Friday, August 14, 2009

Cock-Eyed

An issue: where the hell do you mount the radar eye on the R2? It's not in any of the club blueprints. I checked around and here's the deal. The radar eye actually moves around a lot from movie to movie. It's actually crooked in several important shots in several of the movies. I saw this the other night while watching ESB or ROTJ and I nearly snarfed my drink. I thought it must have been just a trick of the lighting. But no, it's mounted crooked. After working so hard to get everything else straight and true on this project, this discovery really bugged me for several days. But there it was in lots of the reference pictures and movie stills. It also appears that the eye moves up a down a bit across different models of R2. More or less the bottom right and bottom left corners of the eye line up with the right and left corners of the cutouts it sits over, and it looks to be about 3/8" to 1/2" above them. After looking at a lot of movie stills, I also came to suspect that something's off with the club blueprints somehow. The radar eye in several clear movie shots is bigger in proportion to the stuff around it than the one in our club's plans. The right bottom corners of it extend way over almost to the holoprojector hole to the right. But I'm not complaining about the plans. Given the job of trying to codify the measurements of R2 from so many sources and mostly from pictures, the guys in the club have done a great job. In the end, I got over my OCD issues about having things straight and square when I build stuff (I also have a real fetish for good rulers and micrometers), and I mounted that thing crooked:



The little bump on the lower left is where one of my mounting posts on the back of the radar eye is kind of poking up. That's since been carefully sanded down flush. I reserve the right to go back and remount the eye straight later, but for now, I'll let the movie shots be my guide.

How did I mount it?

At first I thought I would use these hanger screws that have a wide thread lag screw on one side and a machine bolt on the other.



But after messing around with these and trying to get them the right length and screwed into the back of my resin radar eye, I changed the plan. I know from rock climbing that the pull out strength on a piece of threaded rod with a good adhesive can be very high--they used to use glue in bolts on routes for clipping. So I cut some 1/2" pieces of threaded rod (maybe 3/16" in diameter) and glued them into the holes I had made in the back of the radar eye with gel super glue. Once those set up, they were bomber. All that surface area with the threads and the glue filling the hole makes a great bond.

Going backwards: how did I locate the holes? When I figured out where I wanted the eye to hang on the dome, I traced it into place with a pencil. Then I figured out where the four screws should go. Then I drilled the dome first. Hold the radar eye back on the dome carefully lined up with the outlined location and you can mark the hole from the inside of the dome with a pencil. That way you get perfect alignment on a tricky placement. Here's the radar eye and the bolts from the inside:







It's just not possible to get the angle of the mounting posts exactly right and the curves make things difficult. So just use a larger bit for these holes through the domes and use a washer on the nuts on the back.

2 comments:

Paul said...

Nice work.

I have noticed a lot of the builders have the radar up too high. SPIKE has been airing all the Star Wars movies this week and I also noted that the radar eye changes angles a lot, yet always seems to be at the same "height" (if that makes sense).

To me, it looks like you got it exactly right.

(I completely understand your OCD in this matter. These parts are expensive and the notion of drilling something where it does not belong can certainly cause great angst!)

Matt McCormick said...

Thanks, Paul. It's pretty clear in A New Hope that the radar eye is straight at least on one of the models they are using. I'm taking that R2 as my reference standard so I may remount the eye straight, but for now it stays. Yeah, getting it placed right and then drilling the holes in the right spot is a big deal--a dome costs nearly 5 bills now, so that's not something you want to screw up. I haven't dropped mine yet, but I know a lot of people have.

MM