Hand Drill: Difference between revisions
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Most have a [https://en.wikipedia.org/wiki/Chuck_%28engineering%29 '''Keyed Chuck'''] which accept [https://en.wikipedia.org/wiki/Drill_bit_shank#Straight_shank '''Parallel Shank'''] drills with a capacity of up to 6mm diameter. The handle turns a large '''[[:Category:Gears|Bevel Gear]]''' which meshes with one or two smaller '''[[:Category:Gears|Pinions]]'''. The '''[[Gear Ratio]]''' provides the neccessary '''[[Mechanical Advantage]]'''. | Most have a [https://en.wikipedia.org/wiki/Chuck_%28engineering%29 '''Keyed Chuck'''] which accept [https://en.wikipedia.org/wiki/Drill_bit_shank#Straight_shank '''Parallel Shank'''] drills with a capacity of up to 6mm diameter. The handle turns a large '''[[:Category:Gears|Bevel Gear]]''' which meshes with one or two smaller '''[[:Category:Gears|Pinions]]'''. The '''[[Gear Ratio]]''' provides the neccessary '''[[Mechanical Advantage]]'''. | ||
The better quality drills always have two '''[[:Category:Gears|Pinions]]''' and the '''[[:Category:Gears|Gears]]''' are fully enclosed to avoid the danger of trapped fingers! | The better quality drills always have two '''[[:Category:Gears|Pinions]]''' and the '''[[:Category:Gears|Gears]]''' are fully enclosed to avoid the danger of trapped fingers! | ||
Young children may have difficulty drilling holes which are truly '''[[Squareness|Square]]''' to the surface ''(e.g. of a disc to make a wheel)''. A simple '''[[Jig]]''' can be made which supports a Hand Drill within a sliding frame to assist. In use, one child operates the drill and another holds the work-piece to be drilled . . . . but . . . | |||
<span style="color: blue">'''Activity:''' | |||
Consider how to design and make a simple '''[[Jig]]''' to hold the work whilst drilling discs to make wheels - ideally one which 'self-centres' the discs. | |||
</span> | |||
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[[Category:Drilling and Boring]] | [[Category:Drilling and Boring]] | ||
Revision as of 15:01, 19 March 2016
Hand Drills (aka Wheel Brace) are a useful addition to a toolbox and can complement Electric Drills when there is a need to:
- drill just a few small holes
- drill pilot holes
- countersink holes
Most have a Keyed Chuck which accept Parallel Shank drills with a capacity of up to 6mm diameter. The handle turns a large Bevel Gear which meshes with one or two smaller Pinions. The Gear Ratio provides the neccessary Mechanical Advantage.
The better quality drills always have two Pinions and the Gears are fully enclosed to avoid the danger of trapped fingers!
Young children may have difficulty drilling holes which are truly Square to the surface (e.g. of a disc to make a wheel). A simple Jig can be made which supports a Hand Drill within a sliding frame to assist. In use, one child operates the drill and another holds the work-piece to be drilled . . . . but . . .
Activity:
Consider how to design and make a simple Jig to hold the work whilst drilling discs to make wheels - ideally one which 'self-centres' the discs.