Rods for 622

As I was starting to turn up the crank pins, I figured I’d better find out if they would fit through the holes in the rods. They don’t, but rather than keep dragging out the whole etched sheet, I parted them off. Then, thought I, well I may as well fold them over and solder them up so they’re a little more robust. So here they are: ahead of schedule.

I left the folding tab on the crosshead end of the main rods until I re-drill the holes as these filled up with solder.

I had conjectures that the two layers of half etch, plus an extra full-thickness area on the back bottoms would make these rods slightly more robust than those on . Low and behold, they definitely feel stiffer.

10 thoughts on “Rods for 622

  1. Those look great Rene!

    As to their stiffness relative to previous rods, you may already be aware, so for that I apologize, but it would go up as the fourth power of the ratio of the thicknesses

    A little increase in thickness pays *big* dividends!

    md

      1. Dumb follow up question, what parts did you etch in phosphor bronze vs nickel silver and why? Strength vs flexibility?

        I’m assuming that phosphor bronze is slightly stronger than brass, so that is why you went with that?

      2. PB is an okay material for light springs. The equalizing springy beams drove selection of PB for the thinner sheet, which otherwise would have been brass. I chose NS for the thick sheet so parts that will be bare metal will look more like steel.

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