<p>The most common way to install a glass bed (assuming it's literally a piece of borosilicate glass) is with binder clips. Glass <em>is</em> an insulator, so you may need to adjust your bed temps by a few degrees, and it will take somewhat longer to warm up.</p>

<p>You shouldn't need any firmware changes, but will need to adjust whatever z homing you do. If you have a limit switch currently, you'll need to move it by the thickness of the glass. If you have an inductive probe, it should still continue to work, but your z-offset will need to be adjusted. If you have BLTouch or a piezo, nothing should need to change there.</p>

CC BY-SA 4.0
2019-04-15T20:27:58.430Z
you might want to adjust the firmware a tiny bit in the heating behavior region though: the expected hysteresis of a bed with a glass sheet is flatter and you should run a PID tune.
Trish
CC BY-SA 4.0
2019-04-15T20:36:02.570Z
@Trish is that the case if you keep measuring temp at the bed heater? I'm surprised that you'd see noticeable performance changes with the addition of something outside of that system..
kolosy
CC BY-SA 4.0
2019-04-15T21:17:41.333Z
You can also tape the glass to the aluminium bed using kapton tape if you are concerned about hitting the binder clips.
0scar
CC BY-SA 4.0
2019-04-16T01:41:33.417Z
If you use clips and have exposed traces under your hotbed, cover the clips with insulating tape.
Davo
CC BY-SA 4.0
2019-04-16T13:08:02.280Z
@kolosy by increasing the mass of the heatbed (adding glass), one increases the total thermal capacity. This means, that the heat from the bed distributes onto the larger body: Comparing pre and post mod, the temperature curve of the modded bed is expected to be flatter and taking longer to heat to the same temperature. If you have a very trigger happy Thermal-Runaway-Protection with very narrowly designed heating curve, the slower heating behavior might trip it as it is outside of the expected curve.
Trish
CC BY-SA 4.0
2019-04-16T14:50:49.307Z
@Trish I agree that the system as a whole behaves the way you describe. However, if the thermocouple/thermistor is not moved from its original location, it will likely not see the difference.
kolosy
CC BY-SA 4.0
2019-04-18T13:26:54.197Z
I believe that heat loss to the ambient air would be more intense than if there's glass on top.
It shouldn't trigger thermal runaways, but you may want to PID tune anew if you notice any overshoot.
towe
CC BY-SA 4.0
2019-04-15T18:44:18.797Z
2019-04-15T18:44:18.797Z
kolosy
<p>I have an Anet A8 clone printer with a heated aluminum print bed. I'm considering purchasing a glass bed to add on top of the aluminum. When adding a glass bed on top:</p>

<ul>
<li>How would I go about installing the glass onto the aluminum bed? Is the major concern here just affixing it?</li>
<li>How do you adjust for the added thickness of the bed in the printer? Is this just through a limit switch adjustment or something firmware/software related?</li>
<li>How much do you adjust your heat (if at all)? Does it take a longer warm-up time due to having to heat the glass?</li>
</ul>

<heated-bed><anet-a8><glass-bed>
When installing a glass bed, what do you change?
Pᴀᴜʟsᴛᴇʀ2
# When installing a glass bed, what do you change?

(Asked by: username_0 on 2019-04-15)

I have an Anet A8 clone printer with a heated aluminum print bed. I'm considering purchasing a glass bed to add on top of the aluminum. When adding a glass bed on top:

* How would I go about installing the glass onto the aluminum bed? Is the major concern here just affixing it?
* How do you adjust for the added thickness of the bed in the printer? Is this just through a limit switch adjustment or something firmware/software related?
* How much do you adjust your heat (if at all)? Does it take a longer warm-up time due to having to heat the glass?

**Tags:** heated-bed, anet-a8, glass-bed


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## 1 answers

### Answer by username_1 on 2019-04-15. Score: 3 | Accepted answer

The most common way to install a glass bed (assuming it's literally a piece of borosilicate glass) is with binder clips. Glass *is* an insulator, so you may need to adjust your bed temps by a few degrees, and it will take somewhat longer to warm up.

You shouldn't need any firmware changes, but will need to adjust whatever z homing you do. If you have a limit switch currently, you'll need to move it by the thickness of the glass. If you have an inductive probe, it should still continue to work, but your z-offset will need to be adjusted. If you have BLTouch or a piezo, nothing should need to change there.

> **Comments:**
> **username_2**: you might want to adjust the firmware a tiny bit in the heating behavior region though: the expected hysteresis of a bed with a glass sheet is flatter and you should run a PID tune.  
> **username_1**: @username_2 is that the case if you keep measuring temp at the bed heater? I'm surprised that you'd see noticeable performance changes with the addition of something outside of that system..  
> **username_3**: You can also tape the glass to the aluminium bed using kapton tape if you are concerned about hitting the binder clips.  
> **username_4**: If you use clips and have exposed traces under your hotbed, cover the clips with insulating tape.  
> **username_2**: @username_1 by increasing the mass of the heatbed (adding glass), one increases the total thermal capacity. This means, that the heat from the bed distributes onto the larger body: Comparing pre and post mod, the temperature curve of the modded bed is expected to be flatter and taking longer to heat to the same temperature. If you have a very trigger happy Thermal-Runaway-Protection with very narrowly designed heating curve, the slower heating behavior might trip it as it is outside of the expected curve.  
> **username_1**: @username_2 I agree that the system as a whole behaves the way you describe. However, if the thermocouple/thermistor is not moved from its original location, it will likely not see the difference.  
> **username_5**: I believe that heat loss to the ambient air would be more intense than if there's glass on top. It shouldn't trigger thermal runaways, but you may want to PID tune anew if you notice any overshoot.  

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