Tips and techniques

 

These galleries show some tips and ideas for helping make the manipulator.

Experienced machinists might bear with us as we are facilitating constructors with no previous experience and please forward any ideas or criticisms that you feel might help.

 

Cutting, drilling and marking

  • Two tips in one image! Cut square by keeping hacksaw aligned against jaw edges, the jaws are hardened so you won't damage them. Grip screw by thread rather than head for better grip.
  • When drilling the cylinders and discs (coins) it is very important to support them from underneath to keep them parallel and aligned and to prevent slipping or twisting.
  • Use a sharp wood screw as a cheap and effective punch to give a starting mark for drilling both discs and cylinders.
  • To give a really accurate mark around a cylinder or rod just insert into drill chuck and hold a scalpel blade against desired position. SAFETY NOTE - only do this with drill rotating away from you! If the rotation is towards you the scalpel may catch.

 

 

Finishing and polishing

  • Slide cut rod backwards and forwards on carbide or emery paper until cut marks smoothed away.
  • Slide smoothed rod end backwards and forwards on cloth with an applied dab of metal polish.
  • Insert rod into drill and polish with cloth and polish (or just by hand!).
  • Mirror finish available using simple hand tools and polish.

 

 

Marking coin centres for drilling

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Download and print for use as shown in gallery below
Circlecentre.pdf
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  • Print out circle centre template for marking coin for really accurate drilling of centre.
  • Hold up against window with print away from you but visible by transmission of light through paper.
  • Attach coin to exact centre of template using adhesive tape to sides or, better again, double-sided tape to underside.
  • Invert paper onto bench with coin underneath and strike wood screw punch smartly with hammer to give guiding mark for drilling.

 

TAPPING

There is no mystery or special technique to making a threaded hole and instructions for making a tapped M5 hole are given below.

 

  1. Use wood screw punch to mark hole centre.
  2. Drill 4.5mm hole using drop of oil and keeping drill bit upright and plumb in both planes.
  3. Insert tap into drill and drop of oil to hole. Then 'drill' very slowly into hole keeping drill bit upright and plumb in both planes. After a couple of seconds reverse drill for a moment to clear swarf and then repeat slow tapping. Keep doing this until threading is complete.