From Plan

The text states that the Jib Box is about 7′ x 5′ so I used that to scale the eccentrics. The whole thing is really just a guess at best.

  • The shafting is shown in Purple. I scaled these to 7″. In O scale that is 0.146″. I checked my stock and I have some K&S No.8167 – .114″ brass rod. That scales to 5.472″ Full-Size. K&S No. – 8165 frac{5}{32} / 0.156 rod scales to 7frac{1}{2}". K&S No. 9866 3.5mm / 0.138″ rod scales to 6frac{5}{8}".
    To me these numbers looked way too high. My supposition being that .. well .. this is a drawing and not necessarily to scale. The Jig Box as I have re-created it holds about 14,000 lbs of coal. If we double that for shock as the Jig Bog agitates we get 28,000 lbs. From This Calculator it looks to me that the 0.114 rod would work – giving a safety factor of 3 for steel.
  • The cam shown in Yellow is scaled to a 5″ dia. This gives a 1″ camming action. Since I will be using the 0.114″ rod I will re-draw the eccentrics while keeping that 1″ cam offset.

Modded 1

With the dia of the shafting reduced, I added the cam for the correct offset and then re-sized the eccentric body. The 0.024″ thickness gave me pause. That scales down to 0.019″/0.48 mm. That is a bit on the thin side as I would prefer that it be at least 0.6 mm.

Modded 2

.. and away we go! The walls were increased to a bit over .6 mm, modified the area around the nuts/rods, added a groove.

This is pretty much where I am going to leave this for now.

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