diff --git a/src/main.rs b/src/main.rs
index 239f85c..80c3d40 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -23,9 +23,9 @@ const SUBSTEP_COUNT: u32 = 16;
 fn populate_particles(particles: &mut Vec<Rc<RefCell<Particle>>>, num: u32, cols: u32) {
     for i in 0..num {
         const OFFSET: u32 = 10;
-        let x_pos = (/* WIN_WIDTH/2 - cols/2*OFFSET */ 40 + OFFSET * (i % cols)) as f32;
-        let y_pos = (/* WIN_HEIGHT/2 - (num/cols)/2*OFFSET */ 40 + OFFSET * (i / cols)) as f32;
-        let immovable = i < cols;
+        let x_pos = (/* WIN_WIDTH/2 - cols/2*OFFSET */120 + OFFSET * (i % cols)) as f32;
+        let y_pos = (/* WIN_HEIGHT/2 - (num/cols)/2*OFFSET */40 + OFFSET * (i / cols)) as f32;
+        let immovable = i == 0 || i == cols - 1 || i == (cols / 2);
         let particle = Particle::new((x_pos, y_pos), immovable);
         particles.push(Rc::new(RefCell::new(particle)));
     }
@@ -119,7 +119,12 @@ fn draw_all(
 }
 
 fn main() -> SfResult<()> {
-    let mut window = RenderWindow::new((WIN_WIDTH, WIN_HEIGHT), "Verlet", Style::CLOSE, &Default::default())?;
+    let mut window = RenderWindow::new(
+        (WIN_WIDTH, WIN_HEIGHT),
+        "Verlet",
+        Style::CLOSE,
+        &Default::default(),
+    )?;
     window.set_framerate_limit(60);
 
     let mut clock = Clock::start()?;
@@ -170,21 +175,23 @@ fn main() -> SfResult<()> {
                 let dist_vec = mouse_coords - p_pos;
                 let dist = math::vec_len(dist_vec);
                 if dist < 40. {
-                    particle.borrow_mut().apply_force(mouse_vel * 8000.);
+                    particle.borrow_mut().apply_force(mouse_vel * 800.);
                 }
             }
         }
 
         let dt = clock.restart().as_seconds();
-        let substep_dt = dt/SUBSTEP_COUNT as f32;
-        
+        let substep_dt = dt / SUBSTEP_COUNT as f32;
+
+        //for _ in 0..SUBSTEP_COUNT {
+        apply_forces(&particles);
+        update_particles(&particles, dt);
         for _ in 0..SUBSTEP_COUNT {
-            apply_forces(&particles);
-            update_particles(&particles, substep_dt);
             solve_links(&mut links);
-            update_particle_derivatives(&particles, substep_dt);
-            update_positions(&mut circles, &particles);
         }
+        update_particle_derivatives(&particles, dt);
+        update_positions(&mut circles, &particles);
+        //}
 
         window.clear(Color::BLACK);
         draw_all(&mut window, &circles /* &lines */);