2011-03-05

truss rod

Today I finished the truss rod. It's constructed from carbon steel rod folded in half, a 0.5"x0.25"x0.75" brass block, a brass nut, a washer, and flashing tape.
 Here's the folded end. A map gas torch and a hammer made this quite easy. OK, that's an oversimplification. I first tried this with T-303 stainless and time after time the metal fractured at the bend, once breaking completely apart. I moved up to map gas from propane and got the metal yellow-hot and thoroughly reworked the bend with a hammer and got a nearly acceptable result. After consulting with the luminaries on the MIMForum, I moved to carbon steel rod, which made the bend an absolute breeze. The stainless did thread quite nicely (with a better thread quality than the carbon steel) though it was somewhat resistant to the die.

The brass block, already cut out from the stock bar, ready for marking with the height gauge.
The height gauge is one of those tools that has limited applications, but is so good at those tasks that it's almost indispensable. The granite surface plate it's resting on is also very useful for truing planer and chisel blades, or anything else that needs to be very, very flat.

The block with centers marked and punched, ready for drilling.
This free-machining brass sure is nice to drill. Small, even chips, very smooth.
The pieces all fit together. The threaded end is too long, but otherwise the metalwork is done at this point.

Testing the rod. Yup, it bends good!

Trimmed the threaded section, and wrapped the rods in metal flashing tape. The added width of the tape brings the width from 0.1875" up to almost exactly 0.2", just the right width as I've got a 0.200" router bit.

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