diff --git a/c2usb/cam/pcb.pl b/c2usb/cam/pcb.pl
index 291a3bf..31a75b3 100755
--- a/c2usb/cam/pcb.pl
+++ b/c2usb/cam/pcb.pl
@@ -1,7 +1,7 @@
 #!/usr/bin/perl
 
-$d = 2.54/1000*12;
-$r = $d/2+0.25;
+$d = 25.4/1000*35;
+$r = $d/2;
 
 
 sub orig