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.

a few more pictures of Bender

So what more do I talk about now he's pretty much completed...
The head can rotate 360 degrees, and is positively retained.
The shoulder joint can rotate 360 degrees with stops at 8 locations.
The wrists can rotate 360 degrees as well.
The legs, and waist are rigid.

The wall thickness of the body metal is ~4mm (between 1/8" & 3/16") - the original wall thickness of the propane cylinder (44Kg, 100lb).

The head is made from an old NuSwift 9 Kg (20lb) Dry Chemical Powder fire extinguisher with a steel wall thickness of 1/8" (~3mm), and retaining the original bronze valve fitting for the antenna attachment. The boss for the pressure gauge was cut out, and replaced with a patch cut from another extinguisher.

The teeth panel is made form some colourbond offcuts - pretty springy sheet typically used for the manufacture of roofing/ fencing panels. It's a simple flat rectangle which is then rolled and placed inside the head, with the painted surface viewed through the open mouth. The springy-ness of the steel makes it press against the inside of the head, and conform to the curve wonderfully.

The dimensions were taken from a number of places, including a die cast model, a windup toy, several pictures from the internet, and the "How to Draw Bender" feature hidden inside one of the DVD discs. Even when he was complete, he looked as though his legs were too short, but I triple checked, and it's right - I guess Mom's friendly robot company never adhered to DaVinci's proportion model when they designed him.

I'll commence the construction photos shortly - if there's detail I miss that you want explained, let me know.

At this stage I don't plan on issuing dimensions other than the basics. I am happy enough to detail the construction, colours, etc.