X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=blobdiff_plain;f=rocket.scad;h=23594977fbc513f9738af15b5e91d9a98ca1fc3b;hb=HEAD;hp=bc763e947cfba8b7996f5705abd54470c73a2a76;hpb=e56fd7c0dba21d55347cb95a26ec2d2bd17ca27d;p=things.git

diff --git a/rocket.scad b/rocket.scad
index bc763e9..2359497 100644
--- a/rocket.scad
+++ b/rocket.scad
@@ -2,23 +2,55 @@
 // The Estes A8-3 and C6-7 motors have diameter of 17.7 mm,
 // length 69.5 mm. The Estes Alpha launch pad has rod diameter 3.4 mm.
 
-motor_diam = 17.7 + 0.5; // add some tolerance
+motor_diam = 17.7 + 1.2; // add some tolerance
 motor_len  = 69.5 + 0.5;
-motor_wall = 2;
 
 segment_overlap = 15;
 
-thin_wall = 0.9; // depends on the print width
-thick_wall = 2.2*thin_wall;
+loose_fit_diam_diff = 1.1; // cylinder with outer diameter d1
+	// will fit loosely into the hole with inner diameter
+	// d1 + loose_fit_diam_diff
+tight_fit_diam_diff = 0.4; // cylinder with outer diameter d1
+	// will fit tightly into the hole with inner diameter
+	// d1 + tight_fit_diam_diff
 
-clip_spring_angle = 45;
-clip_spring_depth = 20;
+thin_wall = 1.0; // depends on the print width
+thick_wall = 2*thin_wall + loose_fit_diam_diff/2;
+	// motor_diam + 2*thick_wall is the outer diameter of the rocket
+motor_wall = thick_wall; // above the motor
 
-rod_diam = 4;
+clip_height = 3.5;
+clip_width = 1.2;
+clip_clearance = 1.0;
+clip_inner_space = motor_diam/2 - 1.5;
+
+rod_diam = 3.4 + 1;
 rubber_beam_height = 3;
+rubber_beam_width = 1.5;
+
+fin_thickness = 1.5;
 
 eps = 0.01;
-infty = 1000;
+infty = 250;
+
+// rod holder
+
+module rod_holder() {
+	// rod hole holder
+	hull() {
+		translate([motor_diam/2 + thick_wall + thin_wall + rod_diam/2, 0, 0])
+			cylinder(r = rod_diam/2 + thin_wall, h = thick_wall);
+		translate([motor_diam/2 + thick_wall - thin_wall - rod_diam/2, 0, 0])
+				
+			cylinder(r = rod_diam/2 + thin_wall, h = 3*thick_wall);
+	}
+}
+
+module rod_hole() {
+	// rod hole
+	translate([motor_diam/2 + thick_wall + thin_wall + eps + rod_diam/2, 0, 0])
+		cylinder(r = rod_diam/2, h = infty);
+}
 
 //----------------- MOTOR MODULE -----------------------------
 
@@ -27,7 +59,7 @@ module fin() {
 		h2 = 20,	// far end height
 		h_off = motor_len, // height offset of the far height
 		w = 30, // distance of the far height
-		fin_w = thin_wall)
+		fin_w = fin_thickness)
 	translate([0, -fin_w/2, -h1])
 	hull() { 
 		cube([eps, fin_w, h1]); // near end
@@ -42,7 +74,7 @@ module fin2() {
 		w2 = 23,	// bottom/far end width
 		h_off = 60, // height offset of the far height
 		w = 30, // distance of the far height
-		fin_w = thin_wall)
+		fin_w = fin_thickness)
 	translate([0, -fin_w/2, -h1])
 	hull() { 
 		cube([eps, fin_w, h1]); // near end
@@ -51,49 +83,32 @@ module fin2() {
 	};
 };
 
-rod_hole_height = 15;
+rod_hole_height = 20;
 rod_hole_side = 1.5*(rod_diam + thin_wall);
 
 module motor_module_solid()
 {
-	// the lowest part is for joining the segments
-	cylinder(r = motor_diam/2 + thin_wall, h = segment_overlap + eps);
+	// cone from loose_fit to tight fit, 1/3 of segment overlap
+	cylinder(r1 = motor_diam/2 + thin_wall,
+		r2 = motor_diam/2 + thick_wall - thin_wall - tight_fit_diam_diff/2,
+		h = segment_overlap/3 + eps);
+
+	// tight fit cylinder, 2/3 of segment overlap
+	translate([0, 0, segment_overlap/3])
+		cylinder(r = motor_diam/2 + thick_wall - thin_wall - tight_fit_diam_diff/2,
+		h = 2*segment_overlap/3 + eps);
 
 	// conical joint between the two cylinders
 	translate([0, 0, segment_overlap - thick_wall + thin_wall])
-		cylinder(r1 = motor_diam/2 + thin_wall,
+		cylinder(r1 = motor_diam/2 + thick_wall - thin_wall - tight_fit_diam_diff/2,
 			r2 = motor_diam/2 + thick_wall,
 			h = thick_wall - thin_wall + eps);
 
-	// protrusions to hold the main tube in place
-	for (a = [60, 180, 300]) {
-		rotate([0, 0, a]) {
-			translate([motor_diam/2 + thick_wall - thin_wall/2 - thick_wall, 0, 0])
-				cylinder(r1 = thick_wall-thin_wall/2, r2 = thick_wall, h = segment_overlap/3 + eps);
-			translate([motor_diam/2 + thick_wall - thin_wall/2 - thick_wall, 0, segment_overlap/3])
-				cylinder(r = thick_wall, h = 2*segment_overlap/3 + eps);
-		};
-	};
-
 	// the thick cylinder above it
 	translate([0, 0, segment_overlap])
 		cylinder(r = motor_diam/2 + thick_wall,
 		h = motor_len + motor_wall - segment_overlap);
 
-	// clip spring
-	translate([0, 0, motor_len + motor_wall])
-		intersection() {
-			translate([motor_diam/2+6, infty/2, 4])
-			rotate([90, 0, 0])
-				cylinder(r = 8, h = infty);
-			cylinder(r = motor_diam/2 + thick_wall, h = infty);
-			rotate([0, 0, -clip_spring_angle/2+eps])
-				cube(infty);
-			rotate([0, 0, clip_spring_angle/2-eps])
-				scale([1, -1, 1])
-				cube([infty, infty, 8]);
-		};
-
 	// fins
         for (a = [60, 180, 300]) {
                 rotate([0, 0, a])
@@ -102,21 +117,20 @@ module motor_module_solid()
                         fin2();
         };
 
-	// rod hole holder
-	hull() {
-		translate([motor_diam/2 + thick_wall - rod_diam/2 - thin_wall,
-			0, segment_overlap])
-			scale([1, 1.4, 1])
-			cylinder(r = rod_diam/2 + thin_wall, h = eps);
-		translate([motor_diam/2 + thick_wall + rod_diam/2, 0, segment_overlap + rod_hole_side])
-			scale([1, 1.1, 1])
-			cylinder(r = rod_diam/2 + thin_wall, h = rod_hole_height);
-		translate([motor_diam/2 + thick_wall - rod_diam/2 - thin_wall,
-			0, segment_overlap + 2*rod_hole_side + rod_hole_height])
-			scale([1, 1.4, 1])
-			cylinder(r = rod_diam/2 + thin_wall, h = eps);
+	// motor clip
+	for (angle = [120, -120]) rotate([0, 0, angle]) intersection() {
+		translate([clip_inner_space, -infty/2,
+			motor_len + motor_wall + clip_clearance])
+			cube([clip_width, infty, clip_height]);
+		rotate([0, 0, -60])
+			translate([-infty/2, 0, 0]) cube(infty);
+		rotate([0, 0, -120])
+			translate([-infty/2, 0, 0]) cube(infty);
 	};
 
+	translate([0, 0, motor_len + motor_wall])
+		scale([1, 1, -1])
+		rod_holder();
 };
 	
 module motor_module() {
@@ -145,36 +159,22 @@ module motor_module() {
 					cylinder(r = 3, h = infty);
 		};
 
-		// clip spring
-		for (r = [-clip_spring_angle/2, clip_spring_angle/2]) {
-			rotate([0, 0, r])
-			translate([-thin_wall/2, 0, motor_len + motor_wall - clip_spring_depth])
-				cube([infty, thin_wall, infty]);
-		};
-		translate([0, 0, motor_len - eps])
-		intersection() {
-			cylinder(r = motor_diam/2,
-				h = thick_wall + 2*eps);
-			rotate([0, 0, -clip_spring_angle/2+eps])
-				cube(infty);
-			rotate([0, 0, clip_spring_angle/2-eps])
-				scale([1, -1, 1])
-				cube([infty, infty, 8]);
-		};
-		
-
-		// rod hole
-		translate([motor_diam/2 + thick_wall + eps + rod_diam/2, 0, 0])
-			cylinder(r = rod_diam/2, h = infty);
+		rod_hole();
 	};
 };
 
 // -------------------- CENTRAL TUBE ---------------------
 
-central_tube_h = 85;
+central_tube_h = 97;
+
+central_clip_r = 12;
+central_clip_w = 4;
+central_clip_wall = 1.5;
+central_clip_clearance = 2.5;
 
 module central_tube_solid() {
 	cylinder(r = motor_diam/2 + thick_wall, h = central_tube_h);
+	rod_holder();
 };
 
 module central_tube() {
@@ -183,13 +183,7 @@ module central_tube() {
 		translate([0, 0, -eps])
 			cylinder(r = motor_diam/2 + thick_wall - thin_wall,
 				h = infty);
-	};
-	// rubber band holder
-	intersection() {
-		cylinder(r = motor_diam/2 + thick_wall - eps, h = central_tube_h);
-		translate([motor_diam/2-thin_wall, -infty/2,
-			segment_overlap + thick_wall])
-			cube([thin_wall, infty, rubber_beam_height]);
+		rod_hole();
 	};
 };
 
@@ -218,7 +212,7 @@ module front_cone_body() {
 	translate([0, 0, segment_overlap])
 		bezier_cone([
 			[ 0, motor_diam/2 + thick_wall ], // start
-			[ cone_h/2, motor_diam/2 + thick_wall ], // cp 1
+			[ cone_h/4, motor_diam/2 + thick_wall ], // cp 1
 			[ cone_h - motor_diam/2 - thick_wall, motor_diam/2 + thick_wall ], // cp 2
 			[ cone_h, 0 ],
 		], 40);
@@ -238,7 +232,7 @@ module front_cone() {
 			translate([0, 0, segment_overlap])
 				bezier_cone([
 					[ 0.7*thin_wall, motor_diam/2 + thick_wall - thin_wall ], // start
-				[ cone_h/2-0.7*thin_wall, motor_diam/2 + thick_wall - thin_wall], // cp 1
+				[ cone_h/4-0.7*thin_wall, motor_diam/2 + thick_wall - thin_wall], // cp 1
 				[ cone_h - motor_diam/2 - thick_wall + thin_wall - 1.4*thin_wall, motor_diam/2 + thick_wall - thin_wall ], // cp 2
 				[ cone_h - 1.4*thin_wall, 0 ],
 			], 40);
@@ -254,37 +248,21 @@ module front_cone() {
 		translate([0, 0, -eps])
 			cylinder(r = motor_diam/2, h = segment_overlap + 2*eps);
 	};
-	// rubber band holder
-	intersection() {
-		cylinder(r = motor_diam/2 + thin_wall/2, h = segment_overlap);
-		translate([motor_diam/3-thin_wall/2, -infty/2,
-			segment_overlap/2 - rubber_beam_height/2])
-			cube([thin_wall, infty, rubber_beam_height]);
-	};
 };
 
-module thread_holder() {
-	rotate([0, 90, 0]) {
-		translate([0, 0, -1.5]) difference() {
-			cylinder(r = 10, h = 3);
-			translate([0, 0, -eps])
-				cylinder(r = 8, h = 3 + 2*eps);
-		};
-	};
-}
+debug = 0;
 
-// thread_holder();
-
-/*
+if (debug == 1) {
 // debug
-difference() {
-	// front_cone();
-	// central_tube();
+difference($fn = 16) {
+	front_cone();
+	central_tube();
 	motor_module();
 
-	translate([0, 0, -eps]) cube(infty);
+	translate([0, 0, -infty/2]) cube(infty);
 };
-*/
+
+} else {
 
 // production
 $fn = 128;
@@ -299,3 +277,5 @@ translate([motor_diam + thick_wall, 0, 0])
 rotate([0, 0, 240])
 translate([motor_diam + thick_wall, 0, 0])
 	front_cone();
+
+}