I'm sure there are plenty of other reasons, I take from it that...LancsRick":sslbtti9 said:I don't doubt you for a minute custard I just can't figure it out in my head! Unless the next board you put in upside down so Amy variance cancels out?
Its a project to show that one needs to have components that sit well on edge so you can apply this technique to assembling/marking out components with more accuracy.
I've also noticed the error at the top as is pictured as being more apparent when sitting on edge on bearers, simulating a wider panel, instead of just sitting the work on the bench, or a square against the face.
I've since ditched the titemark style marking gauge for this, (thicknessing tall stiles) and switched to a stainless steel analogue calipers instead just feeling around
and locking it at the lowest spot in the panel, instead of striking a line around the whole panel ...I've only being doing this on door stiles for the next while, but will use this technique in future.
I use the marking gauge for marking mortises now, but the calipers for marking the tenons, getting me within test fitting tolerances.
Another reason to get a nice low angle plane or a wooden try