Bambu Lab P1P/X1C full plate first layer test print

Another first layer test print.  This print makes use of as much of the bed area as possible, without having to disable the filament cutter standoff.  X1C users should print without the flow calibration pattern enabled. 

Useage 1:  

A simple printable pattern to check the function of the firmware ABL and identify problem spots on your bed or build surface. 

Usage 2 (more difficult - perform at your own risk! and watch the test pattern print, being ready to cancel the print if you get a nozzle collision):

Can be used to reveal low and high spots in the OE bed.  Bambu lab doesn't offer a mesh visualizer for the bed.  Beds are measured and a mesh of the applied correction is stored in the printers memory.  Turning off ABL when you print, simply instructs the printer to make use of the last measured bed mesh for the current print.

With some careful tuning and a known flat object (the size of your OE bed) you can use this test pattern to help locate high and low spots on the OE bed.  To do so you'll need to first tram and level the printer bed using a known flat object (a piece of glass, mirror, tooling plate, etc - cut to the size of the OE bed and verified to be flat). With the flat surface in place, follow the factory procedure to properly tram your bed (located in the bambu lab wiki). Download and add the 3D model to your slicer, center the print and setup to use the filament of your choice.  

Now, start a print WITH bed leveling active - once the printer completes the bed leveling process you may cancel the print - the new leveling mesh is stored to memory and is now based on your known flat build surface (ie. glass/mirror/or other verified flat surface).  Now remove the flat surface that the mesh was established on, install your build plate and print this model without ABL (bed leveling) activated.  The printer will use the mesh stored in memory for the flat surface it previously measured, but will be printing on top of the OE bed and build sheet.  If the OE bed is not as flat as the previously sampled surface the hills and valleys in your existing OE bed will present themselves.  A valley (or low spot) in the bed will show up as unconnected first layer lines, while a hill (or high spot) will show visible signs of scuffing.  

Photo Notes:  

The results are pretty interesting!  I performed the printing following the procedure under “Usage 2” above.  A known flat object (cast tooling plate, surfaced flat to within 0.002 inches across the plate) was sampled by the printer and a new bed leveling mesh established in memory. I then ran the test prints without ABL active for both the OE and OE+Correction beds.  The prints on the left were made with no corrections to the OE (factory) bed.  Warps in the bed (even those that ABL normally does a good job of correcting) are clearly spotted.  The print on the right was again printed with ABL turned off - but this time, the OE bed was corrected using the same piece of cast tooling plate, installed in the machine on top of the warped OE bed.