Boza wrote:Konstantin the Red wrote:I just hit links with a heavy hammer -- about 1,5 kilo -- to flatten them between the hammer and an anvil. I flatten cut links, overlap them, then flatten the overlaps more to finish flattening the entire link.
Konstantin, so in other words, you cut then overlap. Do you have any pics related to this? I'm cutting the links already overlapped, with small chisel. Btw yesterday I tried flattening by hammer/anvil only, it works fine after some practice; open question to me is whether I'll be able to punch resulting 0.9 mm thickness with tools as of now, but will try
I find it easier to cut, flatten, overlap, flatten again. When they are overlapped after getting at least the link ends flattened, the ends don't slip off each other the way leaving the links' wire round will do. Without that first flattening there was an awful lot of slipping off and other defects. When I started flattening the ends quite flat, the defect rate went to just about zero. Almost the only links I couldn't use were the ones I lost in the lawn from hitting them the wrong way with the hammer and launching them off the anvil too fast to see them go. They would just vanish!
The process takes two mandrels, the initial mandrel and the final diameter mandrel. The initial mandrel is about 1,5mm larger than the final one. Other tools are a hammer and anvil (or substitute for an anvil), a wire cutter or 200mm-size bolt-cutter, a hard surface such as concrete or a steel plate, and either a large plank of wood or a needlenose plier.
The overlapping methods I use depend on whether I want to do something else along with overlapping or not.
1. Roll With Pressure. Put some pre-flattened links still at their original coiled diameter onto the smaller final-diameter mandrel. Roll the links and mandrel back and forth on a hard surface -- I use the concrete of my patio -- with a length of thick wooden plank, pressing down quite firmly. The pressure and the rolling back and forth squeezes the links down to the final-mandrel diameter, which is the links' finished diameter. Inspect the links afterwards, as some of them may not quite be squeezed down far enough and will need adjusting.
Some links will be either too large or too small after adjusting, from variations in hand cutting them from the coils initially, or else from poor cutting. Cull these out of the batch and use them for other projects. Markings on the nose of a needlenose plier make a good gauge. I use three marks: next-size-smaller, just-right, and too-large/next size larger.
For adjusting links that need help, I correct their overlap to the desired amount, and then see if this has made the link too small or too large. The desired overlap is about 3/16 of an inch, or about 7mm.
After all this, back they go to my anvil to flatten out the overlaps as thin as the rest of the link is, so the overlaps spread out nearly twice as broad as the rest of the link. A controlled blow with a heavy hammer works better than hitting the link hard and fast with a lighter hammer: the link needs a few hundredths of a second to spread out properly, so the overlap takes on a cross section like =, rather than one of two triangles, which is something you can't rivet.
2. Squeeze With Pliers. This one's simpler to explain: take the pre-flattened initial-diameter links and squeeze them down on the end of the final-diameter mandrel with pliers. I use needlenose pliers for this. I inspect each link as I squeeze it down, culling out links of the wrong sizes. The right size links just accumulate on the mandrel until I take them off and put them in their container, awaiting normalizing/annealing and piercing for rivets.
This method works well while watching television or reading The Armour Archive on your computer.
