OnRobot HANWHA 3FG15 User Manual page 126

Hardware Specification
.
The thread size is the commonly used G1/8"; allowing for standard fittings, blinders and
extenders to be fitted directly to the VG grippers.
Vacuum
Vacuum is defined as the percentage of absolute vacuum achieved relative to atmospheric
pressure, i.e.:
% vacuum Bar
0.00rel.
0%
1.01 abs.
0.20rel.
20%
0.81 abs.
0.41rel.
40%
0.61 abs.
0.61rel.
60%
0.41 abs.
0.81rel.
80%
0.20 abs.
The vacuum in kPa setting is the target vacuum. The pump will run at full speed until the target
vacuum is achieved, and then run at a lower speed necessary to maintain the target vacuum.
The pressure in the atmosphere varies with weather, temperature and altitude. The VG
grippers automatically compensate for altitudes up to 2km, where the pressure is about 80%
of sea level.
Air flow
Air flow is the amount of air that must be pumped to maintain the target vacuum. A completely
tight system will not have any air flow, whereas real life applications have some smaller air
leakages from two different sources:
• Leaking vacuum cup lips
• Leaking workpieces
The smallest leak under a vacuum cup can be hard to find (see picture below).
kPa inHg Typically used for
0.00rel.
0.0rel.
101.3 No vacuum / No lifting capacity
29.9 abs.
abs.
20.3rel. 6.0rel.
23.9 abs. Cardboard and thin plastics
81.1 abs.
40.5rel. 12.0rel.
18.0 abs. Light workpieces and long suction cup life span
60.8 abs.
60.8rel. 18.0rel.
12.0 abs. Heavy workpieces and strongly secured grips
40.5 abs.
81.1rel. 23.9rel.
Max. vacuum. Not recommended
20.3 abs 6.0 abs.
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