A multiple-spindle drilling head drives several tools from a common input. Explore a schematic central-gear arrangement and calculate spindle speed from the input speed and driver-to-spindle tooth ratio.
Multiple-Spindle Common-Drive Calculator
Enter a declared spindle count, input speed and gear tooth counts. The worksheet reports the ideal output-speed magnitude, external-mesh direction relationship and simultaneous tool positions. It does not select a drill head or predict machining performance.
Equation Used
- One declared driver gear meshes externally with N equal spindle gears.
- All gears are ideal involute gears with compatible module or diametral pitch and no slip.
- The schematic identifies tool positions for a common-feed head; feed movement is not simulated.
- Torque, power, losses, stiffness, backlash, feed, chip load, drill geometry, workholding, pitch accuracy, cycle time and safety are excluded.
The common input sets each spindle speed through the entered tooth ratio. The schematic shows rotation and tool positions; feed travel and machining time are not simulated.
A common drive rotates several drilling spindles
Multi-spindle-head patents show several drilling units powered from one motor or input shaft. One documented prior-art layout uses an output gear meshing with several surrounding gears, then universal joints and telescoping splined shafts to reach adjustable parallel drills. The head advances the selected positions together.
The animation is a declared connection map: one central driver, equal output gears and one tool position per output.
A common-drive topology reference
Multiple-spindle heads are useful when a repeatable set of tool positions must work together. Actual spindle placement, engagement and feed depend on the selected head; patents also show adjustable and selectively retractable units.
Ideal external-gear speed ratio
One external mesh reverses direction. The equation does not establish available torque, power or allowable cutting conditions.
Declared drive example
For six declared spindle gears, a 1,200 rpm input, 24 driver teeth and 36 teeth per spindle gear, every ideal output turns at 800 rpm in the opposite direction and six tool positions are available for simultaneous feed.
Spindle speed and machining performance
The gear ratio sets ideal spindle speed, but it does not determine cutting feed or cycle time. Those depend on the tools, workpiece, engagement, machine power and setup. A physical head also needs a layout with adequate gear clearance and appropriate shafts and bearings.
Multiple-spindle drilling questions
Do all heads use one central gear?
No. This is a declared topology; patents show gear trains, common shafts, universal joints and other arrangements.
Do all declared spindle positions have to drill?
Not necessarily. Some designs selectively retract or disengage units.
Does output rpm determine safe drilling feed?
No.
Multiple-spindle drilling references
- US3682560A, Multiple-Spindle Drilling Machine: describes several drilling units driven from a common power source, simultaneous feed, and a prior-art output gear with universal and telescoping shafts.
- DE3118515A1, Multi-Spindle Drilling and/or Milling Apparatus: describes multiple tool spindles driven together through gearing and individually movable units.
- US4066378A, Multi-Spindle Drilling Machine: documents simultaneous multi-spindle drilling and adjustable pitch-circle arrangements.
- HOMAG DRILLTEQ D-500 brochure: manufacturer example documenting a 32 mm drilling-spindle spacing.
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