The Carbon Fiber Construction Of Large Propellers

October 6, 2018 by Brian Benchoff 11 Comments

Props for your little RC airplane or drone are effectively consumables. They’re made of plastic, they’re cheap, and you’re going to break a lot of them. When you start swinging something larger than 12 inches or so, things start getting expensive. If you’re building gigantic octocopters or big RC planes, those props start adding up. You might not think you can build your own gigantic carbon fiber propellers, but [Tech Ingredients] is here to prove you wrong with an incredible video demonstration of the construction of large propellers

The key ideas behind the build are laid out in a video demonstration for building a single prop. The base begins with a CNC wire cut foam air foil. This foam airfoil is first modified for the attachment point by cutting a plug out of the root of the airfoil which is filled with epoxy.

With the skeleton of the airfoil complete, the build then moves on to laminating the foam core with carbon fiber. The epoxy itself is West Systems Pro-Set laminating epoxy, although we suspect the ubiquitous West Systems epoxy used for all those live-edge ‘river’ coffee tables will also work as well. This epoxy is spread out on a table, the carbon fiber laid over it, and a second layer of carbon fiber (check ‘yo biases!) laid over that. This is wrapped around the foam core, then cured with an electric heating pad.

Of course, this is only a demonstration of making a single blade for a prop. The next trick is turning that single blade into a propeller. This is done with a cleverly machined hub, attached through that epoxy plug placed in the foam core. The results are just as good as any large prop you could buy, and this has the added benefit of being something you made, not bought.

This is really a master class in composite construction, and well worth an hour’s of YouTube viewing. You can check out the intro video below.

Continue reading “The Carbon Fiber Construction Of Large Propellers” →

Industrial 3D Printing Uses Layers Like We’ve Never Seen Before

September 19, 2018 by Mike Szczys 20 Comments

We’ve seen FDM printers lay down layers by extruding plastic in a line. We’ve seen printers use sintering and lithography to melt or cure one layer at a time before more print medium moves into place for the next layer. What we’ve never seen before is a printer like this that builds parts from distinct layers of substrate.

At the International Manufacturing Technology Show last week I spoke with Eric of Impossible Objects. The company is using a “sheet lamination process” that first prints each layer on carbon fiber or fiberglass, then uses a hydraulic press and an oven to bake the part into existence before bead-blasting the excess substrate away. Check out my interview with Eric and join me below for more pictures and details.

Continue reading “Industrial 3D Printing Uses Layers Like We’ve Never Seen Before” →

3D-Printed Punch And Die Stand Up To Steel

February 16, 2018 by Dan Maloney 8 Comments

When you think of machine tooling, what comes to mind might be an endmill made of tungsten carbide or a punch and die made of high-speed steel. But surely there’s no room in the machine tool world for 3D-printed plastic tools, especially for the demanding needs of punching parts from sheet metal.

As it turns out, it is possible to make a 3D-printed punch and die set that will stand up to repeated use in a press brake. [Phil Vickery] decided to push the tooling envelope to test this, and came away pleasantly surprised by the results. In fairness, the die he used ended up being more of a composite between the carbon-fiber nylon filament and some embedded metal to reinforce stress points in the die block. It looks like the punch is just plastic, though, and both were printed on a Markforged Mark 2, a printer specifically designed for high-strength parts. The punch and die set were strong enough to form 14-gauge sheet steel in a press brake, which is pretty impressive. The tool wasn’t used to cut the metal; the blanks were precut with a laser before heading to the press. But still, having any 3D-printed tool stand up to metal opens up possibilities for rapid prototyping and short production runs.

No matter what material you make your tooling out of, there’s a lot to know about bending metal. Check out the basics in our guide to the art and science of bending metal.

Continue reading “3D-Printed Punch And Die Stand Up To Steel” →

Vacuum Molding With Kitchen Materials

December 26, 2017 by Brian McEvoy 14 Comments

Vacuum pumps are powerful tools because the atmospheric pressure on our planet’s surface is strong. That pressure is enough to crush evacuated vessels with impressive implosive force. At less extreme pressure differences, [hopsenrobsen] shows us how to cleverly use kitchen materials for vacuum molding fiberglass parts in a video can be seen after the break. The same technique will also work for carbon fiber molding.

We’ve seen these techniques used with commercially available vacuum bags and a wet/dry vac but in the video, we see how to make an ordinary trash bag into a container capable of forming a professional looking longboard battery cover. If the garbage bag isn’t enough of a hack, a ball of steel wool is used to keep the bag from interfering with the air hose. Some of us keep these common kitchen materials in the same cabinet so gathering them should ’t be a problem.

Epoxy should be mixed according to the directions and even though it wasn’t shown in the video, some epoxies necessitate a respirator. If you’re not sure, wear one. Lungs are important.

Fiberglass parts are not just functional, they can be beautiful. If plastic is your jam, vacuums form those parts as well. If you came simply for vacuums, how about MATLAB on a Roomba?

Thank you [Jim] who gave us this tip in the comments section about an electric longboard.

Continue reading “Vacuum Molding With Kitchen Materials” →

Pi Handheld With A Mindblowing Enclosure

November 2, 2017 by Lewin Day 14 Comments

The Raspberry Pi is possibly the world’s most popular emulation platform these days. While it was never intended to serve this purpose, the fact remains that a small, compact computer with flexible I/O is ideally suited to it. We’ve featured a multitude of builds over the years using a Pi in a mobile form factor to take games on the go. [Michael]’s build, however, offers a lot more than a few Nintendo ROMs and some buttons from eBay. It’s a tour de force in enclosure design.

The build starts with the electronics. In 2017 it’s no longer necessary to cobble together five different accessory boards to handle the controls, battery charging, and display. Boards like Kite’s Super All In One exist, handling everything necessary for a handheld game console. With this as a starting point, he then set out to recreate Nintendo’s classic Game Boy, with a few tweaks to form and function.

It’s a textbook example of smart planning, design, and execution. We are taken through the process of creating the initial CAD drawings, then combining 3D printed parts with wood and carbon fibre for a look that is more akin to a high-end piece of hi-fi gear than anything related to gaming. The attention to detail is superb and the write-up makes it look easy, while [Michael] shares tips on how to safely cut carbon fibre to make your own buttons.

The final results are stunning, and it’s a great example of why a fine piece of wood is always a classy way to go for an enclosure. For another great example, try this walnut keyboard, or check out the roots of the Raspberry Pi Game Boy movement.

Delivery Drone Aims To Make Package Handoffs Safer Than Ever

September 15, 2017 by James Hobson 18 Comments

Picture this: you’re at home and you hear a rapping on your door. At last!– your parcel has arrived. You open the door, snatch a drone out of the air, fold it up, remove your package, unfold it and set it down only for it to take off on its merry way. Hand-delivery courier drones might be just over the horizon.

Designed in the [Laboratory of Intelligent Systems] at Switzerland’s École Polytechnique Fédérale de Lausanne and funded by [NCCR Robotics], this delivery drone comes equipped with its own collapsible carbon fibre shield — it fold up small enough to fit in a backpack — and is able to carry packages such as letters, small parcels, and first aid supplies up to 500 g and to 2 km away!

Continue reading “Delivery Drone Aims To Make Package Handoffs Safer Than Ever” →

Electric Longboard With All-New Everything

August 21, 2017 by John Baichtal 15 Comments

We love [lolomolo]’s Open Source electric longboard project. Why? Because he completely re-engineered everything while working on the project all through college. He tackled each challenge, be it electronic or mechanical as it came, and ended up making everything himself.

The 48″ x 13″ deck is a rather unique construction utilizing carbon fiber and Baltic birch. In testing the deck, [lolomol] found the deflection was less than an inch with 500 lbs. on the other end. He modified the Caliber II trucks to add four 2250W Turnigy Aerodrive brushless outrunners driving the wheels with the help of belts. The motors are controlled by VESC, an Open Source speed controller. There are a lot of fun details, like the A123 lithium cells equipped with custom battery management system PCBs.

The board sports 5W RGBW headlights that are so bright he can only run them at 10% PWM, plus RGB LED underlighting. All of it is controlled by an onboard Linux box. You can check out [lolomolo]’s GitHub repository for code, schematics, and CAD files. His Instructable for this project also has more design notes and thoughts.

If sweet longboards are your bag, check out the 3D-printed longboard and the long-distance electric longboard we published previously.