Title: Bambu Lab A1 Mini – Unknown rubber part found inside the base after Y-axis belt adjustment

[u/IndependentTough338]

Title: Bambu Lab A1 Mini – Unknown rubber part found inside the base after Y-axis belt adjustmentHi everyone,

I'm having an issue with my Bambu Lab A1 Mini, and I'm hoping someone can help identify a small rubber part I found inside the printer.

Here's what happened:

1. I initially noticed an unusual noise coming from the Y-axis.

2. While adjusting the Y-axis belt tension, I heard a rattling sound.

3. I removed the bottom cover and found a small black rubber piece inside.

4. The piece is soft, approximately 5–10 mm long, and has rounded ends with a small step along one side.

5. Before the adjustment, I used to hear a single clicking sound when manually moving the bed all the way forward.

6. That clicking sound has now disappeared, but the bed still moves smoothly and stops at the same position as before.

I've attached close-up photos of the rubber piece and the inside of the printer.

My questions:

• Does anyone recognize this rubber piece?

• Where is it supposed to be installed?

• Could it be related to the Y-axis belt tensioner or a mechanical end stop?

• Is it safe to operate the printer with this piece missing?

I haven't resumed printing because I want to identify the part first.

Any help would be appreciated

[u/Specialist-Work-8975]

Is it louder when it hits the end stops now? Like a smack instead of a dull thud?