D-Lab 2: Spindle March 17th 2008

Project Update

Gantt Chart

Spindle

Shaft

Turning Threads

Fitting the Bearings Angular contact bearings lightly press fit to the shaft

Spindle Interior Shaft with the preloaded angular contact bearings and the rear roller bearing

Exterior Components The exterior consists of the headstock, end cap and housing

Creation of the Housing Starting with a solid 3in rod of aluminum

Spindle Exterior The finished product

Lathe Error Sources

Final HTM Output:

Spindle Error Sources Bearing errors (radial play, ball size, race profile, etc.) Machining errors: Concentricity of shaft features Concentricity of housing features Clearance fits Uneven deformation due to interference fits, preload, etc. Thermal gradients Errors in chuck registration

Spindle Error Test

Bearing Calcs Front bearing Rear bearing Reaction force: 400 lbs Desired life: 5000 hours Desired speed: 4000 RPM C10 = 4250 lbs Select A/C bearing set with dynamic load rating = 6560 lbs Rear bearing Reaction force: 200 lbs C10 = 2125 lbs Select Conrad bearing with dynamic load rating = 3210 lbs

Shaft-Bearing-Housing Fits From Barden literature for A/C spindle bearings Bearing-housing fit Normal accuracy, low to high speeds, moderate temperature = .0004 (nominal) clearance Bearing-shaft fit Inner ring clamped – very low runout, high radial rigidity = .0002 (nominal) interference

Tool Holder Joint Stiffness