I have modified it, (hopefully) making all the gears interlocking and self-contained, eliminating the need for a hub/spokes assembly. I was originally using bearings between the spokes and gears. This is bad.
However, the interlocking nature of the gears requires the entire gearset be printed as an assembly, rather than individual parts. I know that this is a problem for those of you with a printer less than several thousand dollars. Sorry. I’ll put out a fix at some point.
WARNING: This has never been printed, and might not even work.
This would be very very difficult to print and clean IMHO, it would be a job for soluble supports, which i do not have ATM you could always pay a service to make it, but that gets expensive. (pay per cm3)
I wouldn’t say SLS is necessary, i would say that dissoluble/powder support would be, you could get it printed at shapeways or imaterialize, but it will be spendy (it would also be sls)
I also thing that you could snap this together after printing, if you are really good at those puzzle ball things ( there is enough flex in the plastic that it would let you bend it together)
Not only would it be possible to snap together after print. I doubt it would be stable enough to hold its own weight. I’ve had gear bearings fall apart from gear play in combination with flex in the grabbed outer gear.
Printability aside, I don’t see what is holding this thing together. Sure, any single gear is held by its neighbors but what keeps the sphere from just expanding (move all gears away from center) and falling apart? Is there some scaffolding I fail to see?
@Camerin_hahn probably but I still don’t see that it would work as intended (other than by mutual gravity in a flat gravitational field, but I am no astrophysicist…)
Each gear always has at least one tooth locked between each neighboring gears’ rings. The inner rings keeps all the years from sliding outward. At least, that’s the idea…
@Frank_Rey there are 6 sides to a cube and nothing constrains it tangentially. it is constrained on 5 sides out of 6, so it can grow in the 6th direction without anything stopping it
which side is not constrained in your eyes?
I see two But neither are issues.
I think we are confusing something here.
look up Six degrees of freedom it shows why space is usually represented as a six sided box
or …
A triangular pyramid has four sides and can be held in three dimensional space.
6 sides/degrees of restraint are not required to hold things in place. 4 sides of constraints from 6 degrees of motion means two degrees are unconstrained.
One of the two is the rotation about the radius of the whole sphere(or the orbit of the gear).
The other is the axial rotation of the gear about its center point .
The animation shows exactly that .
So you are not interested in someone attempting to print this anymore?
This thing reminds me of thePuzzles Downunder’s Puzzle Bank Ball.
“I live in 3 dimensional space and have 6 degrees of freedom, What about you ?”
If all gear edges pull away at the same rate (radial to each the gear), it is not constrained, this would result in a even growth in diameter. Each element is constrained if nothing else moved, however the rest of the elements can move, so as a whole the system is not constrained.
Ah, I just remembered what I was thinking when I made this.
The radius of curvature of the gears is constant. Initially, I planned to make the overlap of inner/outer rings significantly larger, so that the small gear was almost completely covered. This theoretically prevents radial expansion, truly making the gearset interlocking and self-containing.
Alas, I had the “bright” idea to shrink the overlap area so that the inner and outer rings of both gears would roll without slipping, making the motion of the gears significantly smoother (theoretically) and reducing friction.