Hi John,
The customer doesn't like braces !! - ahh - when you don't know what you don't know. This frame as drawn is currently a hinged mechanism and hence is not a rigid frame.
Ideally timber frame structures should be mirror imaged and your drawing does not reflect this practice. Your current design will give rise to eccentric load distribution - not a good idea.
This is a very empty frame with no secondary load sharing paths to follow in the event of a joint failure.
A cross section is not a frame design - it's part of the design and hence I would respectfully suggest that you should make contact with a competent person who can help you produce a good working design.
Ken Hume P.Eng.
