Answered Leveling the print bed of a C2 printer

Update: In the Projects area, you will find more information relating to this message.

After looking at various posts to this forum, I have noticed that folks are having printing issues which can be traced back to bed leveling. This procedure probably will work for the R2 printer as well.

This article will attempt to answer the question of "How do I know that my print bed is truly level?"

The basics: The Z-Offset and Fine Tune Z-Offset wizards

Tools: a sheet of Avery 5160 labels (for shimming), a sheet of 20 weight copier / laser printer paper (height gauge), scissors, (optional: a digital micrometer to measure the extremely fine distances)

With a scissors, cut a 2 inch by 4 inch (50mm by 100mm) piece from the 20 weight paper. This piece will become your height gauge. It should be 0.1 mm thick. You can verify this measurement by using a digital micrometer.
The Avery 5160 labels will be your shim material for correcting the tilt in the print bed. Just cut a label in half to get 2 patches.

Procedure:

STEP1)

Tap the control screen: Utilities -> Wizards and start the Z-Offset wizard



Lay the paper height gauge on the print bed.


Gently move the paper side to side keeping the paper under the nozzle. Note how easy the paper slides.

On the touch screen, the height button defaults to 0.1 mm. Tap the button and change the height to 0.2 mm. Keep tapping the Z+ button to close the gap between the nozzle and the paper. When the gap appears to be very small, tap the height button and set the height to 0.05 mm.

Next, slide the paper just a small amount. You are testing for resistance while trying to move the paper. Tap the Z+ button and then test the gap for resistance by sliding the paper. Tap & slide, tap& slide, etc. until you feel the paper being grabbed by the nozzle.
At this point, tap the Z- button to lower the print bed. Test for resistance by sliding the paper.

You will reach a height where the paper slides easy, you use the Z+ button and the paper feels like it is dragging on the bed. Use the Z- button and the resistance disappears.

The height where the paper drags is the correct height. Tap the Done button and save this height adjustment. Write down the height printed on the screen (like -13.6 mm as an example)

STEP2)

Load in a brightly colored filament using the Utilities -> Filament Load wizard and follow the directions on the screen.

STEP3)

Start the Fine Tune Z-Offset wizard and follow the directions on the screen. An Instructions page will be shown. For the "Bed is too high" example, when viewed from the top, that filament will appear to be almost transparent and extra wide. For the "Bed is too low" example, when viewed from the top, the filament will appear to be narrow.



Advance to the adjustment screen by tapping the arrow in the upper right screen.



The upper right of the screen is a triple dash icon. That icon is for the Options page as shown below.


Tap the Test Offset button and lay down a line of filament. Tap the Options icon and tap the Switch to other corner option. Then tap the Test Offset button again.

If the print bed is not truly level you might get two lines looking like this next image>



Note how the left line is wider than the right line of filament. In this example, the right side of the print bed to lower than the left side of the print bed. Ideally, both lines of filaments will be the same width. As you can clearly see, this is not the case. If the lines are even in width, then skip the Shimming section and proceed with the Adjustment section.

Shimming:

Using the Avery labels, add one layer of labels to the magnetic posts as shown below.



Set the print bed back in place and start over at Step3. Repeat as necessary to get two filaments to be the same width.

Adjustment:

At this point, you have cleared all of the filament from the print bed using the Options page. (within the Fine Adjustment Z-Offset menu).

Tap the Test Offset button and print some lines of filament. The width of the filaments should look like these:



If the bed is too high, the filaments will be wider and more transparent (thinner filament). If the bed is too low, then the filaments will look much thinner (and taller).

Repetition here: Pick a direction to adjust the bed height based on the filament width. Tap the Bed Up or Bed Down buttons and adjust the bed height. Tap the Test Offset button and print a line. Check it against the previous line and adjust up or down. Then print another line. Check it for proper width. Then repeat as needed.

Once you have the height where you are happy with it, clear the bed of filament (via Options). Tap the Switch to circles mode (via Options)

With a cleared print bed, tap the Test Offset button and print several circles. Check the circles for uniformity (see below):



And with that, you are finished!! Congratulations on leveling the print bed. Tap the Options icon and then "Save and Exit" to finish the procedure.