Saturday, December 24, 2011

Cable Splicing Clamp - Complete

This piece is the adjustable part of the clamp to hold the cable secure while the splice is formed.  On Rich's clamp this piece is made from 1/2" round stock.  Rather than buy another 36" piece of steel for a 3/4" long piece I decided to make this from some of the 1" x 1/2" bar stock. The other advantage to this is it will be self aligning while clamping the cable.  The first step was to drill the center hole for the 3/8" bolt and 2 end holes for the 1/4" bolts.  I used the center drill to start the holes then drilled through with a 1/8" drill for a pilot hole.
The 3/8" bolt hole was drilled with a size Q drill for tapping the 3/8-24 threads.  For convenience I used the same size drill for the other 2 holes.  They just need to clear the bolts so the piece slides easily without turning.
The idea was to notch the ends with the band saw to make assembly easier.  What I hadn't thought enough about was that the three holes are not on a line.  That's why I like making drawings before I start cutting metal.  The solution was to cut to the end holes from 2 sides leaving a tab to keep the bar from turning.  In the end it's how I would make another one.  I'd just move the hole over a little so the tab is closer to the bolt.
The next step was to cut the Vee at the top center for the cable loop to set in.  I then removed some of the metal to give the bar a pleasing shape.  OK you could live without that but come on Craftmen take pride in their work.  The shaping was finished with files and the belt sander.

The adjustment bolt was threaded into the bar with the thumb wheel o
installed.  Some Locktite was use as well as tightening the bolt so it bottomed out.
The head of the bolt was cut off.  A thin washer was added as a bearing.
The end of the bushing was flared with the pointy end of a body hammer.  The hole in the base was chamfered  to allow the peened end of the bushing to flare out and lock the base to the block but still pivot.  I found, in use, this didn't hold well and fixed it with a 1/32" deep counter bore in the bar with a 9/16" drill instead of the chamfer.  Then peended the bushing as shown, rotating the pointy (not round) hammer to peen it in multiple spots.  Much better.
When I went to install the holding plate I found I had not tapped the holes squarely.  I didn't want to make another one so I clamped each end in the vise and bent it slightly to get the bolt aligned.  It may be crude but it worked perfect after lots of thinking to make sure I bent the ends the right direction.

Before assembly all the fabricated parts were  grit blasted for a nice finish.  Keep it lightly oiled with Corrosion-X and it should last for years.  The 2 slider bolts were cut to leave no threads sticking out of the plate, and installed with locktite.

I like it!  Thanks for the loan Rich.

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