Building Bender's body - part 1

Bear with me, I'm still learning how to use these blog tools. Building the body started with cutting up this damaged/condemned 44Kg (100lb) propane cylinder. If you look closely, you can see the neck ring is damaged, and the valve has been removed. I had let it sit vented for over 6 months for another project, but that project got shelved so it was donated to this cause.
After cutting away the rounded top (to become the top of Bender's shoulders), the next step was to mark out the cuts based on the amount of taper I wanted in the body. Thankfully the length of Bender's body worked out to be 6mm (1/4") above the welded seam. I then calculated the reduction in circumference at the waist, compared to the shoulders, and split it evenly on each side of the two side seams. I also calculated the minor changes in level of the top cut, compared to the tapered body once the two halves would be joined - this resulted in a 5mm (3/16") sliver being cut at the top edges tapering to nil at right angles to the side seams. The 1mm sliver at the base was ignored until welding the floor in.

The removed pieces were cut out first...


and then I commenced cutting around the bottom of the body. I cut in this order to keep the panels attached to the rest of the cylinder for stability - I hate it when steel moves around whilst being cut. The flat red dome piece on the ground is the removed top section - the red paint is probably overspray from something else... I used the cylinder for holding up things being painted for months until I cut into it.

The two panels butted up against each other on the welding cart. From the top (Bender's shoulders) the two panels form a circle with the same diameter as the removed top piece. At the bottom (facing up in this photo) - Bender's waist - the two panels form a pointed ellipse shape due to the intersecting circle segments. Making this round was quite a chore.