I’m still behind on blogging what I’m currently working on. There’s plenty of new photos in the build section of the gallery and I’ll eventually get some down time and catch up.

I finally unwrapped the remaining blue parts I painted over the weekend. They came out okay, but not great. The power coupler shown below had some paint leak underneath the tape and I had to clean it up. I used my old friend “Acetone” who seems to work great on a lot of stuff these days, like oozing silicon and epoxy. I just have to remember to use it in a well ventilated space.

The tape also lifted up a chunk of paint on one of power couplers, but I think it’ll do for now.

Here’s the coin slot and octagon port, note the paint lifting at the edge again. I’m gonna have to learn how to do this masking right someday.

And, I couldn’t resist trying some of the parts out for size

I also assembled some of the other parts now that they’re painted. These are Daniel D’s small vents, they’re very cool and over engineered to make my life a little easier to install them. They should be a snap to get into the frame.

On the other hand, the large side vents don’t have any screws to hold the plate in place. I’ve tried silicon to hold them together, but I’m not sure if it’s going to hold and I may need to try epoxy. I’m hoping to bond a bracket to the back to allow me to screw it to the frame somehow.

I decided to redo the front vent louvers. I’d originally hot glued the pieces together, but it didn’t hold so I borrowed another trick from Victor and used some silver foil tape instead. I’ve no idea why I had this in my tool bag, but I did and it saved me my daily trip to Ace Hardware 🙂

This stuff is super sticky and seems to hold the structure together really well. I’m not sure if you can see it in the picture but along the sides and corners are strips of the silver foil tape.

Click on the image to see a close up shot.

Once the piece is flipped around and in place you’ll not be able to see the tape

I also forgot to post this photo a few weeks ago where I sanded down the surface of the front vent surrounds. I’m pretty sure these are water cut or something, and the finish will be beaded when you get them – they look more like they’ve been painted with rattle can aluminum paint instead. A quick once over with some sandpaper fixes it.

In closing here’s a quick photo of a bunch of parts ready to install in the skins

I’ve had an incredible busy weekend working on R2. I’m getting close to re-assembling him with all the skins and parts bolted on and everything painted.

If you’re browsing the gallery for new photos you’ve probably spot a lot of new work over the weekend. I tend to upload photos quicker than I can blog them here 🙂

Throughout the 4 day holiday weekend I’ve been slowly prepping and painting everything that I could, including the legs, feet, ankles etc. Every time there was some downtime I’d turn around pick something up of my paint table, take it outside and give it another coat. I must have applied 3 or 4 coats of the white by now. The paint job isn’t perfect but it’ll do for now, plus I’ll probably be weathering him at some point soon.

I also finished painting all the remaining blue pieces, mostly body detail parts like the octagon ports, power couplers and vents . Once the skins are done and fixed to the frame I’ll be in good shape to start mounting the parts.

I started to use a self etching primer on some of the latest alu parts. I’d been looking for a self etching primer locally for a while and I finally found some in stock at Kragen’s. The problem with the small local auto places is that they seem to only carry one can of some paints, and refuse to special order – so each time I looked they were out. Anyway, it got lucky this time and I picked up the Duplicolor primer (olive green top.) You can see the olive colored parts in the first photo.

I guess my new hypo blue formula is

Duplicolor Self Etching Primer – wait 30
Rustoleum White Primer – wait 30 (maybe apply 2nd coat after 15 mins)
Rustoleum Purple – wait 30-45
Duplicolor – wait 30-45
Rustoleum Clear Coat (maybe two coats)

The biggest thing I probably worked on was gluing the skins together. I’d flip flopped a few times on how how I was going to do this. I really like how Victor has left the inner skins unpainted to show off the panel detail. But having an aluminum frame makes it a lot harder to mount the skins separately, so I’d probably need to paint them in one go. I’d considered using silicon to bond things together, but from some tests I’d done with some of the doors panels, it delaminates at the edges too easily. Cleanup is also hard and it’s difficult to remove all the excess silicon. If you’ve ever tried to paint over silicon you’ll know how bad that can be. The door panels I’d glued together had small fish-eye marks once I painted them. I think I can work around it, but all the other panels will be epoxied I think.

After a bunch of emails back and forth with friends, and a phone call or two – In the end I opted to use a cheap home-brand 60 minute epoxy from Ace Hardware. It’s supposed to setup in 60 minute, hard to the touch/movable in 4 hours and sets fully in 24, but even after 2 hours it was still very soft. Which was good news as it allowed me plenty of time to clean up the excess that squished out. I only had enough clamps for one half of the skins so I tackled the back set first. I’m hoping to get to the front set tonight then on to mounting them on the frame.

I think in the end there was over 60 clamps, paper snaps and clothes pegs stuck to the frame.

This morning the skins had definitely stiffened up, and I’m glad that I’d made sure they were sitting in the correct curved shape I marked on the workbench before going to bed.

Talking of mounting the skins I’ve flip flopped on how best to do this too. Like anything to do with R2 building there always more than one way to go, and there is never a right or wrong answer. I have skin mounting systems from Daniel and Darren, both are very different with pros and cons to each. Darren’s quick snap mounts are made from plastic and allow quick and easy removal, where as Daniel’s are aluminum and require screws to hold everything together. Having experimented with both I’m opting to go with Daniel’s mounting blocks for now.

I also worked on getting the skirt finished this weekend. I didn’t quite finish it ready for painting, but I did get the strips mounted. It probably took close to 4 hours to drill and tap all the small holes.

I started off by marking up where the strips would go and drilling a series of holes.

I then clamped each strip one by one into place, center punched through where the strip needed to be drilled, tapped the hole, reattached to the skirt, repeat for the second hole. That’s a total of 48 holes and 24 taps needed. I also had to cut down each screw as they were too long!

The holes in the strips do not go all the way through, so tapping them was hard and didn’t leave much for the 4-40 screws to hold onto.

Each strip had to be tweaked and filed to get it to fit, and due to the construction of the skirt, some strips are too long and need filing down in length. I’m also going to have to bondo/fill in the gaps before painting.

I’m sure there was more done this weekend, but that seems to cover most of it for now.

Last week I finally got around to cutting out the skin panels and tackling the rear door. After I’d figured out the right tool for the job, removing the panel was a breeze and clean up was quick and easy.

Next up was the rear door. The outer skins already have it partially precut, but the inner skin is solid and it’s up to the individual to decide if they want to add a door or not.

I really wanted a rear access panel/door to make it easier to maintain things, but I’d been dreading cutting but it had to be done. The plan is to have a totally removable door fixed with magnets.

I started off by fixing the outer and inner skins together, outer skin door panel, and marked out where the back panel sits on the inner. I then drew a line just inside that by about 1/8″.

It’s probably worth noting that the only panel I removed from the inner skin was the two long doors. I wanted to keep the skin as ridged as possible, and if I’d removed any more sections before cutting it would have been very flex and prone to bending while cutting.

I then clamped on a scrap piece of aluminum from one of the front door panels and used it to guide the dremel.

Here it is after cutting – not bad and pretty straight.

I did the same to the top edge and the other side

Here’s the door cut out and shown with the outer skin

I cleaned up all the edges with a file and I was done.

I also cut out some extra space on the inner skins for the octagon ports and power couplers to help them sit flush with the outer skin.

I have two different versions of the octagon ports, the old tacked box version and another set from Michael McMaster. To be honest I really like the newer version from Michael but it requires a lot more work on the frame to get it to fit, so I decided to use the older version.

Over the weekend I’d tried to mark out where the ribs/strips would go on the skirt. It was late and I couldn’t figure it out and it looked all wrong. The next morning I called a few friends and they confirmed that this is a tricky step. I’d checked and rechecked the angles but it still didn’t look right. The outer ribs where too close together and the center one’s too far apart. I tried eye balling from reference photos (see first photo), but I still wasn’t happy.

Today I printed of the skirt plans full size and straight away I could see that I’d screwed up drawing out my own version of the plans/angles full size.

The moral of the story is check, recheck, check again – go away, sleep, and check again before bugging your friends 🙂

Over the holiday I’ll try and get the ribs drilled, tapped and secured to the skirt ready to painting next week.

I’ve been very busy the last few days and a bit tardy posting to the blog. However, I’ve made a lot of progress on the skins and legs, and will hopefully catch up with all the blog entries over the holiday weekend.

In the meantime here’s a quick tip for those of you cutting out your skins.

This may not be to everyone’s liking and my old my woodwork teacher would hate me for this, but I used a sharp wood chisel to punch out the pieces. I didn’t use a hammer or anything, I just had to push hard to break the tabs. Even on the super thin laser lines there was no marks left on the skin to speak of. I just lined up the chisel on the inside and pressed down on the little tabs.

I’d tried a bunch of different methods, from using a small saw blade on the wider cut-outs, to a Stanley knife on the thiner lines, I even tried a thin Dremel disc, but none worked as well or as quickly as the chisel. I found that the dremel would easily mark the skins or cut a wider undesirable lines and the knife blade would dull too quickly.

A few nights ago I finished the last few parts of my frame structure and also constructed a real battery harness that will sit above the center leg mounting plate.

It will hold 3 standard 12v 7amp batteries in the droid a nice low center of gravity. I’m hoping the design will allow easy access for charging and removal.

The bottom plate is the center foot mount and attaches to frame ring #4.

It’s based on a photo I saw on this site and thought it was a good design to hold the batteries.

Things are moving forward fast now that I have the basic outline of a frame done. I’d been putting off a lot of things waiting on it, including installing the Rockler Bearing/Lazy Susan.

I decided to leave the original plastic wrapper on while I drilled the holes, and I also pulled back the plastic and taped off the area on both sides where I would be drilling to make doubly sure nothing would get inside the bearing and lock it up later.

First Problem – I tried to align it inside the dome ring using the tried and tested method of using coins to center it, but there was an issue. If you’ve been following my progress and have a good memory you’ll remember that the dome ring wall varies in thickness. On the outside it’s perfectly round, but on the inside it varies a lot, making it hard to use coins to center the bearing in place.

Using some calipers I figured out 4 spots where I though the wall thickness seemed to be close enough and placed my coins there. It wasn’t perfect, and I was repeatedly tweaking and re-measuring for the longest time. In the end 3 nickels and a one cent taped together seemed to do the trick. They weren’t tight tight, so I used some clamps to lock the bearing in place while I drilled.

Drilling into the dome ring went fine and I don’t think I got any metal shaving in the bearing. After that, and in short order I popped out the little plastic lugs and drilled out the outer bearing ring holes to attach it to the frame.

I still need to attach Daniels inner dome plate and get slightly longer screws that attach the Rockler to the dome, but that’s an easy fix.

I was able to use a friends lathe and mill again last night, and got a few more parts of the frame made. I’m now at the point where it actually looks like a frame, and can hang it from the legs if I want. I Still need to machine 8 more rods for the lower section and I should be done.

Some advice on tools – don’t buy a cheap Harbor Freight Tap and Die Set. They’re not worth the money and I wasted an evening last week fighting the small crappy tap wrench that came with mine. Trust me go out and buy a beefy set or just the taps you need and a good $20 tap wrench. Your hands and patients will appreciate it.

Someone also gave me a tip that I’ve not tried yet, but supposedly you can use a cordless drill to tap the hole using forward and reverse and low torch. My drill is dead and waiting a new battery otherwise I this would have saved me a lot of time. Hopefully it’ll show up before I need to tap my last set of rods.

Next thing on my list to machine are two plates to attach the center Ankle/Leg to the bottom of the frame.

Oh! and did I tell you this thing weights a ton?