# Heat bed inconsistent **URL:** \ **Category:** Snapmaker 2.0 (3-in-1)\ **Created:** [June 5, 2022, 1:57pm UTC](https://forum.snapmaker.com/t/heat-bed-inconsistent/26186 "2022-06-05T13:57:51Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![clewis](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.snapmaker.com/clewis/32/3255_2.png) [@clewis](https://forum.snapmaker.com/u/clewis)\ **Post date:** [June 7, 2022, 4:06pm UTC](https://forum.snapmaker.com/t/heat-bed-inconsistent/26186/4 "2022-06-07T16:06:20Z")
It’s easy to check how flat your bed is with a straight edge and a flashlight. Put the straightedge on the bed, and shine a flashlight from behind. Any light you see seeping under the straightedge is unevenness. People on the forums have spent some time manually correcting really bad beds. Two results I found searching the forums for “flatten”: > [@On achieving a perfect level](https://forum.snapmaker.com/t/on-achieving-a-perfect-level/5440/31): > > They were right about what I was able to estimate with the measurements on the calibration card. Comparing their M851.cpp file with the default Marlin 2.X one, they gutted a fair bit of the code. Theirs is 44lines (with the Marlin license header), and the stock on is 99 (with Marlin license header) Mainly they pulled out the parts that would let you see and set the X&Y offset. Since the module comes with a probe, it’s not super crucial. However, if someone wanted to change the probe type they… > [@Is a consistent first layer across whole of A350 build plate actually possible?](https://forum.snapmaker.com/t/is-a-consistent-first-layer-across-whole-of-a350-build-plate-actually-possible/20740/1): > > Now i have solved my sloping bed issues, I continue to try and get the first layer to be the same across the entire build plate. the image below shows where I perceive I am failing. this is the print held up to a screen to act as a light box. The source STL is [Bed Level Calibration Square Grid by wsreith - Thingiverse](https://www.thingiverse.com/thing:4894942) It is printed on a metallic PEI coated plate i purchased ages ago but have not used until today. This gives much better results than the black stock surfa… I’ve also heard that some people will preheat the bed, then quickly do a 5x5 calibration before the bed cools off too much. Although there was talk of the firmware preheating the bed before calibration rather than doing it cold. I haven’t kept up with that (I have an Original, so I only know about the 2.0 problems from reading the forum.) --- _[View the full topic](https://forum.snapmaker.com/t/heat-bed-inconsistent/26186)._