# 💡 Tutorial: Turn Your Snapmaker U1 into a Dedicated Filament Dryer (Firmware Bypass)

**URL:** <https://forum.snapmaker.com/t/tutorial-turn-your-snapmaker-u1-into-a-dedicated-filament-dryer-firmware-bypass/42677>\
**Category:** Tips & Guides\
**Created:** [July 27, 2026, 7:24am UTC](https://forum.snapmaker.com/t/tutorial-turn-your-snapmaker-u1-into-a-dedicated-filament-dryer-firmware-bypass/42677 "2026-07-27T07:24:48Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![chaicl](https://avatars.discourse-cdn.com/v4/letter/c/ecb155/32.png) [@chaicl](https://forum.snapmaker.com/u/chaicl)\
**Post date:** [July 27, 2026, 7:24am UTC](https://forum.snapmaker.com/t/tutorial-turn-your-snapmaker-u1-into-a-dedicated-filament-dryer-firmware-bypass/42677/1 "2026-07-27T07:24:48Z")

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Snapmaker officially recommends using the heated bed and a ventilated cardboard box to dry filament. However, if you try to run a raw `G4` timer script via USB to keep the bed hot, the U1’s firmware blocks it with a “Please Select Filament” error.

Here is the “Slicer Hijack” workaround to bypass the multi-toolhead gatekeeper and safely run drying cycles on the U1:

**The Setup (One-Time):**

1. In SnOrca, clone your U1 printer profile and name it **“U1 - Filament Dryer”**.

2. Delete everything in the **Machine end G-code** box so it is completely empty.

3. Replace everything in the **Machine start G-code** box with this exact script:

Plaintext

```auto
M140 S65 ; Heat bed to 65C (Change for different filaments)
M190 S65 ; Wait for bed to reach target
M104 S0 ; Keep nozzle cold
M106 S0 ; Keep part fan off
G4 P21600000 ; Dwell for 6 hours in milliseconds (Change as needed)
M140 S0 ; Turn off bed heater
M84 ; Disable stepper motors
M2 ; Terminate print job immediately

```

**How to Use It:**

1. Place your wet spool on the heated bed. _(Pro-tip: Elevate the spool on four small printed cubes to protect the plastic flanges from direct conductive heat and allow airflow)._

2. Cover the spool with a cardboard box (I used the box that had contained the 4 spools) that has a few small ventilation holes poked in the top.

3. In your new SnOrca dryer profile, add a dummy shape (like a Voron cube) to the build plate.

4. **The Trick:** Assign the dummy cube to a filament profile that is _currently loaded_ on your U1.

5. Slice and export to your USB drive.

When you run this file on the U1, the firmware sees a valid toolhead match, allows the job to start, runs your thermal timer, and immediately terminates the print safely via the `M2` command before the toolhead ever moves!

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<div class="post-metadata">

**Author:** ![chaicl](https://avatars.discourse-cdn.com/v4/letter/c/ecb155/32.png) [@chaicl](https://forum.snapmaker.com/u/chaicl)\
**Post date:** [July 27, 2026, 7:29am UTC](https://forum.snapmaker.com/t/tutorial-turn-your-snapmaker-u1-into-a-dedicated-filament-dryer-firmware-bypass/42677/2 "2026-07-27T07:29:41Z")

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Just found another method from [Rodrigo Sclosa](https://github.com/rodrigosclosa)

> **[GitHub - rodrigosclosa/snapmaker-u1-bed-filament-dryer-codes: Filament drying cycles for the Snapmaker U1 with...](https://github.com/rodrigosclosa/snapmaker-u1-bed-filament-dryer-codes?fbclid=IwY2xjawTT5rVwZG9mBWV4dG4DYWVtAjEwAGJyaWQRMTZXUmNuOEdlZDA2RXMweDFzcnRjBmFwcF9pZBAyMjIwMzkxNzg4MjAwODkyAAEegJ6nzRYoA2WJy4WSwrHggy1-7RZcdraO15GNsYmh1oqGB_hewcxzbAsNo6M_aem_NoF_i2sm5W2D5_VCDPO4oQ)**
>
> Filament drying cycles for the Snapmaker U1 with full status on the front screen — name, thumbnail, progress bar, bed temp and cancel button. Runs as a print job instead of a macro, so the stock touchscreen displays everything natively. PT-BR docs included.