Wall-Climbing Robot Grabs Prize

May 19, 2020 by Bryan Cockfield 24 Comments

Gravity is a nice thing to have most of the time, but sometimes it would be nice to be able to ignore it for certain applications. Rock climbing, for example, would be much easier, as would performing bridge inspections in the way that a group of mechanical engineering cadets (students) at The Citadel, a military college in South Carolina, were tasked with doing. Frustrated with the amount of traffic backups that normal bridge inspections caused, they invented a robot that defies gravity, and won a $10k prize for their efforts.

The result is essentially an RC car with a drone built in, or looking at it another way it’s a drone with wheels. The car is able to drive on vertical surfaces to inspect the bridges by using its propellers to force itself onto the surface. The lack of complicated moving parts or machinery, like a cable suspension system or other contraption, makes this device exceptionally versatile for the task at hand, reduces the amount of time needed for inspections, and can do them more safely and without closing lanes of traffic. The group hopes to build a second prototype soon and present it to the Department of Transportation for approval for more widespread use.

The need for tools like these is in high demand now as well, especially in the United States where crumbling infrastructure is often not thought about, taken seriously, or prioritized. Even for bridges that aren’t major pieces of infrastructure, tools like these will prove to be very useful.

Thanks to [Ben] for the tip!

Re-used Materials Make Tiny Offroad Track For Micro R/C

May 3, 2020 by Donald Papp 3 Comments

What does one do with tiny 1:35 scale remote controlled off-road vehicles? Build appropriately-tiny tracks for them to drive on, of course. That’s exactly what [David] did when he created his fantastic rock crawling track that he has dubbed the ‘4×4 Arena’, and what’s even better is that he used leftover foam inserts and acrylic paints and materials to do it, and didn’t have to spend a penny.

The original track is only just visible in the back; the new track expands it considerably.

This isn’t [David]’s first track. He originally made a smaller rock-crawling track he called Rubble Wasteland for the tiny vehicles, and he liked it so much he expanded it considerably. The new track builds on the original and is three levels deep, sports tight cave-like passages, tunnels, tricky climbs, and and realistic terrain textures.

An enormous photo gallery is right here, and other than the first and final images, it’s roughly in chronological build order. If your curiosity has been piqued about the tiny 1:35 scale remote controlled vehicles that this track is built for, around gallery page nine is where pictures of what makes these tiny things tick begins.

We have seen some amazing projects in the RC field; like this tiny 3D printed truck, and in-depth details of a micro RC plane that weighs only 2.9 grams.

How To Slice Lightweight Aircraft Parts For 3D Printing

February 21, 2020 by Lewin Day 5 Comments

Historically, remote control aircraft were produced much like their early full-sized counterparts. Wooden structures were covered with adhesives and taut fabric membranes. Other techniques later came to the fore, with builders looking to foam and other materials. Of course, these days 3D printers are all the rage, so perhaps one can simply print out a whole plane? As [sahevaantaneja] discovered, it’s not that easy!

One of the foremost problems is the process of slicing. This is where 3D geometry is transformed into the G-code which defines the path taken by the 3D printer during production of a component. Slicer software is generally optimised for working with mostly-solid objects, and some tweaks can be required when working with thin-walled designs.

These challenges come to bear with an aircraft design, which, by necessity must be lightweight. [sahevaantaneja] does a great job of explaining the journey of discovery in which their design was optimised to work with conventional slicers. This allowed the various components to be printed without errors, while retaining their strength to survive in flight.

The design was successful in test flights – a great reward after much experimentation. We’ve seen other 3D printed designs take flight, too. Video after the break.

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Cheap Strain Relief By Casting Hot Glue In A 3D Print

February 11, 2020 by Donald Papp 52 Comments

[Daniel Roibert] found a way to add cheap strain relief to JST-XH connectors, better known to hobby aircraft folks as the charging and balance connectors on lithium-polymer battery packs. His solution is to cast them in hot glue, with the help of 3D printed molds. His project provides molds fitted for connectors with anywhere from two to eight conductors, so just pick the appropriate one and get printing. [Daniel] says to print the mold pieces in PETG, so that they can hold up to the temperature of melted glue.

The 3D models aren’t particularly intuitive to look at, but an instructional video makes everything clear. First coat the inside surfaces of the mold with a release agent (something like silicone oil should do the trick) and then a small amount of hot glue goes in the bottom. Next the connector is laid down on top of the glue, more glue is applied, and the top of the mold is pressed in. The small hole in the top isn’t for filling with glue, it’s to let excess escape as the mold is closed. After things cool completely, just pop apart the mold (little cutouts for a screwdriver tip make this easy) and trim any excess. That’s all there is to it.

One last thing: among the downloads you may notice one additional model. That one is provided in split parts, so that one can make a mold of an arbitrary width just by stretching the middle parts as needed, then merging them together. After all, sometimes the STL file is just not quite right and if sharing CAD files is not an option for whatever reason, providing STLs that can be more easily tweaked is a welcome courtesy. You can watch a short video showing how the whole thing works, below.

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Floating On The Breeze With A Full Size RC Paraglider

January 23, 2020 by Danie Conradie 12 Comments

For many people the gateway drug to aviation is radio-controlled aircraft, and in [Andre Bandarra]’s case this led to paragliding. Now he has combined the two, turning his full size paragliding wing into an RC aircraft. (Video, embedded below.)

The primary controls of a paraglider are very simple, consisting of two brake lines that connect to the trailing edge of the wing. When a line is pulled, it increased drag on that side of the wing, causing it to turn. [Andre] connected the brake lines to two 3D-printed spools, which are each powered by a large RC servo that he modified for continuous rotation. These are mounted on a slim wooden frame that also holds the battery, RC receiver, an old electronic speed control to step down the battery power, and attachment straps for the wing. Without enough mass, the wing would just get blown around by the lightest of breezes, so [Andre] hooked a cloth bag filled with sand to the frame to act as a counter weight.

On the first test flight the wind was too strong and the sandbag too light, making it impossible to control. The hardest part of the flight is the launch, which requires the help of someone who knows how to fly a paraglider. The second test day had much better success. With only a slight breeze and a heavier sandbag, the contraption flew beautifully, floating slowly across the beach. He admits that there are a number of improvements he can make, but as a proof of concept using parts he had lying around, it was a roaring success.

For paragliding from flat ground, you can always strap a motor to your back, like the open source OpenPPG electric paramotor. For more crazy RC flying contraptions, also keep an eye on guys at [Flite Test].

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Compact 3D Printed Hovercraft Is Loungeroom Floor Fun

December 26, 2019 by Lewin Day 7 Comments

Hovercraft come in all shapes and sizes. and while they’ve largely disappeared as a major commercial transit option, they remain popular in the hearts and minds of makers everywhere. [RCLifeOn’s] latest project concerns a compact, indoor-sized hovercraft piloted via FPV, and it looks to be brilliant fun.

The build consists of a 3D printed chassis, with a skirt cut out of a garbage bag and held on with press-fit clamps. Twin ducted fans are employed, one for propulsion, the other for levitation. A 5GHz FPV camera is nestled on top of the rear fan housing to provide a video feed for the pilot.

The craft was somewhat uncontrollable in initial testing. Tweaks to the weight distribution and the addition of a bigger rudder helped tame the rig. [RCLifeOn] also demonstrates a unique way of balancing damaged fan assemblies in the field; it’s a technique we’ll keep in the back of our mind for future use.

The trick to a good hovercraft build is light weight, big control surfaces, and a good skirt. You can even go off-book and use the Coanda effect, if you’re so inclined. Video after the break.

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Race RC Cars From Anywhere On Earth

August 31, 2019 by Lewin Day 9 Comments

Racing games have come a long way over the years. From basic 2D sprite-based titles, they’ve evolved to incorporate advanced engines with highly realistic simulated physics that can even be used to help develop real-world automobiles. For [Surrogate.tv], that still wasn’t quite good enough, so they decided to create something more rooted in reality.

The game is played in a web browser. Players are assigned a car and view the action from a top-down camera.

Their project resulted in a racing game based on controlling real RC cars over the internet, in live races against other human opponents. Starting with a series of Siku 1:43 scale RC cars, the team had to overcome a series of engineering challenges to make this a reality. For one, the original electronics had to be gutted as the team had issues when running many cars at the same time.

Instead, the cars were fitted with ESP8266s running custom firmware. An overhead GoPro is used with special low-latency streaming software to allow players to guide their car to victory. A computer vision system is used for lap timing, and there’s even automatic charging stations to help keep the cars juiced up for hours of play.

The game is free to play online, with the races currently operating on a regular schedule. We look forward to trying our hand at a race or three, and will be interested to see how the latency holds up from various parts of the world.

We’ve seen other remote RC builds before; usually featuring the power of the Raspberry Pi. We’ve also covered useful techniques for low latency video for real-time applications. Video after the break.

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