<p>I recently upgraded my Ender 3 Pro with a <a href="https://printermods.com/products/direct-drive-mod-for-creality-ender-3-cr-10" rel="nofollow noreferrer">direct drive kit</a>, primarily so I can print soft materials like TPU. I bought a spool of <a href="https://rads.stackoverflow.com/amzn/click/com/B07VBKDM74" rel="nofollow noreferrer" rel="nofollow noreferrer">Overture TPU</a> to try it out.</p>
<p>I'm getting really bad stringing on every print, to the point where it's pretty much unusable. This is my first time printing with TPU, so I'm at a loss for what to do.</p>
<p><strong>Direct Drive mod</strong> -
After modding the printer I did a few prints with PLA, and it works great with very little stringing. So I assume I assembled the mod correctly and that's not the issue.</p>
<p><strong>Material</strong> -
Reviews of the Overture TPU on Amazon mostly say it has low stringing and are generally positive, so I'm assuming it's not just bad filament.</p>
<p><strong>Temperature</strong> - The consensus in the Amazon reviews seems to be that 230°C is the sweet spot. I did a temperature tower from 205 °C to 230 °C by 5 °C, and the print quality and stringing was pretty much uniform throughout.</p>
<p><strong>Retraction</strong> - I tried with retraction off, then with 1 mm, 2 mm, and 6.5 mm, in various combinations with temperature and speed. Results varied in details, but all were pretty bad.</p>
<p><strong>Speed</strong> - I tried slowing down to 15 mm/s (from Cura's default of 50). Results got even worse.</p>
<p>Following are photos of a stringing test with various combinations of settings.</p>
<p><a href="https://i.stack.imgur.com/GF47t.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GF47t.jpg" alt="PLA - 205 °C - Layer thickness 0.2 mm - Retraction 1 mm" /></a>
PLA for reference - 205 °C - Layer thickness 0.2 mm - Retraction 1 mm</p>
<p><a href="https://i.stack.imgur.com/qBOOk.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qBOOk.jpg" alt="TPU - 205 °C - Layer thickness 0.2 mm - Retraction 2 mm - Print speed 15 mm/s" /></a>
TPU - 205 °C - Layer thickness 0.2 mm - Retraction 2 mm - Print speed 15 mm/s</p>
<p><a href="https://i.stack.imgur.com/vgTIt.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vgTIt.jpg" alt="TPU - 230 °C - Layer thickness 0.2 mm - Retraction 1 mm - Print speed 15 mm/s" /></a>
TPU - 230 °C - Layer thickness 0.2 mm - Retraction 1 mm - Print speed 15 mm/s</p>
<p><a href="https://i.stack.imgur.com/SygEx.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SygEx.jpg" alt="TPU - 230°C - Layer thickness 0.2 mm - Retraction 1 mm" /></a>
TPU - 230 °C - Layer thickness 0.2 mm - Retraction 1 mm</p>
<p><a href="https://i.stack.imgur.com/JLrgw.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JLrgw.jpg" alt="TPU - 230 °C - Layer thickness 0.2 mm - Retraction 2 mm" /></a>
TPU - 230 °C - Layer thickness 0.2 mm - Retraction 2 mm</p>
<p><a href="https://i.stack.imgur.com/LVlGv.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LVlGv.jpg" alt="TPU - 230 °C - Layer thickness 0.2 mm - Retraction 6.5 mm" /></a>
TPU - 230 °C - Layer thickness 0.2 mm - Retraction 6.5 mm</p>
<p><a href="https://i.stack.imgur.com/uwuMV.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uwuMV.jpg" alt="TPU - 230 °C - Layer thickness 0.12 mm - No retraction" /></a>
TPU - 230 °C - Layer thickness 0.12 mm - No retraction</p>
<p><a href="https://i.stack.imgur.com/lUOSK.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lUOSK.jpg" alt="TPU - 240 °C - Layer thickness 0.2 mm - No retraction" /></a>
TPU - 240 °C - Layer thickness 0.2 mm - No retraction</p>
<p>Is there something else I should try to reduce stringing? Is it possible that I just got a bad spool of TPU? Or is it more likely something's wrong with my printer?</p>

[{'answer_id': 14378, 'author': 'user77232', 'author_id': 12857, 'author_profile': 'https://3dprinting.stackexchange.com/users/12857', 'pm_score': 0, 'selected': False, 'text': '<ol>\n<li>Print it as a whole object</li>\n<li>Use 20% infill.</li>\n<li>Profit!</li>\n</ol>\n'}, {'answer_id': 14379, 'author': 'Rik', 'author_id': 16860, 'author_profile': 'https://3dprinting.stackexchange.com/users/16860', 'pm_score': 1, 'selected': False, 'text': "<p>That depends very much on what your goal is with the box. If it needs to be hollow and you don't need any access to the inside (and also prefer it to be printed in one piece) than the answer provided by user77232 would probably be the best.</p>\n<p>Alternatively, if you need access to the inside of the box you would probably be best off printing the box in two pieces. A box and a lid. This way you can print the box without support and also save on material that would otherwise be used as infill.</p>\n<p>The amount of light coming into your box also depends on the translucency of your material and brightness of the light source. To find the required wall thickness would be a matter of testing with the desired material.</p>\n"}]
['https://3dprinting.stackexchange.com/questions/14381', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/16902/']