2013年6月21日星期五

What You Need to Get Started with an Electric RC Airplane?

I'm very glad to read the RC airplane beginner guide by docbruin. He shares his own experience for all RC airplane hobby newbie to easy overcome some of the hurdles to becoming an accomplished RC pilot.

Here is the original post from docbruin and you may gain inspiration for starting your RC hobby.

The Radio Controlled (RC) Airplane hobby has been around for years. I first tried my hand at it about 20 years ago, but didn't have the time to devote to learning the basics and ultimately gave up. I have recently gotten back into the hobby and have learned that there are many things available now that make learning much easier. My intention with this article is just to get you started, not teach you how to fly. I will give you some resources for learning to fly as well though.

In this article I will talk about what you will need to get started with an electric RC airplane. Electric RC airplanes use batteries instead of a liquid fuel (nitro). I won't go into nitro fuel RC airplanes in this article. I have flown with both and found that the electric is easier for a beginner to start with. Using an electric RC airplane you can charge the batteries and put them in, do your preflight checks, and go. Nitro planes require a little more preparation and initial expense. I'll leave writing about the nitro plane basics to someone else!

Before you start, do some research. Go to your local hobby shop or online and talk to people who fly RC airplanes. Visit a local flying club and just watch them fly for an afternoon. Ask lots of questions. Do plenty of research on the internet. There are many good RC forums with a wealth of information. Two that I visit often are Wattflyer and RC Universe. This research should give you an idea if you want to take the plunge into the electric RC airplane hobby.

While all of us would love to be the person described at the top of this article, zooming around the sky at will on our first day out, it is just totally unrealistic. You will need to start flying with a trainer of some kind. No, it won't be a Mustang or some high speed sport plane, but don't let that discourage you. As you learn on the trainer you will become more and more confident and controlled flight will become more natural.

I also highly recommend that you start out using an RC Flight Simulator program. Now many beginners reading this will dismiss the simulator as an unneeded expense, or waste of time, and I understand that. I know you want to get flying, not "play on a simulator". I was the same way. But trust me on this, the simulator is money and time well spent. I'd rather crash a hundred times on the simulator than go out once with my new plane and come home with a garbage bag of parts.

It is very beneficial to join a local RC flying club and/or find a local instructor that can assist you in learning to fly. A good instructor can get you up in the air and flying properly much faster and easier than you can on your own. They have been where you are and have learned many tips and techniques that you'd never learn on your own. Listen to them! I do understand that not everyone lives where a club or instructor is available. Don't let that discourage you. You can learn on your own, just understand that it takes much more time to learn flight techniques and makes the simulator an even more important item.

Consider joining the Academy of Model Aeronautics (AMA). They provide insurance, information and other benefits to members. Most clubs will require AMA membership before joining the club or flying with them.

START WITH THE SIMULATOR

Make the flight simulator your first purchase. There are many good ones available, some for free and some that you have to buy. Check the reviews and discussions online and talk to other flyers to get an idea of which program might be best for you. I use the Phoenix RC Flight Simulator. Another popular one is the RealFlight RC Simulator. There are many others that are good as well, so again, do some research and see what you think you'd like.

When you get the simulator also make a note of the price of that high performance plane you really want. Now when you start using the simulator go ahead and try flying that high performance plane first. Count how many times you crash it in the first hour and calculate how much money you would have thrown away if it was a real RC airplane, not a simulation. This should convince you that the simulator was inexpensive by comparison. Now switch to a trainer in the simulator and start learning takeoffs, simple flight, and landing. Many of the programs have trainer functions and there are many flight instruction guides, both online and in book form that can help you become familiar with basic RC flight. As you get more comfortable with the simulator, add in some wind. Most of the sims have a setting for this. This is important because depending on where you live, perfectly calm days may be rare, so you'll need to know how to fly with some wind.

Many simulators will allow you to plug your transmitter into your computer and use it with the sim. This is a big help because you are using the same actual transmitter with the simulator that you will be using in the field. I'll cover transmitters later on so just make a mental note of that option for now.

Also, if you are used to computer flight simulators, such as MS Flight Simulator or a warbird sim, take note that the RC simulator will be entirely different. With the RC simulator you are flying from one spot on the ground, just like where you would be standing in real life. You are not in the cockpit like you are in other non-RC flight simulators.

YOUR FIRST ELECTRIC RC AIRPLANE

Start with a trainer! I'll say it again, start with a trainer! If you don't, you will crash, probably within a minute (if that long), and go home to your spouse with an expensive bag of RC airplane debris. It's even worse if it happens in front of your spouse! Now understand that you will crash a trainer, but they are made to be much more forgiving on impact and much more controllable.

Many trainers are made of a foam type construction, so that they are lightweight and more resilient during a crash. This also helps them glide in a more stable position than a large, heavy weight plane made out of other materials. The light weight and lower speeds of a trainer allow you time to correct flight mistakes more easily and will lessen the damage in a crash. Take note, though, that the lighter weight makes the airplane more susceptible to wind effects.

Select a high wing trainer as they are more stable. A high wing trainer has the wing over (or on top of) the airplane's fuselage (body). I won't go into detail as to why they are more stable here, as the explanations of that can easily be found online.

I had mentioned above that some transmitters can be connected to certain RC flight simulators. Depending on the RTF package you get, your transmitter may or may not be compatible with your simulator. If you want to use the same transmitter with both the sim and the real RC airplane, I would check for compatibility before you buy. If the RTF package transmitter won't work with the sim you can buy a more advanced model of transmitter that will. It's an added expense so you'll have to decide what you want to spend on your new hobby. I have a Spektrum DX6i that I used with both the simulator and the Champ when starting out. There are many other brands and types of transmitters available, so again, do your research and see what would work best for you.

Most electric RC airplanes use "LiPo" (Lithium-ion polymer) batteries. They provide less weight and a longer run time than other battery types, such as NiMH (nickel-metal hydride). Take note though that, as with all batteries, you should use care when using and charging LiPos. Handled properly they are safe, but mishandled they can be dangerous. There is a great deal of information available on the proper charging and use of LiPo batteries, and RTF airplane packages such as the Champ include specific directions and warnings in their instruction manual. Please take the time to make sure you fully understand how to handle batteries safely!

If you've reached this point you are probably anxious to get in the air! Again let me suggest getting some help from an instructor at a local RC club to get you started. Whether you are doing that or going it alone, make sure you read the airplane manual and understand it. Follow the directions step-by-step. The instructions will vary depending on which airplane and transmitter you have, so I cannot give you specifics here. Choose a safe flying area as outlined in your airplane's manual (bigger planes need a bigger area). Make sure you have completed all the manual specified safety, function, and range checks. Set a maximum flight time limit based on the batteries and airplane you have so that you don't over discharge the battery. You can get a good idea of time limit from other flyers, online info, forums, etc. When you are sure that everything is in order, you are ready to fly! You will experience both enjoyment and nervousness as you take to the air. That's the thrill of flight! Enjoy!

Read more on: http://docbruin.hubpages.com/hub/RCAIRPLANES 

In his post, he recommends two good RC forums: Wattflyer and RC Universe which come with wealth of RC wiki and there are a lot of wide experience RC pilots. Next post, I want to share you more places for you to learn about radio control hobbies. Please stay tuned. 





2013年6月18日星期二

Missed Schedule on scheduled posts because of crons and transient data

Many people still have issues about (not so) future posts going live. When the target date hits, its goes red, says "Missed Schedule" and continues on without it.
There are other issues that may be showing up on the box such as an enormous call back log (>1,000,000 hits/day from its own IP to wp-crons.php). Cache clean up failings, and other background routines fail.

I have spent the last week tracking this down on numerous servers and have this list of routines to fix it:

Is the server cognizant of its own domain? WordPress curls out to "http://yourdomain.com/wp-cron.php..." If the server is not configured to know its own domain and IP address of yourdomain.com' the self call to the cron will fail.
Some servers are behind a firewall that doesn't allow traffic to echo back. Meaning, it knows yourdmain.com = an.ip.addr.ess and sends a connection out through the firewall... which then doesn't come back in. The firewall must be configured to know that an.ip.addr.ess is internal and it must echo it back to the source machine.
Of course curl must be enabled and installrf in PHP so check php.ini for extension=php_curl.dll
Easiest way to check is to review the logs and see if there are calls to your /wp-cron.php file. If there is not, the cron mechanism can't call itself.

you can by-pass some of these in the wp-config.php with:
define('ALTERNATE_WP_CRON', true);

------------------------------

if that doesn't fix your problem or your log file shows hits to wp-cron.php... in fact its flooding your logs and adding unnecessary strain to your server then its an internal cron failure.

program errors: Are there errors in the log file indicating that a function that is called by the cron is failing? If so the cron job never completes, never gets unschedule, and is subsequently called repeatedly without completetion. Fix the error!
W3 Cache. If any site establishes an object cache, object-cache.php gets written to /wp-content/. This turns object caching on for all sites, whether they are configured or not. If the cron detects that object caching is on, it stores the cron id/task in the obj-cache to be passed around instead of the DB transient data. When the cache is not working your cron key to run the job is being tossed to the wind. After /wp-cron.php starts and gets an empty transient it will exit, leaving the task unprocessed in the queue and results in wp-cron being called repeatedly.
in the /wp-cron.php, you can log the value of $doing_cron_transient = get_transient( 'doing_cron'); and see what the cron task is getting.
If its empty, your cron keys are being tossed.

Look for /wp-content/object-cache.php. If its there, all sites are running as object cached even if they are not configured. configure all the sites to use it properly.
Or rename object-cache.php ... that will remove object caching from all sites, which could break the initiating offender, but restore cron operations and transient data to all other sites.

If its the object caching on the set_transient/get_transient calls, then more than just the cron jobs and schedule posts are failing.

Look through error logs for 'cron' and 'wp-cron' as the called URI or in the stack trace.

to by-pass the object-cache issue you can modify the wp-cron.php to:

if ( empty( $doing_wp_cron ) ) {
        if ( empty( $_GET[ 'doing_wp_cron' ] ) ) {
                if ( $doing_cron_transient && ( $doing_cron_transient + WP_CRON_LOCK_TIMEOUT > $local_time ) ){
                        return;
                }
                $doing_cron_transient = $doing_wp_cron = time();
                set_transient( 'doing_cron', $doing_wp_cron );
        } else {
                $doing_wp_cron = $_GET[ 'doing_wp_cron' ];
                if($_GET[ 'flush' ])  //ADDED
                  $doing_cron_transient = $doing_wp_cron; //ADDED
        }
}


then OS level cron a call to $time = time()
http://yourdomain(s).com/wp-cron.php?doing_wp_cron=$time&flush=1
every 5 minutes.

This will cause the cron to continue without the transient ID and resolve back-logged tasks within an hour.

2013年6月14日星期五

URL Shortener With Your Domain

Some of you may have read the advantages and disadvantages of URL shorten service or may have noticed that those problems cause by using URL shorten service. In one of my article I also collect some opinions what people say.

Today, I realize that some URL Shorteners may provide us advance URL shorten service. After search on Google, I find a post from +Brankica Underwood.

Here is his original post. 


You probably heard of bit.ly as one of the most popular URL shorteners and you've probably used it some. But wouldn't it be cool if you had your own custom URL shortener!?
Something like http://brankica.me/oisblog
Well that is easy and I will show  you how to do it in less than a minute!
First, you will need a domain name you will use as a shortener. I used the brankica.me I scored a few days ago. You can use anything, just make sure it is not some long domain name. For example, if I was a Canadian citizen, I would have bought branki.ca.
So think of variations you can use, your blog name shortened, etc. I decided to go with my name because I want to use it for all of my sites and social media and I thought it sounds cool (plus I could not think of something short and cool).
When you get the domain name, go to bit.ly and log in. Go to Settings and then Advanced.

Once there, choose the link in this option at the top of the page:

It will be tiny bit different for you (mine is already set up). Click on the link and in the next window you will be able to add the URL you want to use as your custom shortener.
When you add it, hit the button and bit.ly will give you a number you need to put in your domain name DNS record, instead of the one you already have there. It won't be hard, when  you look at your domain info, there is only one number that looks similar – replace it with the one bit.ly gave you. Save changes.
Go back to bit.ly and click Verify so they can see if it is working. It took me literally about a minute to set this all up!
When you are done, make sure your new URL is set up as a default like mine is in the image above.
Shorten your links now, you are done!
Why would you do this?

Well besides the links being pretty, they can help you in branding. People notice small things like these, I know I notice every time someone has a custom URL. So why not, it will only cost you the domain name, and if you have some, it may not cost you anything.
The bit.ly service is free for this so why not use it 


Just reminder: before following the instruction, there is something you should know:
1.You need to have your own domain
2. You have permission to alter its DNS records.
3. Provide your personal phone number, and one of bitly customer services will contact you. 

2013年6月6日星期四

mBuyNow Supply RC Accessories for RC Model Enthusiasts


mBuyNow continues to supply high quality and original RC engines and other accessories for online customers. All the DLE engines are made by original manufactures and with reliable qualities. mBuyNow also provides other accessories like brushless motors, balance chargers, and others.



For RC model enthusiasts, it always essential to have reliable equipment. A well performed engine may help users win a flight race, and the motors and chargers are useful tools to engines. For example, the DLE 55RA gas engine, which was an advance of DLE 55 as it was rear exhausted. This rear exhaust design is easy for users to install a tuned pipe, and offer a quick throttle response. The electronic ignition has also been developed as easier to start, less noise and much better performance.                                              
   
Meanwhile, there are also other useful accessories in stock. RC accessories especially for gas engines like iMAX balance charger, power supply, speed controller and brushless motors. These are essential parts for flight use.

mBuyNow provides these RC accessories with trustful quality and reliable service. It tries hard to provide a free and enjoyable online shopping experience to every potential customer.

2013年6月5日星期三

RC Model Hobby Store Collection 2013

Here is a list of radio control model hobby links which are useful and interesting.

Overseas model shops - English
mBuyNow – RC gasoline engine, measurement, RC battery charger, motor (UK)
Model Motors - manufacturer of electric motors AXI modeling, MiniAC, VM, gear and accessories
RCPlanet - radio control cars, trucks, helicopters, airplanes and boats
HorizonHobby - all types of RC models, kits and accessories  
RC-Hobbies - Remote Control Hobby, most of RC hobby model and accessories  
TroyBuiltModels - Giant Scale RC planes, jets, warbirds and accessories
HobbyKing - RC planes, quadcopters and accessories (HK)
RCmodelCentre - radio control planes, rc helicopters, rc cars and rc boats
RCmodel - RC car, plane and RC parts
RCheliWiki - radio controlled helicopter related
AmainHobbies - RC cars, planes, and helicopters
Nitrotek - petrol remote control car, nitro cars, RC petrol cars and RC helicopter
QPstore – DLE, CRRPRO brand RC engine, SkyRC brand charger and motor
GoodLuckBuy electronic products, digital products and RC accessories (China)
Radical RC Transmitter and receiver batteries, servo extensions, switch harnesses, etc.
PeakModel Aircraft Engines, accessories, motors, propeller, brushless ESC
HiModel Manufacturer of radio control Cars, Trucks, Airplanes (China)


Overseas model shops - Other languages
Fun Models - helicopters and airplanes
NATAAIR.sk - EPP Foam acro models, 2-stroke petrol Engines, aircraft and kits, Trnava
ModelHobby - RC modely - lietadlá, vrtulníky, autá a príslušenstvo. Plastikové modely
MP JET - Model engines, gearboxes and broad sortiment of screws, control linkages and accessories for flying models.
IMI HOBBY - IMI Nitra - maloobchodný a veľkoobchodný predaj


NZ Model Shops
436 Model Shop - Provide the Model Aircraft fraternity for more than 20 years
Foamworks - Foamworks retail shop is now closed.
Top RC Model Ltd - A huge range of ARFs in stock at amazing prices.


CZ model Magazine
rcrevue.cz erospion.wz.cz flight.cz model-hobby.cz modelcentrum.cz letec.wz.cz rcmm.sweb.cz rcmodely.cz




Enrich Your Summer Equipment--Find a Fashion Scuba Diving Light for You


More and more people enjoy going swimming or diving as the coming of summer. Having a diving scuba during your underwater exploring, it will be more interesting.



 
mBuyNow had different styles of scuba diving headlight and flashlight. Take the 55W Professional HID Scuba Diving Torch for example, it was made of aluminum case with waterproof standard IP68, underwater 120m; can be use for diving and rescue. Other features are as following:                        
* Battery capacity: 6600mAh
* Irradiation distance: >1.2km
* Lighting Period (h): >120mins

If you are going to diving, the first thing is equipped with enough security tools. And knowing something about rescue is also necessary. mBuyNow provides you various diving flashlights to choose, and you will get close to sea safely when under deepwater.



2013年6月4日星期二

mBuyNow Offers Super Bright Flashlight for Summer Camp Use


Summer days are coming. It’s good time for kids or adults to enjoy themselves during summer camp. To make your trip more convenient and interesting, mBuyNow offers a series of flashlights or mini torch to use. With these bright lights, you will be safe at night. They can assist you with your childcare needs in a safe and exciting environment.


mbuynow HID torch light


There are quite a lot of flashlights to choose, which is the best? For camping, it depends on time and number of people. If you plan not to stay too long outside, a mini torch is enough. Usually it can serve 2-3 hours continuously. You can also bring a spare on in case of emergency.

Flashlight is quite essential for outdoor activities during night. For night camping, a bright flashlight can help you see clearly during dark. Especially when your kids came with you together, a warm light will provide them a safe environment.

For the sake of customers, mBuyNow put forward a series of flashlight with various power and styles. They can be small and colorful with 3-5W power for kids or short time use; they can be strong and durable professional flashlight with 85W super brightness for long time use. You can choose whatever you want according to your needs.

Feel free visit www.mbuynow.com for more detail.

2013年6月2日星期日

technorati

82D9TQXCN2TX

How to Fix the Missed Schedule Post Error in WordPress


Wordpress has release the new plugging of WP Missed Schedule Fix Failed Future Posts on 2013-5-31. Users plagued by missed schedule post error now can download on http://wordpress.org/plugins/wp-missed-schedule/

This plugin not decrase server performaces, why it check WordPress "Virtual Cron Job" Function Behavior, to no waste resources, and not "Physical Cron Job" at scale!

For not use too many resources, process 10 items per session, every 1 minute.
The default 10 Failed Future Posts per session, every 1 minute, was introduced for compatibility with default WordPress Items Feed Syndication.

This plugin is designed, on fact, for heavy use of Scheduled Future Posts and RSS Grabbing (as FeedWordPress or WP-O-Matic), but also work well with a simple WordPress Blog or for use as a CMS.

New WP Missed Schedule Features and Future Updates.

Actual Version:

1. √ Introducing (a New Idea of sLa) Check Key Tag Authenticity.
2. √ Added Support for WordPress 3.6+ Coming Soon Release.
3. √ Compatibility of W3 Total Cache and other Caching Plugins.
4. √ JetPack and others Social Publishing Plugins Transparency.
5. √ Interference Free with others Scheduled Cron Jobs a scale.
6. √ All in One Gold Versions with vary Frequency of Checking.
7. √ HyperDB Table Query Formatting Compatibility.
8. √ Preemptive Support WordPress 3.7+ ~ 3.8+ Future Releases.
9. Introducing Check Plugin Authenticity Before Activation.

Future Version:

1. Admin Dasboard Options Control Panel.
2. Admin or User Customization of all Plugin Options.
3. Manual change the User Level Permissions.
4. Manual change the Frequency of Checking.
5. Manual change the Number of Sessions.
6. Manual change the Number of Failed Posts Fixed.
7. Manual Scheduling Plugin Action.
8. Enable or Disable Header and Footer Log.

In the Future Version 2013/214 of this plugin, it will be introduced the New Admin Dasboard Options Control Panel to Optimize all of its Features!
Scheduled Posts Regression #22944 fixed on WP 3.5.1 is not related to this plugin.

The configuration of this plugin is Automattic! and not need other actions from the Administrator except installing, uninstall or delete it, but, for completely automatization, try on put it on /mu-plugin/ directoy, and also your activation is Automattic! starting from first installation.

No need to delete anything from hosting space when deactivate!
No need to delete anything from hosting space when deleted!
No need to delete anything from the database when deactivate!
No need to delete anything from the database when deleted!
No need to delete anything from the wp_option when deactivate!
No need to delete anything from the wp_option when deleted!
wp_option table is auto cleaned when deactivate or deleted!
Not need other actions except installing or uninstall it!

Full Compatible with WordPress Versions from 2.6+ to 3.5+ add Preemptive Support for Coming Soon 3.6+ and Future 3.7+ ~ 3.8+ Releases. Ready to Single, Network Multisite installations, and old WPMU 2.6+ to 2.9+ (latest is 2.9.2) Multi Users. Also it is possible to work on old versions from 2.1+ to 2.5+ (latest is 2.5.1) and legacy 2.0+ branch, but the result is not guaranteed. Run on Shared, Dedicated, Cloud and VPS Hosting, with high and low resources. Work under GPLv2 or later License. Implement GNU style coding standard indentation.


Other solutions:
http://www.wpbeginner.com/plugins/how-to-fix-the-missed-schedule-post-error-in-wordpress/

http://teqsnacks.com/2010/01/31/missed-schedule-failed-cron-wordpress-bug/