Switching between TPU and PETG filament on your Atomstack printer requires several steps to ensure a smooth transition and avoid damaging your printer or producing undesirable results. Here's a breakdown:

Before switching:

1. Check nozzle compatibility: Make sure your nozzle can handle the temperature range of both filaments. Most standard brass nozzles are suitable for both, but double-check the specifications.
2. Prepare your printer: Heat the nozzle to the TPU printing temperature (around 210-230°C). Feed through some TPU filament to purge any remaining PETG residue.
3. Prepare your PETG filament: Cut off the tip of the filament to ensure a clean feed.

Switching to PETG:

1. Increase nozzle temperature: Gradually increase the nozzle temperature to the recommended PETG range (around 230-250°C). Allow sufficient time for the nozzle to stabilize at the new temperature.
2. Filament change procedure: Follow your Atomstack printer's manual for the specific filament change procedure. It usually involves unloading the TPU filament, feeding the PETG filament, and purging excess material. Consult online resources or the manufacturer's website if you need additional guidance.

Printing with PETG:

1. Adjust settings: Ensure your slicer settings (print temperature, cooling fan speed, retraction, etc.) are appropriate for PETG. Refer to your specific PETG filament recommendations for optimal settings.
2. Monitor the print: Pay close attention to adhesion and warping, especially in the initial layers. Adjust bed temperature or other settings if necessary.

Switching back to TPU:

1. Decrease nozzle temperature: Gradually decrease the nozzle temperature to the recommended TPU range, following the same precautions as before.
2. Repeat filament change procedure: Unload the PETG filament and load the TPU filament, purging thoroughly to remove any remaining PETG.
3. Adjust settings: Ensure your slicer settings are back to the optimal values for TPU printing.

Additional tips:

• Consider using a dedicated nozzle for each filament to avoid temperature changes and potential clogging.
• You can perform a "cold pull" with nylon filament to remove any residual material after switching filaments.
• If you plan to frequently switch between filaments, a multi-material printer might be a better long-term investment.

Specific instructions for your Atomstack model:

Unfortunately, I need more information about your specific Atomstack model to provide more detailed instructions and troubleshooting tips. Knowing the exact model name will help me access the relevant resources and procedures.

Remember, safety is always paramount when working with 3D printers. Wear appropriate safety gear and follow your printer's manufacturer instructions carefully.