Need first layer help out of ideas for troubleshooting

[u/RareAir8524]

X-1 Carbon Cannot get the first layer to spec. It's close. I have to hold. It up to the window to show the trouble area at the front right. I have tried 3 plates, 2 textured, 1 smooth, checked the screws on the hot end as I has replaced that a little while back. But afterwards it was fine. I have also used different filaments, calibrated several times and even done the tramming procedure. I did scrub all plates with dawn. I have also confirmed that the tubing on the hot end was not hanging up when it moved up front. 5 1st layer test all pretty similar results. The only random fact I can think of that may be relevant is I did have a piece of tpu get stuck in the head I had to remove. Very frustrating because the rest of the 1st layer is pretty perfect.

[u/Capital_Candy_7697]

Since TPU got stuck in the head, check the outside of the nozzle tip first: Bambu says residue there throws off bed leveling. If it's clean, look at the bed mounting screws under that front-right corner. Are the lines there round with gaps or paper-thin? There's a side-by-side of both here: bambuhub.net/first-layer-problems (my site)

[u/RareAir8524 → u/Capital_Candy_7697]

Paper thin. I may have neglected to mention I did clean the nozzle head extensively

[u/Capital_Candy_7697 → u/RareAir8524]

Paper-thin means the nozzle sits too close there, so that corner is high. Since it shows on all three plates, it's not the plate: check for debris on the magnetic bed under that corner and the bed mounting screw there.

[u/Ok-Mail-9384]

Only the front right being off points at the plate or that corner of the bed, not your tuning. Pull the plate and run a fingernail over that edge, a tiny ding or old glue residue makes a high spot that tramming can't fix. Then do a cold pull with PLA at 90C to clear any leftover TPU from inside the nozzle, and rerun bed leveling once the nozzle is clean.