Giant Spirograph Delights Children, Dwarfs Banana

giant spirographLate last year at a craft show, [hahabird] and a friend came across a laser-cut Spirograph and they both had a go at it. After mocking his friend’s lack of fine motor skills, [hahabird] was struck with the idea of making a giant-scale Spirograph that would (hopefully) be less frustrating for kids of all ages.

He generated the gears using an InkScape plugin, and then moved the project to Illustrator for adjustments. After nesting the inner gear drawings, he was able to print them out on one 3×3′ piece of paper at the local FedEx-Kinko’s. To make a template for routing he pieces that make up the eight-foot diameter outer ring, [hahabird] first cut it out of MDF and then bolted that to plywood. The outer ring’s size was dictated by the number of sections that fit on a 4×8 piece of plywood.

The challenge of the inner cogs was to make them move smoothly and still mesh with the teeth of the outer ring. [hahabird] solved this by mounting casters on raised platforms, which double nicely as handles. Each inner cog has a series of PVC couplers that take the 1″ PVC chalk holder insert.

So far, [hahabird] has cut 22-, 35-, and 44-tooth cogs, all of which are painted in nice, bright colors. According to his reddit comments, he will have a video or gif of it in a few days. We hope he makes the plus sign cog and the tongue depressor piece, too.

Roboceratops: A Robot Dinosaur That Defies Extinction

roboceratopsInspired by a childhood love of dinosaurs, [Robert] set out to build a robotic dinosaur from the Ceratopsian family. After about a year of design, building, and coding, he has sent us a video of Roboceratops moving around gracefully, chomping a rope, and smoothly wagging his tail.

Roboceratops is made from laser-cut MDF and aluminium bars in the legs. That’s not cookie dough on those legs, it’s upholstery foam, and we love the way [Robert] has shaped it. Roboceratops has servos in his jaw, neck, tail, and legs for a total of 14-DOF. You can see the servo specifics and more in the video description. [Robert] has full kinematic control of him through a custom controller and is working to achieve total quadrupedal locomotion.

Inside that custom controller is an Arduino Mega 2560, an LCD, and two 3-axis analog joysticks that control translation, height, yaw, pitch, and jaw articulation. For now, Roboceratops receives power and serial control through a tether, but [Robert] plans to add an on-board µC for autonomous movement as well as wireless, a battery, an IMU, and perhaps some pressure/contact detection in his feet.

The cherry on top of this build is the matching, latching custom carry case that has drawers to hold the controller, power supply, cable, tools, and spare parts. Check out Roboceratops after the break.

Continue reading “Roboceratops: A Robot Dinosaur That Defies Extinction”

Manual Pick and Place

picknplacePopulating a large surface mount PCB can take forever. [craftycoder] from Freeside Atlanta has built a great looking manual pick and place machine, removing the need for tweezers. No more will passives stick to your tweezers while you are trying to place them on your PCB!

We have seen a lot of pick and place machines in the past few years. What makes this one stand out is its simplicity and the no-nonsense build. This pick and place is built on an MDF platform, uses bearings from Amazon, standard 12 mm rails, and has a small camera for a close-up look at your part placement. Sure it is a manual method, but it beats painstakingly placing each part with tweezers. It would be interesting to see how much this entire build cost; we expect that it was not too expensive. See this thing in action in the video after the break.

We hope this project has inspired you to go out and make something cool! If so, let us know what you have made!
Continue reading “Manual Pick and Place”

Portable audio rig that turned out great

portable-audio-rig

[Michael] wanted a stereo that he could use outside, be it at the beach, beside the pool, or while tailgating. He decided to build this boom box himself, and didn’t cut any corners when it came to a professional looking finish.

Because of the locale in which he plans to use the stereo he went with a set of marine speakers. They’ll have no problem standing up to water, and since they’re used in boats they should also be able to take a beating during transport. To feed it he uses a Lepai T amp which is seen above.

After cutting each piece of the case out of MDF he started working on the openings to receive the components. This involved quite a number of layout lines and some work with a compass to map out the circular openings. He built a recessed panel on the back to interface the power cord for charging. Inside is an 18 Ah battery. A set of switches lets him turn on the charger and choose between powering the amp from battery or from the power cord.

[via Reddit]

A Little Geneva Drive Made of Wood

MDF Geneva drive in action

Long ago, before servo motors and linear actuators were common, clever mechanical devices were what engineers used to produce the needed motion for their processes. The CNC-cut Geneva Drive may not be fit for industrial use, but this type of device has been used in everything from film projectors to rotating assembly tables. The constant rotation of the driving wheel is translated into intermittent motion by the [Maltese cross] driven wheel.

The drive and Maltese cross section of this particular drive are made out of MDF with the exception of a putty material that the motor shaft press-fits into. The article claims that this is the only Geneva drive in existence made out of MDF, however, we’d love to see that proven wrong in the comments!

If you’d like to make one of these yourself, CAD and G-code files are given for the hand-cranked version that this Drive is based off of in a separate post.  If you’re not familiar with how a drive like this works, or would just like to see everything in action, be sure to check out the video of it after the break! Continue reading “A Little Geneva Drive Made of Wood”

CNC milled bicycle frame jig

This bicycle frame jig is cut from MDF. It’s the latest in a growing trend that we love to see: the increasing availability of manufacturing techniques for the common hacker. This is a Kickstarter project, and alas it appears the designs are not available for you to cut your own. But we love the potential this shows, and maybe you can use the concept the next time you’re welding together a frame for something.

We really never look at building traditional frames at home. Mostly it’s the oddities that catch our eye. But if you’re into cycling and want to get your own custom-fit frame this has got to be the lowest-cost option available. In fact, you can get the jig and a tube set for under $600. The frame can be fit with just a few hand tools (a hack saw and a file). It uses lugs so the joints will be strong as long as you get the pipes fitting well enough for a quality welded joint.