Engineering problem · FDM, no moving parts
VG-90 non-contact vortex gripper
Published with the customer's permission.
A robot has to lift glass bottles off the conveyor straight out of the annealing lehr: wall temperature 110 °C, the surface tacky with lubricant aerosol, cycle time 0.9 s. A mechanical gripper marks the glass and jams as the parts expand; a vacuum cup cannot seal against the curved neck.
Solved in a single part
- Compressed air at 4.5 bar enters the side port and spreads through an internal annular manifold built into the wall.
- Six spiral channels of matched length (±2 %) carry the flow down to tangential nozzles — flow variation between nozzles stays below 4 %.
- Eight vanes spin the jet into a vortex: pressure at the chamber centre drops to −0.32 bar and the bottle floats 0.4 mm off the face. Holding force 9.5 N — gripping with no contact and no moving parts.
- The same air purges the face continuously, carrying heat away: the printed polymer never exceeds 65 °C.
Why additive was the only route
- The manifold and spiral channels are enclosed inside the body — milling or casting cannot produce this geometry without a split line and seals.
- Printed flange-down, Z along the part axis: the channels are self-supporting (overhang ≥ 42°), no supports are needed, and the layers work in compression under bolt preload.
Metal inside the printed part
- Four brass M6 bushings for the ISO 9409-1-50-4-M6 flange — they take up polymer creep under 9 N·m preload; installed by heat-set press fit.
- A brass G 1/8″ threaded insert in the port, a Ø6 h6 steel dowel pin, a steel wear ring on the face and three elastomer pads — protection against accidental contact.
Data sheet
- Envelope
- Ø98 × 71 mm
- Port
- +82 mm from axis
- Material
- PA6-CF, 100 % infill
- Nozzle / layer
- 0.4 mm / 0.12 mm
- Mass / air flow
- 118 g / 62 l·min⁻¹
- Test
- leak-tight at 6 bar
PA6-CF, printed bodyBrass: bushings, G 1/8″ insertSteel: dowel pin, wear ringElastomer: face pads