Here's my problem:

In making corner posts for barbed wire fence I am using 4x9 steel posts spaced 8 foot. I need to set a diagonal 2" post for support between the two. It's always a 'hit and miss' on getting the right cope and angle between the two sizes and have wasted way too much pipe. How would the pros do this job? I've tried just using the good 'ol H configuration but it doesn't always hold up to tensioning. Certainly there has to be some sort of template one could use to get the copes right. If so any source ideas?
Your help is greatly appreciated.