Lesson 1Operation sequence planning: facing, center drilling, rough turning, step turning for shoulders, finishing passes and final length controlDescribe planning a complete turning sequence, from facing and center drilling through roughing, step turning, finishing, and final length control. Emphasize minimizing setups and preserving datums for accuracy.
Defining primary datums firstTypical order of turning operationsCombining cuts to reduce setupsLeaving stock for finishing passesFinal checks before part removalLesson 2Detailed steps to turn 40 mm bar to 35 mm shoulder and to 30 mm reduced end, including order and datum selectionProvide detailed steps to turn a 40 mm bar to a 35 mm shoulder and 30 mm reduced end. Emphasize datum selection, order of cuts, tool changes, and measurement points to maintain concentricity and shoulder accuracy.
Selecting datum face and diameterRough turning to near 35 mmTurning the 30 mm reduced sectionBlending shoulder and fillet radiusFinal finishing and inspection stepsLesson 3Roughing parameters for medium carbon steel: recommended cutting speed, feed and depth of cut (typical values and reference sources)Define roughing parameters for medium carbon steel, including typical cutting speeds, feeds, and depths of cut. Show how to use catalog data, machine power limits, and rigidity to choose safe, productive roughing settings.
Typical roughing speed rangesSelecting feed for stock removalDepth of cut versus horsepowerUsing manufacturer data tablesBalancing tool life and removal rateLesson 4Chip control, coolant selection and application for medium carbon steelDetail chip control and coolant practices for medium carbon steel. Explain chipbreaker use, feed and depth influence on chip shape, coolant types and concentrations, and correct nozzle placement for safe, stable turning.
Chipbreaker selection and setupAdjusting feed for chip breakingCoolant types and mix ratiosNozzle positioning on manual lathesDry cutting versus flood coolant useLesson 5Finishing parameters for medium carbon steel: target cutting speeds, lower depths/feeds for Ra 1.6 µm and reference sourcesDefine finishing parameters for medium carbon steel, including typical cutting speeds, feeds, and depths of cut to reach Ra 1.6 µm. Explain how to balance tool life and surface finish and how to use data from catalogs and standards.
Typical finishing cutting speed rangesFeed and depth for Ra 1.6 µm surfacesEffect of machine rigidity on finishUsing toolmaker catalogs and ISO dataAdjusting parameters from trial cutsLesson 6Facing and length control techniques: use of stop collars, parting-off allowance, and end-face tolerance managementCover facing and length control on de lathe, including use of stop collars, soft jaws, and parting allowances. Explain how to achieve flat, square faces and maintain end-face tolerances over multiple identical parts.
Facing tool geometry and setupUsing stops and collars for lengthAllowances before parting-offChecking face flatness and squarenessControlling length on repeated partsLesson 7Center drilling and use of centers: sizes, depths, and when to use tailstock supportExplain center drilling and de use of centers for supporting work. Cover drill sizes, depths, correct center forms, lubrication, and when to use tailstock support to prevent deflection and improve dimensional accuracy.
Types and sizes of center drillsCorrect center drilling depthLive versus dead center selectionLubrication of centers and tipsWhen to support long slender workLesson 8Parting-off best practices and preventing chatter or plunging errorsProvide best practices for parting-off medium carbon steel, focusing on tool selection, blade overhang, and feed control. Explain how to prevent chatter, tool breakage, and plunging errors through setup and parameter choices.
Choosing parting blade widthSetting blade height and overhangFeeds and speeds for parting steelReducing chatter and squealAvoiding tool jamming at breakthroughLesson 9Tool setup and offsets: tool height, lead angles, toolpath thinking for manual and CNC lathesExplain tool setup and offsets for manual and CNC lathes, including tool height, lead angles, and toolpath planning. Show how to avoid rubbing, chatter, and collisions by correct offset entry and trial cutting.
Setting tool height on centerlineLead angle and approach directionEntering and checking CNC offsetsTrial cuts and wear offset updatesPlanning safe approach and retractLesson 10Tool selection: turning inserts (grades/coatings), tool nose radius, HSS vs carbide choices and why for each operationExplain how to select turning inserts and tool materials for medium carbon steel. Compare HSS and carbide, review grades and coatings, and show how nose radius and geometry affect finish, chip control, and tool life in each operation.
ISO insert shapes and chipbreakersCarbide grades for medium carbon steelWhen HSS tools are still appropriateChoosing tool nose radius by operationCoating selection for dry and wet cutsLesson 11Dimensional checks between lathe operations: where and when to measure to maintain tolerancesCover when and where to measure parts between lathe operations to maintain dimensional tolerances. Discuss tools such as micrometers and calipers, thermal effects, and strategies for in-process checks and final verification.
Selecting micrometers and calipersMeasuring diameters near shouldersControlling length and face squarenessCompensating for thermal expansionRecording and reacting to measurement dataLesson 12Chamfering procedure: tool geometry, single-pass vs multi-pass chamfers and inspectionDescribe correct chamfering procedures on de lathe, including tool geometry, approach angles, and single-pass versus multi-pass methods. Explain how to set chamfer size, avoid burrs, and inspect chamfers accurately.
Chamfer tool geometry and anglesProgramming chamfers on CNC lathesSingle-pass versus multi-pass chamfersMeasuring chamfer width and angleDeburring and edge quality checks
