Can I build a heatbed assembly without a glass print bed?

I've been searching everywhere near where I live and can't find a piece of glass or mirror of the size required so I was wondering if it's possible to print straight onto the bed?
Thanks
Ben

I wouldn't. The board is somewhat textured and would transfer the pattern (circuit board texture, lettering, etc.) onto your printed part. Also, removing the part from the surface would be problematic, especially if stuck. Scraping the board would diminish the surface, causing subsequent parts to stick even worse, or pull the surface paint off the bed.

You can find borosilicate glass on eBay [CLICK] or score a piece for cheap (or free!) from a glass shop, who will cut it to size for you.

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-David

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The pcb is also quite flexable and will bend down if you put any weight on the center, like a printed part.

Edited 1 time(s). Last edit at 01/14/2015 07:35PM by Dust.

Assuming you're talking about printing PLA, and a standard PCB print bed, then the answer is, maybe.

The glass has 2 main functions, firstly it gives a flat surface which is essential for printing (the print head needs to be a consistent distance from the print bed, across the whole bed). PCB's tend not to be particularly flat, and flex fairly easily, so you would need to find a way to mount it flat with no flex.

The second advantage of glass is it provides good adhesion for PLA. I don't know if your print would stick to the PCB but you couldI solve that by covering the bed with blue painters tape (masking tape).

I've currently got a 200mmx200mm acrylic mirror. Would it be possible to superglue this to the Heatbed if I managed to level it as its too small to screw to it? Is my thought correct that the assembly consists of an mdf board then the heatbed and then a print surface in a sort of sand which?
Thanks
Ben

It's possible to do that, yes. I've also seen beds made of just glass and a PCB. You could absolutely do that with glass, but I don't know how well it would work with acrylic -- I'd heat it in the oven to make sure it stays stiff and flat at those temperatures. It might also not conduct heat well enough to be practical. I highly recommend using real glass, ideally borosilicate -- that link MindRealm sent has some for ~$20.

Acrylic will not work. The Prusa I3's that use acrylic as the carriage have been warping if it is not insulated from the het bed, and you do not want to glue the print surface to your heat bed either. If the print surface gets damaged, warped or cracked, you could lose the heatbed also.

Your best choice is to find your local home center like Lowes or Home Depot, and get them to cut a piece of glass for you. Your next option would be to find a cheap picture frame and take the glass from that, but you would have to also purchase a glass cutting tool and cut it down to size yourself.

If you still can't find glass then go for a sheet of aluminum and either cut it down or have it cut down.

The way to fasten the print bed to the heat bed is with 3.17cm binder clips. You can find these any where that carries office supplies.

Acrylic will melt faster than your filament. Don't you have glass on your windows where you live ? So you can find some glass in your neighbourhood. Or find a sheet of aluminium and resize it with a hacksaw.

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Collective intelligence emerges when a group of people work together effectively. Prusa i3 Folger (A lot of the parts are wrong, boring !)

Good advice:

Quote
jrcaster
find a cheap picture frame and take the glass...

Be careful using aluminum, or anything else that is electrically conductive, so that you don't short out anything (led connection, power wiring, grid) on the heated bed circuit board!

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-David

Find me online at:
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Check out my FolgerTech Prusa i3 (plexi) at MindRealm.net

Quote
MindRealm
Good advice:

Quote
jrcaster
find a cheap picture frame and take the glass...

Be careful using aluminum, or anything else that is electrically conductive, so that you don't short out anything (led connection, power wiring, grid) on the heated bed circuit board!

This is a good point as well.

Bottom line is that I would not skimp on the bed just to save money. The glass helps a lot, and you might ruin your heatbed by printing directly on it.

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Blue Ice

blog at [contemporarymaker.com]