Glass Bed (Page 3 of 9)

I like that a lot Danny, I think I am going to replicate it, with one minor change. Using Kapton tape to electrically insulate the original aluminium bed from the wire. But doing the same process. That way I can still keep my separate glass sheets easily.

I have found this stuff on ebay: Conductive Pad

I am thinking about using 2 layers of it to sandwich the nichrome wire to effectively make my own heat mat, then place that between glass and alu of the original bed. Create a new bit of loom going back to the Sanguino. So if it doesn't work, or fails I can still go back to using the stock heating set-up, and keep using the stock thermistor.

I got it from ebay, it's a couple of quid for a 5 meter roll. (more than enough!)

The only reason I didn't do it like this was that I could only get 6mm pyrex sheet. keeping the original bed would have meant having to get a longer z screw, or putting a stand-off on the existing one, or flipping it over.

if you can get thinner glass, (easy if you're not bothered about heat safe glass) then there is no reason that you couldn't/shouldn't keep the original bed.

Cool, thanks for the answer. Sorry to hear your bed was warped.

I did my PVA wash with the bed hot on my glass bed. I ramped it up to about 80-90, then painted on the dilute mixture. The water cooks off, leaving the PVA dry within a minute or so. I then took a little fine grit sandpaper and just lightly roughed it up. I seem to get pretty good sticking, though I do run my bed at 100. Prints pop off all by themselves as the bed cools.

I am thinking about picking up some nichrome though now and aiming for something like what you did, since I wonder if my bed is heating evenly because I occasionally have a corner lift a little. It only really happened on one part with a fairly small footprint; it may be that my printer was slightly not level, and if I had been able to find where in slic3r 0.9.8 to turn on a raft I would have to help stick the print down (anyone know where?). I also run a fairly thin sheet of glass (~2.5mm), so a thicker sheet might even out heating a little better.

Glad the new bed is working out for you!

Hairspray works really well for myself. Also a note for anyone who might care. Charcoal drawing fixative, is the same as Hairspray, only fragrance free but more expensive. It's a trick my dad used, to not pay the more expensive prices for the fixative.

I was having some warping problems with large parts printed on glass with hairspray.  I switched to ABS glue and it seemed to solve all of my problems. My only complaint is that it is very messy to work with and a pain to clean up.

My main problem has been parts coming loose, especially anything with a small footprint. . I will clean off the glass and try hairspray, failing that, abs glue.

10ish minutes or so.  Faster than my self cleaning oven...

This printed at .75, even with a 3mm brim

http://www.thingiverse.com/thing:39075

I have actually  have created a glass bed that has nichrome wire sandwiched between 2 sheets of glass.

The nichrome wire that I used is too thick I think.  It is 1 Ohm per foot, and I used 2 6 foot sections to get to 3 Ohms (I am at about 3.3 Ohms).

I can't get the bed to heat up over about 55C though.  I tried using an electric train transformer to power just the heater, but even that did not heat things up much.  I was thinking of trying thinner nichrome that is used for foam cutters, and then seeing if I can power the bed with a transformer.

Right now I am using regular glass, but I have some tempered glass coming in the next few days that I'll be using instead of the regular glass.

I like to call my printer my Frankendoodle printer.

I'll post some photos once I've got things tweaked some more.

my aluminium bed would not be ready to print.
(print would lift right off the kapton and just not stick) until it was over 85 degrees C)
my evenly heated glass bed prints happily at around 70degrees C.

I'm guessing that the hot spot created by the resistor in the centre, (and measured slightly off centre) caused inaccurate temp readings. and wildly different temperatures over the bed, (which is why things could stick at the middle and not at the edges.

that said, I'm still not thrilled about how long my bed takes to heat up, so I may also get some more wire and re-wire the bed possibly for a 1 or 2 ohm total resistance with a relay to control the current and a separate power supply for faster bed heating.