RepRap Simpson Puts A New Spin On Delta RepRaps

September 18, 2013 by Adam Fabio 23 Comments

Just when you think you’ve seen it all in the 3D printer world, something new pops up! [Nicholas Seward] posted a video of RepRap Simpson, his latest project. Simpson is a delta robot – but unlike any delta we’ve seen before. Previous offerings vertical rails on which the arms travel. As you can see, this design mounts three articulated arms directly to the base of the printer, using steel cables as part of the joint mechanism.

Judging by [Nicholas’] posts on the RepRap forums, Simpson’s grounded delta design has already gone through a few revisions. The basic geometry though, has remained the same. [Nicholas] calls this edition a “Proportional Gear Drive Joint Simpson”. The name may not roll off the tongue, but the movements are incredibly smooth, organic, and fast.

As with any delta design inverse kinematics play a huge role in the software. [Nicholas] is trying to simplify this with an optical calibration system. For the adventurous, the equations are posted on the forums, and a python Gcode preprocessor is posted on Thingiverse.

Even Simpson’s base received special attention. It’s built from a water jet cut piece of basalt. We like the use of opposed helical gears on the large joints, as well as the guitar machine heads used to tension the cable drive. One thing we are not sure of is the longevity of system – will cable stretch play an issue? Will the printed parts suffer wear from the cables? Only time will tell.

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Stewart Platform Reinvents The Wheel So You Don’t Have To

September 18, 2013 by Adam Fabio 20 Comments

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[Dan Royer] has noticed that most university projects involving a Stewart platform spend more time building a platform than on the project itself. He hopes to build a standard platform universities can use as the basis for other projects.

Stewart platforms are six degree of freedom platforms often seen hefting flight simulators or telescopes. The layout of the actuators allows movements in X,Y,and Z as well as pitch, roll and yaw. While large platforms often use hydraulic systems to accelerate heavy loads quickly. [Dan] is looking at a smaller scale system. His platform is built of laser cut wood and uses six steppers to control motion.

One of the harder parts in designing a platform such as this is creating a mechanical system that is strong, precise, and smooth. With so many linkages, it’s easy to see how binding joints could bring the entire thing to a grinding halt. [Dan] is currently using RC helicopter ball joints, but he’s on the lookout for something even smoother.

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Robotic Tentacles For A Disturbing Haunted House

September 16, 2013 by Brian Benchoff 9 Comments

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[ivorjawa] is putting on a haunted house this Halloween that we really don’t want to go to. His robot tentacle is already supremely creepy, and we’re assuming it will only be more frightening once it’s covered in fabric and foam rubber.

Each tentacle can move on two axes thanks to four steel cables running through this strange Geiger-esque contraption. In the base of the tentacle are two stepper-motor driven cylinders that take up slack on one cable and draw out another cable. Two of these control boxes, driven by a stepper motor and an Arduino motor shield, allow the tentacle to reach out and grab in any direction. You can check out the mechanics of the build on [ivorjava]’s flickr

On a semi-related note, even though we’re more than a month out from Halloween, we should have more Halloween builds in our tip line by now. If you’re working on one, don’t be afraid to send it in, even if you’re just showing off a work in progress.

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Fully Automated Watering Robot Takes A Big Leap Forward Toward Greenhouse Automation

September 12, 2013 by Todd Harrison 44 Comments

Greenhouse owners might find [David Dorhout]’s latest invention a groundbreaking green revolution! [David]’s Aquarius robot automates the laborious process of precision watering 90,000 square feet of potted plants. Imagine a recliner sized Roomba with a 30 gallon water tank autonomously roaming around your greenhouse performing 24×7 watering chores with absolute perfection. The Aquarius robot can do it all with three easy setups; add lines up and down the aisles on the floor for the robot to follow, set its dial to the size of your pots and maybe add a few soil moisture sensors if you want the perfect amount of water dispensed in each pot. The options include adding soil moisture sensors only between different sized plants letting Aquarius repeat the dispensing level required by the first plant’s moisture sensor for a given series.

After also digging through a pair of forum posts we learned that the bot is controlled by two Parallax propeller chips and has enough autonomous coding to open and close doors, find charging stations, fill its 30 gal water tank when low, and remember exactly where it left off between pit stops. We think dialing in the pot size could easily be eliminated using RFID pot identification tags similar in fashion to the Science Fair Sorting Project. Adjusting for plant and pot size as well as location might easily be automated using a vision system such as the featured Pixy a few weeks back. Finally, here are some featured hardware hacks for soil moisture sensing that could be incorporated into Aquarius to help remotely monitor and attend to just the plants that need attention: [Andy’s] Garden sensors, [Clover’s] Moisture control for a DIY greenhouse, [Ken_S’s] GardenMon(itoring project)

[David Dorhout] has 14 years experience in the agriculture and biotech industry. He has a unique talent applying his mad scientist technology to save the future of mankind as seen with his earlier Prospero robot farmer. You can learn more about Aquarius’s features on Dorhout R&D website or watch the video embedded below.

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BREWSTER Fetches Your Beer Automatically

September 8, 2013 by Mike Szczys 18 Comments

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Afraid that if you leave the room you’ll miss the best play of the game? Now you don’t need to move your rear end in order to grab the next brewski. BREWSTER was developed to fetch cold beers from the fridge and deliver them to you automatically.

The robot started as a roomba but has been heavily repurposed with the addition of a mechanical arm on top of the chassis. This not only lets BREWSTER grip a can of beer, but it can first open the mini fridge and reach far enough inside to get one from the back. This requires no modification to the refrigerator, but the low clearance of the roomba does call for a mini-fridge sitting at floor level. Check out a demo run in the video after the break. We think the current version is running on a pre-coded route; this project is just waiting for a spin-off that has mapping and machine vision.

The alternative to this single can delivery would be to make the entire icebox into a robot.

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Jack The DVD Ripping Robot

September 5, 2013 by Brian Benchoff 56 Comments

[Andy] had a fairly large problem on his hands. For the last 15 years, he’s been collecting DVDs, and since he began, he’s run out of space on his shelves for these miraculous plastic discs. Everything’s going to the cloud now, so he decided to build a media server, replete with rips of all his DVDs. As anyone who has ever tried to rip a movie knows, this can be a very long and tedious process. His solution to this should be something near and dear to all of us – he decided to build a robot to rip all his DVDs automatically.

With a brand new 3D printer, [Andy] set to work on designing Jack the Ripper Bot. The design has two trays mounted to a standard computer DVD drive, an ‘in’ tray and an ‘out’ tray. The frame of the machine bolts directly to the drive, and the entire contraption is driven by only three standard hobby servos.

The robot is driven by a Raspberry Pi, but the ripping actually takes place on an old laptop. [Andy] says it takes about an hour and a quarter to rip a DVD, so a full ‘in’ tray of 24 discs means about 28 hours of ripping time. Feeding the machine once a day is a lot better than returning to the computer every hour or so, we think.

All the STLs for the printed parts and the software for the Raspi and computer are up on [Andy]’s github, should anyone want to upgrade this to a Blu Ray ripper.

Thanks [Stephen] for sending this one in.

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Finally, A Practical Use For The Leap

September 3, 2013 by Brian Benchoff 15 Comments

Robots used in laparoscopic surgery are fairly commonplace, but controlling them is far from simple. The usual setup is something akin to a Waldo-style manipulator, allowing a surgeon to cut, cauterise, and stitch from across a room. There is another way to go about this thanks to some new hardware, as [Sriranjan] shows us with his Leap-controlled surgery bot.

[Sriranjan] isn’t using a real laparoscopic surgery robot for his experiments. Instead, he’s using the Le-Sur simulator that puts two virtual robot arms in front of a surgeon in training. Each of these robotic arms have seven degrees of freedom, and by using two Leap controllers (one each in a VM), [Sriranjan] was able to control both of them using his hands.

We’ve seen a lot of creative applications for the Leap sensor, like controlling quadcopters, controlling hexapod robots, and controlling more quadcopters, but this is the first time we’ve seen the Leap do something no other controller can – emulating the delicate touch of a surgeon’s hand

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