Sunday, March 25, 2012

Severing to Isolate Mass





When a student is learning how to draw a taper without a cold shut there are several well known tips to include in the lesson. Most are designed to work when the stock has been cut with a blunt end as with a chop saw or band saw. The problem is avoided almost entirely if the stock was cut off on the hardy or with a handled hot cut.


Now that I have a hydraulic forging press in operation I cut a lot of stock with it. Recently I was making buds which will be incorporated into some daylily sculptures and needed quite a few short lengths of 1/2”, 9/16” and 5/8” round stock. The first step was to mark the cut point of each piece with a steel tape and presto pen. The next step was to notch each pen mark so the cut off point could be felt when placed hot into the severing tool.


The notching die is a bottom die made from a piece of hex shaft drill rod so the edge angle is 120º. In my press it makes a 1/16” - 1/8” deep notch in the stock cold. The press is powerful enough to completely sever the stock cold but the drop shoots off like a bullet and is too hazardous for any stock thicker that 1/8”.


I think the safe way to sever is with hot stock cut and a scissor tool. I bought mine from Old World Anvils and have one set up for a power hammer and the other for the forging press.


http://www.oldworldanvils.com/phtooling/tooling_scissor.html


The resulting ends are nicely tapered and each of the hot cut drops falls right into the collection pan right at waist level. These pieces are heated again and pressed into various open face dies I made to size and roughly shape each type of bud. The flash is removed and the stem drawn out and then they are ready for adding any final detail.


The tapered ends facilitate filling the die cavities and preventing cold shuts when tapering and overall I think this method of cutting is nearly effortless, less expensive and less time consuming than using the bandsaw.


http://www.persimmonforge.com/

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