Free-space 3D printer
A technique for additive manufacturing that avoids the necessity of having a build plate. The illustrative embodiment comprises two anchor plates from which a structure is constructed that forms at least the initial support for the object to be manufactured. The envelope of the structure can be a cylinder, a box, an n-sided prism, a hyperboloid of one sheet, a cone, the frustum of a cone, a pyramid, and the frustum of a pyramid.
1. A machine comprising:
a first anchor plate that comprises f filament anchors labeled p(1,0) through p(1, f−1), wherein f is an odd positive integer;
a second anchor plate that comprises f filament anchors labeled p(2,0) through p(2, f−1);
a filament nest comprising a fiber-reinforced filament that is laced from filament anchor p(1,a) to filament anchor p(2,b) to filament anchor p(1,c); and
a deposition head configured to move between the first anchor plate and the second anchor plate, and to lace the fiber-reinforced filament from the first anchor plate to the second anchor plate to the first anchor plate;
wherein
b =( a+e )modulo f
and
c =( b+e )modulo f;
wherein a, b, and c are non-negative integers in the range 0≤a, b, c<f; and
wherein e is a positive integer such that e<f and e and f are relatively prime.
2. The machine of claim 1 further comprising a chassis for maintaining the relative spatial position of the first anchor plate relative to the second anchor plate and the fiber-reinforced filament under tension.
3. The machine of claim 1 further comprising a motor connected to the first anchor plate for varying the relative angular orientation of the first anchor plate to the second anchor plate.
4. The machine of claim 1 further comprising a tensioner connected to the chassis for controlling the tension of a filament looped between a filament anchor on the first anchor plate and a filament anchor on the second anchor plate.
5. The machine of claim 1 wherein the f filament anchors on the first anchor plate are arranged in a circle, spaced approximately
360
°
f
degrees apart, at radius R 1 ; and
wherein the f filament anchors on the second anchor plate are arranged in a circle, spaced approximately
360
°
f
degrees apart, at radius R 1 .
6. The machine of claim 1 wherein the f filament anchors on the first anchor plate are arranged in a circle, spaced approximately
360
°
f
degrees apart, at radius R 1 ; and
wherein the f filament anchors on the second anchor plate are arranged in a circle, spaced approximately
360
°
f
degrees apart, at radius R 2 ; and
wherein R 1 <R 2 .
7. The machine of claim 1 wherein the f filament anchors on the first anchor plate are arranged in a square having a diagonal of D 1 ; and
wherein the f filament anchors on the second anchor plate are arranged in a square having a diagonal of D 1 .
8. The machine of claim 1 wherein the f filament anchors on the first anchor plate are arranged in a square having a diagonal of D 1 ; and
wherein the f filament anchors on the second anchor plate are arranged in a square having a diagonal of D 2 ; and
wherein D 1 <D 2 .
9. The machine of claim 1 wherein filament anchor p(2,b) comprises a hook, and wherein the deposition head is further configured to loop the fiber-reinforced filament onto the hook.
10. The machine of claim 1 wherein the fiber-reinforced filament of the filament nest is further laced from filament anchor p(1,c) on the first anchor plate to filament anchor p(2,d) on the second anchor plate, wherein d=(c+e) modulo f.