The design I am using in this guide is for a very simple 42 inch bastard sword.
The guide presented here is fairly universal and can actually be used for any length of weapon between 18 and 60 inches simply by changing the dimensions.
For daggers (less than 18 inches) it is better to use a 6mm rather than 12mm former but the rest is identical.
For weapons above 60 inches in length a more substantial core is needed or they become too whippy.