diff --git a/stepper.py b/stepper.py
index 5d8a426..544da71 100644
--- a/stepper.py
+++ b/stepper.py
@@ -43,12 +43,12 @@ class Stepper(EnvExperiment):
             delay(5*us)
 
         while True:
-            for i in range(full_range):
+            for i in range(used_range):
                 self.step_left.pulse(5*us)
                 delay(5*us)
             delay(50*ms)
 
-            for i in range(full_range):
+            for i in range(used_range):
                 self.step_right.pulse(5*us)
                 delay(5*us)
             delay(50*ms)