Lead brick casting

====== Aluminum PoC ======

Made some molds out of aluminum as a proof of concept.  Moving to steel to reduce warping and make cleaning easier

Original brick size: 6 x 2.5 x 1

Used 8 x 3 x 0.25 slats for top/bottom

Used 8 x 1.25 x 0.125: for main sides

Successfully cast several good bricks

Drilled vent holes in top two corners

Rested at angle under 20 lb lead pot

Fill hole sized experimentally after original hole seized up too easily

Only made one mold.  It warped after a few bricks due to difficulty cleaning it to make good seals


====== Iron production ======

Make 4 molds to ease cooling and other production

Experiment with fluxing sides to make lead not stick

Plan to semi-automate based on diagram: MDI / hand written g-code.  No CAM SW

Reduce mold slats to minimum size?  Not sure how beneficial the extra was
  * Think its main advantage was easy of machining: easier to grab
  * Consider reducing slightly but not to min size
  * Min: 6 + 2 * 0.125 = 6.25
  * Cut to 7" to leave slightly over 0.5" each side to grip