it's a better safe than sorry / belt-and-braces approach!