Designing strong parts without too much material

Hello,

I would like to know if there are some documentations about designing strong parts without using too much ABS/PLA? I can see really nice parts arround, with flangs and other little stuffs in order to avoid flexion and so.

I guess it needs a good backgroud in this 'profession', but there are maybe some basic tips and tricks to avoid common mistakes...

Thanks,

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Frédéric

Could be a good idea to create a wiki page with the compilation of what you gather.

Here's some old paper I found (they do not use the same terms than in reprap but it is all quite self-explaining)

[citeseerx.ist.psu.edu]

Material Characterization of Fused Deposition Modeling (FDM) ABS by Designed Experiments Michael Montero1, Shad Roundy1, Dan Odell1, Sung-Hoon Ahn2 and Paul K. Wright1 2001

Also in: Rapid Prototyping Volume 8 · Number 4 · 2002 · pp. 248–257 q MCB UP Limited · ISSN 1355-2546 DOI 10.1108/13552540210441166

Conclusions of the study:

Rule 1. Build parts such that tensile loads will be carried axially along the fibers.
Rule 2. Stress concentrations associated witha radius can be misleading. If a radius area

will carry a load, building the radius with contours is probably best.

Rule 3. A negative airgap increases both strength and stiffness.
Rule 4. Shear strength between layers is greater than shear strength between roads.
Rule 5. Small bead width increases build time. Small bead width increases surface

quality. Wall thickness of the part should be an integer multiple of the bead width.

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Allen Teitelbaum's 2009 master thesis seems a good source too:

PROPOSED BUILD GUIDELINES FOR USE IN FUSED DEPOSITION MODELEING TO REDUCE BUILD TIME AND MATERIAL VOLUME


[drum.lib.umd.edu]

also (if you can get it)

Examining Potential Design Guidelines for Use in Fused Deposition Modeling to Reduce Build Time and Material Volume

Paper no. DETC2009-87491 pp. 73-82
doi:10.1115/DETC2009-87491
[scitation.aip.org]


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Then there's this project at Univ. Paderborn:

[dmrc.uni-paderborn.de]

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Hope this helps...

Edited 1 time(s). Last edit at 08/31/2011 04:48PM by Lanthan.

Thanks for the links!

In fact, I was first looking for more general design rules, like for parts made with other processes (injection, molding)...

I guess that FDM specific rules need a great skeinforge understanding, which is not my case!

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Frédéric

You may want to look up classes on light weight construction. Light weight construction isn't about using aluminium vs. steel, but about putting material only where it is needed. The Eiffel Tower in Paris is a nice example of light weight construction, even if it weights hundreds of tons.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

That's exactly what I'm looking for! Thanks for the trick.

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Frédéric