With two successful Build Your Own Quadcopter classes now behind us, the third class is up on the roster now on the weekend of May 24-25, 2014.
As mentioned in the class description, participants will need to bring a few things with them to the class.
A few people have asked why the radio and battery aren't just included in the price of the class. The main reason is that some people who want to take this class may already have their own radio equipment. Making them buy another radio seems pointless.
My goal here is to provide a quick start guide to buying the equipment you need to bring to the class. If you have any questions, please feel free to contact me. I will gladly talk your ear off about RC flying :-)
Here are the things you'll need to bring:
- An RC radio transmitter, capable of at least 6 channels
- An RC radio receiver, capable of at least 6 channels
- A LiPo battery pack, 3-4S (3-4 cell in series), in the 2000 - 4000 mAh range
Let's take a quick look at the RC Transmitter. You're looking for a few key features:
- Mode 2 (vs. Mode 1). I will explain in detail in the class, but it determines which functions each stick controls. Most radios are convertible between Mode 2 and Mode 1, but it's just easier to get a Mode 2 to begin with.
- At least 6 channels. This is a must-have. 7-9 channels is better.
- Programmable - The ability to adjust various key aspects of how the transmitter interprets your stick commands and sends them out to the receiver.
- Channel reversing - The ability to reverse the output of any channel. This is a must-have.
- Adjustable endpoints - the ability to determine what the minimum and maximum values are for each channel. Not a must-have, but very very handy.
- Rates and Expo (exponential interpretation) - the ability to adjust the sensitivity of the controls - very useful for beginning pilots. Not a must-have, but you won't regret it.
- Channel Mixing - the ability to take the inputs of more than one channel and create a "virtual" channel that combines the inputs. Optional, but can be useful for more complex aircraft. You will want this feature if you are going to get serious about flying RC.
- Multiple model memory - The ability to store all of your programming options for more than one model. Not required, but most programmable transmitters already have this feature.
The RC receiver is a bit simpler to choose:
- It needs to talk the same RC language as your transmitter. Generally speaking, they need to be the same brand, or at least state they are compatible with your transmitter brand and model.
- It needs to support at least 6 channels. 7-9 would be better.
The battery is a fairly simple choice. You're looking for a 3S (3 cells, wired in series) 2000-4000 mAh Lithium Polymer (LiPo) battery. The higher the mAh rating, the longer flight time you get. It doesn't matter which connector is on the end of the battery. It's easy to put any connector on you like.
While not required for the class, you will also want a charger for your battery. There a ton of them out there - ranging from $20 to $1000. What's the difference? Mainly, the more expensive chargers have more charging options, can treat your batteries a little more kindly (thus extending their life) and generally charge much quicker. The more expensive chargers have the disadvantage of taking only DC in, which means you need a power supply as well. The $20 charger will be smaller, more portable, and just plug right into AC.
For the budget-minded person, here is a setup that will get you a transmitter, receiver, battery and charger that will meet all of the criteria listed above for $150 - $200:
- Turnigy 9XR Mode 2 transmitter from HobbyKing. ($51) This 9-channel programmable transmitter comes without a radio module, allowing you to choose from a variety of modules with differing lingo and capabilities.
- FrSky Combo Pack from HobbyKing. ($53) Includes a transmitter module, compatible with the Turnigy 9XR, and a matched receiver. Both support 8 channels.
- Turnigy 9XR Safety Protected 11.1v (3s) 2200mAh 1.5C Transmitter Pack. The 9XR doesn't come with a battery - this is the battery you'll need for it.
Battery - Here are a few batteries you can choose from.
- Turnigy 3S 3000mAh LiPo battery from HobbyKing. ($15) I have a few of these; they have performed well and the price is right.
- ZIPPY Flightmax 3000mAh 3S1P 20C LiPo battery from HobbyKing
- Turnigy nano-tech 3300mah 3S 25~50C Lipo Pack
- Turnigy 3300mAh 3S 30C Lipo Pack
Charger - Here are a few different chargers to choose from.
- HobbyKing 1S-4S LiPo balancing charger. ($28) Plugs into AC or DC. Not fancy but will get the job done.
- Hobbyking ECO SIX 80W 6A 2~6S Battery Balance Charger AC/DC w/PSU ($30) A bit fancier.
- IMAX B6-AC Charger/Discharger 1-6 Cells ($44) AC or DC. Another step up.
You only need to pick one battery and one charger. I gave a few choices because the the stock availability tends to vary quite a bit.
A quick note about ordering from HobbyKing - they are famous for back-ordering things and typically ship directly from China - don't wait until a week before the class to order - you probably want to give them closer to a month of lead time to be safe.
Additional Note: The items listed above tend to go out of stock regularly. They usually come back in stock withinin a few weeks. In the past I have recommended the Turnigy 9X radio (predecessor to the 9XR) as an alternative when the 9XR is out of stock - but due to recent experiences I am no longer recommending the Turnigy 9X as an alternative to the 9XR. Out of the box, it doesn't really work well for the quadcopter we're building. It can be made to work, but that requires upgrading the firmware, and that's really out of the scope of this class. I will keep an eye out for a decently-priced alternative when the 9XR is out of stock, but as of right now I don't have one. My advice is to order early and get your 9XR well in advance of the class, or you may end up buying a radio locally at the last minute and spending a lot more money.
The transmitter and receiver are the most important things to consider. If you have the budget and think you may really get into RC, splurging a bit on the radio might be worth considering. There are a lot of options out there. Personally, I am a Spektrum fan. Futaba, JR and Airtronics all make great radios, but the models that have the functionality you need are going to be more expensive than the Chinese clone route listed above.
It's worth noting that Spektrum and JR are owned by the same company, use the same technology and are of equivalent quality.
I will list a couple of name-brand options here that will work for the class:
- The Airtronics RDS8000 combo will get you an 8-channel transmitter and receiver for about $200. I've never used any Airtronics gear, but this one will work for the class.
- The Spektrum DX7s combo will get you a 7-channel transmitter and receiver for $300. I owned a DX7 for 6 years and only sold it last year when I upgraded to a DX8. It's solid, easy to program and works great.
- The Spektrum DX8 gives you one more channel, better quality sticks (they just feel nicer), more options, and a bit easier to program. You'll need to pick up a DSM2 or DSMX receiver to go with it. You may be able to shop around and find a combo with both a DX8 and receiver. I have a DX8 and an AR8000 receiver and it works great.
There's also a new player in the RC market - FrSky. I recommended their transmitter module/receiver combo above for the Turnigy 9XR - but FrSky now has their own transmitter called the Taranis. A friend of mine has one - and it is really a nice radio. Frankly, I'd be recommending these to everyone if they were readily available - but pretty much everyone has them on backorder for the forseeable future. They retail for around $200 - they have 16 channels and can pretty much do everything that Futaba's top of the line $3000 radio can do. You can find the Taranis for sale on eBay usually, but they're going for $300 and up. Oh - and they also run open-source firmware. They're designed to be tinkered with and hacked. I'll be getting one myself if I can find one at close to retail price.
Prices go up from there. Yes, there are cheaper Futaba, JR and Airtronics radios out there. Frankly, the Turnigy 9XR + FrSky combo are better than the cheaper brand name radios.
If you find a deal somewhere on a radio that looks like it will work but you are not sure, please feel free to drop me an email (firstname.lastname@example.org) and I will be glad to have a look and make sure it will work for you. You can sometimes find great deals on eBay.