Setting first layer height on an Elegoo Mars 2 Pro

I’m a fan of my new Mars 2 Pro, but the instructions booklet that came with it is… lacking. In this post I attempt to expound on the process for setting the first layer height.

Step 1 – Loosen the build plate!

This is it: the most important step. If you accidentally forget to loosen the set-screws on the build plate, it can potentially crack your LCD. (This is less likely if you’ve previously done the first layer height adjustment, but still…)

Loosen the two hex bolts on the side and front of the build plate mount:

Wiggle the plate to make sure it’s free, and line it up as best possible with the printer.

If the plate is too close to the LCD screen or vat for comfort, raise it by using the front touchscreen.

Tap “Tools”

Then “Manual”

Finally select “10.00mm” and click the “Up” arrow to raise the bed by 1 centimeter.

Step 2 – Remove the resin vat

Another important one: undo the two thumb screws and set the resin vat aside.

My vat has a 3D printed cover on it, yours may not look the same.

Step 3 – Clean the printer!

Once the resin vat is removed, make sure both the build plate and LCD “UV / Printing” screen on the Mars are clean. I recommend cleaning gently with an isopropyl (IPA) wipe, or IPA on a paper towel. Dry thoroughly.

I use these 70/30 wipes pictured on the right hand side below. They aren’t amazing, but they do leave less lint than a paper towel.

Step 4 – Arrange a piece of paper on LCD

Take a piece of regular printer paper and cut it so that it fits between the vat mounts on the printer. Place it on top of the “UV / Printing” LCD screen.

Step 5 – Home the printer

It’s time for the moment of truth! I hold the piece of paper with one hand, and hit the Home button on the front “UI” LCD screen with the other. The printer build plate will slowly lower until the Z-stop limit switch is activated.

From the main menu screen of the printer, click: “Tools” -> “Manual” -> and then the “Home icon” button.

Step 6 – Tighten the build plate

I like to wiggle the build plate a little to make sure it’s sitting flat and even on the paper and LCD panel. Then I hold it with one hand and tighten the two hex bolts with the other. I snug the bolts down pretty tight, but I doubt it’s necessary.

Step 7 – Adjust the first layer height

Now that the build plate is secure, it’s time to set the layer height.

Without changing anything yet: if you’ve tightened the build plate properly, you should be able to tug a little on the paper and it won’t move. Pretend you’re trying to pull it out from under a textbook, not a whole lot of force.

  • If the paper didn’t move at all: continue reading!
  • If it moves freely (no resistance) then go back to the top of this post and try re-homing.
  • If it moved with a little bit of friction, continue below but skip the first “Up” button press.

In the “Tools” -> “Manual” menu screen, select “0.10mm” as the distance. Every time you press the up or down arrows the build plate will move by that much.

Tap the “Up” arrow button once. If you listen closely you should hear a faint “blip” as the Z-axis motor turns a fraction of a rotation.

Give the paper another small tug. You are looking for it to slide with a little friction, and also slide backwards by pushing near the front (like in the video below), but folds into waves and doesn’t move backwards while holding further away. Use the “Up” and “Down” buttons to adjust until the resistance is right, then continue to the next step!

On my printer I usually have to hit the “Up” arrow twice to get the right amount of paper resistance. I recommend erring on the side of too low than too high.

Step 8 – Save the first layer height

Here’s where the Mars’s UI lets us down, it’s easy to forget to actually save this height we’ve spent so much time hunting!

Tap the “Back” button to return to the “Tools” menu:

Tap the “Set Z=0” button to save the current height:

Tap “Confirm” to commit the save:

That’s it! You’re done!

Go print something 🙂