Pneumatic Rivet Squeezer Set-up
The set up of a pneumatic rivet squeezer is different for riveting and dimpling.
For riveting -- Always start with a gap when the squeezer is fully activated. The initial gap should be the skin thickness plus the length of the "finished" rivet. Once the rivet is squeezed if the butt of the rivet is squeezed too little add shims or fine adjust until the butt of the rivet is the correct size. It is better to have the rivet squeezed too little than to over-squeeze.
For dimpling -- The dimple dies should touch each other without any gap. The male die should be in the fixed part of the yoke and the female in the set holder that moves when the squeezer is activated. When dimpling, place the aluminum over the male set holder and trip the squeezer trigger very fast and at full throttle. This will "slap" the dies together to create a nice crisp dimple.
Caution -- Pneumatic squeezers have enough power to spring a yoke. Most yokes spring a little during dimpling and riveting, but do not operate a squeezer with less than zero clearance in the yoke as this may permanently bend the yoke.