$fn=50;

motorheight=42.1;
motorwidth=40.5;
wanddickemotor=3;
wanddickelinks=5.5;


cylinderdiameter=22.2;

motorholedistance=(motorheight-31) /2;
leftholedist=7;
M3HoleDiam=3.4;
M3HeadDiam=5.8;

difference() {
    mainbody();
    translate([motorwidth,wanddickelinks,0]) motorholes();
    leftholes();
}

//modules

module mainbody(){
    cube([motorwidth + wanddickemotor, wanddickelinks ,motorheight]);

translate([motorwidth,wanddickelinks,0])cube([wanddickemotor, motorheight, motorheight]);
    
    translate([motorwidth + wanddickemotor,motorheight * 2 /3,motorheight]) rotate([0,0,180]) linear_extrude(3) polygon([[0,0], [0, motorheight * 2 /3], [motorwidth * 2 /3, motorheight* 2 /3]]);
}

module motorholes(){  
    translate([0,motorheight/2,motorheight/2])rotate([0,90,0])cylinder(h=wanddickemotor, d=cylinderdiameter, $fn=130);
    
    translate([0,motorheight - motorholedistance,motorheight - motorholedistance]) MotorM3Hole();
    
    translate([0,motorheight - motorholedistance, motorholedistance]) MotorM3Hole();
    
    translate([0,motorholedistance,motorheight - motorholedistance]) MotorM3Hole();
    
    translate([0,motorholedistance, motorholedistance]) MotorM3Hole();
}

module leftholes() {
    // bottom left
    translate([leftholedist,0,leftholedist]) LeftM3Hole();
    //bottom right
    translate([motorwidth - leftholedist,0,leftholedist]) LeftM3Hole();
    // upper left
    translate([leftholedist,0,motorwidth - leftholedist]) LeftM3Hole();
    // upper right
    translate([motorwidth - leftholedist,0,motorwidth - leftholedist]) LeftM3Hole();
}


module MotorM3Hole() {
    rotate([0,90,0])cylinder(h=wanddickemotor, d=M3HoleDiam);
}

module LeftM3Hole() {
    rotate([270,0,0])cylinder(h=wanddickelinks, d=M3HoleDiam);
    translate([0,wanddickelinks-3,0]) rotate([270,0,0])cylinder(h=3, d=M3HeadDiam);
}