What is the blank die concept that you guys are talking about?
basicly it's the outside shape of the die with a nice flat & square bottom so it can be used with a Wilson die. There is no hole in the middle of the die blank, and it becomes the ram on an arbor press. No real advantage over a good arbor press, but just saves having t make room for one. Even better would have been an outside affair to save doing this. The idea takes off from the old Hood Press that would take 7/8-14 dies as well as Wilson dies. Love to have one, but ain't springing for the average price of $560!
Interestingly, I built a press of my own design about twelve years ago out of some scrap piece of a titanium / magnesium alloy. It used three 1" diameter bars of Thompson rod sliding thru Ampco 16 bronze busings with about .001" clearence total. Used the Forster sliding jaws (had two extra sets gathering dust). The part that actually held the jaws was made of 4150 pretreat steel that was held in place with four .50" hollow steel pins that had bolts running thru them. After assembly the slots were cut square with the guide rods (I had a slot that was .485" wide and much bigger in diameter). There was also a nitrided 4150 pad that held the sliding jaws to act as a wear plate. There was no priming device, and the basic handle was fabed out of 3/4" square tubing that had roughly .20" wall thickness. The pivot points used spherical rod ends or roller bearings all the way thru (ended up being a nightmare to get right). The jaws opened via the same system that Forster used. Max length on cases was about 2.3", so the press was much smaller. The wear plate was about .31" thick, and had three jack screws under it to make it perfectly square with the ram (turned out to be a real mother to get right). The whole shebang weighed about half of what a Forster Co-Ax weighs, and with three hollow guide rods was extremely square. Traded it for Marlin 38-55 rifle! Wish I'd kept it!!
To do it all over again, I'd left the jack screws out. The ball & roller bearing linkage really made the press smooth as glass, but ended up making several sets before I finally got the correct centerlines. The press had maybe 75% of the power the Forster had (way more than enough) on paper, but with all the bearings in it, it was probably closer to 90% due to decreased loss of friction. The third guide rod at the rear was also a bear, and ended up making an adjustable alignment plate that was dowl pined on assembly. I would not have used hollow Thompson rod if I did it all over again. I would have used 4150 ground rod that was nitride hardened and ground between centers to fit each bearing. The Thompson rod is better quality (52100 bearing steel), but making a way to lock it in place was not exactly fun (you can't thread the O.D.) I might also add that I used steel threaded inserts whereever the threads went into the alloy frame.
But alas I had three SIP jig bores setting there unused, and had plenty of time on my hands. I was supposed to make one for the boss and his boss as well, but we got busy again.
gary
