December 28th, 2015- February 12th, 2016: The Deprecated Dome
The first two months of this process was spent finishing the dome of BB-8. At the time, my plan was to create a static office decoration. With that approach in mind, I didn't give much thought to anything beyond 'make it look as awesome as possible.' This section shows the stages of printing/prepping/finishing my first BB-8 dome which ultimately ended up being way too heavy for the functional droid project this ended up becoming. Below you can see the log for the building of this dome
BULK PRINTING
It was at this point in the build I made a real effort to start documenting each stage. The pictures from here are more frequent and hopefully my explanations can be a little more helpful.
With all the sub-pieces glued into their final configuration I can start prepping each piece for paint by filling gaps, sanding and priming.
Rather than keep each piece at the same stage of the process, I started taking some pieces to the next level as I continued to work on the others. In practice, this basically meant I began finishing parts in order from smallest to largest.
February - June 2016
As with the deprecated dome, I had an issue with some un-used body panels. This one isn't quite as linear as the dome because I worked on it in parallel with the internal drive mechanism. For the sake of organization over chronology, I moved all the pictures of these body parts to this next section. So bear with my Tarantino-ing here.
February 12th, 2016
So why all these useless parts? As I mentioned earlier, there was a point in the build when I knew I would not be satisfied putting in all these hours for a simple decoration. After seeing some successful approaches to drive mechanisms I decided to give a functional droid a shot. James Bruton of XRobots' V3 design was the one that appealed to me most. Due to some initial size changes and being hindered by a smaller printer, I started recreating the file in 3D Studio Max so I can export print files and change things on demand to test ideas/accommodate the parts I bought which would ultimately be different than the parts XRobot's used his build.
February 14th, 2016
February 16th, 2016
February 17th, 2016
February 22nd, 2016
With the Makerbot down, I called makersupport and got the impression "best case scenario" would be a few weeks. I had been eyeing up the Taz5 anyway, so this hiccup ended up being the final push I needed to make the purchase. Amazon Prime had it to my door in 2 days.
February 25th, 2016
March 18th, 2016
Now that the ball was prepped for the internal drive mechanism it's time to start building! The logical thing would be to start with the carriage or 'banana,' but after watching the video of James (XRobots) building the flywheel I knew my excitement would force me to start there.
March 18th, 2016
With the batteries in hand I can wire up the motor for the first motorized roll test.
With the bottom "drive" portion of the internal mechanism scquared away it's time to focus on the top "head" portion.
March 21st, 2016
Next up is the top of the head control arm, the Body Magnetic Mount (BMM)(no not poop). This is anohter instance where my build will differ drastically from XRobots' . I'm planning on making a heavier head than James did thus I need more magnet power. I began designing a different configuration.
In addition to needing more magnetic pull, the heavier head will require a bit more counter-weight. Adding static mass to the bottom of the ball will keep the top-heavy droid from falling out of control. I had a bit of lead left over from my flywheel fill, so I decided to create some weight containers that would attach to the banana.
My goal at this point is to make this next installation to the ball the last one. Getting all this stuff in and out is tricky and stressful. Once everything is "in there, in there" I can start adding the top half parts and wiring. I'm trying to think of any parts I can add on now which won't hinder the installation but will save me time on having to install 'into' the ball.
I solved my wiggly motor problem and made the ball a lot smoother but didn't correct the tilted axis part at all. That was due to all the weight in my saddle bags being towards the back of the ball. So before I can go further I have to balance this out. I know it can be done with the inertial measurement unit (IMU) and stabilization through software, but why not at least try to start with a balanced droid? One problem, though, I'm out of lead shot.
With everything back in the droid, everything staying un-wobbled, and everything balanced, I'm ready to move onto the rest of the installation.
Now that all the mechanics are in, I can start on some of the electronics. The first thing I need to do is pair my two bluetooth modules. Then get the remote controller transmitting data over that bluetooth. Then get the ball all wired up and receiving that data.
April 24th, 2016
I'm a little late catching up on the blog, but that's only because I usually update the blog when I hit a roadblock...and generally speaking that hasn't happened lately. I did have a pretty busy work week last week that kept me away from droid progress, but I more than made up for it this weekend.
First, I got the bluetooh modules paired so the remote control can talk to the droid. Not much I can post to "show" that, but suffice it to say it works and has been tested again and again, were good.
Now let's get the hand set taken care of.
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I tested everything out with some code printing to the Serial Monitor of my Arduino and we're all good. Handset controls talking to Arduino Pro Mini Talking to Bluetooth talking to other bluetooth talking to Arduino Mega (cchhhaaaaiiiinnnnn keep us together [RUNIN THE SHADOWS])
Next up is to mount all the electronics into the droid. But before I can do that I have one small piece of maintenance that needs to be done. In part 9 of James's series he noticed a "fundamental mechanical flaw" in the design. Long story short it can be corrected with a set of guide wheels running higher on the potentiometer side. I installed those before I congested everything with the electronics mounts.
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With that done I can mount my electronics.
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This is always the most frequently asked parts list, so here we go:
Amazon Link to Arduino MegaAmazon Link to Motor Controller
Amazon Link to Inertial Measurement Unit (IMU)
Despite my best efforts, I fried two motor controllers. There is nothing more humbling then flicking a switch, hearing a pop, and watching that smelly puff of smoke rise in the air. Bye bye money, hello amazon delivery man.
April 28th, 2016
There is a lot of repetition in the next 4 videos. I was making them and posting them for various audiences (friends who kind of get what I'm doing, my facebook friends who don't know what I'm doing, and the BB-8 club who know even better than I do what I'm doing) so rather than try to decide which video was best I just posted everything I had from that week. The videos show a progression from getting the side to side stabilization working to driving it front to back for the first time.
It was about this time in the build when I realized my current finished dome was going to be significantly too heavy. I had the idea to print a 96% scale head which could be printed in one piece on my Lulzbot Taz5. I printed in a practically no-infill density with 3 perimeters. The weight difference was substantial.
June 4th, 2016
Generally speaking, I'm happy with the locomotion. Time to start focusing on the body skins/panels. First I have to tackle the issue of how I am going to attach them. One thing I can't stress enough is how awesome/important it is to find someone in the club who is building a droid similar to yours and bounce ideas off of. For me, that person was Ian Martin over at Dejarik Creations. We were both pretty much building the droid in the same way, the only difference was after finishing the cheese wheel, I focused first on the inside on the ball and he focused first on the outside of the ball. This worked out great as we both had someone on the other side who had already tackled some problems. This was most prevalent in the case of the external frame. Ian NAILED it. It was perfect. I just had to modify it to fit my larger cheese and it was printing the same day.
Now it's time to start focusing on the body panels. For the triangles I am reprinting them as Cary triangles with the built in hole for mounting. There are holes in the frame to align with these.
This next bit was the second scariest part of the build (the first being powering up the motors for the first time before I knew everything worked). I'm going to be drilling straight into the cheese to embed the inserts.
Now on to the shimming
Below is a scrolling gallery of the weathering process.
Next up for the body is clearcoating the panels and wiring up the body LEDs. I think I can do both at the same time as I disassemble the droid. I decided to go with neopixels for the body so I can create or not create animation cycles for the body panels. I did a quick print of a section of panel one and wired up my first sets of neopixels.
After all the testing fun it's time to get rolling on this thing. The arduino powering all of these neopixels is going to be mounted on the back of Panel 2. I downloaded a printable case for the Arduino Uno from thingiverse and glued it into place. Panel 2 seems like a good place to start my NeoPixel installation.
Now that the lights on the body were taken care of, I was 'technically' ready to seal this ball up and focus on the head. A few things held me back (1) I'm not confident the magents would hold the head on in their current configuration. (2) The main drive wheel slips WAY more than I'm happy with. (3) My remote control needs to be rebuilt to add in the functionality of the head. I got to talking with another builder about using the R2 SHADOW system on the BB8. I spent a month or two trying to implement that and get it all set up , but ultimately it just wasn't working for me. The advantages didn't seem to outweigh the problems I was running in to. So I abandoned that. That leaves me with my original 3 problems to solve.
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The Final Dome
Since I started this blog with the "deprecated dome" section I should end it with the final dome as that's the last thing that will be complete. I'm going to start working on it while I'm still prepping the panels but will keep this section separate and last for clarity sake. I never really stopped working on the dome from the get go. I've done several iterations with different mounting systems, different skirt/ring combos, etc etc. As of this posting I think i have printed my final dome section, which is saying something. I'm about 80% sure I've printed my last skirt/ring combo and even less certain I've printed my last pie/top combo. Whats the reason for so many iterations? WEIGHT. I'm trying to find the best way to trim weight off this thing while still having it look good. My goal is 3.25lbs for the entire dome including lights and sounds. I think it's possible.