Next it was time to set about making the little clear slightly curved display cover. If casting in clear resin, most will cure
in a silicon mould but it takes ages. So a different approach was needed.
I made a master, and then
decided to do a quick vac formed sort of mould, without the vacuuming. I cut a square out of a piece of hardboard that fitter
snugly over the master, then cut a small square of clear plastic from a box front I had laying around. The clear square was
then placed in the oven for a few minutes, and then when hot and all floppy, it is taken out, and laid on the master, and the bit
of board pressed firmly down. You perhaps get ten seconds at most before the plastic has gone to hard to form a clean shape,
so itís drop it on and press hard.
The end results cam out fine, and once the new mould is waxed and polished
the clear resin can be poured in and let to set. Itís left overnight the popped out the mould in the morning, and bingo a nice
clear display screen. Simple but very effective.
With the main body just about done, I turned to the end cap. This looking at the screen caps is a sort of knob type bit with knurling
on the sides and a slight recess pattern on the underside. It was mentioned to me by a friend it looked like a very old pritt stick
glue stick, which is might have been, who knows.Now as this resin is quite brittle, knurling is out as it just chews it up. The simplest
method is to make the end cap in aluminium. This is easy to work with and knurls a treat.it is a tiny fraction wider than the main
body so taking the knurling into effect, the main body was turn and the bottom shaped then the knurling added. As always anything
made in alloy looks nice when done, and this was no exception.
With the main size and shape sorted out, a few indent lines are added for effect and to match the screen used version. There is nothing
high tech here, just a few lines cut into the rod, as the same distances as the one in the screen cap.The top end has a bit more detail,
and for this I had to rely on several wonky angled shots and some source material I gather while researching the part. It is recessed
slightly with a detailed part in the middle. Nothing over the top, just some simple but effective detail to finish it off.I turned
the main end on the rod, but for the inner detail bit I made this separate and glued it in later. That way if it looks too big or
small a new one can be made and tried in place, without having to remake the whole thing.
So we start off again with a rod of tooling resin as this is the best stuff to work with for things like this. While itís easy to
machine down, it also comes up really smooth when sanded with very fine paper, giving the perfect finish.The first job it to machine
it down to size. Itís taken down in stages, so not to risk damaging the surface. While this resin is good to work with it is a bit
brittle, and you need to take care when working with it or it can chip.There seemed to be several version of this locator around,
and as none of them seemed the same size or had the same details I went back to the screen caps to work from.There are a series of
really good shots near the end of the film when Ripley is going to rescue Newt, and she loads up with weapons. At this point in the
film, you see her stick the locator onto the gun with duct tape.While there are no measurements for this piece freely available, but
the carry handle looks almost the same as the M16 style and that along with the tape and hand measurements gives a good guessimate
of sizing. Unless the proper originally used item in known measurements are just rough or approximate. As long as its within a few
millimetres of the proper one I am happy with that.
This page shows how I made my location tracker. This is again one of the easier things to make as it really just a rod of resin with
a few added details. The hardest parts are making and casting the clear bit for over the display, and also the distance screen piece
need to be made up on a CAD program and then printed off. Not particularly hard, but getting it right is important.
With the master copy finished, all the bits are moulded in silicon, ready to make a few copies.
You can see the first out the mould, with the extra resin round the pouring spout. This allows for when the mould is put under
pressure and the level drops. As the pressure rises, the air is compressed, and the resin level drops. Put too little
resin in and the level will drop below the main item being cast, meaning it s throw away.
Once its set and
removed from the pressure pot, the end of the main body and end piece are machined to fit together.
body is airbrushed a browny green, and left to dry overnight. Then the bottom is stuck on with some epoxy glue, and the display
screen added, with the distance label behind. Another piece all done.