Europeenne de Rotatives ER 32

Multi-spindle bar automatic (Index MS, Tornos MultiSwiss, Davenport): processes bar stock (raw round bar) from a magazine feeder, cutting parts progressively from the bar as it advances through the machine. All parts start as round bar and are cut to final geometry during the production cycle. Suitable for turned parts (cylindrical outside diameter, bores, threads). Rotary transfer machine (Europeenne ER 32, Hydromat EPIC): processes pre-formed blanks (stampings, forgings, sintered parts) loaded onto a rotary indexing table. The blank already has its primary shape from the upstream forming process; the rotary transfer machine adds precision drilling, boring, threading, and facing operations. Suitable for complex non-cylindrical parts requiring machining in multiple faces. These are complementary technologies - bar automatics for round turned parts, rotary transfer for blank-fed complex components.

ER 32 blank types: (1) Cold-headed blanks - steel or aluminum parts formed by heading (suitable for bolts, pins, complex fasteners); (2) Stamped blanks - flat sheet metal stamped to near-net shape (pump covers, end plates, disc components); (3) Forged blanks - steel forgings for automotive suspension parts, connecting rods, rocker arms; (4) Die-cast blanks - aluminum and zinc die castings for automotive housings, brackets, and connector bodies; (5) Powder metal (sintered) blanks - PM gears, bushings, and structural parts requiring precision machining post-sintering; (6) Screw machine pre-turned blanks - parts requiring additional drilling/threading after bar turning. The blank must be sized to fit in the workpiece carrier and position accurately for the first station operation. Part fixturing at each station is typically by expanding mandrel, chuck, or precision locating pins.

On the ER 32 (assuming 12 stations): all 12 stations operate simultaneously during the machining portion of the cycle. Station 1 may be drilling (8 seconds), Station 2 reaming (5 seconds), Station 3 threading (6 seconds), Station 4 boring (10 seconds). The cycle time is determined by the slowest station (10 seconds in this example), not by the sum of all operations (29 seconds total). After the slow station completes, the table indexes (2 seconds) and all stations start simultaneously again. Effective cycle time: 10 + 2 = 12 seconds per completed part. Equivalent single-spindle machining center for the same part: 29 seconds machining + tool changes = approximately 50-60 seconds total. Rotary transfer advantage: 4-5x throughput for this part complexity. For parts with 8+ operations, the advantage grows because all operations occur in parallel.

Each ER 32 station has independent CNC servo axis control for the machining head: typically X (radial) and Z (axial) axes minimum; Y axis added for off-center operations; A rotation axis for angled operations. The CNC at each station can be programmed for: fixed cycle operations (drill, bore, ream, tap); multi-pass operations (rough bore then finish bore); and programmable feed rates per operation for material-specific optimization. All station CNC programs execute simultaneously during the machining cycle. The inter-station coordination (index timing, station synchronization) is managed by the machine master controller. For product family changeovers: each station program can be recalled independently, enabling fast reconfiguration within a related part family without mechanical retooling if the workpiece geometry is similar.

Break-even analysis for ER 32 vs CNC machining center: For a hydraulic valve body requiring 12 operations (6 drills, 3 bores, 2 taps, 1 ream): CNC machining center cycle: 90 seconds per part = 40 parts/hour. ER 32 rotary transfer: 12 second cycle = 300 parts/hour. Capital cost: ER 32 $800K vs CNC machining center $80-150K. To match ER 32 throughput, need 7-8 CNC machining centers at $80-150K each = $560,000-$1,200,000 in total CNC capital. At 300 parts/hour from one ER 32 vs equivalent CNC investment: the crossover depends on annual volume, machine utilization, and labor rates. General guideline: rotary transfer becomes economically superior above 500,000-1,000,000 parts/year for a consistent part family. Below this volume, flexible CNC machining centers provide better capital efficiency for mixed production.