Onyx is way hotter in the center compared to the edges

[mcosman]

Is it normal for the Onyx to get significantly hotter in the center Vs the edges? Was I supposed to Soldier the Vias? or just cover them with Kapton. I checked the Instructions and I don't think I skipped any steps. Since the Thermistor is in the center it just never gets more than luke warm around the edge of a large print.

[dpmacri]

I think that's normal (or at least mine does the same thing). I think the problem is that the traces are spaced evenly in a linear fashion from center to edge, so a given square area has a smaller amount of total space near the outer edge than near the inner circle. I recall seeing something about a new design (perhaps with the Orion?). Ideally, the traces should be spaced such that they're further apart near the center to try to get a consistent trace coverage in any given area of the circle.

[Jimustanguitar]

The design on the Orion does address this. Hopefully the full size Max will get an update soon too.

Printing on an aluminum or copper plate would help even this out.

The other problem I see is that the thermistor is right in the center where every print with a solid bottom starts. I think this causes a false reading from the temp of the hotend that let's the bed heater cool a little and potentially warp/detach your part.

[cope413]

What I found helps a good amount to even out the heat is a sheet of aluminum foil under the glass.


BUT BEFORE YOU DO THIS - YOU MUST READ THIS CAVEAT

You MUST cover the traces on the Onyx with kapton (I believe Gene recommends this in his build manual) and you MUST cover the leads for the heated bed wires, resistor, and LED with kapton as well.

IF YOU DON'T, AND YOU PUT FOIL DOWN, YOU WILL SHORT IT OUT AND POTENTIALLY COST YOURSELF A GOOD AMOUNT OF MONEY AND TIME.

[626Pilot]

You mean the solder pads, right? The traces are all insulated. I've had a sheet of foil over mine for months. No short.

[mcosman]

Two layers of heavy foil helped this immensely. Of course I had already placed Kapton over everything during assembly. Thanks for the quick tip.