<p>I've gone on quite a few sites (thingiverse, grabcad, etc) in search for a coiled tube, but I have yet to find anything suitable. There are a few coils ("springs") but no coiled tubes (i.e. the springs are hollow). Maybe my searching hasn't been good enough! But I was wondering if this is a limitation to 3D printing models? </p>

[{'answer_id': 4333, 'author': 'Tom van der Zanden', 'author_id': 26, 'author_profile': 'https://3dprinting.stackexchange.com/users/26', 'pm_score': 2, 'selected': False, 'text': '<p>No, this is not a limitation. You should be able to create a coiled tube in almost every 3D design software package. However, how to do this depends on the specific 3D design software in use.</p>\n\n<p>You\'d generally do so by creating a cross-sectional profile (i.e. a hollow circle) and then sweeping it along a helical path. Another option is to first create a spring/coil, and then hollow it out (some CAD packages have a tool/command for this, usually called "shell").</p>\n'}, {'answer_id': 4335, 'author': 'EvilTeach', 'author_id': 1397, 'author_profile': 'https://3dprinting.stackexchange.com/users/1397', 'pm_score': 2, 'selected': False, 'text': '<p><a href="https://i.stack.imgur.com/EWIOa.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EWIOa.jpg" alt="Openscad Proof of concept"></a></p>\n\n<pre><code>// Openscad proof of concept\n$fn=90;\n\nlinear_extrude(height = 50, center = true, convexity = 10, twist = -1000)\ntranslate([10, 0, 0])\n\ndifference()\n{\n    circle(r = 3);\n    circle(r = 2);\n}\n</code></pre>\n'}, {'answer_id': 4348, 'author': 'Mr. Meeseeks', 'author_id': 7657, 'author_profile': 'https://3dprinting.stackexchange.com/users/7657', 'pm_score': 4, 'selected': True, 'text': '<p>I managed to do it in the end using AutoDesk 123D.</p>\n\n<p><a href="https://i.stack.imgur.com/izeeR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/izeeR.png" alt="enter image description here"></a></p>\n\n<p>Did it by making two coils of differing radius, then subtracting the smaller from the larger. I made each coil using the instructions found here:</p>\n\n<p><div class="youtube-embed"><div>\r\n                <iframe width="640px" height="395px" src="https://www.youtube.com/embed/KfXV0mfy7XY?start=0"></iframe>\r\n            </div></div></p>\n\n<p>So there we go...</p>\n\n<p>Printed it out just now without supports - in the orientation shown - and it came out fine. Used a brim, though (don\'t want it rolling away!) </p>\n'}]
['https://3dprinting.stackexchange.com/questions/4332', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/7657/']