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.

Designing the model of Bender

As I mentioned at the beginning, I was initially inspired to build a model of Bender when sitting at the front step one day, gazing tired at some of the scrap metal, and noticed a familiar shape. I sat there for several minutes looking at the top half of a fire extinguisher which was being used to cover the valve of a propane cylinder - the domed top, the straight sided extinguisher, and the rounded top of the propane cylinder looked familiar, but I couldn't place it. It was the head and shoulders of Bender.
I'd admired the work done by Simon Jansen at http://asciimation.co.nz/bender/index.html, and knew I'd never have the spare time to build what he had, but after seeing the shapes in my own scrap metal, I started making plans.
I collected a few images off the web - copies shown here - if there's a copyright issue - sorry - they're images found by Googling, and used them as a starting point.

These side and front view images were found somewhere - I believe a fan had done up a 3D model of Bender and rendered these based on that.
I sat down with my own models (a diecast model, and one of the tin walking models) and recorded every dimension possible. I then built up a spread sheet of these dimensions, and scaled them to suit the diameter of a propane cylinder, and a NuSwift DCP fire extinguisher. The NuSwift has an outside diameter of 187mm. All dimensions were scaled to the relevant sizes, and recorded. As you can appreciate, there was some range in the eventual sizes, so these were tweaked based on pipe sizing, and "how it looked".





This is a photo of the "plans" I used when working on Bender. All dimensions have ranges on them, and there are small notes to myself here and there about things I expected to have problems with. Not shown are the other 16 pages of notes, designs (rejected, or used) and other ideas I had whilst doing the design.

For the construction notes in this blog (still getting used to that word... I think I'll betray my age by calling this a website, with pages) will be broken into the following pages;
Body, Base/Feet/Legs, Arms, Hands, Head, Eyes (good and failures), Antenna, Progress shots, Painting, Assembly, and then I'll do the Accessories and a few more finished shots.