Next Round of Filling for R5-D4 Utility Arms for Droid #2

Today I finally got around to filling some of the pinholes that were revealed when I applied primer for the R5-D4 utility arms for droid #2.



I'll let this set a while and then sand it smooth, and repeat as needed.

First Coat of Primer for R5-D4 Utility Arms for Droid #2

Time for the ugly truth to be revealed, time to spray some primer on the R5-D4 utility arms for droid #2, to see how much more filling and sanding work remains.



And sure enough, there is some ugliness. Most of this is on the side edges of the arms, less so on the front-facing surfaces.



I'll let the primer dry and then I'll work on filling those in.

JB Welded Pivot Rods for R5-D4 Utility Arms for Droid #2

Time to epoxy in the pivot rods for the R5-D4 utility arms on droid #2. But first, I need to make a small correction. The rods aren't perfectly perpendicular to the arms. This is probably due to the way I clamped the arms to the drill press table when I drilled the holes. This is fixable, it happened when I did the R5-D4 utility arms on droid #1.

The pivot rod is askew on each arm by a degree or two.



I'm drilling 0.0055" wider than the pivot rod diameter.



Now the pivot rod can sit perpendicular inside the hole in the arm.



But wait, isn't the rod loose in the hole? Yes. So, I used a toothpick to slather JB Weld in the hole.



And in goes the pivot rod.



I cleaned up the excess JB Weld on both arms in preparation for fitting them into the droid.



I used tape, quarters and scrap paper to prop the arms to be centered in the skins, so that when the JB Weld cures overnight, the pivot rods should be in the correct orientation.

Sanded, Drilled R5-D4 Utility Arms for Pivot Rods for Droid #2

Today I sanded smooth the most recent filling work I did on the R5-D4 utility arms for droid #2.



It was time to turn my attention to drilling the holes in the utility arms that house the pivot rods. Earlier I had made alignment marks, based on the pivot rods in the blue arms (underneath the white arm).



With those marked, I was able to get to drilling. I measured how far I wanted to drill, and put a piece of tape on the drill bit as a depth indicator.



I used an old towel to protect the arms as I set them in a vise for drilling.



I used a level to make sure the alignment mark was, um, level.



The drill also has a level, so I can make sure I'm drilling straight into the resin.



And I drilled the hole.



Compared to the blue arm, the pivot rod depth is a pretty close match.



I repeated the process for the other arm and checked the fit in the droid.



Looks good. I think this is the first time in 4 sets of utility arms that I did this right on the first try for both arms.

More Minor Filling for R5-D4 Utility Arms for Droid #2

I noticed a few more areas on the R5-D4 utility arms for droid #2 that needed some filling, so I took care of that.



There were other spots as well, but you get the idea.

Filed and Sanded Bottom R5-D4 Utility Arm, Cut Pivot Rods for Droid #2

More filing and sanding, this time for the bottom R5-D4 utility arm for droid #2. I'll spare you most of the tedium and just show a couple pics.



Next, I worked on cutting the pivot rods for the utility arms. I sized up how long they need to be by using the blue arms as a guide.



I cut the rod to size.



And repeated for the other arm.



I filed flat spots on the pivot rods, for drilling a small hole.



And drilled holes in the pivot rods. These holes are for if/when I attach a servo motor to the frame to open and close the arms, like I have in droid #1. The servo horn would use a paper clip that goes through the holes to pivot the arms open and closed.



Soon I plan to drill the ends of the arms to accommodate the pivot rods.

Continued Filing Bottom R5-D4 Utility Arm for Droid #2

This evening I continued the grandeur that is filing the R5-D4 bottom utility arm for droid #2.

File, file, file... sand, sand, sand.



The right side is shaped correctly. Yesterday I pretty much mangled the left side. Oh well.



I still get to do the top arm, yea.

Unclipped Second Set of R5-D4 Panels, Started Filing and Sanding Tips of Utility Arms for Droid #2

The silicone had cured for the second set of front R5-D4 skin panels for droid #2, so I was able to unclip them.



Next, my least favorite part of utility arm preparation, filing off some of the claw part of the arm, so that it can swing open and shut, through the holes in the skins. I wish that all utility arms came with this already done, but they don't.

I marked up the arm and started filing.



Every once in a while I'd take the arm to the droid to see how close the arm was to being able to pivot into and out of the skins. Still a little more to do.



Eek, I went further than I intended to on this area.



Luckily, none of that is visible on the front face of the arm. Still, I need to be more careful. That's as good and excuse as any to call it quits for tonight.

More Hole Filling in R5-D4 Utility Arms for Droid #2, Glued Second Set of R5-D4 Framed Front Skin Panels

It's inevitable, filling the blemishes on the utility arms always takes a few passes. I hunted for more imperfections, and found and filled them.



While that's drying, I glued together the second set of front panels for R5-D4 for droid #2, again using GE Silicone II.



Returning to the utility arms, I sanded down the glazing putty, but alas, found a few more spots that needed application.



While these are pretty small, they are on front-facing corners, so I want to fill them so they don't draw attention.

Sanded Glazing Putty on R5-D4 Utility Arms for Droid #2

Tonight I spend about an hour sanding the glazing putty on the R5-D4 utility arms for droid #2. I used 220, 400 and 600 grit sand paper in the process.



Nothing too glamorous. I'll take another pass at this tomorrow.