See how how I roped you in with "model"? "Click bait" I think the tech savvy boys call that.
Some discussion here lately on Cushing's knapping model, which I think has gone a bit askew. Again, for those interested, read it for yourself, about 10 pages in under "The making of arrows", :
http://onlinelibrary.wiley.com/doi/10.1525/aa.1895.8.4.02a00010/epdfCushing's model is clearly divided into two pieces: What happens at the quarry and what happens away from the quarry. At the quarry is the spalling and bifacing steps. Away from the quarry are the finishing, use and resharpening steps.
The focus to date has been on an interpretation of one of the finishing techniques. But, before that happens, you need a biface to finish. An impression has been given that the soft hammer direct percussion methods that are the mainstay of modern knapping fall outside of Cushings model. They very clearly do not. Per Cushing, the hammer stone derived spalls are then made into bifacial preforms using direct percusion on top of the knee or a padded stone using antler, bone or soft stone set in a "lightweight handle". He notes this is done ""with almost incredible rapidity", later claiming production of "seven finished knife and arrow blades in exactly 38 minutes". So basically Cushing says direct percusion on the leg, just like most of us do it, but he replaces the billet with a hammer type tool.
Hammer stone spall, raw Texas chert, piece from center of nodule, 95mm L by 85mm W by 23mm T.
Using the base of an elk spike antler lashed to a T shaped branch with rawhide to create a hammer like tool, then used for all flaking of this spall, 10 minutes later, 75mm L by 47mm W by 7.5mm
T:
Sample of flakes harvested for use as tools, 2 inches plus:
It is at this point I would switch to indirect percussion and/or pressure to finish the piece. However, I would stress for newer knappers, you absolutely do not need to push your preforms this far with direct percussion. Go as far as you feel comfortable with, then switch to indirect. Over time you will find yourself being able to go further and further with the direct, which mostly just saves time.
The idea behind Cushing's model is to send your best knappers to the quarry, let them make the "blanks" which everyone else can then relatively easily finish and use as needed. If I and 4 other "professional" preform makers went into the quarry with some young guys to quarry and spall, leaving the "pros" to biface, we could very easily make 120 quality, late stage bifaces and still only have to work 5 hours that day with a 20% failure rate. One trip for a day or two a month is a couple thousand bifaces with all kinds of time left for the other hundred things that needed to get done yesterday!
Keith