about scara joint 3 issue ...

int kinematicsForward(const double * joint,
                      EmcPose * world,
                      const KINEMATICS_FORWARD_FLAGS * fflags,
                      KINEMATICS_INVERSE_FLAGS * iflags)
{
    double a0, a1, a3;
    double x, y, z, c;

/* convert joint angles to radians for sin() and cos() */

    a0 = joint[0] * ( PM_PI / 180 );
    a1 = joint[1] * ( PM_PI / 180 );
    a3 = joint[3] * ( PM_PI / 180 );
/* convert angles into world coords */

    a1 = a1 + a0;
    a3 = a3 + a1;

    x = D2*cos(a0) + D4*cos(a1) + D6*cos(a3);
    y = D2*sin(a0) + D4*sin(a1) + D6*sin(a3);
    z = D1 + D3 - joint[2] - D5;
    /*c = a3;*/ /*(my kins without c=a3; .... standard kins with c=a3;)*/
	
    *iflags = 0;
    if (joint[1] < 90)
	*iflags = 1;
	
    world->tran.x = x;
    world->tran.y = y;
    world->tran.z = z;
    world->c = c * 180 / PM_PI;

const int yes_is_scara = 0;
const int no_isnt_scara = 1;
...
...
case  yes_is_scara:
the joint3 has a strange fluctuation of 2-6 degrees during the translation of only X and Y axes in TeleOp .... while it should look completely still than Cartesian system ...;
break;
case no_isnt_scara:
ooopss .... 
break;
default:
 break;