from the a-couple-of-extra-degrees-of-freedom dept.
Researchers Find a Faster, More Efficient Way to 3D Print:
Two researchers at Penn State have created a new system for five-axis additive 3D-printing that reduces the amount and density of support materials needed for making printed objects.
In a paper entitled "Process planning for five-axis support free additive manufacturing," doctoral candidates Xinyi Xiaoa and Sanjay Joshi proposed using a 3D printer with a movable build plate or extrusion arm to turn objects in 3D space as they're printed, thereby making every surface "flat" as its being extruded.
[...] The researcher's project focuses on a new predictive model for print preparation that makes it far faster to prepare objects for printing on a five-axis 3D printer.
"Using a five-axis deposition machine has the potential to build structures without the need for supports," the researchers wrote. "However, there is a lack of automated process planning software to support the full use of five-axis machines. [We introduce] an automated method that allows reorienting the part during the build using a five-axis machine."
Journal Reference:
Xinyi Xiaoa, Sanjay Joshi. Process planning for five-axis support free additive manufacturing [$], Additive Manufacturing (DOI: 10.1016/j.addma.2020.101569)
(Score: 1, Informative) by Anonymous Coward on Thursday January 07 2021, @01:36PM (4 children)
Though a dome or even an arch is very strong, 3D printing of them is very hard as the "2D process" of printing by approximating a curve by stepping squares makes part of the arch unprintable without supports. try bridging from one side to another in a curved line... the plastic is pulled striath and is out of place. Even support structures this printing can fail, since the curve is still not supported during the past.
I just spend two weeks on approximating a the curved under side of a dome with a series of barrel arches and legs / dams seperating them so it can be printed on the unseen inside with an extract supports. So the legs dams seprate the space in 10mm segements along the x axis then print an arch between two dams folling the general arch of dome messaured at lowest side of the dome. Hence a series of archs but each surface is fstraight / lat in both x and y axis. It works but the starting math is bad until getting into a routine. It looks ok but takes up more space and material. But at least I do not have use slicer routine to create it. IT would used 2x again as much martial to support the dome and print it from the bottom of object to top... 200mm up.
(Score: 2) by slinches on Thursday January 07 2021, @06:36PM (1 child)
I wonder how this would work with an actual dome? I can see how the examples shown can be sliced in nice clean ways to facilitate printing, but continuous 3D curvature like a dome would be trickier. Does it pick some different orientations and print it in segments or can it do a continuous manipulation of the print surface so the layers fall tangentially? Either way, there will be a point at the top where you can't fill the center due to lack of clearance to the print head.
(Score: 2) by ElizabethGreene on Thursday January 07 2021, @07:52PM
5-axis slicing and printing a dome would consist of placing the outer ring of the dome and then printing a continuous loop onto that ring at ever more shallow angles until your collision detection detected the printhead was too close to the printed work. At that point you'd bridge across the (hopefully small) remaining gap and print the remainder of the profile similar to how it's done on non-5-axis machines.
A better example of 5 axis slicing would be printing the revolution of a + sign. To print that you'd print the column first up to the base of the cross arm as in standard printing then rotate 90 degrees in one axis and print the first layer of the cross arm tangentially. With that done you could return to the normal orientation and print the remainder of the part. The lack of support material under the cross arm is the material savings.
I tried to write a 5 axis slicer once, and I found it was an exceptionally hard problem. If they've made substantial progress on it then good on them.
(Score: 2) by Username on Friday January 08 2021, @02:08AM (1 child)
Can't you just change the orientation of the part, or use a better fixture?
(Score: 0) by Anonymous Coward on Friday January 08 2021, @04:25AM
No the outside of the dome was other buddy’s com g out in in different directions. Think about trying to print the US Capital building upside down. It just leads to even more supports and material wastey
(Score: 2) by looorg on Thursday January 07 2021, @04:07PM (2 children)
How will less support material change the structure of it? As in will it become more brittle etc and will the structural integrity of the items change?. Is this the support material that you keep or is it the support material that you wash out -- as there are both kinds?
(Score: 0) by Anonymous Coward on Thursday January 07 2021, @04:46PM
The support material is just there for situations where the print wouldn't be connected to anything. For example If you wanted to print something with an overhang, you'd need to either lay it on it's side or use supports so that you're not printing into thin air. This has no impact on the ultimate strength of the print and such supports are typically removed immediately after completion of the print. They exist purely because the intermediate structure may be impossible due to overhangs or slopes that aren't steep enough to be maintained.
By adding those additional orientations, they can eliminate most of the support material leading to faster prints with less waste. I doubt this completely removes the supports, but it should drastically cut down on that waste.
(Score: 0) by Anonymous Coward on Thursday January 07 2021, @05:19PM
Think of the post that placed under a floor or bridge to hold it while poring the cement. Same Idea. Those posts are not needed after the bridge is built and will be removed. Same here.
Anothe way to look at it is print a "M" notice the center down point. since this is sliced along the Z-axis first (they way it is stacked up). The first few layers will have nothing under that point, so when the printer tries to print it.. it is just goo in air. a support or scaffolding is need to printed so the point can printed on top it.... then the rest of "M". Once done the "arms" of the "M" will hold it up. The scaffolding can be just tossed out.
(Score: 2) by takyon on Thursday January 07 2021, @05:01PM
https://spectrum.ieee.org/tech-talk/computing/hardware/xolography-printing [ieee.org]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 4, Insightful) by ElizabethGreene on Thursday January 07 2021, @07:40PM
Only a person with no regard for the intellectual property rights of others would choose to read this paper for free at https://scihubtw.tw/10.1016/j.addma.2020.101569 [scihubtw.tw] instead of paying the Dutch corporation Elsevier for the privilege of reading it. When considering this wholly immoral decision note that scientific paper authors pay Elsevier to host the papers and receive no financial benefit when you buy it.
(Score: 0) by Anonymous Coward on Thursday January 07 2021, @07:46PM (1 child)
Speaking as someone who 3d prints plastic and resin...
...good like calibrating that...or paying for the machine...
This will be a commercial-only tech for the foreseeable future.
(Score: 2) by ElizabethGreene on Thursday January 07 2021, @07:59PM
Adding 5 axis *hardware* to a small CNC mill is pretty cheap. Example: https://www.ebay.com/itm/CNC-Engraving-Machine-Rotary-Table-H-Style-A-Axis-B-Axis-4th-5th-Rotational-Axis/262408923307?hash=item3d18ca68ab:g:xr4AAOSwAolak3GX [ebay.com]
5-axis *software* (the stuff that turns a model into a toolpath) for a CNC mill is stunningly expensive. i.e. Fusion 360 has it for $500 per year and that is an absolute steal.
RhinoCam 5 axis was $10k last time I looked.
(Score: 0) by Anonymous Coward on Thursday January 07 2021, @08:44PM (2 children)
My brother is an engineer who works in the R&D department of a major company and uses million dollar 3D printers every day. He was telling me yesterday you can get machines with 2 printer heads that can print in two materials, one structural and one in a temporary support material, if needed. The support material can dissolve in hot water or something like a rice crispy that is easy to break off later. So it sounds like people are also solving the supports problem in different ways.
(Score: 0) by Anonymous Coward on Thursday January 07 2021, @09:19PM
There are multiple solutions:
1) scaffolding / supports - cost is extra material and time also slight imperfections since the two surfaces need to be VERY close and some time touch. Sanding can help clean it up
2) two heads with 2 materials - one being water solvable. Again extra material and time to print, Cleanup is quick - but two heads makes printing two colors or even opaque and translucence a lot more fun.
3) "laser" fused - large vat with "liquid plastic". makes nice surfaces but printing a "dot in space" requires bridging to another piece, then post print remove the connecting threads, so imperfections. sanding or other burn of can help.
This is now another solution - I am looking forward from changing from a "2D" plus layering of the head tracking, to something moves in a fully "3D" way.
(Score: 2) by ElizabethGreene on Saturday January 09 2021, @06:29PM
Dissolvable support material is a great solution, but it's expensive. e.g. $40 for a 500 gram roll of PVA. It's expensive enough that the smart way to use it is to print the bulk of the support material in your normal material and only the interfaces in PVA.
It dissolves in hot water, which is nice.
(Score: 2) by Username on Friday January 08 2021, @02:13AM (2 children)
Doesn't 5 axes 3d printers already have rotation in two directions? Are they different somehow with 4-6 axes CNC machines? Why is it axis instead of the plural axes?
(Score: 2) by mhajicek on Friday January 08 2021, @06:04AM
There have already been 5 axis hybrid additive/subtractive machines for years. Here's one from 2015:
https://youtu.be/oaIOrQi2HLM [youtu.be]
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 2) by martyb on Friday January 08 2021, @03:32PM
Fun with English. A child who is 5 years old is a 5-year old child. A man who is 6 feet tall is a 6-foot tall man. A sledgehammer that weighs 8 pounds is an 8-pound sledgehammer. A bottle of beer that contains 16 ounces is a 16-ounce beer. Drawing on a very ancient memory, I want to call $number-$unit an "adjective phrase", but I could be mistaken. Hope that helps!
Wit is intellect, dancing. I'm too old to act my age. Life is too important to take myself seriously.