//Code modofied by Jeff Jacob
//Original code (and strange variable names) by unknown.

function sprocket_speed_ratio_1(form) {
   drvspeed=form.drvspeed.value;
   ddiam=form.ddiam.value;
   dspeed=form.dspeed.value;
   drvdiam=Math.round(dspeed*ddiam/drvspeed*10)/10
   form.drvdiam.value=drvdiam;
   }

   
function sprocket_speed_ratio_2(form) {
   drvdiam=form.drvdiam.value;
   ddiam=form.ddiam.value;
   dspeed=form.dspeed.value;
   drvspeed=Math.round(dspeed*ddiam/drvdiam)
   form.drvspeed.value=drvspeed;
   }
   
function sprocket_speed_ratio_3(form) {
   drvdiam=form.drvdiam.value;
   drvspeed=form.drvspeed.value;
   dspeed=form.dspeed.value;
   ddiam=Math.round(drvspeed*drvdiam/dspeed*10)/10
   form.ddiam.value=ddiam;
   }
   
function sprocket_speed_ratio_4(form) {
   drvdiam=form.drvdiam.value;
   drvspeed=form.drvspeed.value;
   ddiam=form.ddiam.value;
   dspeed=Math.round(drvspeed*drvdiam/ddiam);
   form.dspeed.value=dspeed;
}



function length_of_vbelt(form) {
   d=parseFloat(form.OPdiam.value);
   D=parseFloat(form.LPdiam.value);
   c=parseFloat(form.centerdistance.value);
   var L=2*c+1.57*(D+d)+Math.pow((D-d),2)/(4*c);
   form.vblength.value=Math.round(L*100)/100;
   }
   
function push_pull_cyl(form) {
   d=form.rod.value;
   p=form.psi.value;
   D=form.bore.value;
   pi=3.14159;
   R=Math.round(p*pi*D*D/4);
   r=Math.round(p*pi/4*(D*D-d*d));
   form.push.value=R;
   form.pull.value=r;
 }   

 
 function push_pull_cyla(form) {
   d=form.rod.value;
   p=form.psi.value;
   D=form.bore.value;
   degree=form.angle.value;

   pi=3.14159;
   factor=Math.sin((degree*Math.PI)/180);
   R=Math.round(factor*p*pi*D*D/4);
   r=Math.round(factor*p*pi/4*(D*D-d*d));
   form.push.value=R;
   form.pull.value=r;
   }
   
   
function speed_of_cyl(form) {
   d=form.rod.value;
   s=form.stroke.value;
   D=form.bore.value;
   G=form.gpm.value;
   p=G*3.85
 
   pi=3.14159;
   R=Math.round(p*10/(pi*D*D/4))/10;
   r=Math.round(p*10/(pi/4*(D*D-d*d)))/10;
   form.extspeed.value = R;
   form.retractspeed.value = r

   et=Math.round(form.stroke.value/R*10)/10;
   rt=Math.round(form.stroke.value/r*10)/10;
   ct=Math.round((et+rt)*100)/100; //I'm fairly certian that this is wrong as it is a negative time.
   form.extendtime.value= et;
   form.retracttime.value=rt;
   form.cycletime.value= ct;
 }
  
 function displacement(form) {
   GearCtoC=form.GearCtoC.value;
   GearWidth=form.GearWidth.value;
   GearOD=form.GearOD.value;
   drvdiam=Math.round(((GearWidth*GearCtoC)*(GearOD-GearCtoC)/70*1200)*10)/10
   form.Disp.value=drvdiam;
   }
   
 function horsepower(form) {
   d=form.eff.value/100;
   p=form.psi.value;
   D=form.gpm.value;
   r=1714;
   R=Math.round(D*p*d/r*10)/10;
   form.hpower.value=R
   }
   
function capacityr(form) {
   d=form.ht.value;
   p=form.width.value;
   D=form.length.value;
   R=Math.round(D*p*d);
   r=Math.round((R/231)*100)/100;
   form.rcci.value=R;
   form.rcg.value=r;
   }
   
   
function capacityc(form) {
   p=form.length.value;
   D=form.diam.value;
   pi=3.14159;
   R=Math.round(p*pi*D*D/4);
   r=Math.round((R/231)*100)/100;
   form.rcci.value=R;
   form.rcg.value=r;
   }
   
   
function vehicle_speed(form) {
   d=form.rpm.value;
   D=form.od.value;
   pi=3.14159;
   R=Math.round(d*pi*D/12);
   r=Math.round(R*60/5280);
   form.vsfm.value=R;
   form.vsmph.value=r;
   }