Procedure for Transferred holes assignment

 

Select material.

1.         Aluminum blocks ideally 3” X 3” X ½” however a smaller size is acceptable.

 

Machine bocks square.

2.         Machine blocks to a even ¼” for instance 2.750”, 2.500” 2.250 etc.

2a.       Clamp blocks face on in a pair and fly cut one edge until cleaned up.

2b.       Flip blocks over and machine opposite edge to final size.

2c.       Put one block aside and clamp the other (by the newly machined edges), on parallels with an un-machined edge protruding (sticking out) from the vice.

2d.       Change cutter to an end mill.

2e.       Machine edge until cleaned up.

2f.        Put block aside and machine the second block as the first.

2g.       Clamp both blocks with the end milled side down in the vice.

2h.      Change cutter back to fly cutter.

2i.        Fly cut both blocks to finished size.

 

Layout.

3.         Set height gauge to .250” and layout one block four ways.

 

Punch cross hairs.

4.         With a center punch on a solid surface prick punch all four cross hair marks.

 

Drill top block.

5.         Drill top block with the clearance drill for ¼ - 20 (one fractional size above the screw size)

 

Transfer holes to lower block.

6.         With the matching transfer punch for the clearance hole transfer the four hole to the lower block, be sure to securely clamp blocks together.

 

Re-punch transferred holes.

7.         With a center punch deepen the transfer punched holes.

 

Drill tap hole.

8.         With the tap drill for ¼ - 20 drill the four holes in the lower plate.

 

Tap holes.

9.         With a ¼ -20 tap, tap all four holes, ensure that tap is perpendicular to the work and use oil.

 

Attach plates.

10.       With four ¼ - 20 screws securely attach the two blocks.