[Cerrado] 3mm glass plate on Prusa i3 MK2S?  

Re: 3mm glass plate on Prusa i3 MK2S?

OK, so the tempered glass is for the Mk1 (not Mk2); it is a lot smaller than the Mk2 bed.

The probe only works when about 1mm above the bed, so adding 3mm of glass will render the probe pretty useless - expect a few crashes.

There is a way to use glass; you have to slice with a 3mm offset and put the glass on the bed after the 9-point calibration but I don't think that's what you are looking to do...

Peter

Re: 3mm glass plate on Prusa i3 MK2S?

I'm a bit puzzled as when I asked Prusa about this they said that 1) these glass plates would fit my MK2S, I even gave them the website reference, and 2) that I just needed to recalibrate for the additional thickness of the glass. What you're telling me now contradicts both?

I've gone ahead and contacted Prusa again and they've indeed stated that the glass plates won't fit, they're too small, so I'm getting a refund for those, however I would still like to obtain glass plates elsewhere so I can use those. How confident are you the PINDA probe won't work with an additional 3mm added?

Re: 3mm glass plate on Prusa i3 MK2S?

I saw someone using successfully a glass on the mk2 on youtube some weeks ago but I don't have the link. You should look for it to get an idea.

Re: 3mm glass plate on Prusa i3 MK2S?

I am not a fan of printing on glass on the MK2S but it can be done. You have to add a pause in your gcode just after the calibration, to give you time to put the glass on. Someone made a youtube video about it already.

Re: 3mm glass plate on Prusa i3 MK2S?

Matt's Hub have done a good review of this:
https://mattshub.com/2017/04/11/printing-on-glass/

Re: 3mm glass plate on Prusa i3 MK2S?

Thanks everyone, that's the information I was looking for. I guess there's no way to use the PINDA probe *with* the glass plate?

Re: 3mm glass plate on Prusa i3 MK2S?

I think it will be to far away from the metal inserts in the bed.

Re: 3mm glass plate on Prusa i3 MK2S?

Thanks everyone, that's the information I was looking for. I guess there's no way to use the PINDA probe *with* the glass plate?

It is possible to get Kapton tape 200mm wide; that could be applied to the PEI and would give a nice smooth finish and would not affect the probing.

Peter

Re: 3mm glass plate on Prusa i3 MK2S?

@Peter,

Thanks for the suggestion. I'm actually using 50mm Kapton tape at the moment, the problem is the bond to the PEI is not strong enough, so when you remove a printed piece you leave airbubbles trapped under the Kapton tape which are hard to remove or cause wrinkles, which then cause visible imprints on the next print.

Re: 3mm glass plate on Prusa i3 MK2S?

@Peter,

Thanks for the suggestion. I'm actually using 50mm Kapton tape at the moment, the problem is the bond to the PEI is not strong enough, so when you remove a printed piece you leave airbubbles trapped under the Kapton tape which are hard to remove or cause wrinkles, which then cause visible imprints on the next print.

You will probably get more stick with the 200mm wide tape. Whenever I have used it, it sticks, well just like the proverb. A light spray of wet water first then squeegee the water, turn on the heater and there's no letting go.

Peter

RE: 3mm glass plate on Prusa i3 MK2S?

Posted by: sander.s

Thanks everyone, that's the information I was looking for. I guess there's no way to use the PINDA probe *with* the glass plate?

The only way I can imagine without modifications to the printer firmware is getting a very thin sheet of glass and gluing it to a steel sheet. That will make it hold well on the Mk3 and will also work with the probe. But you'll need to get into the 0.5mm-1mm range, which may be challenging. I've done that successfully with Garolite for Nylon printing.

RE: 3mm glass plate on Prusa i3 MK2S?

Posted by: Vojtěch

Posted by: sander.s

Thanks everyone, that's the information I was looking for. I guess there's no way to use the PINDA probe *with* the glass plate?

The only way I can imagine without modifications to the printer firmware is getting a very thin sheet of glass and gluing it to a steel sheet. That will make it hold well on the Mk3 and will also work with the probe. But you'll need to get into the 0.5mm-1mm range, which may be challenging. I've done that successfully with Garolite for Nylon printing.

I thought I saw someone had done that with one of those glass  screen protectors meant for a tablet-sized display. Might not be the full print area, but definitely something.

Just don't try to flex your bed to remove the part 😀

RE: 3mm glass plate on Prusa i3 MK2S?

That protective glass can handle a lot of flex actually. Although I'd be rather curious whether the oleophobic coating that's on these screen protector wouldn't prevent anything to stick to the glass ... but then maybe not, I know that sugars (like spilled pop drinks) tend to stick very well to the phone screens.

RE: 3mm glass plate on Prusa i3 MK2S?

Posted by: Vojtěch

That protective glass can handle a lot of flex actually. Although I'd be rather curious whether the oleophobic coating that's on these screen protector wouldn't prevent anything to stick to the glass ... but then maybe not, I know that sugars (like spilled pop drinks) tend to stick very well to the phone screens.

So long as there are no scratches or pits from which a crack can propagate... yes. Once there is one, game over.

Well, oleophobic != sugar repellent. Sugars are polar and so will stick to anything designed to repel non-polar compounds. The coating shouldn't be a problem as I believe it's easily removed with either an IPA or acetone wipe since the screens specifically tell you not to use IPA for cleaning since it will remove this coating.

RE: 3mm glass plate on Prusa i3 MK2S?

I was wondering whether PLA or PETG, being polyesters, would be polar enough to stick to the coating.

I don't think that IPA will immediately remove the oleophobic coating, although it is reported to degrade the coating over time.