3D Printing: How thin can I make the wall of a pipe? (4 Solutions!)
Channel: Roel Van de Paar
Date: 2019-06-24

3D Printing: How thin can I make the wall of a pipe?


The Question: For a science project, I'm 3D-printing some custom pipes and tubes to regulate
the flow of gas (a combination of ethyl alcohol and water vapor) through an
apparatus. They need to be pretty small, as the entire experiment is designed
on a small scale. I'd also like the use a little filament as possible.
How thin can I make the walls of these pipes and tubes before either they
collapse or gas leaks out? I know that's possibly an engineering issue, but I'd
also need to take resolution into consideration. Ideally, the pipes would be
about two centimeters in diameter, possibly a little larger or a little smaller
in some parts. I'd most likely use ABS, but PLA is my backup in case there's
some unforeseen reaction between the gas and the pipes.
The printer I'm using is an FDM printer, a version of the MakerBot Replicator.

Solutions Sample (Please watch the whole video to see all solutions, in order of how many people found them helpful)

== This solution helped 10 people ==
The thinnest wall your printer can print is determined by its nozzle size, and
will be a little thicker than that nozzle size.
A great challenge when dealing with thin, hollow cylinders is that the cross-
section has very little surface area and it can delaminate easily, especially
if the tube is long.
You could try printing the tube with a very thick extrusion with, and using
only a single perimeter. That would give better gas-tightness and layer
adhesion than two, thinner perimeters, but it may turn out too fragile for your
application. In that case, you'll need to print additional perimeters. Sticking
to thicker extrusion widths would still be beneficial.
At a two centimeter diameter I'd say the single perimeter has a decent chance
of working if you handle them gingerly.

== This solution helped 6 people ==
The thinnest possible will be a single outline, so the best you can possibly do
is slightly larger than your nozzle size.
The biggest issues I see in terms of making a thin airtight tubes are:
 * Complex geometry: anywhere you have overhangs you may need to increase
 the wall thickness to ensure a sealed overlap. Bridging will need extra
 layers to ensure good layer adhesion and any supports will have to be
 removed carefully to not damage the surface.
 * Perimeter start/end: The joint where the perimeter starts/ends not only
 has to seal to the layer below but it has to seal with the now cooling
 start point. This could be especially problematic if all of your layers
 are started at the same point (which visually produces a vertical seam)
 because you don't have a smooth perimeter on the previous layer and any
 imperfections in the joint are compounded.
Thoughts:
 * Print on end where possible: You'll get a higher quality outer perimeter
 if your layers are full rings instead of printing up both sides of a pipe
 on its side.
 * If you can manage a single perimeter when printing on end try using the
 "spiral vase" setting, which will smoothly raise the z position and print
 as a spiral instead of printing discrete layers. This removes any issues
 related to sealing the start/end of a perimeter.
 * If you're printing with multiple perimeters increment the wall thickness
 in multiples of the nozzle size to ensure the perimeters are sealed
 together. Having the perimeters not bound together increases the chance
 of leaks and reduces stiffness.
 * Do the pipes have to have the same thickness all along them? You can
 probably reduce thickness to save material for simple geometry (straight
 sections) if you change thickness gently.

With thanks & praise to God, and with thanks to the many people who have made this project possible! | Content (except music & images) licensed under cc by-sa 3.0 | Music: https://www.bensound.com/royalty-free-music | Images: https://stocksnap.io/license & others | With thanks to user Tom van der Zanden (https://askubuntu.com/users/26), user mbmcavoy (https://askubuntu.com/users/5704), user HDE 226868 (https://askubuntu.com/users/61), user EvilTeach (https://askubuntu.com/users/1397), user 1337joe (https://askubuntu.com/users/17), and the Stack Exchange Network (https://3dprinting.stackexchange.com/questions/223). Trademarks are property of their respective owners. Disclaimer: All information is provided "AS IS" without warranty of any kind. You are responsible for your own actions. Please contact me if anything is amiss at Roel D.OT VandePaar A.T gmail.com.