Monday, September 09, 2013

Grandpa's Collection

After Grandpa died I had asked mom if I could have his wooden clamps, the ones he used to hold together the chairs he repaired that are in our dinning room.  I got those, as well as his collection of screws, nuts, washers, bolts, and other small fasteners all in three small wooden boxes.  It took a long time, many winter evenings were spent sorting them out while the television was on.

Today I used four bolts from that collection.  I needed something to hold the bars that hold the 4-bar motor stabilization mechanism in place.  The 8-32 bolts I bought were too small, the 1/4-20 bolts I bought were too big.  Having sorted out previously I found a film container with 12 10-24 bolts.  I only needed 4.  I used http://www.physics.ncsu.edu/pearl/Tap_Drill_Chart.html to figure out which size drill I needed, my calipers to search through the drills I have (bought a toolbox for $5 that had many drill bits and other lightly rusty tools in it about a year ago, cleaned everything up and have used many of the tools.)  I found what I was looking for, drilled, and then because this was in the 1.125 thick metal that I broke the 1/4-20 tap in earlier I counterbored from the backside with a 1/4" drill bit.  Then I hand tapped the 4 holes, 1/2 turn forward, 1 turn back, 1.5 turns forward .5 back... 4 successful mounting points.

As I had time this evening I made a drilling fixture for my spring buttons, which also is a locating fixture for the pedestal mounting rivets.  Now the rivets are purely for show but I wanted them evenly spaced.  while centerdrilling the pedestal mounting rivet holes I thought why not locate and drill all the other for show rivets at the same time.

Anna came down and helped me.  We used the end rivet locating jig to scribe a mark of horizontal for each hole and then looked at the CAD drawing and used the calipers to measure how far each hole was from the end.  Marked the hole with a centerpunch and a mark from a magic marker.  Centerdrilled many holes, then drilled many holes.  Last because all the holes on the left side line up with the right side we matched the parts up and used the transfer punches to mark the locations on the second piece.

That is when bedtime snuck upon us.  Hugs and kisses and cleaning up the shop, a photo of the progress, the centerdrilling and drilling of the right side will have to wait for Thursday.


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