Gear reducing on a horizontal milling maker calls for accurate estimations to guarantee precise tooth accounts and appropriate meshing. This article outlines the necessary computations for spur gear generation, covering cutter option, empty prep work, indexing, deepness of cut, and machining criteria. The process thinks a typical involute tooth kind with a 20 ° stress angle.
(how to make calculations for gear cutting in horizontal milling machine)
** 1. Cutter Selection: **.
Equipment cutters are module-specific and classified by tooth variety. An 8-cutter set (No. 1 to 8) covers varying tooth matters:.
– ** Cutter No. ** = Feature of gear teeth (N):.
No. 1: 135– Rack|No. 2: 55– 134|No. 3: 35– 54|No. 4: 26– 34 |
No. 5: 21– 25|No. 6: 17– 20|No. 7: 14– 16|No. 8: 12– 13.
* Instance: * A 28-tooth equipment needs Cutter No. 4.
** 2. Blank Size Calculation: **.
The outside diameter (OD) of the gear blank should accommodate the complete tooth deepness:.
– ** OD ** = (Number of Teeth + 2) × Component (M).
* Example: * For a 28-tooth equipment with M= 4 mm: OD = (28 + 2) × 4 = 120 mm.
** 3. Deepness of Cut (Complete Depth): **.
Total axial depth to attain right tooth elevation:.
– ** Depth ** = 2.25 × Component (M).
* Instance: * M= 4 mm → Depth = 2.25 × 4 = 9.00 mm.
* Note: * Roughing cuts (e.g., 8 mm) precede a completing cut (1 mm) to lessen deflection.
** 4. Indexing Estimation: **.
A splitting head (40:1 ratio) places the blank. Indexing turns per tooth:.
– ** Transforms ** = 40/ N (N = variety of teeth).
For fractional turns, utilize an index plate.
* Instance: * 28-tooth gear → Transforms = 40/28 = 1.42857 turns.
Using a 21-hole plate: 0.42857 × 21 ≈ 9 holes. Hence, 1 full turn + 9 holes on 21-hole circle.
** 5. Spindle Speed (RPM): **.
Based upon cutter product (HSS) and workpiece:.
– ** RPM ** = (Cutting Rate × 1000)/ (π × Cutter Size).
* Example: * Cutting rate for mild steel = 25 m/min; cutter Ø = 80 mm:.
RPM = (25 × 1000)/ (π × 80) ≈ 99.5 → ** Set 100 RPM **.
** 6. Feed Price: **.
Table feed (mm/min) relies on feed per tooth (f) and cutter teeth (Z):.
– ** Feed Price ** = f × Z × RPM.
* Instance: * f = 0.08 mm/tooth; Z = 16; RPM= 100:.
Feed Rate = 0.08 × 16 × 100 = 128 mm/min.
** Important Arrangement Notes: **.
– Center the cutter radially and axially relative to the blank.
– Secure the blank rigidly in between centers or a component.
– Confirm dividing head positioning alongside the table travel.
– Use reducing liquid for steel/alloys to prolong device life.
** Validation: **.
Post-machining, evaluate tooth thickness with gear calipers or a comparator. Academic chordal tooth thickness (s) and addendum (a) are:.
– ** s ** = M × N × wrong( 90 °/ N)
. -** a ** =M [1 + (N/2) × (1– cos( 90 °/ N))] * Instance: * M= 4 mm, N= 28 → s ≈ 6.63 mm, a ≈ 4.16 mm.
** Final thought: **.
(how to make calculations for gear cutting in horizontal milling machine)
Exact computations in gear milling avoid undercutting, extreme reaction, or premature wear. Mastery of these fundamentals– cutter geometry, indexing, and machining characteristics– ensures dependable gear production on horizontal milling devices. Constantly cross-reference equipment handbooks for particular configuration tolerances.