Aircraft Tools Blog

Setting Up a Pneumatic Squeezer

Set up of the squeezer is slightly different depending on the type of work being done.

When riveting with the squeezer start with a gap (while the squeezer is fully activated) that is equal to the skin thickness plus the length of the "finished" rivet.  After the rivet is set, the butt of the rivet should be within tolerance.  If it is squeezed too much, add shims or fine adjust the set holder so the butt of the rivet is the correct length.  If it is too long, shorten the gap by removing shims or adjusting the adjustable set holder.  A rivet is better when squeezed too little than to much.

When dimpling, the dimple dies should touch each other slightly without any gap.  The male die should be installed in the fixed part of the yoke and the female die should be in the fixed set holder that moves up and down when activated.  When dimpling, place the aluminum part over the male set holder and trip the squeezer trigger very fast and at full throttle in order to "slap" the dies together and create a nice crisp dimple.

Do not have less than "zero" gap when dimpling as pneumatic squeezers have enough power to spring the yoke.  Never use an adjustable set holder for dimpling as it will damage the threads on the set holder.  Most yokes have a slight spring during dimpling and riveting but go back into the original position.  If dimpling with negative clearance you could permanently deform the squeezer yoke.