Perimeters: more is better, an abstract

(please forgive any spelling or grammar errors)(i cant be the first person to think of this, but i will pass it along none the less)

So Ive been tinkering with perimeters in repetir and have learned a cool trick i'd like to pass along.
Ive learned through experience and trial and error to drastically decrease infill while majorly increasing the number perimeters.

thesis: for structural parts of reasonable thickness, a high perimeter number can be substituted for high infill in order to attain high strength parts at low weight.

this method of increasing strength is effective because it maximizes surface contact between lines of material where it is easiest. Think of the level of infill and number of perimeters as an investment. where you invest your filament will return a certain amount of strength based on amount of adhesion. notice in the picture the area shown for infill and the area of adhesion for perimeters. they are drastically different. perimeters return a much much higher amount of adhered surface area. The perimeters provide the absolute maximum surface area for adhesion not just for the other lines in this layer but to the shells in layers above and below. in the case of shells in the middle of the parim* they maybe completely enclosed by materiel. notice the middle shell in this picture it boasts 100% adhesion in 2 dimensions.



example param: 9 perimeters 10-15% infill
this print failed due to a jammed head however after i reprinted it, this prototype was used on the line at my company. it weighed very little and had strength comparable to injection molding. I wish i had more hard data on this subject but my lab will not let me toy around on personal projects to measure strengths.


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pros:
high strength
less material used
almost always water tight( didn't expect this, but tested with a cup of 6 perimeters)
faster, often people will opt to have perimeters print at a higher speed then infill. it tends to lay down well quickly. further more because you will be printing less lines, hence less time.
lighter

cons
not practical for small parts with very small thickness. its not that i does not work, but repiteir i've found commonly makes slicing errors that dont look good in tiny parts.
hollow feel, less dense this is another aesthetic drawback. I like a solid feeling part. on large parts particularly the low infill will give the part a low density. this is not a real problem it just tends to make the part feel cheap in some but not all cases.

take it ass you will. I use this method religiously.

constructive crit?
@tesseract
@Mike Kelly
@Printed Solid
@mark tomlinson