Horizontal Profile Projector | For Shafts & Threads | PP 400H PP 600H

Technology Overview

What is a Horizontal Profile Projector?

In a horizontal profile projector, the optical axis is horizontal and the part is positioned along that axis — supported between precision centres, in V-blocks, or on the motorised stage. The magnified profile is projected horizontally onto the vertical glass screen.

The key difference from vertical models: horizontal projectors are ideal for cylindrical, shaft-type, or elongated workpieces — parts that have a clearly defined axis of rotation or a length to be inspected.

The horizontal configuration allows the full cross-sectional profile of a shaft, lead screw, or threaded rod to be seen in a single view, with the thread axis perfectly aligned to the projection axis.

Optomech horizontal models (PP 400H and PP 600H) incorporate heavy-duty stages with motorised movement operating on ball screws and precision linear motion guides — enabling smooth, repeatable positioning across the large traverse.

Applications

Thread pitch, angle, and root radius measurement on external threads
Lead screw helix profile verification
Worm gear tooth form inspection
Shaft shoulder and relief groove measurement
Spline profile verification
Needle and pin diameter measurement along length
Hob and broach profile checking
Long punch and die profile inspection

Vertical vs Horizontal — When to Choose Which

Choose Vertical (PP 300TL–PP 600VE)

Parts that rest flat on a stage — stampings, gears, inserts, PCBs, small machined components. The part must not exceed Ø210mm. Vertical models have XY stage traverses up to 250×150mm.

Choose Horizontal (PP 400H / PP 600H)

Parts with a defined axis: shafts, threaded rods, lead screws, worm gears, hobs. The horizontal configuration aligns the part axis with the optical axis for true cross-section view.

Not Sure?

Contact Optomech — describe the part geometry and our application engineers will specify the correct model. We've solved this choice for 1,000+ customers over 45 years.

Key Differences

How Horizontal Projectors Differ from Vertical Models

Motorised Stage

Unlike vertical models that use manual screwless XY stages, the PP 400H and PP 600H incorporate heavy-duty motorised stages driven by precision ball screws and linear motion guides. This enables smooth, controlled traversal across the full 250×150mm (PP 400H) or 300×600mm (PP 600H) measuring range — critical for tracking long features across shaft lengths.

Horizontal Optical Axis

The optical axis is perpendicular to the projection screen (horizontal). The part is positioned along this axis — its cross-section is what appears on the screen. For a threaded rod, the screen shows the full thread form in profile, including pitch, included angle, root radius, and crest flat simultaneously.

Centre-to-Centre Measurement

Precision centres (Small: 125mm centre height; Large: 200mm centre height) are used to mount shafts and cylindrical parts with their axis exactly aligned to the optical axis. This eliminates tilt error and enables accurate measurement of the full working length of the part.

Twin Condenser Surface Illumination

Horizontal models use twin condenser surface illumination (rather than fibre-optic guides) for surface illumination, delivering brighter, more uniform surface lighting suited to long cylindrical workpieces. Profile illumination uses 24V/150W halogen lamps as on all Optomech models.

PP 400H

Horizontal, Ø400mm screen, 250×150mm traverse, motorised stage, 175kg

Screen

Ø400 mm glass

Traverse X×Y

250 × 150 mm

Max Part Dia

Ø170 mm

Load Capacity

25 kg

Contour Accuracy

±0.05%

DRO Options

OP-250 / OP-500 / OP-1000

The PP 400H is Optomech's 400mm horizontal profile projector — designed for the inspection of shafts, threaded components, lead screws, and other cylindrical or elongated workpieces. The motorised stage operates on ball screws and precision linear guides for smooth traversal across the 250×150mm measuring range. The Ø400mm glass screen provides generous viewing area for thread-form inspection and shaft profile measurement. Parts up to Ø170mm diameter and 25kg load are accommodated. Linear encoders (1µm resolution) and rotary encoder (1 arc-second) feed all three DRO options. Surface illumination uses twin condenser lamps for uniform, high-intensity lighting across the full part length. At 175kg and 1450×550×3100mm, the PP 400H requires floor installation with adequate ceiling clearance.

PP 600H

Horizontal, Ø600mm screen, 300×600mm traverse, motorised stage, 250kg (Flagship)

Screen

Ø600 mm glass

Traverse X×Y

300 × 600 mm

Max Part Dia

Ø210 mm

Load Capacity

25 kg

Contour Accuracy

±0.05%

DRO Options

OP-250 / OP-500 / OP-1000

The PP 600H is Optomech's flagship horizontal profile projector — an instrument of exceptional capability for the most demanding shaft and thread inspection requirements. The Ø600mm screen (four times the area of a 400mm screen) enables inspection of large, complex profiles in a single view. The 300×600mm traverse — the largest in the Optomech range — allows measurement along up to 600mm of part length without repositioning, making it ideal for long lead screws, long hobs, and multi-start worm gears. Parts up to Ø210mm diameter are supported. At 250kg and 1800×900×1900mm, the PP 600H is a substantial installation requiring dedicated floor space. Delivered with NABL-traceable calibration certificate.

Specifications

PP 400H vs PP 600H — Full Specification Comparison

Specification	PP 400H	PP 600H
Screen Size	Ø400mm	Ø600mm
Magnification (Std.)	10×	10×
Optional Lenses	5×, 20×, 50×, 100×	5×, 20×, 50×, 100×
Top Plate	515×125mm	650×230mm
Traverse X×Y	250×150mm	300×600mm
Working Area	515×125mm	650×230mm
Max Part Dia	Ø170mm	Ø210mm
Load Capacity	25 kg	25 kg
Contour Accuracy	±0.05%	±0.05%
Surface Accuracy	±0.05%	±0.05%
Linear Measurement	Encoder 1µm	Encoder 1µm
Angular Resolution	Encoder 1 sec	Encoder 1 sec
DRO Systems	OP-250/500/1000	OP-250/500/1000
Profile Illumination	24V, 150W	24V, 150W
Surface Illumination	Twin condenser 24V, 150W	Twin condenser 24V, 150W
Stage Movement	Motorised ball screw	Motorised ball screw
Net Weight	175 kg	250 kg
Dimensions (L×W×H)	1450×550×3100mm	1800×900×1900mm

Key Application

Thread Inspection with Horizontal Profile Projectors

Why Horizontal is Essential for Thread Measurement

Threads on cylindrical parts (screws, lead screws, threaded rods, worm shafts) must be inspected in a cross-section view that shows the thread form — pitch, included angle, crest flat, root radius, and thread height simultaneously.

In a vertical projector, a threaded shaft would need to be tilted to present the thread axis to the optical axis — introducing error and requiring the tilting support accessory with careful setup.

In a horizontal projector, the shaft is mounted between centres with its axis aligned to the optical axis. The thread form is presented perfectly in the projection plane with no tilting error.

Thread parameters measurable on the Optomech PP 400H and PP 600H using overlay charts or DRO: pitch (mm or TPI), included angle, half-angle symmetry, crest flat width, root radius, thread height, flank angle deviation.

Thread standards covered: metric (ISO 68-1), unified (UNC/UNF/UNEF), Whitworth (BSW/BSF), ACME, trapezoidal, stub ACME, British Pipe (BSPP/BSPT), and NPT/NPTF.

Thread Parameters Measurable

Pitch (mm / TPI)
Included angle (°)
Half angle (left & right flanks)
Crest flat width
Root radius
Thread height
Major / minor diameter
Flank angle deviation from nominal

Digital Readout Systems

Choose Your Intelligence: Three DRO Options

Every Optomech profile projector is paired with a Digital Readout system. Choose the tier that matches your inspection requirements — and upgrade later without replacing the optical instrument.

Standard

OP-250

Digital Readout

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2-axis or 3-axis LCD readout — direct X and Y coordinate display from linear encoders

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Zero-set, absolute / incremental switching, inch–metric toggle

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Linear error correction for glass scale calibration

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No computer required — self-contained measurement display

Best For Simple go/no-go inspection; trained operators making rapid pass/fail decisions

Recommended

OP-500

Advanced DRO + Edge Detector

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All OP-250 features, plus automatic edge detection — eliminates operator-dependent edge identification

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Circle measurement, distance functions, angle calculation on-screen

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Significantly improves measurement repeatability in repetitive inspection tasks

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Optional RS-232 data output to PC or quality system

Best For Production inspection; reduces operator skill dependency; faster throughput

Advanced

OP-1000

Computerised Metrology Software

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AutoCAD DXF import — overlay nominal profile onto live projected image

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Full geometric measurement: points, lines, circles, arcs, angles, distances

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Automated dimensional report with pass/fail, tolerances, GD&T

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Reverse engineering: trace actual profile → export as DXF

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SPC integration — real-time control charts and trend monitoring

Best For Product development, SPC programmes, complex contour analysis, reverse engineering

Optical Technology

Precision Optics: The Heart of the Instrument

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Telecentric Projection Lenses

Horizontal models use the same high-resolution telecentric projection lenses as vertical models — 10× standard, 5×, 20×, 50×, 100× optional. For horizontal projectors, telecentric optics are especially critical: the part extends along the optical axis, and any non-telecentric lens would show different magnification at different points along the shaft length. Telecentric projection ensures every cross-section is measured at exactly the same magnification, regardless of its position along the Z-axis.

5×

10×

20×

50×

100×

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Dual Illumination System

Profile (Transmitted) Illumination: 24V / 150W halogen lamp projects a collimated beam through the workpiece, creating a sharp shadow silhouette on the screen. This is the primary mode for all contour measurement — threads, radii, gear teeth, complex forms.

Surface (Reflected) Illumination: Twin condenser lamps direct light directly onto the part surface from both sides. Reveals surface features, steps, holes, and markings that are not visible in silhouette. Standard on PP 400H and PP 600H horizontal models.

Tip: For complete inspection of a part that has both external contour features and surface markings or holes, use both illumination modes in sequence — profile light first for dimensional measurement, then switch to surface light to verify feature presence.

Configuration Options

Optional Accessories for Horizontal Profile Projectors

Small & Large Centres

Precision hardened centres for mounting cylindrical and shaft-type parts along the optical axis. Small centres: 125mm centre height. Large centres: 200mm centre height. Essential for accurate shaft and lead screw inspection.

V-Blocks with Clamps

For supporting shafts and cylindrical parts without using centres. Available in 40×40mm and 20×20mm sizes.

Vertical Glass Support Plate

A flat glass plate (105mm Ø, 125mm centre height) for holding thin, flat parts vertically in the horizontal light path — enabling flat parts to also be inspected on the horizontal projector.

Overlay Charts

Standard thread profile charts (metric, unified, Whitworth, ACME, trapezoidal) and radius sets for direct visual comparison on the screen.

Rotary Table

125mm glass window, 360° graduation, 5-minute vernier. For angular positioning of components relative to the optical axis.

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NABL Certified

NABL Calibration Certificate

Every PP 400H and PP 600H is supplied with NABL-traceable calibration certificate (Certificate No. C-0068). Accepted for ISO 9001, IATF 16949, and AS9100 QMS audits.

Industries

Industries that Rely on Horizontal Profile Projectors

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Lead Screw & Ball Screw

Thread form, pitch accuracy, and lead error measurement. Critical for machine tool and CNC axis manufacturers.

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Automotive Powertrain

Worm gear tooth inspection, shaft shoulder profiles, spline geometry, and bearing seat measurement.

✈️

Aerospace Fasteners

Precision aerospace bolt threads, stud profiles, and close-tolerance threaded fittings inspected to AS9100 requirements.

🛡️

Defence & Ordnance

Cartridge cases (external thread), fuze components, projectile driving bands, and precision screw-thread gauges.

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Machine Tools & Tooling

Hob profile inspection, broach tooth verification, tap thread form checking, and ground thread gauge calibration.

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General Precision Engineering

Any manufacturer of threaded components, cylindrical shafts, or elongated precision parts requiring accurate, non-contact profile measurement.

FAQ

Frequently Asked Questions

What is a horizontal profile projector and when should I use one instead of vertical? +

A horizontal profile projector positions the part along a horizontal optical axis, projecting its cross-sectional profile onto a vertical screen. Use a horizontal model when your part has a defined cylindrical axis — shafts, lead screws, threaded rods, worm gears, hobs, and similar elongated components. The horizontal configuration aligns the part axis to the optical axis, giving a true cross-section view without the tilt error that occurs when trying to inspect such parts on a vertical projector.

What is the traverse of the PP 600H — 300×600mm? That seems unusual. +

Yes — the PP 600H traverse is 300mm in X and 600mm in Y (along the shaft axis). This is intentional: horizontal projectors need a long Y traverse to follow the shaft length during inspection. The 600mm Y travel allows continuous measurement along a 600mm workpiece without repositioning. The X traverse of 300mm handles diameter variation and radial feature measurement. This is why horizontal projectors have a different traverse geometry from vertical models.

Can I inspect threaded parts on a vertical projector or do I need horizontal? +

For short threaded studs, bolts, and inserts (length under 50mm), a vertical projector with a tilting support accessory can be used for thread profile inspection. For longer threaded parts — lead screws, threaded rods, worm shafts — the horizontal configuration is strongly preferred because the part mounts naturally between centres without any tilt setup, and the full thread length can be traversed without repositioning.

What stage movement do the horizontal models use? +

Unlike vertical models (which use manual screwless XY stages), the PP 400H and PP 600H incorporate motorised stages driven by precision ball screws and linear motion guides. Motorised movement enables smooth, controlled traversal and consistent positioning — important for tracking features along the length of a shaft or lead screw with repeatable encoder readings.

What is the difference between PP 400H and PP 600H? +

The key differences are: screen size (Ø400mm vs Ø600mm), Y traverse (150mm vs 600mm), dimensions (1450×550×3100mm vs 1800×900×1900mm), and weight (175kg vs 250kg). If you regularly inspect parts with lengths up to 600mm, the PP 600H's extended Y traverse is essential. If parts are shorter and Ø400mm screen is sufficient, the PP 400H is the more compact and economical choice.

What thread standards can be inspected with overlay charts? +

Standard overlay chart sets cover metric ISO threads (M), unified threads (UNC, UNF, UNEF), Whitworth (BSW, BSF), ACME, trapezoidal (DIN 103), stub ACME, British Pipe (BSPP, BSPT), and NPT/NPTF. Custom overlay charts can be produced for proprietary thread forms. With the OP-1000 DRO system, full thread parameter measurement (pitch, angle, root radius, crest flat) can be performed mathematically without overlay charts.

Do the horizontal projectors include surface illumination? +

Yes. Both PP 400H and PP 600H include twin condenser surface illumination (24V/150W halogen) in addition to profile (transmitted) illumination. For horizontal models, surface illumination uses twin condensers rather than fibre-optic guides — delivering brighter, more uniform lighting suitable for long cylindrical workpieces.

What is the maximum part diameter and weight for horizontal models? +

PP 400H: up to Ø170mm diameter, 25kg. PP 600H: up to Ø210mm diameter, 25kg. For part lengths, the Y traverse determines the inspection range: 150mm on PP 400H (parts can be longer but only 150mm can be measured without repositioning), and 600mm on PP 600H.

Why Optomech

Four Decades of Optical Metrology Excellence

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NABL-Traceable Calibration

Every instrument leaves Hyderabad with a calibration certificate traceable to national standards. Your QMS audit is covered from day one — ISO 9001, IATF 16949, AS9100 compliant.

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Made in India — Service Assured

Manufactured at our 10,000 sq. ft Hyderabad facility — the home of profile projector manufacturer Hyderabad. Spares are stocked locally. Service response is hours, not weeks. No import lead times on critical components.

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45 Years of Application Knowledge

Since 1981, our engineers have installed Profile Projectors across automotive, aerospace, defence, and medical manufacturing. We understand your inspection challenge before you describe it.

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True Telecentric Optics

Our parfocal telecentric lenses eliminate parallax error and Z-position sensitivity — the two most common sources of measurement uncertainty on inferior optical comparators.

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Scalable DRO Options

Start with the OP-250 for direct inspection. Upgrade to OP-1000 metrology software when your SPC programme demands more. The optical instrument never changes — only the intelligence layer.

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One Supplier, Full Range

Vertical, horizontal, small screen, large screen — standardise on Optomech across all your profile projection needs. Common accessories, common service, single point of contact.

Horizontal Profile Projectors — PP 400H & PP 600H — For Shafts, Threads & Cylindrical Parts