Case specific applications for a fully automatic and efficient power machine

A material discharge machine repeats the same pick-and-place motion several thousand times per shift. The gripper jaw is where that repetition lands. Jaws are usually cut from 7075 or 6061-T6 because the strength-to-weight ratio keeps the moving mass low, and low moving mass lets the axis accelerate without overshooting. A hard-anodized jaw face adds wear resistance at the contact point without changing the geometry.

Where the jaw geometry turns complex is the relief behind the gripping face. That pocket has to clear the part being lifted while still leaving enough wall for the clamp screw. Three-axis work handles it when the relief is open from one direction. Once the relief wraps two sides, a 5-axis cut is faster than two separate setups, and it holds the jaw-to-jaw alignment tighter.

Repeatability matters more than absolute size here. Two jaws that are each 0.02 mm off in opposite directions will drop a part that a matched pair holds all day. We cut jaws in pairs from the same billet when the customer asks, so the thermal history matches.

When not to machine the jaw: a soft elastomer pad bonded to a plain metal back is cheaper and gentler on glass or polished surfaces. Machining only pays off when the jaw needs hard contact points, a specific pocket shape, or vacuum channels cut inside the body.

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  Typical material7075-T6, 6061-T6, 17-4PH for wear faces
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  Tolerance that matters±0.005 mm on the jaw-to-jaw gap
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  FinishHardcoat anodize, Ra 0.8–1.6 μm on contact faces

A vision system reads position to within a fraction of a pixel, then the machine moves to match. That only works when the camera does not shift between calibration and production. The bracket is the part that decides this.

Most camera brackets are cut from 6061 or 6082 plate because aluminium damps vibration poorly compared to cast iron but keeps the assembly light enough for a moving gantry. The real design work is in the mounting face. A face milled flat and then bead blasted gives a repeatable seating surface; a face left as-machined from a band saw cut does not.

Angle brackets create a second problem. Bending a plate gives a radius at the corner, and that radius moves the optical axis when the plate springs back. Cutting the bracket from solid on a 5-axis center avoids the bend entirely and keeps the two mounting faces square to each other. The trade-off is stock removal: a bracket cut from solid block costs more material than a bent one.

For brackets under 150 mm, a 3-axis mill with a good vise is often enough. Longer brackets need either a 4-axis setup with a tombstone or a 5-axis cut, because re-fixturing a long part is where squareness is lost. If the bracket carries a lens tube over 200 mm, plan for a stress-relief pass before the finish cut.

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  Flatness that holds focus0.02 mm over the mounting face
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  Best process for L-brackets5-axis from solid, no bend radius
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  AvoidWelded brackets near the optical path

Guide rail mounting pads look simple. They are not. The rail sits on two or more pads, and any height difference between pads tilts the carriage. A tilt of 0.01 mm over a 300 mm rail shows up as binding at the ends of travel, and the servo draws more current to push through it.

We machine guide pads as a set, not one at a time, and measure them on the same setup. Height tolerance of ±0.005 mm across a set is achievable on a three-axis machine when the pads are clamped to a common plate. Splitting the set across two machines on two days is how that tolerance disappears.

Bushings and bearing housings are lathe work. The bore-to-outer-diameter concentricity is the number that matters, and it is easier to hold on a mill-turn center than on a lathe with a second op. For a housing with a bore under Ø30 mm and a wall under 4 mm, boring after the outer profile is turned avoids the distortion that comes from clamping a thin wall.

Indexing plates carry the most demanding geometry on the machine. Slots, dowel holes and the rotary table interface all have to agree with each other and with the encoder. Position tolerance of ±0.01 mm across a 400 mm plate is normal for us. Anything tighter than ±0.005 mm across that span needs a temperature-controlled room and a CMM report, and it needs the plate stress-relieved before the final cut.

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  Guide padsMachined and measured as a matched set
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  Thin-wall housingsBore after OD to limit clamping distortion
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  Indexing platesStress relief before finish machining

Automatic machines run millions of cycles. Material choice is less about peak strength and more about how the part behaves after a year of that.

Aluminium 6061-T6 is the default for brackets and plates. It machines fast, takes anodize well, and holds tolerance without stress cracking. 7075 gives roughly double the yield strength, but it is less weld-friendly and anodizes to a darker, less uniform color. Use 7075 where weight is critical and the part is not welded.

For wear surfaces, 17-4PH stainless in the H900 condition holds up better than any anodized aluminium. It costs more to cut and needs a passivation step after machining. Bearing bores and dowel holes that see constant sliding contact are the usual place it earns its price.

Finishing is where a lot of automatic-machine parts get ruined. Hardcoat anodize adds 25–50 μm per surface and it is not perfectly uniform on sharp edges. A dowel hole anodized after machining will be undersized. Specifying masked bores costs a step but keeps the fit.

If a part carries a laser-marked serial, keep the character height at 1.5 mm or above. Smaller marks fill in after anodize and stop being readable.

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  Default6061-T6 for brackets, plates, housings
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  High wear17-4PH H900 for bores and sliding faces
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  Anodize growth25–50 μm per surface, mask critical bores