Bed temperature discrepancy

I happened across a YT vid testing the bed temps across different printers. What they discovered was that on all printers, the configured temps were hit on the bottom of the bed where the heater is but on the top of the bed where the filament is placed the temps were off.

I tested my P1S(P-Conv) as I was seeing PLA curling on the corners of prints. The default PLA bed temp is 65deg which the bed hits, again like others, only on the bottom. On top the bed temp was at 60deg.

I checked with a thermal cam and confirmed that the top bed temps are about 4-5 deg lower on the top of the bed.

I haven’t had a chance to test bumping that temp up to 70deg to see if it helps the print curl problem.

Just thought I would share this finding.

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It’s not the actual number that matters, it’s using a number that works in the same conditions as the test procedure.

I think the recommended bed temperatures are likely determined using printers with the temp sensor under the bed. If most printers have similar differences between top and bottom temps, using the indicated temperatures should give good results.

If the recommendations were derived using top-of-bed numbers, then you would want to match that number on the top of your bed.

That is pretty standard for 3D printers. You always have this, as you can not measure on top of the printbed. What is a bit worrying is the difference in the thermal image. Can you give more information about how much the temps differ on top of the print surface?

Regarding your curling: For PLA 60°C is already quite high.The glass temperature is in that range. I always print with lower bed temperatures, actually I mostly use the cold plate for PLA.

But just try using a brim to support these edges. That should fix it.

You can minimize the temperature difference by pre heating the bed with an enclosed printer.

As Woznik said, that’s pretty standard and can’t be changed, due to the laws of thermodynamics, w/o putting the temperature sensor where it would interfere with the print.

And, unless you have an industrial thermal cam that’s $300 or more, the accuracy is pretty crappy. Have actually run a test on them for work. All we look for with the cheaper ones is a hotspot, not an actual temperature, as they can be off by up to a few degrees. Don’t care what they claim the accuracy is. It’s hit or miss with each individual camera.

It’s the reason we use contact temperature sensors for important measurements when possible. (At 1200 C they die long before getting there. :laughing: :crazy_face: )

So? If 5 degree’s is going to mess up your print your settings are wrong, PS I print PLA at 35C, on the PEI plate, never a single issue

Great job , we had issues in the rear left corner with warping in other thread on was measured variations in the bed temp but not ideal and was not sure if it was the bed or some thermal issue in the left corner
I did tests with PLA 50C and ASA 110C both the same with PLA was able to solve it
Can you please bump it to 100C and take a few pictures lets say in the beginning and 5-10 minutes apart with more focus on the left rear quarter of the plate . It will be great to see the variation at start and how long it takes to become almost even or with in 2-4C variation or at least after first

Other wise i print PLA at 50C plate all the time

Great job , we had issues in the rear left corner with top layer print issues and small warping in other thread on was measured variations in the bed temp but not ideal and was not sure if it was the bed or some thermal issue in the left corner
I did tests with PLA 50C and ASA 110C both the same with PLA was able to solve it not ideal
Can you please bump it to 100C or 110C and take a few pictures lets say in the beginning and 5-10 minutes apart with more focus on the left rear quarter of the plate . It will be great to see the variation compare to center at start and how long it takes to become almost even or with in 2-4C

was not sure if it was the plate or some thermal cooling issue in the corner , but ASA is printed with no fans

Other wise i print PLA at 50C plate all the time