I am unable to find exact information about servo tolerance.
For example very popular Futaba 3001 tend to have a lot of loose because ot the gear precision, yet when they run all is ok (besides that they are slow).
On the other hand Hitec HS-425 appears to me to have null loose.
Hitec HS-225 have little loose and is very fast servo, but in order to hold its position requires huge power.
Most digital servos tend to be either slow and fast, but have precise gears. Yet, they consume a lot of power to hold their position.
My question is: how to find a servo that will not be buzzing, and will hold its precision with minimal current draw, without any slop on control surfaces. Typical RC modeler budget.
Any ideas what is the rule of finding such servos? Even brand names give me bad surprises. I guess the solution would be with some specific gear ratio+tight gear tolerance, but how to define it? Hitec and Futaba preferred, I would like to find the rule rather than example.
Is the gear precision deteriorating with global economy progressing?
My fav looks HS-425BB, but I don;t know why so cheap for the purpose, and where is the catch thah other servos cannot get this precision at this price levels.
Dutch engineer is the first man in history to fly like a bird with self- built wings
Engineer Jarno Smeets (31) is the first man in history to have made a successful short flight with his self-built wings modeled on the movement and structure of real bird wings. Assisted by an electronicsystem of his own design, Smeets took off from the ground in a park in The Hague last sunday 18th of March 2012. The flight of an estimated hundred meters lasted about a minute, after which Smeets landed safely.
Until now people had assumed that it was impossible to fly with bird-like wings using human muscle power. Smeets designed his own system to solve this problem, using two Wii controllers, the accelerometers from a HTC Wildfire S smartphone and Turnigy motors. This combined mechanism provided Smeets with extra power to move his17m2wings and allowed him to move his arms freely without any risk of breaking them. The system is a wireless (haptic) concept. The wing itself was built out of a kite and carbon windsurf masts (as flightpins).
Human Bird Wings is an independent project initiated from the personal ambition and vision of Dutch engineer Jarno Smeets. “Ever since I was a little boy I have been inspired by pioneers like Otto Lilienthal, Leonardo da Vinci and also my own grandfather”. Six months ago Smeets started researching.Smeets has developed and realized his wings with support from an independent team assembled under the Human Bird Wings project, sharing his progress through a well documented blog and YouTube channel. He has offered his followers an open source concept in building bird wings. Aided by helpful suggestions of his audience he was able to successfully finish his bird wings concept.
With this project Smeets has proven that modern technology and robotica can create realistic futures from seemingly impossible engineering dreams to fly like a bird
The peace group CODEPINK and the legal advocacy organizations Reprieve, and the Center for Constitutional Rights are hosting the first international drone summit.
On Saturday, April 28, we are bringing together human rights advocates, robotics technology experts, lawyers, journalists and activists for a summit to inform the American public about the widespread and rapidly expanding deployment of both lethal and surveillance drones, including drone use in the United States. Participants will also have the opportunity to listen to the personal stories of Pakistani drone-strike victims.
Time: 9:00am-6:30pm
Location: Mount Vernon Place United Methodist Church, 900 Massachusetts Avenue NW, Washington, DC 20001
On Sunday, April 29 we will have a strategy session to network, discuss and plan advocacy efforts focused on various aspects of drones, including surveillance and targeted killings.
Time: 10:00am-4:00pm
Location: United Methodist Building, 100 Maryland Avenue NE, Washington, DC 20001
Sunday’s session is for representatives of organizations and individuals who want to be actively involved in this work. If you are interested in attending Sunday’s session, please email Ramah Kudaimi at rkudaimi@gmail.com.
Details:
Topics will include:
the impact of drones on human lives and prospects for peace
the lack of transparency and accountability for drone operations, including targeted killings
disputed legality of drone warfare
compensation for victims
the future of domestic drone surveillance
development of autonomous drones
drone use along U.S. borders.
Speakers will include:
Clive Stafford Smith, director of UK legal group Reprieve that represents drone victims
Medea Benjamin, author of forthcoming book Drone Warfare: Killing by Remote Control
Pardiss Kebriaei, attorney with Center for Constitutional Rights
Shahzad Akbar, attorney with Pakistani Foundation for Fundamental Fights
Rafia Zakaria, Amnesty International-USA Board of Directors
Sarah Holewinski, director of Campaign for Innocent Victims in Conflict (CIVIC)
Hina Shamsi, ACLU national security expert
Jay Stanley, ACLU privacy expert
Tom Barry, drone border expert with Center for International Policy
David Glazier, law professor who served 21 years as a US Navy surface warfare officer
Amie Stepanovich, legal counsel at Electronic Privacy Information Center (EPIC).
Peter Asaro and Noel Sharkey from the International Committee for Robot Arms Control (ICRAC).
Hello everyone. Recently I port the MinimOSD to the Remzibi OSD's harware, so a poor man can enjoy MinimOSD's convenience now (no need to modify APM's software anymore).
Because of the limited flash space of Atmega16, the code of OSD is slightly changed, and it is not compatible with Michael's original config tool. So I adapt the config tool as well.
The Remzibi's OSD uses Megaload bootloader, so please use the Megaload programmer to upload the firmware. (The config tool can also upload the firmware, but I have to admit that it is not quite good right now.)
Anyway, here is the firmware and config tool, and here is the source code.
Had a little fun flying in a local park here in Johannesburg, South Africa. Used a GoPro Hero on my own design anti-vibration mount and my quad running the newly released v2.5 firmware. Click on the photo to go to the youtube video.
Quad specs:
APM2
KDA20-22L motors from Hobbyking, 11x4.7 APC SF props
2 x Super Simple 25-30A ESC's from Hobbyking, two more on the way
2 x Hexfet 25A ESC's from Hobbyking (2 of 4 were DOA)
If you think things might happen like this soon in the USA you should look at the NextGen roadmap recently released. Some dates that are quite far away in there. I will let you read it for yourselves....
It has been a crazy week! Thanks so much for all the help testing and great data. Ironed out a lot of bugs and added some new features. I can't thank the beta testers enough for the ideas, suggestions and patience! You guys rock. :)
The Mikrokoter workflow is solid and generates great maps. Thanks Martin R.
The Arudplane/Copter workflow is in progress and working good. It needs work still. Thanks Rigel, Irving Stafford and Jeff Taylor for the help.
The MAVinci and Pteryx workflows are solid and generating good maps. Thanks guys!
I am pretty sure we can accept any sort of log file with associated imagery, we are calling that "generic".
Today I finished a "mosaic only" mode, which will just accept imagery. No flight data or anything. It simply builds a mosaic and downloadable geotiff. This is great for people with just aerial imagery! Thanks Hazelden for the images and idea. (still super rough, just the framework is completed)
We have a new feature which calculates the area of each tile and also the estimated area of the entire mosaic.
Almost finished a workflow which builds an SRTM3 DEM underlay with contour lines of your flight area. Your mosaic is the top layer.
Tons of more features and bug fixes. Memcache for the win on the UI!
Many performance improvements.
Thanks DIYDRONES!
Re-deployed to a larger dedicated EC2 instance.
Shoot me a message with some information about your flight platform or if you just have aerial imagery you'd like to build maps from. Please let me know if you have any questions or comments!
On a side note, I finally got my 3DR quad flying. So cool! Lost a few more props but it is very stable, my only issue at this point is wobble on descent. :D
Mikrokopter Flight, Showing Area of Tile
Area of Imagery
MK Flight with SRTM3 DEM Underlay, Contour Lines Every 10m, Shaded Relief Added
ArduPlane Flight from Irvin Stafford. Blended Mosaic
So I decided to add another chip (pic18f46j50) to my IOIO to generate a nice PPM signal.
After that I used nearly the same board to catch Accelerometer, gyroscope, barometric pressure and temperature (ms5607) and GPS and to send it in the Frsky receiver, and plugged the frsky transmitter to the IOIO board.
So I'm able to retrieve the data sent according to the frsky protocol and data from my custom hub and display it on a custom android app :
Now I'm planing on remaking a complete pcb including the IOIO chip and my ppm chip, potentiometer, switchs, ...
Some of you may know the history of this site, which began with a project I did back in 2007 with my kids to try to get a Lego Mindstorms robotics kit to fly a plane (it worked). That was part of a series of science/tech projects I did with the kids, and the search for other good ideas led to the site GeekDad, which is now part of the Wired empire and has spawned three books, including a New York Times bestseller.
Now the GeekDad/DIY Drones connection has come full circle, with a GeekDad community site, based on the same Ning platform as we're using here at DIY Drones. If you've got kids, this is well worth joining. Plus note the cute little-kid-flying-a-quadcopter we put in the header graphic above!
I have released the second version of my 3D printable quadcopter the PL2Q Hugin, the first one was the PL1Q Vampire. There is a lot of improvements on this new version, also more focused at FPV and areal video..
Well I just recieved my FPV 168 from HK.com. The only damage I was able to spot from shipping was the tip of a horizontal stab. Here are my plans for the build.
I want to have a pan and tilt camera hanging on the underside of the fuselage. I bought the pan and tilt system from ServoCity. I got 2 continues rotation servos. My second payload will be a 12 mega pixel still camera to take pictures of the ground for mapping.
The telemetry is using a 2.4 GHz with a 1W amplifier on the ground xBee.
I have allot of planing to do to get it up and running. Still awaiting all my parts to start the build. I will keep pics coming once i get started.
Some who have followed my blog posts will know that I have been working on my HDwing design series for a return-to-launch glider concept using ArduPilot Mega. Everything I have revealed so far has been based on relatively conventional flying wing ideas. Till now...
This forward-swept flying wing concept was inspired by the work of Justin Ammon (EdgeRC / birdofprey) that I spotted on www.rcgroups.com A period of spreadsheet analysis and messing about with various X-plane simulations over te Christmas/New Year break demonstrated to me that, whilst unlikely to be a walk in the park, a forward swept wing could be made to work and would yield some worthwhile advantages over a mainstream flying wing.
A bunch of CAD work and several iterations later, based on an acceptably flying X-plane model, I came up with this design and I am now committed to bringing it to reality.
One of the difficulties with the forward swept design, especially as a pusher, has been to establish a workable centre of gravity position. This necessitates the use of a protruding fuselage (a deviation from the pure flying wing) but offers an advantage of placing a payload area virtually right on top of the CoG. Thus the design can accept a wide variation in payload mass and still be (X-plane) flyable. How this translates into real world usefulness is yet to be seen, but it bodes well.
The drag-based yaw stablity of a conventionally swept wing also no longer works with a forward swept design, so the addition of a vertical stabiliser fin is required. Bad for stealth, I know!
The nose cone has been sliced off at an angle to yield a removable camera pod as well as a large access aperture for working on the interior of the airframe. I am designing in a removeable avionics tray so that the majority of the avionics and payload can be mounted on a lightweight demountable chassis to aid bench testing, modification and repair.
The location of the battery at just ahead of the CoG will allow me to increase its capacity with minimal adjustment to balance. It is also is attached to the avionics tray for ease of complete systems-level bench-testing.
Personally, one of the attractions of the forward swept wing is that, similar to a canard design, all of the wing surface is lifting to produce pitch stability. The lift distribution isn't the most theoretically efficient, but at higher speeds and lower C_L, this is not such a huge penalty. The X-plane simulation shows a best L/D of about 19:1, which is not so bad for such a stumpy, low aspect ratio craft. My earlier HDwing designs didn't get this far and they had the advantage of winglets and a lift distribution closer to the theoretical optimum.
The forward swept wing layout does come with some compromises but also offers compensatory advantages to exploit. There is a whole host of detail design work to be done, but hopefully a worthwhile UAV airframe will result. Time will tell.
.... While waiting for his green card, the 21-year-old was marooned in his apartment, unable to work, attend school or obtain a driver’s license.
On the other hand, he had an Internet connection. A Nintendo Wii. A radio-controlled toy helicopter his mother had given him to help kill time.
Tinkering with the Wii’s control wand and a $60 gyroscope he had purchased on eBay, he modified the helicopter to fly itself, just like the $5 million Predator unmanned aerial vehicles deployed by the U.S. military.
Five years later, Mr. Munoz is co-founder and CEO of 3D Robotics, a San Diego-based company that has 18 employees and earned more than $300,000 in revenue in December producing components for hobbyist drones.
