Maybe Your Next Robot Should Be A Cyclocrane

October 6, 2016 by Gerrit Coetzee 43 Comments

At my university, we were all forced to take a class called Engineering 101. Weirdly, we could take it at any point in our careers at the school. So I put it off for more interesting classes until I was forced to take it in one of my final years. It was a mess of a class and never quite seemed to build up to a theme or a message. However, every third class or so they’d dredge up a veritable fossil from their ranks of graduates. These greybeards would sit at the front of the class and tell us about incredible things. It was worth the other two days of nondescript rambling by whichever engineering professor drew the short straw for one of their TAs.

One greybeard in particular had a long career in America’s unending string of, “Build cool stuff to help us make bad guys more deader,” projects. He worked on stealth boats, airplanes with wings that flex, and all sorts of incredibly cool stuff. I forgot about the details of those, but the one that stuck with me was the Cyclocrane. It had a ton of issues, and as the final verdict from a DARPA higher-up with a military rank was that it, “looked dumb as shit” (or so the greybeard informed us).

A Cyclo-What?

The Cyclocrane was a hybrid airship. Part aerodynamic and part aerostatic, or more simply put, a big balloon with an airplane glued on. Airships are great because they have a constant static lift, in nearly all cases this is buoyancy from a gas that is lighter than air. The ship doesn’t “weigh” anything, so the only energy that needs to be expended is the energy needed to move it through the air to wherever it needs to go. Airplanes are also great, but need to spend fuel to lift themselves off the ground as well as point in the right direction. Helicopters are cool because they make so much noise that the earth can’t stand to be near them, providing lift. Now, there’s a huge list of pros and cons for each and there’s certainly a reason we use airplanes and not dirigibles for most tasks. The Cyclocrane was designed to fit an interesting use case somewhere in the middle.

In the logging industry they often use helicopters to lift machinery in and out of remote areas. However, lifting two tons with a helicopter is not the most efficient way to go about it. Airplanes are way more efficient but there’s an obvious problem with that. They only reach their peak efficiency at the speed and direction for which their various aerodynamic surfaces have been tuned. Also worth noting that they’re fairly bad at hovering. It’s really hard to lift a basket of chainsaws out of the woods safely when the vehicle doing it is moving at 120mph.

The cyclocrane wanted all the efficiency of a dirigible with the maneuverability of a helicopter. It wanted to be able to use the effective lifting design of an airplane wing too. It wanted to have and eat three cakes. It nearly did.

A Spinning Balloon with Wings

Four wings stick out of a rotating balloon. The balloon provides half of the aerostatic lift needed to hold the plane and the cargo up in the air. The weight is tied to the static ends of the balloon and hang via cables below the construction. The clever part is the four equidistant wings sticking out at right angles from the center of the ship. At the tip of each wing is a construction made up of a propellor and a second wing. Using this array of aerofoils and engines it was possible for the cyclocrane to spin its core at 13 revolutions per minute. This produced an airspeed of 60 mph for the wings. Which resulted in a ton of lift when the wings were angled back and forth in a cyclical pattern. All the while, the ship remaining perfectly stationary.

sdsafd — There’s a really great description of its operation in the article this photo came from.

It really didn't like strong winds. — It really didn’t like strong winds.

Now the ship had lots of problems. It was too heavy. It needed bigger engines. It was slow. It looked goofy. It didn’t like strong winds. The biggest problem was a lack of funding. It’s possible that the cyclocrane could have changed a few industries if its designers had been able to keep testing it. In the end it had a mere seven hours of flying time logged with its only commercial contract before the money was gone.

However! There may be some opportunity for hackers here. If you want to make the quadcopter nerds feel a slight sting of jealousy, a cyclocrane is the project for you. A heavy lift robot that’s potentially more efficient than a balloon with fans on it is pretty neat. There’s a bit of reverse engineering to be done before a true performance statement can be made. If nothing else. It’s just a cool piece of aerospace history that reminds us of the comforting fact that we haven’t even come close to inventing it all yet.

If you’d like to learn more there’s a ton of information and pictures on one of the engineer’s website. Naturally wikipedia has a bit to say. There’s also decent documentary on youtube, viewable below.

Photo Credits: Rob Crimmins and Hal Denison

Choosing A ‘Scope: Examining Bandwidth

October 5, 2016 by Jenny List 72 Comments

A few weeks ago I asked the Hackaday community for some help and advice in buying a new budget oscilloscope. Thank you very much to those of you who responded both here online and in person among my friends closer to home. I followed the overwhelming trend in the advice I received, and bought myself a Rigol DS1054z, an instrument with which I am very happy. It’s a nominally a 50 MHz scope, but there’s a software hack that can bring it up to 100 MHz. How fast can it go?

My trusty Cossor, its 2 MHz bandwidth as yet unverified.

This question became a mini scope-shootout after a conversation with my Hackaday colleague [Elliot] about measuring oscilloscope bandwidth, and then my fellow Oxford Hackspace members producing more than one scope for comparison. You know who you are, thank you. I found myself with ready access to several roughly equivalent models and one very high-end one in specification terms representing different strata of test equipment manufacture, and with the means to examine their performance.

Continue reading “Choosing A ‘Scope: Examining Bandwidth” →

Raspberry Pi, Send Me A Letter

October 4, 2016 by Al Williams 20 Comments

The abundance of small networked boards running Linux — like the Raspberry Pi — is a boon for developers. It is easy enough to put a small cheap computer on the network. The fact that Linux has a lot of software is a double-edged sword. On the one hand, it is a good bet that anything you want to do has been done. On the other hand, some of the solutions are a bit large for a tiny embedded system.

Take, for example, e-mail. Historically, Linux hosts operate as mail transfer agents that can send and receive mail for all their users and possibly even relay mail to others. In today’s world, that’s usually overkill, but the capability is there. It is possible to install big mail transfer agents into a Raspberry Pi. The question is: should you?

What Do You Want?

The answer, of course, depends on what you want to do. If you have a dedicated board sending out text and maybe even files using an external mail server (like, say, Gmail), then the answer is no. You don’t need a piece of software listening for incoming connections, sorting through multiple users, and so on.

Luckily, there are some simple solutions if you know how to set up and configure them. The key is to avoid the big mail programs that do everything you don’t need.

Mail Front Ends

Let’s tackle sending mail first. If you try to grab the mailutils package, you’ll see it drags along a lot of stuff including mysql. Keep in mind, none of this will actually send mail. It just gives you some tools to get mail ready to send.

Luckily, the bsd-mailx package has a lot less overhead and will do the job. Look at the man page to see what options you have with mailx; you can do things like attach files, set a subject, and specify addresses.

It is a little difficult to set up for Gmail, though, thanks to Google’s security. You’ll need the certutil tool from the libnss3-tools package. You’ll need to create a certificate store, import Google’s certificate, and then set up a lot of options to mailx. I don’t suggest it. If you insist, though, you can find directions on the Web.

SSMTP

By default, programs like mailx and other Linux mail commands rely on a backend (often sendmail). Not only does that drag around too much overhead, it is also a full mail system, sending and receiving and relaying–overkill for our little Pi computers.

Luckily, SSMTP is available which only sends mail and is relatively lightweight. You need a configuration file to point it to your mail server. For Gmail, it would look like this:

#
# Config file for sSMTP sendmail
#
# The person who gets all mail for userids < 1000
# Make this empty to disable rewriting.
root=postmaster

# The place where the mail goes. The actual machine name is required no 
# MX records are consulted. Commonly mailhosts are named mail.domain.com
mailhub=smtp.gmail.com:587

# Where will the mail seem to come from?
rewriteDomain=yourdomain.com

# The full hostname
hostname=yourhostname
AuthUser=YourGmailUserID
AuthPass=YourGmailPassword
UseTLS=Yes
UseSTARTTLS=YES
# Are users allowed to set their own From: address?
# YES - Allow the user to specify their own From: address
# NO - Use the system generated From: address
FromLineOverride=YES

You can use a mail agent like mailx or you can just use ssmtp directly:

ssmtp someone@somewhere.com

Enter a message on the standard input and end it with a Control+D (standard end of file for Linux).

Google Authentication

There’s only one catch. If you are using Gmail, you’ll find that Google wants you to use stronger authentication. If you are using two-factor (that is, Google Authenticator), this isn’t going to work at all. You’ll need to generate an app password. Even if you aren’t, you will probably need to relax Google’s fear of spammers on your account. You need to turn on the “Access for less secure apps” setting. If you don’t want to do this on your primary e-mail account, considering making an account that you only use for sending data from the Pi.

Sending Files

Depending on the mail software you use, there are a few ways you can attach a file. However, the mpack program makes it very easy:

mpack -a -s 'Data File' datafile.csv me@hackaday.com

The above command will send datafile.csv as an attachment with the subject “Data File.” Pretty simple.

Receiving Mail

What if you want to reverse the process and receive mail on the Pi? There is a program called fetchmail that can grab e-mails from an IMAP or POP3 server. It is possible to make it only read the first unread message and send it to a script or program of your choosing.

You have to build a configuration file (or use the fetchmailconf program to build it). For example, here’s a simple .fetchmailrc file:

poll imap.gmail.com
protocol IMAP
user "user@gmail.com" with password "yourpassword" mda "/home/pi/mailscript.sh"
folder 'INBOX'
fetchlimit 1
keep
ssl

You can leave the “keep” line out if you don’t mind fetchmail deleting the mail after processing. The file should be in your home directory (unless you specify with the -f option) and it needs to not be readable and writable by other users (e.g., chmod 600 .fetchmailrc). According to the fetchmail FAQ, there are some issues with Gmail, so you might want to consider some of the suggestions provided. However, for simple tasks like this, you should be able to work it all out.

In particular, the mailscript.sh file is where you can process the e-mail. You might, for example, look for certain keyword commands and take some action (perhaps replying using ssmtp).

Special Delivery

You might not think of the Raspberry Pi as an e-mail machine. However, the fact that it is a pretty vanilla Linux setup means you can use all sorts of interesting tools meant for bigger computers. You just have to know they exist.

Homemade Capacitors Of A Mad Scientist

October 3, 2016 by Steven Dufresne 26 Comments

Once upon a time I was a real mad scientist. I was into non-conventional propulsion with the idea of somehow interacting with the quantum vacuum fluctuations, the zero point energy field. I was into it despite having only a vague understanding of what that was and without regard for how unlikely or impossible anyone said it was to interact with on a macro scale. But we all had to come from somewhere, and that was my introduction to the world of high voltages and homemade capacitors.

And along the way I made some pretty interesting, or different, capacitors which I’ll talk about here.

Large Wax Cylindrical Capacitor

As the photos show, this capacitor is fairly large, appearing like a thick chunk of paraffin wax sandwiched between two wood disks. Inside, the lead wires go to two aluminum flashing disks that are the capacitor plates spaced 2.5cm (1 inch) apart. But in between them the dielectric consists of seven more aluminum flashing disks separated by plain cotton sheets immersed in more paraffin wax. See, I told you these capacitors were different.

Big wax cylindrical capacitor

Exposed wax of the capacitor

The experiment and the capacitor’s interior

I won’t go into the reasoning behind the construction — it was all shot-in-the-dark ideas, backed by hope, unicorn hairs, and practically no theory. The interesting thing here was the experiment itself. It worked!

I sat the capacitor on top of a tall 4″ diameter ABS pipe which in turn sat on a digital scale on the floor. High voltage in the tens of kilovolts was put across the capacitor through thickly insulated wires. The power supply contained a flyback transformer and Cockcroft-Walton voltage multiplier at the HV side. As I dialed up the voltage, the scale showed a reducing weight. I had weight-loss!

But after a few hours of reversing polarities and flipping the capacitor the other way around and taking plenty of notes, I found the cause. The weight-loss happened only when the feed wires were oriented with the top one feeding downward as shown in the diagram, but there was no weight change when the top wire was oriented horizontally. I’d seen high voltage wires moving before and here it was again, producing what looked like weight-loss on the scale.

But that’s only one of the interesting capacitors I’ve made. After the break we get into gravitators, polysulfide and even barium titanate.

Continue reading “Homemade Capacitors Of A Mad Scientist” →

Maker Faire Multicolor And Multi Material 3D Printing

October 3, 2016 by Brian Benchoff 25 Comments

The next frontier of desktop 3D printing is multi-material and multi-color prints. Right now, you can buy a dual toolhead for a Lulzbot, and dual toolheads from other companies exist, although they are a bit rare. In the next few years, we’re going to see a lot of printers able to print dissolvable supports and full-color 3D printers.

Printing in more than one color is almost here, but that doesn’t mean we’re on the cusp of a complete revolution. Multi-material printing is lagging a little bit behind; you’ll be able to print two colors of PLA next year, but printing an object in PLA and ABS is going to be a bit tricky. Printing something in PLA and nylon will be very hard. Color mixing, likewise, will be tricky. We can do it, the tools are getting there, but think of this year as a preview of what we’ll be doing in five years.

Continue reading “Maker Faire Multicolor And Multi Material 3D Printing” →

Hackaday Links: October 2, 2016

October 2, 2016 by Brian Benchoff 32 Comments

Hey Elon, three weeks ago I was in Burning Man in the Nevada desert and after I dug myself a nice K-hole I notice that Mars is a lot like the Nevada desert which got me thinking that if we can live here we can live on Mars but then I realized that Mars really isn’t a lot like the Nevada desert because there are toilets here but if we could build toilets on Mars it would be a lot like the Nevada desert? This week Elon Musk unveiled the Interplanetary Transport System at the International Astronautical Congress in Guadalajara. Instead of filling the room with industry experts the highlights of the Q&A session consisted of a woman who wanted to give Elon a kiss onstage and some guy who was super, super high. Discussion of the technical feasibility of a big, heavy window on the Heart of Gold has not appeared anywhere. Zero thought has been given to the consequences of building a civilization consisting entirely of the wealthiest 1% of Earth’s population. I fully support the Interplanetary Transport System; I’m going because this planet sucks.

[FoamieNinja] over on /r/radiocontrol is experimenting with single bladed propellers. Single bladed propellers are the most efficient way of pushing air behind an engine but haven’t really seen widespread use because they’re really weird, and I don’t know if you can do a variable pitch prop like this. You can find these types of props rarely on big-sized aircraft such as vintage J-3 Cubs sporting a 40HP engine. I haven’t seen them on anything bigger.

Next weekend is the Open Hardware Summit in Portland, Oregon. Hackaday is going to be there, and there’s a BringAHack at OSH Park on Thursday. Last year at the summit, the Open Source Hardware Certification was announced. This year, OSHWA is ready to launch their certification program. The takeaway from last year is that Open Hardware Certification will be free, self-certifying, with penalties based on fines for non-compliance.

The ESP32 is here, but most of them are still in a shipping container somewhere in the Pacific. Here’s a breakout board for the Espressif ESP-WROOM-02.

The J-Core is a clean room, open source CPU and SOC. Currently, it’s only implemented in VHDL until someone has a ton of money to burn on an ASIC. Now, the J-Core is supported by Linux. That makes an ASIC just a bit more likely. Thanks [Stefano] for the tip.

MakerBot is not at the New York Maker Faire this year. This is the greatest proof of the imminent failure of MakerBot, but it does deserve some context. In 2009, MakerBot demoed their first printer, the Cupcake, at the New York Maker Faire in Queens, NY. This was, by any reasonable historical reckoning, the introduction of a simple, easy to use, consumer 3D printer to the masses. The current trend of cheap desktop printers began seven years ago this weekend. MakerBot was so successful that it can be argued that Make:, the magazine and the faire, has tried to take credit for the consumer 3D printer ecosystem, simply because they hosted the launch of the Cupcake. Over the years, everyone has tried to ride MakerBot’s coattails. Since then, a few things happened. Last month, MakerBot introduced a new line of (China-manufactured) 3D printers, and they don’t have a booth. The reasons for this could be that Maker Faire is horrifically expensive for any vendor, and MakerBot is going to be at CES next year anyway, but this is it. The MakerBot obituary was not premature. We won.

Calling All Procrastinators

September 30, 2016 by Mike Szczys 13 Comments

We have your number… you’re one who likes to while away the daylight hours, then make a mad effort throughout the night to finish everything before the sun again rises. In fact, that describes a lot of us Hackaday writers.

Put those well-honed cramming skills to good use this weekend, because Monday morning is the deadline to enter the 2016 Hackaday Prize. The current challenge is to show us your Assistive Technology. Prototyping some hardware to make life a little bit better for people dealing with a disability, to help those who are aging in place, to provide more widespread access to health care, and the like. We will pick 20 entries from this challenge to win $1000 each and become eligible for one of the five huge prizes.

Huge prizes you say? We’re talking about a grand prize of $150,000 and a residency at the Supplyframe Design Lab in Pasadena, plus four other cash prizes of $25k, $10k, $10k, and $5k. Twenty final projects have been chosen from each of the first four challenges, and there have already been over 1000 total entries! But your chances of pulling a rabbit out of the hat this weekend are still really good. So far there are just under 200 entries in this final challenge — twenty will move forward on Monday.

Call up your friends and stock up on Red Vines and Red Bull (Club Mate if you can get it). Occupy your hackerspace and get to work. If you are pulling all nighter’s in a bid to take Assistive Technology by storm, make sure you let us know on Twitter so we can follow along.