How do I calculate the exact Pitch Diameter (L) for a 2mm GT2 or 5mm HTD belt?

Multiply your desired Tooth Count (H) by the belt pitch and divide by pi (3.14159). For example, a 40-tooth GT2 pulley (2mm pitch) has D_p = (40 × 2) / 3.14159 = 25.46mm; a 32-tooth HTD-5M pulley (5mm pitch) has D_p = (32 × 5) / 3.14159 = 50.93mm.

Why does the central shaft bore include a rectangular notch at the top?

That is a standard DIN 6885 shaft keyway slot. It allows you to slide a square machine key or D-shaft flat adapter into the bore so the pulley transmits high torque without spinning on the motor shaft.

When are the 4 circular lightening holes automatically added?

Whenever the radial web between the central keyway bore and the tooth root circle is wide enough to fit at least Ø6.0mm holes with safe wall margins, the generator automatically places 4 concentric lightening/bolting holes.

Is the entire outer tooth profile a single closed polyline?

Yes! All tooth crests and rounded root gullets are stitched into a single 100% closed, non-self-intersecting LWPOLYLINE on the CUT layer.

TEMPLATE ID: PRE-MEC-006 80 × 16 × 40 mm (T=3mm) Pre-Verified 1:1 Static Files Ready

40-Tooth Synchronous Timing Belt Reduction Pulley (Ø80mm Pitch, Ø16mm Keyed Shaft Bore)

Interactive Parametric 2D & 3D Studio

Live 2D Dieline, Interactive 3D Fold Preview & Custom Size Generator

Pre-loaded with 40-Tooth Timing Belt Pulley (DXF) (80×16×40 mm, T=3mm)

1:1 CAD ENGINE READY

40-Tooth Synchronous Timing Belt Reduction Pulley (Ø80mm Pitch, Ø16mm Keyed Shaft Bore)

1CAD Style & Material SetupMechanical

Select CAD Style / Model (36)Search & Filter

Material Stock Preset (Auto-Sets Caliper T & Kerf K)

Display Units

Scale Lock

1:1 True Scale

2Dimensions (1:1)Millimeters (mm)

Pitch Diameter (D_p mm)80 mm

Center Shaft Bore (Ø mm)16 mm

Number of Teeth (Z / N)40 mm

Thickness (T mm)

Laser Kerf (K mm)

3Brand Logo & 1:1 ExportZero Login

2D & 3D Brand Logo Mockup:

📤 Upload Logo

Print Artwork Bleed Guide:

Embed Spec Sheet & 50mm / 1" Scale Bars (Added on separate DIMENSIONS layer)

Pre-Flight Geometry Audit8/8 PASSED

PASS
Closed Outer Contours: 6 closed LWPOLYLINE cut loop(s) verified
PASS
Zero Duplicate Cut Paths: 272 unique segments (0 laser double-burns)
PASS
Flute & Kerf Tolerance Guard: T=3.00mm, K=0.100mm within structural limits
PASS
ISO Layer Color Separation: CUT (Red), CREASE (Blue), SCORE (Emerald), DIMENSIONS isolated
PASS
1:1 Physical Unit Header: Explicit mm/in SVG viewBox + DXF $INSUNITS=4 + 50mm PDF bar
PASS
Exact 2D Cut Bounding Parity: Cut Bounds 80×80mm === Blank Size
PASS
2D ↔ 3D Kinematic Model Sync: Archetype 'timing_pulley_gt2' synced (1 3D component(s))
PASS
True Vector Sheet Nesting Sync: 1:1 vector paths mapped to multi-up sheet grid

100%

CUT (0.49m) CREASE/SCORE (0.27m)● 6 Loops · Est. Cut: ~24s

1:1 Synced · Blank: 80 × 80 mm

2D 1:1 Unfolded Vector BlueprintBlank: 80 × 80 mm (3.15" × 3.15")

3D Interactive Fold & Orbit (Kraft Board)

80%

0%100%

Camera:

Yaw: -28°Pitch: 24°

⟳ Drag Anywhere to Rotate 3DL=80 × W=16 × H=40mm

Outside Diameter (OD)

80 mm

Tooth Count (Z)

40 Teeth

Circular Belt Pitch

6.28 mm

Center Shaft Bore

Ø 16.0 mm

Direct Pre-Generated 1:1 CAD Files

Download Static Ready-to-Cut Files (80×16×40 mm)

These static files are pre-calculated for 3mm material thickness and 0.1mm laser kerf. Click any format below to download the pre-built static file, or export custom dimensions directly from the interactive Studio above.

↓ Download .DXF AutoCAD / LightBurn ($INSUNITS=4) ↓ Download .SVG Illustrator / Corel (1:1 mm) ↓ Download .PDF 1:1 Print + 50mm Scale Bar

Product Manufacturing Specification Sheet

Calibrated Physical Clearances & Material Stock for 40-Tooth Timing Belt Pulley (DXF)

Parent Parametric Engine: Timing Belt Pulley & Sprocket →

Target Physical Product Size

40-Tooth Synchronous Belt Driven Sprocket (Ø80.0 mm Pitch Circle, 6.28 mm Circular Pitch)

Engineered Internal Cavity & Clearance

Ø16.0 mm Central Bore + DIN 6885 Anti-Rotation Keyway + 4 Radial Weight-Reduction Holes

Recommended Board / Sheet Stock

6.0mm Delrin / Acetal (POM), 5.0mm Cast Acrylic, or 3.0mm Aluminum

Grain / Flute Orientation Rule

Isotropic Engineering Plastic / Metal

Production Engineering Note: Provides a 2:1 speed reduction / 2x torque multiplication when paired with a 20-tooth drive pinion.

Structural Geometry & Material Reference (ISO 5294 Synchronous Belt Drive & DIN 6885 Keyway Standard)

Synchronous timing belt pulleys (such as GT2, HTD 3M/5M, and XL profiles used in CNC machines, 3D printers, and robotics) require rounded root gullets and smooth crest transitions so the toothed elastomer belt engages with zero backlash. Our parametric timing pulley generator computes the exact circular tooth pitch (P = pi × D_p / N), traces a continuous closed sinusoidal-arc outer tooth profile, cuts a concentric shaft bore with an integrated DIN 6885 anti-rotation keyway slot, and adds 4 radial lightening holes on larger pulleys.

Circular Belt Pitch from Pitch Diameter & Tooth Count (P_belt)

P_belt = (pi * D_pitch) / N_teeth

Relates Pitch Diameter (L) and Tooth Count (H) to the linear belt pitch (e.g., set L = 38.2mm and H = 60 teeth for a 2mm GT2 pitch, or L = 64mm and H = 32 teeth for a 6.28mm pitch).

Pulley Outside Crest Diameter (D_outside)

D_outside = D_pitch - 2 * PLD (or D_pitch + 0.15 * P_belt)

Computes the outer crest diameter and rounded tooth root gullet depth (0.34 × P_belt) for smooth belt meshing.

DIN 6885 Shaft Keyway Slot Width (W_key)

W_key = max(2.5 mm, 0.28 * D_bore)

Dimensions the integrated anti-rotation keyway slot at the top of the central shaft bore.

Internal CAD Silo & Related Ready-to-Cut Templates