diff --git a/main/config.hpp b/main/config.hpp
index 1a6c705..a4eb5d0 100644
--- a/main/config.hpp
+++ b/main/config.hpp
@@ -56,7 +56,8 @@ extern "C" {
 #define ENABLE_HALF_STEPS false  // Set to true to enable tracking of rotary encoder at half step resolution
 #define FLIP_DIRECTION    false  // Set to true to reverse the clockwise/counterclockwise sense
 
-#define MEASURING_ROLL_DIAMETER 44
+//#define MEASURING_ROLL_DIAMETER 44 //roll v2 glued
+#define MEASURING_ROLL_DIAMETER 86.6 //roll v3 large
 #define PI 3.14159265358979323846