BIZOMAT MAKEOS · Manufacturing
Angular Cutter or Taper Reamer Fluting Set-up (Head Angle and Indexing)
To flute an angular cutter or taper reamer blank on a dividing head, at what angle do I set the head and what index setting moves between teeth?
Set-up for milling the flutes of an angular milling cutter or taper reamer: the dividing-head setting angle from the number of teeth, the angle of the blank and the angle of the fluting cutter, with the intermediate angles (as the angular cutter fluting tool), and the simple indexing setting between teeth (as the simple indexing tool).
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Number of teeth | Number of teeth to cut on the cutter or reamer. | |
| Angle of the blank | ° | Angle of the blank’s conical face. |
| Angle of the fluting cutter | ° | Included angle of the fluting cutter. |
| Dividing head worm ratio | :1 | Worm ratio of the dividing head. |
| Index plates available | choice | Index plates you have. |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Number of teeth
- What it is
- The number of teeth (flutes) to be cut around the angular milling cutter or taper reamer blank.
- Units and format
- Enter a plain number with no unit. The form accepts 5 to 200. Use a whole number. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 9 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- It also sets the indexing between teeth; some counts cannot be reached with simple indexing and are flagged.
What this means: Angle of the blank
- What it is
- The angle of the blank’s conical face on which the teeth are cut, from the cutter or reamer drawing.
- Units and format
- Enter a number in °: degrees of angle. The form accepts 0° to 85°. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 35° as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Check whether the drawing gives the face angle or the included angle; 0 is accepted and treated as a flat face.
What this means: Angle of the fluting cutter
- What it is
- The included angle of the fluting cutter that forms the tooth spaces, as marked on the cutter.
- Units and format
- Enter a number in °: degrees of angle. The form accepts 20° to 85°. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 55° as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
What this means: Dividing head worm ratio
- What it is
- The number of crank turns that rotate the dividing head spindle one full revolution, stamped on the head or in its manual.
- Units and format
- Enter a number in :1: a ratio to one (type 3 for 3:1). The form accepts 1 :1 to 200 :1. Use a whole number. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 40 :1 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Enter only the first number of the worm ratio, the crank turns per spindle turn.
What this means: Index plates available
- What it is
- The set of index plates you have for the dividing head; the tool searches their hole circles for a simple indexing setting.
- Units and format
- Choose one of 2 options from the list: Brown & Sharpe plates 1–3; Cincinnati standard plate (both sides).
- Example
- The form opens with “Brown & Sharpe plates 1–3” selected as a worked example. Choose the option that matches your case.
Method and formulas
- tan D = cos(360° ÷ N) ÷ tan B; sin E = tan(360° ÷ N) ÷ tan C × sin D; setting angle A = D − E (as the angular cutter fluting tool).
- Angle between teeth = 360° ÷ N.
- Crank turns between teeth = ratio ÷ N (as the simple indexing tool).
- Example: set the head to 21.87° and index 4 turns and 8 holes in the 18-hole circle between teeth.
Limitations
- Handbook set-up for straight flutes on a conical blank.
- Simple indexing only.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Make an angular cutter or taper reamer
- Set the dividing head for fluting a cone
- Check a tooth count can be indexed
Who it is for
- Toolmakers
- Machinists
- Toolroom staff
What you get
- Setting angle and intermediate angles
- Angle between teeth
- Index setting
Interpreting the result
- Check the land width on the first two teeth before cutting the rest.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 833–834, 2107–2121. Topic reference; no source tables or recommended settings are reproduced.
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Open the Angular Cutter or Taper Reamer Fluting Set-up (Head Angle and Indexing) calculator