…. and so anyway, we got off one shot today with the great big heavy harpoon of a bolt we made yesterday.    Before it exploded,  yawing through the plywood on the sand trap, it showed us the following:  10054 grain weight,  208 feet per second, 965 foot pounds of energy.   Slow because of its weight, but not wimpy exactly. In gun world, that’s about the same energy as a .44 magnum.  The good thing is that I only increased washer rotation 15 degrees beyond the tepid twist we had in the last round of testing.   In other words, there is a lot more velocity left to harvest as we continue to increase the torque.  We will have to stop when the bundles  max out with unacceptably high draw weights.  Today’s  draw weight was 3500 lbs.   What is an unacceptably high draw weight?   Now, that is a good question.  Also a dangerous one if we get overconfident.  It is time for some new safety protocols.  More on this later.

Below we see the broken bolt from today’s test laid out on the machine.

This Nessie of a projectile yawed into the target sideways because the starboard bundle was torqued a tad tighter than the port one.   This  shows up in bolt flight as the bolt swooping up and to the left,  relative to the bolt groove.   Confirmation of this disparity between the bundles was evidenced by measurements taken with the new Wheatie meter.  This Mk. 2  model is no longer paunch powered, but has its very own yellow strap and ratchet.  The spring balance replaces the calibrated bruising meter I have packed around for years.  In this photo,  200 lbs of pull  is being applied to the starboard limb to get it to lift away from the stanchion.  By selecting the correct size pin gauge to go into the gap that is formed between the limb and the stanchion,  a relative comparison can be made of the torque in each bundle.  For example,  from the above set up we found that when 200 lbs was applied to the starboard limb, it lifted away from the stanchion .240″.  On the port side it lifted .264″.  Hence the starboard side is more highly torqued.  The closer we get to balancing the bundles, the closer we get to making this baby sing.

My dalliance with super heavy bolts will have to wait a bit.   I happen to have a bunch of 1 1/8″ broom handle material.  (Thanks Richard.)   It is nice and straight and should make good shafting for a dozen or so bolts in the 6,000 grain class.    That is tomorrow’s task.

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