Lesson 5: Dovetails & Tapers
Duration of Days: 3
Lesson Objective
SWBAT: Calculate the "Tailstock Offset" required to turn a specific taper on a lathe.
Solve for the width of a dovetail slide using the Tangent function and "measurements over pins."
How do we ensure two tapered parts fit together perfectly without "wobbling"?
Why is a "measurement over pins" more reliable than a standard caliper reading on a dovetail?
Taper, tailstock, tailstock offset, dovetail slide, point angle, taper per foot (TPF), taper per inch (TPI).
CTE.MFG.C.11 (Identify common power transmission components); CTE.MFG.D.22 (Problem-solving in manufacturing).
Students apply trig to the two most common "complex" features in machining. The purpose is to calculate the dimensions for sliding fits (dovetails) and conical shafts (tapers).
DOK Level: 4 (Extended Thinking
Support: Provide a "Taper Table" for students to check their math against standard industrial tapers (like Morse Tapers).
Extension: Calculate the angle of a Drill Point and how its depth affects the total depth of a "blind" hole.
"The Dovetail Challenge" – A final practical exam where students calculate the dimensions for a matching dovetail set.