Gantry Type CNC Plate Drilling Machine FAQ: Speed, Hole Tolerance, Drilling vs Laser

How many holes per hour can a gantry type CNC plate drilling machine actually produce?

The honest answer depends far more on plate thickness and hole depth than on the machine, because with a single hydraulic-feed spindle the cut time dominates. On a YM-PD2016 with a 5.5 kW spindle (7.5 kW option), a typical Ø20 mm hole through 10-12 mm plate runs at 300-400 rpm and 0.15-0.25 mm/rev, so cutting takes roughly 8-15 seconds, and positioning between holes adds 2-4 seconds at gantry traverse speed. In practice that is 90-150 finished holes per hour on 10-12 mm plate when the plate is already in the clamps. At 25-30 mm plate the same hole takes 25-40 seconds and output drops to 50-80 holes per hour. At 60-100 mm plate, where you are pecking and clearing chips, expect 10-20 holes per hour. Two multipliers matter more than the headline number: batch the drilling so the 12 hydraulic clamps are set once per plate rather than per hole, and keep the flat chain chip conveyor and forced water cooling running - interrupted chip evacuation is the single most common cause of lost output, because a re-drilled or broken-tool hole costs far more than a fast feed ever saves.

What hole tolerance do bolted connections actually need, and can this machine hold it?

For structural bolting under EN 1090-2, standard round holes are generously toleranced relative to what the machine can do: nominal bolt diameter plus 1 mm clearance for M12-M14, plus 2 mm for M16-M24 and plus 3 mm for M27 and above, with hole diameter tolerance around +/-0.5 mm. The critical number in fabrication is not hole size but hole position - the accepted practice is that deviation of an individual hole within a group should stay within about 2 mm in any direction, because a group of holes must line up with the matching plate on site. The YM-PD2016 is rated at drilling precision +/-0.5 mm with +/-0.1 mm re-positioning accuracy thanks to Panasonic servo drives and ball-screw gantry drive on both sides, so it sits comfortably inside both limits - roughly four times the margin on position and well inside the diameter tolerance. The practical caveats are all external to the machine: pause and confirm the first article on a new program, keep the plate clean under the clamps so it cannot shift, and drill pilot or spot first if the plate carries heavy mill scale, which can deflect a new drill at entry and walk the hole off position.

Should plate holes be drilled or laser cut in 2026?

Drill them when the plate is structural, thick, or bolt-critical; laser cut them when the plate is thin and the holes are non-critical. Drilling produces a truly cylindrical hole with no taper and no heat-affected zone, so the bolt bears over the full plate thickness and there is no hard recast layer to crack or ream out - which is why base plates, splice plates and tower leg connections are still drilled. Laser cutting is much faster on 3-10 mm plate and needs no tooling, but every hole comes out slightly tapered (typically 0.05-0.2 mm depending on thickness and focus), leaves a HAZ of 0.2-0.5 mm and a dross edge, and on plate above about 20-25 mm the taper and the cost per hole both climb steeply. A common 2026 compromise in mixed shops is to laser cut the plate outline and drill the bolt holes, or to laser-cut pilot holes and finish-drill them - the pilot removes the mill-scale problem and the drill then only removes a fraction of the material. If you also punch, remember that EN 1090-2 restricts punching for thicker or higher-grade material in tension members, so drilling remains the safe route for anything that needs to be code-clean.

Should holes be drilled before or after thermal cutting of the plate outline?

Drill after the plate has been cut to outline but before any welding - and if you must choose between drilling first and cutting first on a tight plate, drill first only when the cut will be a low-heat process. The reason is thermal: plasma or flame cutting leaves a hardened, slightly tapered edge and pulls residual stress into the plate, and if you drill close to a freshly cut edge (within roughly 10-15 mm), the hole can drift toward the softer or relieved side and the plate can move between clamp release and drilling. Cutting first is still the normal sequence because the cut outline gives you the datum the CNC program needs and because scrap is removed before you load the drilling table. So the practical order is: cut outline, allow the plate to cool, clean dross and scale, clamp, then drill. Keep a 15-20 mm allowance between the hole edge and the cut edge where design permits, and never drill a plate that is still warm from cutting - a 60-80 C plate will expand enough across 2 m to move hole positions by a few tenths of a millimetre.

How do you support large or thin plates so they do not deflect or chatter while drilling?

With a 2000 x 1600 mm table and 100 mm thickness capacity, the workpiece is supported on the machine bed and held by 12 hydraulic clamping cylinders at 7.5 kN each, foot-switch operated, with the option of clamping at the four corners on small workpieces to shorten setup. For thin plate (under about 10 mm) three habits prevent trouble. First, ensure the plate sits fully flat on the bed - a single piece of dross or a burr under the plate turns a rigid setup into a drum, causing chatter, oversize holes and burrs on exit. Second, clamp symmetrically around the drilling zone rather than only at two corners, and use the corner-clamping pattern for small parts so the plate cannot lift. Third, drill with a support directly beneath the hole when the plate spans an opening or overhangs the bed - an unsupported overhang of more than a few hundred millimetres will deflect under thrust and produce an out-of-round hole. For thick plate the opposite risk applies: chip evacuation rather than deflection governs, so confirm the peck depth, keep coolant flow at the nozzle and let the chain conveyor clear chips continuously.

How should drilled holes be inspected, and what does a good first-article check look like?

Inspect in two layers: dimensional, then condition. For dimensions, check the first plate of every new program with a calibrated caliper or pin gauge on hole diameter, a steel tape or height gauge across the hole group diagonals (measure the same diagonal on the matching plate - if both match, the pair will bolt up on site), and a square or dial indicator against the plate face to confirm the hole is perpendicular rather than drilled at an angle. Record the results on a simple first-article sheet with the program number and date. For condition, look at four things: burr height on the exit side (which a worn or mis-fed drill makes worse), roundness, surface finish inside the bore (blue or straw chips and a polished bore mean the drill is rubbing rather than cutting), and breakthrough quality. Then run the second layer: drill five holes, measure all five, and confirm the spread is inside your tolerance - not just that each is nominally correct. If the first article passes but later plates drift, the cause is almost always clamping or a loose tool, not the program, so keep the machine's +/-0.1 mm re-positioning capability meaningful by checking clamp pressure and tool runout weekly.

Can the machine run with roller conveyors and one operator, or does it need a full handling system?

It can run with one operator on a much simpler setup than most buyers expect, because the gantry does the travelling rather than the plate. The base machine is a 3500 x 2650 x 2870 mm footprint at about 6 t, with the gantry driven by dual 2 kW servos on the X axis and 1.5 kW on Y - so the plate only has to be brought roughly into position, not indexed precisely. In practice shops pair it with a powered roller table at the same height as the bed, load with a crane or vacuum lifter, clamp with the foot switch, run the program, unclamp and roll out. That is a genuine one-operator station. What you should consider adding, in order of value: a second roller table on the outfeed side so finished plates do not have to be lifted off backwards, a plate stop or laser pointer to speed up rough positioning, and dust/chip containment if the machine sits close to a blasting booth. Only look at robotic or gantry loading if your plate size is fixed and your volume is high enough to justify it; for mixed-order structural plate work, the crane and a roller table is the cost-effective answer.

What is the real cost per hole, and when does buying beat sending plates out?

Break the cost into four parts, because only one of them is tooling. Consumable tooling for a coated HSS or carbide drill in mild steel is roughly USD 0.02-0.06 per hole at typical life, and rises to USD 0.10-0.25 in stainless or hardened plate where life drops by half or more. Power is minor: a 5.5 kW spindle plus servos, hydraulic pump and cooling draws perhaps 8-12 kW average, so a shift costs a few dollars of electricity. Labour is the biggest line item if you are still drilling manually: with CNC you pay one operator for load/unload only, which typically replaces two to three people on radial drills and removes the marking-out step entirely. The fourth part is scrap and rework, and this is where the calculator usually turns: a mis-positioned or mis-drilled hole in a finished plate can scrap a part worth many times the whole shift's tooling cost. Compare the total against your outsourcing price per hole plus freight and lead time - a machine in this class usually earns its place once you are drilling more than roughly 50-100 plates per month with 20 or more holes each, and it pays for itself faster if late plate deliveries are costing you erection dates.

Technical Specifications of Gantry Type CNC Plate Drilling Machine

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Applications

The Gantry Type CNC Plate Drilling Machine is widely applied in steel structure prefabricated buildings, bridge and infrastructure construction, shipbuilding and marine engineering, heavy machinery manufacturing, power plant and industrial facilities, and offshore wind power structures.

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For more information about Gantry Type CNC Plate Drilling Machine and other steel structure intelligent equipment, contact YOMI CNC Cutting & Welding Machinery. Our team of experts is ready to help you find the best solution for your manufacturing needs.