The blind mortises seem forgiving after you wrestle with the throughs!
My pet 'stop' is temporarily clamped on to help flush the tops.
The leg must be slid home on both tenons while flush to the tops.
blind-and-thru.jpg stop-gives-top.jpg
I aim to build my tenons so that they will slide home with light mallet taps,
and not fall out if inverted. (If dry winter shrinks them, I want to start big as possible)
Fitting all four sides at once can be time consuming and joy-murdering.
Having done a few, I figured out that fitting is best broken down into stages.
I fit the thickness into the mortise, but the tenon is still too wide to enter.
I have taken to tucking the tenon in diagonally as fit test.
Next the width is fit, with tenon tilted off axis---thus taking it's thickness out of the equation,
so we can get some work done.
fit-thickness.jpg fit-width.jpg
As you sneak up on a sweet fit, both thickness and width must slide in at once,
as well as both tenons at once.
both-must-fit-at-once.jpg
***my shiny new strategy***
Last time I built an m&t frame, I got struck with a bolt of insight.
Machining the blind tenons the same length as the through tenons would
be very helpful.
This keeps the crucial shoulder to shoulder length identical.
Such as when pinched between the legs at final assembly.
I struggled in the past to achieve that...due to different rail lengths.
Also, it really helps layout and fitting to have both tenons the same length.
The through tenon needs to be longer than the blind tenon.
This causes the finished rails to be different lengths.
If they are cut to those different lengths before machining the tenons,
you will have your hands full.....
and good luck making exact shoulder to shoulder fit.
continued