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Hello Everyone,

Does anybody know what temp you can heat the PCB Onyx Board to? I was thinking of putting some resistive wire between the bed and the glass to get to higher temp than 110.

Any thoughts?

Thanks for input!

Matt

If you need to go higher than 100C on your heated bed, you might be better off going to an A/C heater.

g.

Hey Gene,

Will this method get me up to 150C?

Thanks,

Matt

wheemzy wrote:Hey Gene,

Will this method get me up to 150C?

Thanks,

Matt

Yes if you choose a suitable power density. I use a 350W 300mm diameter AC silicone heater to heat a 330mm diameter bed, which works out around 0.4W per sq cm. It reaches 150C easily (not that I normally use it that high) and I have had it up to 190C to see how high it will go. Silicone heaters are typically rated for 200C.

You'll also need some kind of aluminum heat spreader that you can attach the heater to - you do not want to slap it on the back of an Onyx. That path leads to tears and failure...and probably fire.

What on earth do you want to print that requires a bed temp of 150C?

g.

Thanks Gene. From what I've read, polycarbonate apparently likes very hot bed temps.

I fiddled with polycarbonate a little. Even at a 150 bed in an enclosure around 35 it would only stick for a layer or two before completely peeling up. It may just not like Kapton, but that was my experience.

I finally received the aluminum heat spreader. A couple of things:

1. Is it ok to use in the melamine Rostock v2 frame? I saw in the item description not to use a wood box, I assume 2 different things....

2. Am I doing away with the onxy altogether, or am I attaching on top of the aluminum?

Thanks for any input!

Matthew

At the range of 150+, I would at very least change out the mellamine snowflake for something else, perhaps https://www.mcmaster.com/#9353k31/=1cyve17 which is theoretically machinable, or garolite/bakelite, which is also machinable, and both are rated as fire retardant. You could potentially also use the aluminum top plate as the structure, and depend on using insulators and low conductivity hardware (Stainless steel, potentially), to avoid locally overheating the rest of the frame.

You do not want to use the Onyx at those temperatures. Standard fiberglass PCB's will delaminate, degrade, and potentially burn if you have issues at those temperatures. Attach the silicone heater to the aluminum, then either flatten the aluminum and attach something like PEI, or use glass on top of it. For poly specifically, it probably will work best using a glass bed with an ABS slurry on top (according to my local engineering filament supplier, and considering the weird stuff they print, like carbon fiber filled PEEK, I believe them), at 100-110. You also very much want a heated enclosure. Keep your temps in the area substantially above normal room temp.

Thank you for the advice Xenocrates.

I actually needed some insulation like this for another project, was thinking of making an electric kiln/furnace.

The sheet is a little smaller than the snowflake. Did you cut the sheet in any particular shape?

Also, I have a band saw and a jigsaw, or should I go out and get another tool?

Thanks again!

Matthew

The calcium silicate board can be cut reasonably with a circular saw or bandsaw. Try to make sure you have three or more teeth in the thickness of the material though, to avoid taking overly large bites from it and potentially cracking it. I'd cut it to fit as much of the bottom as possible, since it's meant to be an insulator, and both fire retardant and high temp.

Thanks, now I just have to figure out the dual extruder upgrade and I should be good to go, for a while at least....