SPC

Speed Control gas springs work by slowing down the speed at which the blank holder travels just before it reaches its start position. This is achieved by damping the Speed Control’s piston rod return speed to 0.4 m/s during the last 30 mm of piston rod travel.

Blank holder bounce often occurs as a result of an excessive press stroke return speed, commonly associated with new generation of presses.

The height of the blank holder lift depends on the speed that the blank holder is traveling at when its supporting gas springs reach their fully extended positions. At this point, the inertia of the blank holder causes it to lift up from its supporting gas springs.

If we assume that at this separation point the only force acting on the blank holder is gravity, then we can calculate the theoretical height the blank holder will lift, at various separation speeds.

In reality, however, there are other factors that affect the blank holder causing these theoretical lift heights to either increase or decrease.

Separation speed [m/s]	Theoretical lift [mm]
0.5	13
0.8	33
1.0	50
1.6	130