After the body rotation, dome rotation was next. Goal was to determine the start position using a hall sensor, and count the steps using a optical rotary encoder. This way it would be possible to return the dome to it’s center position when desired. Turns out, it works rather well:
I’ve continued working on the body parts for R2D2. I made a few more adjustments to the Powercouplers, by splitting the insert into 4 separate pieces., which made putting them in a lot easier. I also found out that the majority of the scenes in A New Hope have the top of the center cone painted blue, so I made that a removable ring so that it can be painted separately from the silver parts.
Next up were the coin returns, which weren’t so much a design to model, but more so to print. I ended up printing them upside down, which gave the best surface finish with all the slopes and reduced the amount of support material (which was still a lot).
Initial painting tests were quite promising, but does show the importance of sanding everything completely smooth, as every imperfection shows through the silver paint.
I’m currently working on the octagon ports. The initial model is ready for it’s test print. I might need to do a few adjustments based on that.
Due to the small indents in the inner part, I had to split them into separate pieces so they could be printed without support. Eventually they would just be glued together and sprayed silver.
It’s been a while since my last post, but I’ve been quite busy researching various parts of my R2-D2 build. Ofcourse I got a bit distracted by my new BigBox printer, and ended up printing a light saber, which is going to be my airbrushing test object.
Speaking of airbrushing, I’ve been trying various possibilities for the metal / aluminium parts of the build. I’ve painted some sample pieces with Vallejo metal paints (aluminium, duraluminium and chrome), but have not yet been really impressed.
I do think I want to go for the not-so-shiny look of the dome from A New Hope, but won’t know for sure until I’ve also tried the solvent based Alcad II paints. I have 3 colors (aluminium, polished aluminium and chrome) to try before I can decide, but given that I need to paint that stuff outside, the gloss black primer is going to have to sit there till the weekend:
I did manage to get a bit of work done on the power coupler model, which was needed as the parts didn’t really fit together the way I had imagined they would. The fit is still a bit too tight, and I’m a bit worried that applying XTC-3D will make that even worse, so I might add a little bit more spacing.
All in all a lot of research, but all slowly taking me closer to actually building R2-D2.
Appearantly creating a more complex shape consisting of multiple separate parts in OpenSCAD is testing the limits. After adding a couple of connectors between parts, the preview slowed to a crawl and exporting parts took ages. So I set out to test various CAD tools to find one that was affordable and easy to work with. For the moment I’ve settled on OnShape while I attempt to make the models for the rear door.
My biggest problem with OnShape so far is that you can only have a couple of private documents, and more importantly they cannot be more than 100Mb. Now you would figure that would be enough for some basic stuff, but with the whole version history even a simple frame as the one above takes up about 30Mb of space. I might end up having to make the design public just to get around the 100Mb limit.
After lots of cutting, I finally removed the last bit of styrene from the skins. Being the perfectionist that I am, I see lots of flaws in my work, mostly near round edges. At some points I hope to build a (Mostly Printed) CNC machine to redo the skins, but for now these will do to give an idea of the size of things. I measured the rear door and it came out the size the blueprints specify, so that can be a good first test for my 3D printed frame.
It’s been a lot of work, but I’m getting close to completing the hand cut styrene skins for R2-D2. I’ve completed both the front inner and rear inner skins as well as the front outer skin. Now all that’s left is the rear outer skin, but that too are a lot of little squares to cut out. Tonight I quickly taped the ones I had finished together, and it suddenly looks like an Astromech.
In the mean time I’ve been doing some investigation into creating my own custom remote controls for driving the droid when time comes. Inspired by StealthRC, I want to create some remotes that can be easily hidden in the pockets of a sweater, and the size and shape of the old Wii Nunchuk seemed to fit quite well.
As I want to use as much off the shelf electronics as possible, I probably need to adjust the width of the controller a bit as the bottom part is too slim to fit the Adafruit Feather. I’m also not sure if I want to stay with the 500mAh lipo that I’ve been testing with, or that I want to see if I can fit the 1200mAh version in.
My plan is to use a raspberry PI as the receiving end of the bluetooth connections (I also ordered a chinese replica of the Playstation Move Navigation controller) and use I2C to control the various subsystems, for which I can then use Arduino’s again.
I’ve made a start cutting the styrene skins for R2-D2, but that has proven to be a lot harder than I thought. It takes several cuts to actually go through the 1mm plastic and quite a lot of pressure. It’s definately not going to be done in a single evening 😉 Additionally I probably need to do some additional clean up; despite the metal ruler it’s hard to make the knife cut completely straight …
Today I started the first steps towards by beginning with the frame design in OpenSCAD. I converted the skins from the Astromech forum and setup some common variables and functions for easily making rings and verticals.
With the new movie coming out, there is no way to miss the star wars hype. I was quite interested in BB-8, the newest droid in the Star Wars collection. During some googling, I ended up finding the BB-8 Builders Club, that offered STL files to 3D print a version. While that’s of course very nice, the real star droid of the Star Wars universe is of course R2-D2. Through the BB-8 builders club, I ended up on the Astromech forum where enthusiasts have collected almost every piece of information available about R2-D2 and his siblings. As I always wanted to create a robot, I decided to use this available information and start planning my own real size R2-D2 droid. One of the first parts has already come in (the bearing for the dome to rotate on), but I plan to 3D print most of the other structural pieces.