Made Backstops for Utility Arms

Tonight I cut out some segments of MDF that serve as "backstops" to keep the utility arms from rotating into the body when they close.

All I need are some small rectangles of MDF of the proper height. I placed a piece of scrap MDF on the horizontal ribs just below where the arms meet the skins, and marked where to cut.



And cut I did.



I cut a second small segment of MDF, and rested it upon the first segment.



With the arm closed such that it was flush with the skins, from the back I marked where to glue down the MDF segment.



And glue I did.




Soon I will paint these black, and glue them onto the frame.

Painted Drivetrain Screws

Since I forgot to do this yesterday, today I painted the drivetrain screws white.



I didn't have time for anything else, but at least this is done.

Cut More PVC Covers for Battery Terminals, Painted Skin Screws White, Widened Knurled Fitting Holes on Foot Shells

Today I came up with a semi-legitimate R2-building reason to return to Mike's. I needed to use his band saw to cut segments of PVC to cover the terminals on the second set of batteries I recently purchased.

About five minutes on the band saw, and my R2 Building at Mike's house was mostly done. These get glued onto the batteries with PVC glue.




Mike did a quality test to make sure the PVC glue is still fresh. It is.




And on they go.



Meanwhile, Mike Senna and Michael McMaster continued working on their WALL•E builds. Mike was busy working on parts for the arm.




Glad those are his fingers and not mine.



Michael finished up the main part of the build of his front box and button panel. He used Mike's finished parts as a guide.





Michael also worked on casting treads from the mold he and Mike made yesterday.



Ever wonder what would happen if the resin decided to harden while it was still being poured? Today is your lucky day (and Michael's unlucky day). That surface is supposed to be smooth, but it looks a little like the aftermath of a lava flow.



As Michael had a 3-hour drive back home, we wrapped things up and headed out. Poor Mike's R2s... they've been demoted to living under the staircase.



Back home, I took a few minutes to paint the screw heads that secure the skins to the frame. I told myself not to forget to paint the screws on the drivetrain too, but of course, I forgot.



There are six screws in this picture, but once painted, they don't stand out anymore.



I finished by fixing a minor problem on the foot shells. The holes on the front foot strips on the outer feet didn't perfectly align with the holes in the styrene foot shells. I needed to file down a few microns of styrene, using a half-round file.



That's better.



Other than installing the back door, and painting the drivetrain screws, I think things are very close to being done now.

WALL•E Build Day at Mike's

What is a WALL•E building post doing in Victor's R2D2 Building Diary? (And before you ask: No, I am not building a WALL•E.) I'll work an R2 angle in before the end of this posting.

Michael McMaster came to town to work on WALL•E building with Mike Senna, and I came by to help. Michael inspected Mike's handiwork to date.



I was put to work to help with the gears, which are made from 3/4" Delrin. First, I needed to cut the Delrin into squares on the table saw.



Three WALL•Es worth (two for Senna, one for McMaster), 12 gears total.



Next, I screwed down the gear template that Mike and Michael made earlier from a similar piece of material, to use as a template for routing.



Before routing, Mike's friend Mark cut the corners off of each Delrin square, using the band saw. Lots of cutting corners.




I took the resulting piece of Delrin to the router, and used the flush-cut bit to cut the Delrin to match the MDF template.




I then drilled a 1/2" hole in the center, for the future motor shaft.



Repeat 11 more times.



Mike and Mark cut keyways into the center hole, using Mike's keyway cutting tool.



A square piece of keystock locks the shaft to the Delrin gear, much like how the Senna R2 drivetrains work.



Meanwhile, Mike and Michael molded a few of their scratch-built parts.





There were other miscellaneous WALL•E building activities as well. I sanded a lot of resin parts of Mike's that he had previously molded and casted, and Michael worked on the screen on the front part of WALL•E.

I told the guys that since this had nothing to do with R2 building, this wasn't going on the blog. They told me it had to, so as a total cheat, Roy Powers and Michael McMaster ended up looking at pictures of my R2 build on my iPad as I was leaving for the night. That was the extent of any R2 involvement. I don't think you can stretch the definition of R2 building much further than this.

Attached Ankle Cylinder Holders, Installed Large Data Port

Tonight I pretty much finished up work on the legs by installing the ankle cylinder holders.

I'm using silicone to attach these to the very bottom of the ankle cylinders.



I simply pressed the parts in place, and I'll let them dry overnight.



Next, I worked on installing the large data port. It rests on the rib just above the top utility arm. I needed to remove the Rockler bearing in order to install the LDP.



I tried various approaches to taping this down. In the end, I used 3M Very High Bond tape on the top and bottom to secure the LDP to the frame.




You may not think so, but the bond is very strong. I was not able to wiggle the LDP out of place. I reattached the Rockler bearing, it rests just above the LDP and skins.



That pretty much fills out the last hole on the skins for droid #2. I still need to paint the screws that attach the skins white, and come up with a strategy for securing the back door. (I'm leaning towards magnets this time.) After that, I'll be able to install the rear power coupler.

Finsihed Installing Under Shoulder Details, Installed Ankle Cylinders, Wedges on Center Ankle, Half Moons, & Foot Strips, Repaired Foot Shell Damage

Back to The Big Droid Put-Together for droid #2.

Tonight I finished installing the under shoulder details on the outer legs. I used the Household Goop product, as I did the other night, this time applying it with a toothpick, since the applicator was somewhat gummed-up.



In it goes.



The legs on the final under shoulder detail were uneven, one was slightly longer than the other, and too long to fit in its spot on the leg.



I used a file to even it out with the other leg.



I again applied Goop to all the surfaces that make contact with the armpit area of the leg.



The fit looks good, these are done.



Next, I worked on installing the ankle cylinders on the center leg. I'm using 1/4" dowel segments to attach the cylinders.



I matched the holes in the backs of the cylinders to the dowels, and started pressing the cylinders in place. It's a tight squeeze, which is good. They won't fall off.



A little more pressing, and they're flush with the leg.



I then worked on installing the cylinder wedges on the center ankle. I again used silicone on the surface that makes contact with the cylinder.



I centered the piece and pressed it in place, and repeated the process on the other side. I'll let the silicone cure overnight.



Next up, installing the resin half moons on the center foot shell doors. I'm using three #4-40 1/2" screws to hold each half moon to its door. I screwed the screws in from the back such that they were barely sticking out of the front surface of the door, so I could align the holes in the back of the half moons to the screws.



A few more twists of the screwdriver, and the half moons were holding tight to the doors.



A quick test on the foot shell shows that things are looking good.



I then installed the foot strips on all three feet. Similar to the installation of the half moons, I started the process by screwing in the screws from the back side, so they just barely stuck out the front side.




And as with the half moons, another couple of turns of the screwdriver had the foot strips holding tight as well. One thing I did differently from droid #1 is that I did not have the screw go through the foot strip, it stops short of bursting through.



Same deal with the center foot shell.



I wrapped up by doing a little foot shell repair work on all three feet. On each shell, I had managed to crack some of the styrene filler out from the top corners. I applied some CA glue using a toothpick to the area needing repair.



I then glued down the stray piece of styrene.



I repeated the process for other two foot shells, which had the exact same problem. I may spray a mist coat of paint later, to help conceal the repair.