Has anyone looked at better ways to attach glass to PCB heatbed?

3D Printing
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1

Has anyone looked at better ways to attach glass to PCB heatbed? I am noticing, especially with my 300x300mm large heated bed pcb that no matter how many binder clips I use with it and the borosilicate glass on top that it still dips in the center. Since I am also using the PCB mounting holes for leveling, we’re a bit out of whack right now.

2

I agree, we need a better solution. Is your PCB on the air or it sits on top let’s say alum?

3

It is in the air, and there is no aluminum.
The PCB is held up by the leveling springs at the edges so it dips in the center a lot. And the glass is on top of it.

4

Cut a piece of MDF and sandwich the PCB.

5

@raykholo ​ I get you. I have the same issue. Sandwinch with a X format cutted MDF or alum to give space for cables and such maybe?

6

PCB sandwich sounds right up your alley Ray. I agree with the other guys.

7

When you are done, use a straight edge of something to make sure your glass is straight.

8

Any concerns about MDF at 60-80 C?

9

@raykholo Not likely, that not even boiling water. Can double check the MSDS though.

10

Maybe cover it with a heat resistant tape?

11

Or cork… But cork doesn’t do shit as an insulator.

12

@raykholo Too flexible.

13

Well, cork in between the MDF and PCB…

14

Fire retardant ply or what ever is called?

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@raykholo Ah. Yeah, or thin sheet of neoprene.

16

I am using MDF below the PCB without any issues. Works with ABS upto 110deg.

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Cool. And is anyone getting issues of the bed getting out of level due to MDF and moisture?

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Corrugated cardboard, like packing boxes are made from. Mine has a z shaped piece pushing the center up because of the distance above the plywood bed but yours will probably be different. Did a lot of experimentation back about 2012 and this worked out best and has been on it since. Double strength window glass on top, in swappable pieces, held with binder clips. Checked and leveled with a digital dual gauge to within the +/- 0.01 resolution of the gauge, never used autoleveling

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Have you thought about floating the glass on the PCB rather than clipping it? I use a silicone thermal heatsink between my glass bed and PCB without anything holding it in place. The tackiness of the thermal heatsink is more than enough to hold it down (it can sometimes be difficult to even get the glass to lift off of the silicone easily.) I use this: https://www.amazon.com/400mm-205mm-Silicone-Thermal-Heatsink/dp/B007PPEW52

Just food for thought.

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I use the method @Paul_Merry uses, works great, binder clips suck