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Difference between revisions of "Float switch"

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(added links to stl files.)
(v3 updated foot section to increase tolerance and socket to add inlet chamfer)
Line 4: Line 4:
The base is internally threaded.  The head needs nuts top and bottom.  Washers would be good too.
The base is internally threaded.  The head needs nuts top and bottom.  Washers would be good too.


[[File:Float-switch-head.stl]]
[[File:Float-switch-head.stl]] rendered on 5/1/2017


[[File:Float-switch-base.stl]]
[[File:Float-switch-base.stl]] rendered on 5/7/2017
 
stl files rendered on 5/1/2017


<pre>
<pre>
Line 29: Line 27:
nt=1;  //nut thickness, switch mounting nuts
nt=1;  //nut thickness, switch mounting nuts
thick=5;    //thickness
thick=5;    //thickness
fph=thick*3;//foot pillar height
eps=0.1;    //epsilon
eps=0.1;    //epsilon
tol=0.5;    //tolerance
tol=0.5;    //tolerance
Line 35: Line 32:
rod=25.4/4; //rod outer diameter
rod=25.4/4; //rod outer diameter
tpi=20;    //threads per inch
tpi=20;    //threads per inch
fph=25.4*5/tpi;//foot pillar height
bfw=ppbd+2*thick;  //base flange width
bfw=ppbd+2*thick;  //base flange width
$fn=40;  
$fn=40;  
Line 41: Line 39:
wr=4; //wrench size for nuts width across flats
wr=4; //wrench size for nuts width across flats
nh=1; //nut height, depth of nut sockets
nh=1; //nut height, depth of nut sockets
$fn=40;


//head
//head
Line 75: Line 72:


module socket(nd,tpi,tl,thick) {
module socket(nd,tpi,tl,thick) {
    //nd = nominal diameter
    //tpi = threads per inch
    //tl = thread length
     ror=nd/2;      //rod outer radius
     ror=nd/2;      //rod outer radius
     pitch=25.4/tpi; //thread pitch in mm
     pitch=25.4/tpi; //thread pitch in mm
Line 81: Line 81:
     sor=ror+thick;  //socket outer radius
     sor=ror+thick;  //socket outer radius
     vert= [for (ang=[0:360/$fn:720]) ang<=45 ? [cos(ang),sin(ang)]*rir : ang<180 ? [cos(ang),sin(ang)]*(rir+td*(ang-45)/135) : ang<=225 ? [cos(ang),sin(ang)]*ror : ang<360 ?[cos(ang),sin(ang)]*(rir+td*(360-ang)/135) : [cos(ang),sin(ang)]*sor];
     vert= [for (ang=[0:360/$fn:720]) ang<=45 ? [cos(ang),sin(ang)]*rir : ang<180 ? [cos(ang),sin(ang)]*(rir+td*(ang-45)/135) : ang<=225 ? [cos(ang),sin(ang)]*ror : ang<360 ?[cos(ang),sin(ang)]*(rir+td*(360-ang)/135) : [cos(ang),sin(ang)]*sor];
        path1=[for(p=[0:$fn]) mod(p,$fn) ];
    path1=[for(p=[0:$fn]) mod(p,$fn) ];
        path2=[for(p=[0:$fn]) mod(p,$fn)+$fn ];
    path2=[for(p=[0:$fn]) mod(p,$fn)+$fn ];
     linear_extrude(height=tl,center=false,convexivity=20,twist=tl/25.4*tpi*360){
     difference(){
    polygon(points=vert,paths=[path1,path2]);
        linear_extrude(height=tl,center=false,convexivity=20,twist=tl/25.4*tpi*360){
          
            polygon(points=vert,paths=[path1,path2]);
}
         }
        translate([0,0,tl-ror*tan(30)]) cylinder(r2=ror,r1=0,h=ror*tan(30));  //inlet chamfer
    }
}
}


//foot
//foot
Line 97: Line 98:
             for (angle=[45:90:315]){
             for (angle=[45:90:315]){
                 rotate([0,0,angle]){
                 rotate([0,0,angle]){
                     translate([ppbd/2+rod/2+tol,0,0]) socket(rod,tpi,fph,thick);  //pillar
                     translate([ppbd/2+rod/2+tol,0,thick]) socket(rod,tpi,fph,thick);  //pillar
                     translate([0,-thick,0]) cube([br-thick,thick*2,thick]); //leg
                     translate([0,-thick,0]) cube([br-thick,thick*2,thick]); //leg
                     translate([br-thick,0,0]) cylinder(r=thick,h=thick);    //foot
                     translate([br-thick,0,0]) cylinder(r=thick,h=thick);    //foot
Line 103: Line 104:
             }  //end for
             }  //end for
         }  //end union
         }  //end union
         translate([0,0,-eps/2]) cylinder(d=ppbd+tol,h=fph+eps); //ping pong ball entry
         translate([0,0,-eps/2]) cylinder(d=ppbd+tol,h=fph+eps+thick); //ping pong ball entry
     }  //end difference
     }  //end difference
}  //end foot module
}  //end foot module
   
 
head();
foot();
//head();
</pre>
</pre>


[[Category: CheapChineseLaser]]
[[Category: CheapChineseLaser]]

Revision as of 20:35, 7 May 2017

This is the source code for the float switch 3d printed parts for the water level detector for the Cheap Chinese Laser. It is made in two parts: the head and the base. You also need 4 pieces of 1/4-20 all thread to connect the two of them and 8 nuts. The base is internally threaded. The head needs nuts top and bottom. Washers would be good too.

File:Float-switch-head.stl rendered on 5/1/2017

File:Float-switch-base.stl rendered on 5/7/2017

/*
low water level detector
safety interlock for cheap Chinese laser at Hac DC
This water level detector is a two piece assembly connected by threaded rod.  This model uses 1/4-20 rod.  The lower foot has a 40mm home in the bottom to insert a pingpong ball as the float.
James Sullivan
4-30-17
Mk 2 - calculated threads
OpenSCAD version 2015.03-1 
*/
ppbd=40;    //ping pong ball diameter
ppbw=2.7;   //ping pong ball weight in grams
shd=2;  //switch hole diameter
shp=10; //switch hole pitch, i.e. center to center spacing of mounting holes on microswitch
wlh=200;    //water level height
sbw=6;  //switch body width
nfw=4;  //nut face width, switch mounting nuts
nt=1;   //nut thickness, switch mounting nuts
thick=5;    //thickness
eps=0.1;    //epsilon
tol=0.5;    //tolerance
br=50;      //base radius
rod=25.4/4; //rod outer diameter
tpi=20;     //threads per inch
fph=25.4*5/tpi;//foot pillar height
bfw=ppbd+2*thick;  //base flange width
$fn=40; 
function mod(num,den) = num - floor(num/den)*den; 
//dimensions taken from Front Door Switch Holder
wr=4;			//wrench size for nuts width across flats
nh=1;			//nut height, depth of nut sockets

//head
module head() {
    difference(){
        union(){
            for(angle=[45:90:315]){
                rotate([0,0,angle]) translate([ppbd/2+rod/2+tol,0,0]) cylinder(d=rod+thick*2,h=thick); //leg cylinders
            }
            cylinder(h=thick,r=ppbd/2+rod/2+tol-thick/2);
        }
        translate([0,0,-thick/2]) cylinder(h=thick*2,r=ppbd/2+rod/2+tol-3*thick/2);
        for(angle=[45:90:315]){
            rotate([0,0,angle]) translate([ppbd/2+rod/2+tol,0,-thick/2]) cylinder(d=rod,h=fph); //leg holes
        }
    }
    translate([sbw/2,(ppbd+rod+tol-2*thick)/(-2),0]) cube([thick,ppbd+rod+tol-2*thick,thick]);
    translate([sbw/2,shp/2,thick]) difference(){ //switch mounting block, aligned with z-plane and x-plane, centered on y-plane
        translate([0,-shp/2-nfw,0]) color("green") cube([thick,shp+2*nfw,2*nfw]);
        for (y=[-shp/2,shp/2]) {
            translate([thick/2,y,nfw]) rotate([0,90,0]) cylinder(d=shd,h=thick*2,center=true);    //screw holes
            translate([sbw-nh,y,nfw]) union(){  //nut sockets
                for (ang=[0,120,240]) rotate([ang,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
            }
        }
        translate([sbw/2+thick,bfw/2-nfw-shp,nfw]) union(){  //center nut socket
            cube([nh*2,wr,wr/sqrt(3)],center=true);
            rotate([120,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
            rotate([240,0,0]) cube([nh*2,wr,wr/sqrt(3)],center=true);
        }
    }
}

module socket(nd,tpi,tl,thick) {
    //nd = nominal diameter
    //tpi = threads per inch
    //tl = thread length
    ror=nd/2;       //rod outer radius
    pitch=25.4/tpi; //thread pitch in mm
    td=pitch*3/4;   //thread depth in mm
    rir=ror-td;     //rod inner radius
    sor=ror+thick;  //socket outer radius
    vert= [for (ang=[0:360/$fn:720]) ang<=45 ? [cos(ang),sin(ang)]*rir : ang<180 ? [cos(ang),sin(ang)]*(rir+td*(ang-45)/135) : ang<=225 ? [cos(ang),sin(ang)]*ror : ang<360 ?[cos(ang),sin(ang)]*(rir+td*(360-ang)/135) : [cos(ang),sin(ang)]*sor];
    path1=[for(p=[0:$fn]) mod(p,$fn) ];
    path2=[for(p=[0:$fn]) mod(p,$fn)+$fn ];
    difference(){
        linear_extrude(height=tl,center=false,convexivity=20,twist=tl/25.4*tpi*360){
            polygon(points=vert,paths=[path1,path2]);
        }
        translate([0,0,tl-ror*tan(30)]) cylinder(r2=ror,r1=0,h=ror*tan(30));  //inlet chamfer
    }
}

//foot
module foot(){
    difference(){
        union(){
            translate([0,0,thick/2]) cube([ppbd+2*thick,ppbd+2*thick,thick],center=true);
            for (angle=[45:90:315]){
                rotate([0,0,angle]){
                    translate([ppbd/2+rod/2+tol,0,thick]) socket(rod,tpi,fph,thick);  //pillar
                    translate([0,-thick,0]) cube([br-thick,thick*2,thick]); //leg
                    translate([br-thick,0,0]) cylinder(r=thick,h=thick);    //foot
                }  //end rotate
            }  //end for
        }  //end union
        translate([0,0,-eps/2]) cylinder(d=ppbd+tol,h=fph+eps+thick); //ping pong ball entry
    }   //end difference
}   //end foot module

foot();
//head();