Saturday, 17 January 2015
The 3D printed Ghostbuster's proton pack that I'm making needs some lights. Today I concentrated on the 'cyclotron' lights. These plans have been created by dedicated fans who have stop framed the original film to produce accurate drawings.
These need to be red when illuminated, but as dark as possible when off. To achieve this, I 3D printed a LED diffuser using clear PLA.
Using superglue, I stuck this to some car window tint that I had left over from creating the skeleton effect for halloween:
This makes the diffuser look 'black' when the LED is powered off:
But reveals a nice red when the led is illuminated.
I'm using TLCR5800 hight brightness LEDs that normaly fit into my Lasertag muzzle flashes.
All the files can be downloaded from Thingiverse.
Sunday, 4 January 2015
My Ghostbusters proton pack replica uses several pneumatic fittings that were available to the prop builders in the 80', but are no longer manufactured.
A result of limited availability and demand has led to some crazy prices for these parts.
The parts that can cause problems are: The Legris Banjo:
I've seen originals of these going for $100 each on ebay, and a resin cast replica which needs some finishing will cost over 20GBP with postage from the US.
Another part is the Legris straight fitting:
These again will cost me around 30GBP to import from the US as a pair.
So I decided to make my own.....
I asked the Iron Man of Maine to measure the ones he has, and I coincidentally had some brass hex bar of exactly the right dimentions.
I had to make two of these, so first I parted the bar:
Then I turned it down to give the pipe exit 'nipple':
I then drilled the hole to 5mm. I did this after the turning down as the nipple walls are quite thin and I didn't want to risk damaging them whilst turning down.
I then turned the part around, and reduced the bar diameter to allow me to thread it, using the oldest tap and die set in my collection. I used this as the threads of the metric dies I have seemed too coarse compared with the reference picture:
I used the end stop chuck to hold the die against the workpiece to get it started:
To create the circular depression in the top of the part, I used an old lathe tool that was made by my wife's late grandfather. This has a really small tip and is right angled to allow me to apply it to the end face of the work piece:
It came out looking really well, but too shiny. So I applied some dilute ferric chloride solution to the machined surfaces for a couple of seconds to dull them, before washing off with water:
For the Legris Banjo, I decided to try 3D printing. They came out quite well, and I smoothed them out with acetone vapour. For a brass like effect, I bought some some antique gold metallic paint. But it was too 'gold' So I added a trace of black.
It came out looking OK, but I tested it on a brass bar I had lying around:
After painting the banjo, I think this is not too bad. I've put the parts on Thingiverse.