Glass Bed (Page 1 of 9)

I like the idea I was thinking of doing this with a piece of aluminum and some thermal grease since my bed is warped some.

I wonder how long it would take to heat the second plate up to temp before you could start printing.

I really hate how long it takes to heat the bed, I've been using a heat gun and that does seem to help quite a bit.

I know 30 seconds can make one of those almost too hot to touch, maybe 50-60C.  I suppose preheating the cover would make it more effective than an insulator like a fire cloth which would need to be heated along with the bed.   It's easy enough to test if you already have a sock and some rice.

Concerning measuring temperature of glass with an IR thermometer: Unless you are using quartz glass, germanium, amtir glass or zinc selenite (you aren't), then the glass is IR-opaque and should give you no trouble in measuring temperature.

That's great news, I will sew up a couple bean bags and give it a try.  Thanks for trying it out Ian.

The nice thing about the cloth or rice bag is you don't have to be standing there the whole time.

I got a couple of pieces of glass from a frame store and mounted one.  It passes the heat through just fine, Pronterface said 86, for the glass the IR gun said 95-100, thermocouple said 87.  I had to put a longer Z adjustment screw in.  The one I had would't reach the switch before the glass got to the nozzle.  Fortunately I happened to have another M3 bolt lying around from who knows what.

I diluted some white glue, 1 part glue to 5 parts water, spread it over the bed and started a print.  I don't know how well it will stick but I have high hopes.  Even if you still have to use Kapton, the convenience of a removable print surface is worth it. 

The first print was a success.  It stuck all of the way around and got all of the way through the print.  I had been having trouble with this one, and had resorted to spreading ABS/Acetone on the Kapton.  It also peeled off without any trouble.  It is another Pony (Daughter 2 had requested Princess Celestia) but the next print is this one - http://www.thingiverse.com/thing:29365  It is a lot more challenging to print and stick.

It doesn't seem to have lost much glue, so I'm just spreading some more on and printing the next thing.

This idea may help solve my problem. The two screws in the middle of the platform are not flush. I've tried to tighten them but they appear to have a slight angle. Since they are not flush with the bed, I tend to tear the kapton at those locations. They also cause indents in the bottom of my print. If I were to use the glass method, I would have a smooth surface to work with. I beleive they cross threaded the screws and they will not seat properly.

Ian, Check this out, I was checking out the "OrdBot" that a new member was commenting on, and saw in this youtube video that they had a mirror as the bed and thought this would work just as well as your glass with the added benefit of being able to see what's happening under your fan contraption.  If nothing else it'll look cool and I enjoy spending your money by giving you ideas.  haha

I'm using 'single strength' (2mm) glass from the hardware store. Two 6x6 pieces were $5, plus another $.40 for a M3 screw and nut.

I've struggled with the level of hairspray that works the best. A fresh fine dusting seems to work best, so I've been cleaning the sheets often.

Having two print surfaces works great.  I can finish a print, swap pieces, and get back to printing pretty quickly.  I did notice the 'new' glass drops the bed temp to about 70, so there is a bit of re-heat process.  I've been putting a folded dish towel on it and it helps. I haven't tried putting the backup sheet of glass either on top of the SD or inside to preheat the glass.  That might help to shorten the reheat time.

B

Here is an interesting thread at the RepRap forum.  One user has found that sandblasting glass works really well for getting prints to stick.  There is also a suggestion for etching.   Borosilicate glass (pyrex) is a popular choice since it is made for high heat, however I'm not sure where you would get it, and have it cut.

Not sure if a airbrush sandblaster would have enough power to "pit" the surface of glass would it?