Drilled Dome for Radar Eye

Today I drilled the dome for the holes that accommodate the mounting screws for the resin radar eye. The steps taken today pretty much follow the Resin Eye Mounting Tutorial that I wrote up.

I want the eye to be located like how it looks in this screen grab from Episode IV, when R2 is being sold by the Jawas. I'm mainly using the lower-left hand corner as a reference for location, as well as the location of the eye on droid #1, which matches this shot.



This looks about right.



Time to trace it. (Of course, I held the eye tightly in place during the actual tracing, so that it wouldn't move.)



I marked four locations to drill mounting holes. The locations were chosen so that they would hit the thickest parts of the resin eye.



I want the holes in the dome to be parallel with the base of the dome, and all the holes to be parallel with each other. This way, the screws will slide in and out of the dome together, all pointing in the same direction. I actually used a level to make sure that the dome was parallel to the ground, and I was able to keep the drill level as well, as I drilled the holes.




I'm using a 0.113" drill bit, for the 1.5" #4 screws that I will use to mount the eye. So far so good...



As is now tradition, I just had to make a big mess of one of the holes. Fortunately, this won't show when the eye is mounted. I really tried hard this time not to let that happen too. The other scratch above the hole for the front holoprojector was already there when I received the dome, so I can't take credit for that.



Next, I used strapping tape to tape down the eye exactly within the outline that I drew earlier. At this point the location is really important, because the next step pairs the location of the eye to the dome.



With the eye taped down on the outside of the dome, I drilled through the holes that I just drilled from the inside, and drilled shallow holes into the back of the resin eye.



These shallow holes serve as a guide for where to drill the deeper holes for the mounting screws.



Here's where things started to go a little off course. I decided to drill the deeper holes in the back of the eye. The holes go about half way deep into the back of the eye.

Just as the holes in the dome need to be parallel with each other and with the base of the dome, these holes in the back of the eye need to be as well. However, there isn't as much reference to go from when drilling the holes in the back of the eye, other than the shallow holes that were drilled in the previous step.

I clamped down the eye to a flat piece of wood and used a drill press to start drilling the holes. Since that worked well enough for droid #1, that's what I did here.



After drilling the two top holes, I checked to see if the screws would be pointing in the right direction. Things didn't look so good. They are definitely pointing too far down. I verified this by also resting the eye flush against the dome and fitting the screws from inside the dome, and the screws were definitely pointing low.



I decided stop, and fill the holes with JB Weld. I'll try again another day. One thing I've learned is that most mistakes are correctable, and I believe this one to be as well. Heck, I've done it before.



I am debating about whether to use the same approach to drilling the holes that I did today, since it did work great for me with droid #1. Another alternative is to tape the eye again tight onto the dome, and drill deeper from the inside of the dome. I can use some masking tape on the drill bit to indicate how deep to drill. This approach might help ensure the holes are all parallel to each other, but it also assumes minimal slop in the holes in the dome. As I'm fond of saying, we shall see...