Lathe Machining: Tools, Operations, and Threading
Lathe Tools and Operations: Part 1
How are Lathe Cylinder Tools Called?
Blades parallel to a straight cylinder.
How Many Types of Facing Tools Are There?
Facing tools for angle ‘i’ to the capping, free, or step.
What is a Squaring Tool Used For?
For flexible parts without a bezel.
What is a Gooseneck Grooving Tool Used For?
For large diameter internal profiling.
What is the Active Part of a Cutting-Off Tool?
The widest and sharpest part.
What are the Advantages of an Inverted Cutting-Off Tool?
Strong vibrations or shocks are not produced.
How is Automatic Advancement Achieved When Drilling on a Lathe?
Mount the drill machine to the carriage.
How is a Large Diameter Drill Held on a Lathe?
It is held with a small dog and the tailstock.
Which Tools are More Robust for Exterior or Interior Work?
Tools with less overhang.
What is an Interior Grooving Blade Like?
It is 90 degrees.
What is the Purpose of These Lathe Tools?
To give a concrete shape to a workpiece.
What is a Constant Profile Tool?
Special tools for series production of pieces where only the cutting surface is sharpened.
Where are Constant Profile Tools Sharpened?
On the incidence face.
Constant Profile Tool Sharpening Calculation
For a constant profile tool with a 50mm height below the center, the sharpening angle for chip removal at 6ยบ is calculated as: H = 0.06xD = 0.06×50 = 3mm.
Advantages of Constant Profile Tools vs. Ordinary Tools
The constant profile tool only requires sharpening on one face, while the ordinary tool requires sharpening on all sides.
What is the Purpose of Knurling?
To make the workpiece more adherent.
Is Knurling a Precision Operation?
No.
What Tool is Used for Knurling?
Knurling wheels.
How is a Knurled Length Achieved?
With automatic movement of the carriage.
How to Achieve a Very Narrow Knurl?
Perform the cylinders without knurling first, then knurl later.
Maximum Overhang for a Tool Without a Bezel?
Greater than or equal to the height of the tool.
Precautions When Assembling a Tool?
Control the cantilever height.
What Type of Lubricant is Used in Knurling?
Oil.
Lathe Operations and Thread Cutting: Part 2
Does the Lathe’s Feed Gearbox Allow All Possible Thread Pitches?
No.
What Types of Threads Can the Feed Gearbox Offer?
Metric, Whitworth.
Gear Ratio for a 2mm Triangular Thread Pitch
For a triangular thread with a 2mm pitch, the gear ratio needed is: 2.3 * 5 = 7 (Pasadena).
When is Oblique Penetration Used?
For large steps.
Which Carriage is Used with Oblique Penetration?
With the orientable carriage.
Can Radial Penetration Be Performed with That Carriage?
With the cross slide.
How is Radial/Axial Penetration Performed?
With the cross slide and orientable carriage.
Pitch in mm for a 14 TPI Thread
What is the pitch in mm for a thread that has 14 threads per inch (TPI)? 25.4 / 14 = 1.81mm.
Pitch in mm for a 3/8 Inch Pitch Thread
What is the pitch in mm for a thread that has a pitch of 3/8 inch? 3/8 * 25.4 = 9.52mm.
How is the Tool Returned?
Retouching the tool and returning it to its site.
Can This Gear Assembly Be Done on a Lathe’s Gear Train?
Can the following gear assembly be done on the gear train of a lathe? 40-A60, 125-A30. No, because C+D is not greater than B.
Calculate Gear Train for 4.5mm Screw on 5mm Lead Screw
Calculate the gear train to put on the gear train of a lathe that has a threaded shaft with a 5mm pitch to make a 4.5mm screw: Pn / Ph = 4.5 / 5 = 9 / 10.
Calculate Gear Ratio for 2.7mm Thread on 6mm Lead Screw
For a lathe with a 6mm lead screw pitch, calculate the gear ratio to make a 2.7mm thread pitch: Pc / Ph = 2.7 / 6 = 27 / 60.
Calculate Gear Ratio for 3 TPI Thread on 6mm Lead Screw
For a lathe with a 6mm lead screw pitch, calculate the gear ratio to make a 3 threads per inch (TPI) screw: 1 inch = 25.4mm. The calculation provided is: Pc / Ph = 25.4 / 6.3 = 254 / 180.
Calculate Gear Ratio for 2.64mm Thread on 12mm Lead Screw
For a lathe with a 12mm lead screw pitch, calculate the gear ratio to make a 2.64mm thread pitch: Pc / Ph = A / B = 2.64 / 12 = 264 / 1200.