Heated Bed Temp Consistency

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Snapmaker 2.0
Original heated bed
2.0 Enclosure
Single extruder
Upgraded power supply
Upgraded linear modules

I see at least a 10 degree C difference depending on where I take a measurement using the grid line intersection points (20mm x 20mm squares) as targets and using a handheld heat measuring device (Micro Temp MT250). I found that the area in the center on X axis (160mm) but closer to the front on Y axis (50 to 70mm) is hottest and usually higher than the value I set. Testing to the left or right from there the temp decreases to a point where it can be 10 degrees (or more) lower as you get closer to the edges. Knowing this I have been able to move the object in Luban to an area of the print space that tends to present a more consistent temp across the base of the object or to an area that is consistently hotter for filaments that need it.

Is this consistent with design specs or product expectations?
Has anyone else measured their bed temps for consistency and did you find similar results?
Is there any plans to update the heating bed to allow for more consistency of temperature for the entire surface. I think heat consistency is having a large impact on my ability to print larger or more precise items since the first layer adhesion is not consistent over a 20mm x 20mm area.

[xchrisd]

Thermal imaging of Snapmaker A350

Out of curiosity I did some thermal imaging of my Snapmaker A350 while printing the test vase with Snapmaker filament and measured the heatbed temperature. [flir_20200213T190456] At the beginning of the print the surface was up to 46°C in the middle and about 30°C at the edges. [flir_20200213T190505] [flir_20200213T205413] While printing the first layer the surface was up to >47°C and stayed that way during the rest of the print. Next time I’ll see what temperatures the heated bed can get…

Thermal Images of 3D Print Bed

I needed a really weak excuse to buy an almost $400 thermal camera attachment for my phone, so I rationalized that taking some shots of my A350 print bed could help give clues to bad bed adhesion on the outer areas of the print bed. I found that the temp variation between the middle and outside parts of the bed is too small to matter, and therefore has nothing to do with my bed adhesion woes But now I have a thermal camera Here’s me heating the bed to 80°c withOUT th…

A350 Heatbed heat distribution

Because of some adhesion problems I was curious about the heat distribution of my A350. Following images are done by a Flir E4+ at 80° C heatbed temperature: Snapmaker A350 original printing mat: [image] [image] Printing on glas: [image] [image] The heatplate itself has some hot and cold spots: [image]

Search for Flir and you’ll get more.
If you have an enclosure printing big objects is fine.

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Although I have read many complaints from other users, I did have a few problems that happened early on. To take those problems out of the equation I ordered a new heated bed for my A350. After receiving/installing it yesterday, I have found that it is more consistent until you get out to the very far edge, last line, of the grid. It is 5 degrees or less different for the majority of the points where the grid lines cross and 10 degrees only on the very outside edge (last 10mm or so). These points are what I targeted for temperature measurement to help add control to my non-scientific experiment’s variables. I can also get things to adhere at more standard temps (55 for PLA instead of 65 or higher).

For what happened in the past:

I am sure I am not the only one whose heated bed cable was caught on the adjacent linear module during homing, or other moves, and was stretched.
That stretching will affect the flow of electrons through the cable and could also stress the connection from the cable to the heat element(s). I also had a nozzle strike very early on but only in the very front left corner. Z was too low, I believe this was a leveling failure that I was too green to understand or catch before it caused damage. I also did not have the emergency stop button yet. Lucky for me I was quick to hit the power switch limiting the damage, but it did move the build plate over and then gouged a nice line in the original heat bed. I am sure those items were contributing to my woes and maybe a source of some other people’s complaints without them realizing the stretch happened or damage it may cause.