Building Bender's body - part 2

So after cutting out the two panels from the propane cylinder, and butting them against each other on the welding table, I welded them together along the seams - pretty heavy tack welding since I expected to have to adjust the fit as the bottom was rounded out.

I tried thumping the body with various sized hammers, I tried swearing up a blue streak, but nothing worked satisfactorily... what to do?...

I carefully marked out some radially spaced lines on the lowest half of the body (to part I wanted to curve the most) and scored them with the angle grinder using a 1mm cut off wheel. I then used a spare automotive screw jack to crank the curve in the direction I wanted. This got it reasonably close to round.
What finally got it to round (unfortunately no photo) was laying the body in a piece of 4" (100mm) channel, and bashing the body from the inside with my "ugly hammer". The "ugly hammer" is something I found in my travels - I suspect it's a railway tool (based on local industry) and is essentially a piece of 3" (75mm) diameter steel shaft - about 350mm (14") in length, with a fairly long 30mm (1 1/4") pipe handle welded at right angles at one end - sorta like a demented golf club. I'd suspect it was used to permit striking things in recesses, based on the marks on it... for me it's a 15Kg (30lb) sledge hammer based on the japanese blacksmith's hammer

Here you can see the tapered body resting on the other half of the cylinder, with the original top section resting above that.
Now that's close to round!!! It took about 6 hours of cussin' under my breath, and hammering/grinding/ rewelding, etc to get to this point, but I was quite pleased with the result


Part 3 of "Building Bender's Body" will cover welding in the crotch plate, and cutting, then hinging and fitting the chest door.

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.

Bender is finally finished

What started with a "that's a funny look" at a 45kG (100lb) propane cylinder, with half a fire extinguisher perched on top (to keep the wasps out of the valve) has finally reached completion.

I was originally inspired by the bender brewing project at asciimation.co.nz.. but figured that my Bender would have to be metal. Since I didn't have any "40%iron, 40%titanium,etc,etc" alloys, I used the propane cylinder, old 9Kg (20lb) DCP extinguishers, pipe, and other bits and pieces to create this:

He stands 1600mm (5' 4") tall to the top of his antenna, and weighs 50Kg (110lb). His head rotates, the expression is changeable, and his arms can be moved at the shoulder joint, and the wrist.

I'll post a few more "finished" pics, and then go back and document some of the construction photos, techniques, and mistakes (I think my do-overs covered half the model)



I made two heads since I expected it to be difficult, and wanted a spare in case I screwed up badly. Thank fully most of my screwups weren't on the head, so I ended up with a spare head. Since I don't have a head in a jar for the photos, I used the spare head - after all we all know Bender enjoys his own company...
The spare head is currently being used for a bookshelf ornament, and is quite a conversation starter once people notice it.
Over the next month (work permitting), I'll finish the spare teeth panels, cigar, robotology symbol, and various eyelids to extend the range of emotions and looks he can have.

The construction photos will include some dimensions, tips, pointers, and oops.

Don't let the helmet fool you, he's not an employee of BHPBilliton Iron Ore - it's just one of the things I picked up off the side of the road when I collected the old fire extinguishers.