Crank Design Guide
Safety
Chamfer all protruding corners. Deburr and break all edges .25 in.+- min.
Corrosion Resistance
Gears are brass.
All steel custom parts painted black.
Black oxide fasteners.
Manufacturing
Plans for Each Part
Square Base
The wooden square base will be sawed and milled to size. Holes will be
tapped and spot faced with universal milling machine.
Cylinder Base
The wooden cylinder base will be sawed and turned to size. Holes will be
tapped and spot faced on universal milling machine
Rotating Plate
The wooden rotating plate will be sawed and milled to size. Holes will be
drilled on a universal milling machine
Top Cylinder
The wooden top cylinder will be sawed and turned to size. Hole will be
drilled on a universal milling machine.
Presumed Process Capabilities
Process Min Tolerances Geometric Restrictions
Sawing +/- .01 in on 1 min. on corners
features No sharp edges
+/- 1 degree on
corners
Milling +/- .01 in. No sharp corners
No small detail in narrow
deep locations
Turning +/- .01 in.
Drilling +/- .001 in. on Holes only
size, shape and
alignment
Minimum Assembly Clearances
Parts Min Clearances
Cylinder Base and Square .013 in.
Base vs. Screws
Calculations
Cylinder Base and Square Base vs. Screws
½ in. screws through two .531+/- .004 in. clearance holes then
into two ½ in. 13 tapped holes
T=H-F/2
T=(.527 - .5)/2
T=.013 in.