Complete bus-body painting line — six robots on 15 m explosion-proof tracks (engineered proposal)
A complete three-coat 2K line for bus bodies of 12,500 × 2,550 × 3,300 mm and 5 t: six Yaskawa MPX-3500 robots on six 15 m explosion-proof seventh axes, three dry booths of 19,000 × 6,800 × 5,300 mm with supply-air conditioning, three ovens and a 20 m heavy-duty roller bed — about twenty 40 ft containers. Quoted, not concluded.
The problem the customer brought
Not enough skilled operators, a manual process that was hard to manage, and finish quality that was hard to control.
Workpiece
Bus bodies 12,500 × 2,550 × 3,300 mm, 5,000 kg, on a floor chain conveyor at 2,000 mm track gauge.
Robots
6 × Yaskawa MPX-3500 (three left, three right, DX200 cabinets, 15 m Ex teach-pendant cables, PROFINET I/O) with six 15 m seventh axes of our own build — explosion-proof motors, Ex cable carriers, single carriage, automatic lubrication and leg covers.
Process and equipment
Three 2K coats: epoxy primer Translack EPX 3300 by airless at 120–150 bar with 0.28–0.33 mm tips; PUR 5405 G90 filler by AirMix at 120–160 bar, 3:1; acrylic-PU high-gloss topcoat. Three dry spray booths 19,000 × 6,800 × 5,300 mm with supply-air conditioning and extraction, three drying ovens, a 20 m heavy-duty floor roller bed and one transfer car; a 380 V to 220 V three-phase transformer for the robots.
Commercial terms
Lead time 3–4 months, EXW; approximately twenty 40 ft containers.
Shipping terms on current projects: EXW, FOB, CIF or DAP. Customer names, plant locations and prices are not published.
How it ended
Stopped at quotation stage. The cost sheet showed robots at about 89 % of their selling price — a mark-up of roughly 12 % — while booths with air conditioning ran at about 80 % and the tracks at about 69 %. On a line like this the margin is in the booths and ovens, not in the robots.
What we do differently because of this project
The customer's technical specification asked in writing for a 2K mixing unit, in-arm mixers, a flushing system and waste-solvent collection; not one of them appeared in the offer, and an item not listed is an item supplied free later. Twenty 40 ft containers quoted EXW also leaves the buyer carrying large clearance and inland costs, so a CPT alternative is now offered alongside, to stop the total investment being underestimated.