Demat Circuit quick build

[metalunamutant]

I decided to do a quick build of a demat circuit from classic DW. Sadly there's no really good pictures of the prop -- anyone know if an original survived? I used the (good) screencaps on this site as a basis. I know they made two It's plastic tubes & discs, paper clip wires, beads & copper wire. I bought tiny brass flat head screws from the hardware store. I love doing early Who props because many can be made fairly cheaply with odd scraps, paint and a little care -- and that's how they did it then.

The tetrahedral center joint (I had to look it up   )  took several tries of cutting angles to get right - and it's still not exactly perfect. I'd really like to 3-d print that 4-angle joint. It really needs to be geometrically perfect for the whole thing to look right.  That center tube joint took much longer than everything else to build. With 3-d printed part ready, the whole circuit could have been built in a few hours!

I had to guess at brass screws on outside discs (#, location), the colored beads (seemed to be clear, blue and green) and the squiggly wire layout. The squiggly wires layout seemed different for each prop.

The outer disc center divot detail is uncertain so I just put a some grommet doohikeys into each the center.

Also, the clear section between center joint and green outer ring below the big plastic disc is the same diameter as the silver joint, not narrower like mine. But this was a quick build so I simply joined the outer discs and center joint with a 1/2" clear tube instead of creating 8 more parts. I'm doing a Doctor Who display next month for a local library and wanted it quick.

Finally -- yes, I built a spare.

Actually, if I had a printable center joint I'd make a dozen of these to sell. It really was easy and cheap to make aside from that center joint piece.

Anyway, on to the pics

[Davros Skaro]

I must say, you've done an excellent job on this for a quick build, what did you use for the green bits if I may ask?

Chris.

[metalunamutant]

Thanks! The green rings (under the outer black disc) were just 5/8" diameter acrylic tubes cut into 1/2" sections then painted tamiya clear green. The green flat disc outside of the outer black disc is a nylon grommet ring I picked up at the local hardware store, painted clear green.

The green outer disc (outside the black outer disc) on the original prop seemed to be either flatted and clear green (probably the end of the clear rod sticking through from the center joint) or maybe a flattened, dimpled greeble from who knows where. The pics just aren't clear. And with 2 props, they may have been differed anyway. I bough 8 cheap nylon grommets from the hardware store, painted them clear green and glued them on.

As for time to build, it took about a week of sessions cutting those tubes just right, and even then one of the outer discs on each is slightly off. Painting and assembly only took a few hours. I'm really considering designing and 3d printing one. It's the only thing that really takes time. If so, I may considering making a kit of this, or selling them.

The wires took a while also. Sticking in the various wires took 90 minutes (the length of the Ark in Space DVD which played while I was working) and I was *still* less than half finished! Next day I remembered I had some jewelry beading tools (short, flat and bend pliers etc) from a project years ago. With those, I finished the rest of the wires in 30 minutes! As always, the right tool for the right job!