Recently, I got my hands on a thermal camera from FLIR, model T420, and I thought about checking the uniformity of the heat on the bed. So I heat up the bed in three, most common for me, temps, waited for the system to stabilize and took the following three thermal pictures:
Set Temp 60C
Set Temp 80C
Set Temp 110C
And here is a digital picture of the assembly
On the thermal pictures, the crosshair pinpoints the coldest spot within the bracketed area, while the rainbow bar on the right of the photo describes the measured temperature range of the entire photo.
It’s obvious that the glass performs quite poorly with regard to the heat surface distribution, especially with the center, the top-left quadrant and all the corners.
I’m sure there are differences in the cameras used, but yours looks worse than the Taz in this one:
http://www.sd3d.com/not-all-heated-beds-are-created-equal/
A void where the power cord is going into the bed is normal, but your upper left corner should be more or less even with the others I would think.
I used a camera I borrowed from my job and it was recently calibrated. I understand that not every bed is the same even within the same product line.
But if you take a closer look at my thermals, you’ll see that at 60C, the temperature sd3d.com also used, the gradient is not that bad. All differences magnify as the set temperature increases, something that sd3d.com didn’t cover.
Since I only have one TAZ5, I can’t compare and know for sure whether my unit is the bad seed or not. But I do know that I should probably start looking for an aluminum bed plate, something that piercet has done successfully long time ago.
I did the same thing but didn’t post the pics (don’t know where they went actually). My bed was about the same. I think it contributes to my edge curling every now and again.
That’s very interesting to know. Thanks for confirming my findings Duncan. If others find the chance to do the same and this proves to be the norm rather than the exception, then I really think that Lulzbot should probably start looking for a metal heated bed instead of the glass.
