So, i am going to talk to a local glass supplier tomorrow about some pyrex
Is 13-1/8" x 14-3/8" close enough in size to the heated bed?
1/8" thick should be ok?
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I think I have thought of a way to modify the printer for a glass bed, all we need is to 3d print a small bracket with a plastic spring holding a washer or other metallic item that moves up and down towards the existing sensor, this way it could measure glass at the required points and then we would remove the sensor adaptor after it was levelled. It should be more consistent than sitting a metal plate on top of the glass bed as it would be the same for all points.
Interesting, a bit over-complicated and not sure why the design uses brass as a non-ferrous target material will result in a shorter sensing distance.
You should ask @stefix yourself. I would assume it’s just what he had laying around. And his numbers show it’s pretty repeatable & quite accurate.
Its right i was using brass for the plate, but how @brvdboss said its just laying around works good and precise.
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You are right in that ferrous metals will detect further, magnets further still, but in actuality the non-ferrous metal is going to give you the most accurate result. At least based on my experience.
We often cheat our proxs by using ferrous metals at work, but our application doesnt require precision.
I hope you would be using the glass as a print bed while 3d plastic printing. But some how I had an image of using the laser to etch an image on a glass pane. I’m not sure that is possible. Normal glass suffers from the tremendous heat in one spot when the surrounding glass is cold causing cracks. But I know nothing…
Yeah its a goal of the community to make it easy to print on a glass bed in terms of calibration methods, since the existing sensor can’t read through the glass to the heated bed.
Glass beds are ideal for their consistently flat and smooth surface.
although it is quite possible to laser engrave glass, not for sure if the snapmaker can do it or not (havent even looked at the laser yet). i am pretty sure that the existing module cannot, the new module in development might be able to, but i think clear is a lot harder to do than tinted so it may not be doable without a more powerful machine such as a co2 laser.
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Not to hijack the thread, but it is possible to engrave (lightly etch) glass on SM 2.0. Need to use something like a sharpie or dry erase marker on clear glass so that it will absorb heat.
-S
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How do you guys mount the glass bed to your heated bed?
I tried binder clips and it wasn’t enough to hold it on the bed.
2mm is way too thin. You will get the same wavy nastiness you get with the standard bed because the glass just isn’t thick or stiff enough. I’ve just cut a piece of 5mm mirror that I’m going to try (I have a piece of the same glass on my old Prusa Mendel, and it has worked well). I think I’ll run with manual levelling as suggested by @onyx0909 .
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I can’t find FiFix’s STL. Thingiverse is terrible.
@Mads0100
Its not online at the moment, but take this (2.7 MB) for now - same version as thingiverse.
Its secured by a password, that I will send everyone who wants it, from my heart.
Only send me a PM. I do it this way only as I am nosiness 
who want to print it.
Have Fun
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FiFix is offline right now, Stefix is working on a revision @stefix
I use 1/8" pyrex glass and its awesome. I am currently trying it with that orange kapton tape on the back side, previously was using a magnetic adhesive sheet.
Testing to see how good it is in those scenarios, and will be doing the same with regular glass too.
looks like stefix beat me to the punch
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@MooseJuice I am using normal windowglas 4mm an its good for me, but take care if you are using higer temperatures for the bed. I killed one at 90°C with ABS. I heard at the mornig terrible noises out oft my hobbyroom. It seems someone was crusing glas, and so it was. the sheet broke and was terminated between the bed and the Z axis!! My best friend (SM2) was not amused
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ut oh lol
i have to revisit the glass clip solution, because the calibration routine likes to bump the fifix off the print head in the upper left corner, then it will push the bed down in the front corner or middle.
Im sure I can find just the right place to put everything so i dont have to worry about it, but for anyone using my glass clips, just watch your machine when its calibrating please.
Could you not stick some thin copper tape to the calibration points on the glass, auto calibrate and then flip the glass so you’re not printing on top of the copper?
The bed is consistently flat, so flipping it wouldnt be an issue if its fitted with brackets that don’t move
and the copper tape i have it so thin, if you laid it smoothly it should be fine?
Am I completely wrong here? I’ve just printed Steflix’s calibration tool, but i keep thinking there has to be a simpler way
As long as you’re careful and properly manage your assumptions that can work. The copper tape is not infinitely thin and not perfectly flat and should be verified to not have any affect (easy, possibly negligible). Also the glass bed is not perfectly flat, and while it is fairly flat by inverting it you’re doubling any dishing error. If you first verify the flatness of the glass with a straightedge that can be guarded against. Some glass is only flat to 0.004"/inch. Hopefully what you’re using is much better.
Personally, I chose to put a magnet sheet on and use the same removable print sheet. That’s pretty close to as easy as possible. Autocalibrates just fine.
Possibly a better method would be to first verify your glass is perfectly flat. Then shim under the glass so that it is perfectly tram with the printhead. Then just 0 out all of the measurements and don’t use auto levelling as you’ve now verified your bed and flat and perpendicular. Just set Z height.
Something in between those 2 extremes would be doing a 3 point plane measurement which unfortunately cannot be done with the stock firmware.