Continued playing with KiCAD and started playing with ideas for 18640 cell holders.

Spent some more time researching power requirements and control of welding equipment.
[[http://www.yourarticlelibrary.com/welding/power-sources/characteristics-of-a-welding-power-source-metallurgy/96842|Characteristics of a welding power source]] has a good overview of basic requirements for a welding source. From the article:
"A conventional arc welding power source is known as the constant current (CC) machine. It has the drooping volt-ampere characteristic curve and has been popular for use in shielded metal arc welding."
Also:
"Apart from SMAW it is used for carbon arc welding, gas tungsten arc welding, plasma arc welding and stud welding."
and
"Steeply Drooping V-I characteristic:

The welding power source with steeply drooping volt-ampere character­istic has a high open circuit voltage and low short-circuit current as shown by curve 1 in Fig. 4.6. It is evident that as the arc length changes between L – δ L and L + δ L, the change in current is very little.

This type of volt-ampere characteristic is best suited for SMAW that is manual metal arc welding with coated electrodes because a slight change in arc length due to the intrinsic movement of the human hand during welding operation will not affect the melting rate of the electrode. Also, high open circuit voltage ensures easy initiation and maintenance of the welding arc."
Also found another good resource text, Arc Welding Control, lots of detail, will take some time absorbing...

Internet searching for diy welding projects yeilded only a handful of diy projects, mostly for spot welders, most seem to be dedicated to spot welding thin aluminum bus bars to battery cells for the creation of battery packs.

The article, [[https://simple-circuit.com/arduino-controlled-bridge-rectifier/|Controlled bridge rectifier with Arduino]] is potentially useful. The difference would be that per the Welder requirements a fully controlled bridge rectifier would be more appropriate as it would act as a current source. Note the use of thyristors (x4) for a fully controlled bridge rectifier. I found the reference, Power Electronics Handbook, in the article quite useful.

Spent some time getting familiar with KiCAD

Reviewed select OSE videos

Reviewed various Open Source prior art materials

CEB Press
Redrew the CEB Press top plate front and rear

Lyman Filament Extruder
16 hrs part research, model, and modeling research (Heater Ring)
1 hr part research (thermocouple)