Inspiration can strike in the most unexpected ways, and for Micke Askernas, the idea to build a full-scale R2-D2 robot came to him in the form of a bottle of bath bubbles.
“I was looking at an R2-D2 bubble bath container that my brother had given me some years before,” Askernas said. “It looked pretty ok, but there were some details that just didn’t look right.”
“In the end, I realized it was a lot of work for such a small thing, and I thought I’d might as well build a full scale robot instead,” Askernas said.
Now, several years later, the Sweden native is plugged into The Swedish R2 Builders, a club for the robot replica enthusiasts. The club is a fixture at Swedish Sci Fi conventions, along with the local 501st, which is George Lucas’ favorite Star Wars costuming organization.
“At the time, I had no idea there was a club for people equally as crazy as me, nor that anyone had built a full-scale replica,” Askernas said. “The R2-D2 Builders club is worldwide, and it helped a lot with ideas and also getting together with friends and having some of the difficult special parts made up for us.”
Both the R2-D2 and the 501st clubs spend much of their time raising money for children’s charities – with a special emphasis on cancer research.
“I have taken R2 to the two biggest children’s hospitals in Sweden, where, if only for a brief moment, the sick children get to forget about their illness and just be kids, and meet their idol — R2, not me,” Askernas said, “It is something that has affected me greatly, and being a father myself, something I really have a soft spot for.”
Askernas said it took him 8 months and endless consultations with Google, as well as visits with a friend who was building an R2 of his own, in order to form the robot’s exterior.
“Most of what looks like metal is metal, but some of it is not. It is really a challenge to find various ways of making building easy,” Askernas said . “After roughly 800-1200 hours, I had a simple, radio controlled robot that worked great.”
Askernas, whose background is in information technology, also built analogue synthesizers within the robot, but he said he just wasn’t happy with the way it was turning out.
“They guy with the big radio was obviously controlling the robot,” Askernas said. “I took a solution from a friend of mine, based on using several Arduino boards in a distributed environment in the robot talking wirelessly to an external Arduino, hooked up to a touch screen and a Wii Nunchuck, and modified to suit my means.”
Basically, that means that Askernas had to rewrite the entire code base from scratch.
“I could have just been content with having him be a big RC car, but I have been trying to make him a proper character,” Askernas said. “ He does not only need to look right, he needs to move right, to sound right, to have the right mannerisms, and that is the challenge I have been working on lately.”
The second challenge Askernas was met with was controlling the speed and direction of the robot. He started with a Sabertooth 2×12 R/C motor controller, and has since upgraded to the Sabertooth 2×25.
“Since the motors are mirroring each other, it mean that one motor had full speed forward and the other full speed reverse,” Askernas said. “Long story short, in the process of getting it right, I put a hole in my wall.”
Askernas’ R2-D2 was his first robot project. He began using a 12V Gel battery, with 20 Ah capacity that he bought at a local hardware store.
“There were a couple of things I didn’t like with this,” Askernas said. “It was heavy, we’re talking 25 pounds for this beast. It was big and it had uneven power from the battery.”
Askernas said when his R2 was fully charged, it was quick and responded the way it was designed, but as the power was drained, it became sluggish and eventually undriveable.
He upgraded to the 8000 mAh MaxAmps battery and bought a second to use as an alternate.
“The battery I chose is quite small and lightweight. I liked that combination,” Askernas said. “In fact, they are so small that I am considering moving them to the feet to lower the center point of gravity inside the R2.”
Askernas said he is toying with the idea of using a LiFePo4 battery.
“Here, we’re talking a battery that weighs maybe 10 percent of a Gel battery, less weight means less power needed to drive the robot and thus less need for a big battery,” Askernas said. “The main drawback of LiFePo4 is the price. Living in Sweden, it also means that in addition to battery costs, I still need to pay an extra 25 percent import tax on top of battery price and shipping.”
Askernas said he chose MaxAmps batteries mainly because of the company’s customer service and expertise in their field.
“I may know a thing or two about electronics and building, but really not about batteries. It always pays off surrounding you with people with good knowledge and understandings of areas you have not,” Askernas said. “That is why I chose MaxAmps, and have been going back to talk about new batteries as well.”
With every minute that he spends perfecting his R2-D2, Askernas said he learns new things about electronics and robot building.
“I have done some theatrical props and animatronic things for others, something I will keep on doing. I have realized I live in the wrong country for creating working special effects for a living, but there is really nothing I can’t do that involves animatronics now, with my knowledge of electronics, 3D design, 3D printing and scratch building,” Askernas said, “Oh, and a good supplier of batteries, of course.”