Tonight I wanted to get those beautiful, light-weight utility arms installed.
First, the shafts have to be sanded and filed down a bit so that they will fit thru the opening in the utility arm. Some people have access to something as elaborate as a lathe to remove some material...I do not, so I used some 60 grit sand paper, a file and attached the shaft to my power drill..
With each shaft now fitting inside the utility arm, I found that I had to add a small washer to the top of each arm. Otherwise the arm would sag and tip downward.
The addition of the washer will make enclosing them inside the frame's utility arm carrier very snug. While the arms will still pivot in and out, they won't do so very freely. If I decide to add servos to these later, I'll have to put some graphite in there.
When it is time to install the vent frame rails to the bottom of the utility arm carrier, I use hex-head screws. Why? I've learned from my first R2 build that if you need to adjust the vent rails, you will not be able to get a screw driver in there at all.
I also do the same to where the vent rails attach to the frame ring.
Before I tighten these up I place the center vents in. There are 10-24 thread holes on the sides of the vent rails to allow 4 machine screws (or set screws) to hold them in place.
And here's how R2-D2 looks now...
