Steve Monro's Posts (2)

Sort by

Part 2 – Building the Copter

3689535766?profile=original

This is the second chapter in my quest to build a flying machine. If this is your first time in joining me in my project of getting a flying machine in the air, I’d encourage you to have a look at Part 1.

In the first installment in this mini series, I spoke about how difficult it’s been to get in to the world of flying copters, due a many acronyms, assumed knowledge and the complexity of the options available.

As I sit here on a return flight to where I am currently living in Brisbane about to down some complimentary coffee and listening to music on the free headphones given to me for the in-flight entertainment, I’m getting the chance to finally reflect on some of the challenges and discoveries I had when building upon my new found hobby.

I had ordered the 3DRobotics hexacopter with the full electronic kit and was super excited when it ordered no more than 5 days later – from the USA. I know that there have been several comments on my last post made about Hobby King as a supplier of equipment. In good faith I had also ordered parts from them too, expecting parts to be delivered within a few weeks of each other at the most. On a side note, I’ve almost given up on expecting the parts from them in time for when I initially needed them – before this week.

I was at my normal job when the box from 3DR arrived. If you are like me, when you go to a shop, usually the box will get opened in the car – this happened again. I’m like a kid who can’t wait to open his presents at Christmas.

 

On a side note, just beware that if you use a P.O. Box to accept deliveries that some couriers may have trouble with delivery. Fortunately the courier rang me asking for a local physical delivery address.

 

So, as the box arrived and I open it up, I quickly discovered there were no instructions in the box, or where to directly find them, and no paperwork saying ‘Congratulations on your purchase, we hope you enjoy flying it. You’ll find more information at X etc…”. I was a little surprised at this. The top of the box had the order and contents/packing slip on the top though.

Because this is a community project that I purchased, I’ll let it slide. Even though projects are community based, I know that model designs change and are regularly improved over time.

To the team at 3DR, here’s an idea. When you make and release versions of the hexacopters, are you keeping an archive of the documentation online for each version of the models that are released? I know this happens with the AurdoPilot board, but what about the frames and kits available too, and including basic documentation?

I’m sure it’s not too hard to keep track of the changes and refinements that go along with the manufacturing.

Why the previous suggestion? Well, The first thing I had to do was find the instructions. This took a little searching to do, because even though 3DR are making it and there are “link placeholders” on their site on the actual product pages they are selling, there are actually no links. (This has since changed – well done.) I needed the specific PDF file which laid out quite well the construction of how to build the new frame. There were random links in the forums, and the Wiki but not easily found.

This is the current link of the 3DR hexacopter instructions.

I also found the photos and step by step instructions from the UK Arducopter site very helpful too.

 

3689535596?profile=originalUpon getting these instructions I printed them out in colour was able to set to work.

My coffee table at home was covered in bits of aluminum, cables, plastic, cool little blue motors and some things called ESCs.

As a child I enjoyed playing with Lego and Meccano, so assembling this new contraption wasn’t too hard to do and as a newbie, I was able to easily do it in under a standard movie time.

The manual made it very easy to understand what went where and how all of the hardware joined together. This was the fun and easy part.

I did have one slight problem and that was because I was missing a little screw to keep one of the motors on the arms. I made a note of which one it was and did it up slightly tighter than the others. I searched everywhere and was extremely careful not to lose any part. All I can put it down to is either quality control and someone not counting to 12, or a screw falling out of the bag there were packaged in because of an air hole and they were lost in transport. It certainly wasn’t the end of the world, so I didn’t really worry too much, and up until this time I haven’t raised it with 3DR – I have since bought a packet of m3 6mm screws though as spares for the legs and other parts for (*cough* when) if I break the copter.

The next part after the initial frame construction was the electronics of the copter – this is where having the laptop on hand helped immensely.

3689535687?profile=originalConstruction

The manual gave step-by-step instructions for the frame and the distribution board (which was thankfully already assembled), but when it came to the electronics, the manual basically said (and I’m paraphrasing here) “Connect the electronics and you are ready to fly”. What the?

I had my AurduPilot controller (which is known as the APM) with lots of plugs available, and also a distribution board available with many wires. Naturally you can see which plugs go where, however because I’m a person that likes to pull things apart to see how they work and put them back together again, it’s taught me a thing or too.

Even when I was working on acid etched circuit boards in my early days in high school I could easily understand how and where power flowed on circuit boards. Even looking at PCBs you can see the copper lines and how circuits join with each other.

The next part threw me. The 3DR distribution power-board totally confused me. It is painted black and has 7 power plugs coming off it. It didn’t make sense to me as to how it was wired up. As I couldn’t see the paths of the electronics, I wasn’t sure of how this thing was truly wired up. I like to ask questions, find out how things work. Taking things at face value sometimes is hard for me until I’ve got a good understanding of a product/item. My old multimeter had died and so I was stuck.

I did however manage to find a schematic of the board online. (http://stuff.storediydrones.com/Hex_Power_Distribution_Board.zip)

Yes! My research was paying off. Next to find an opensource tool read the strange file. Once I could see the wiring of the board on the screen, I was set and good to go. (http://www.cadsoftusa.com/download-eagle/)

As it turns out, according to the schematic diagram of the board, this is how's it's connected under the paint.

3689535782?profile=original

http://store.3drobotics.com/products/hexacopter-power-distribution-...

Before I'd seem the schematic diagram, I was VERY tempted to start doing extra soldering of all the pins, but also for the power plugs too. The board itself is painted, and so at the time - it just didn't make sense.

Oddly enough, I still bought a $12 multimeter and double-checked all the plugs.

3689535821?profile=originalTo most people who have created a copter of some sort, most of this is all second nature, but when you’ve never built anything like this, you want to make sure you get it right before you start powering things up – just in case you short circuit something. I’m sure you’ve blown a fuse, popped a diode or connected batteries the wrong way. When you pay good money for a hexacopter, this is the last thing you want to do.

3689535865?profile=originalAfter studying many images and designs of other people’s copters, I was able to finally connect my system together on the table to see how it would look before it was to be fully installed in the copter itself. Everything looked good. GPS plugged in, ESCs in the right place, loose wires everywhere and so on.

I laid everything out to get a good idea too of how the configuration was going to work as well.

The pictures shown are basically how the cables go together.

In Part 1 of this blog series, you'll remember from the design image how it all goes together. This the actual of how it goes together.

As mentioned before, my order from Hobby King hadn’t arrived and so I had a kit that was half built. I couldn’t do anything else and it was getting to me. I had no battery, or radio system to use the copter. This was really frustrating me – having a half built machine sitting there being unable to progress further because of a lack of parts.

IMG_6531.JPG?width=750Electronics nearly installed.

It was at that stage that I had it suggested to me to try a local hobby shop and see what was available. In all honesty I hadn’t thought about that option – for two reasons. Firstly, this was a completely new field to me and so I didn’t/don’t know of many/any people doing it as so had assumed it to being a super niche market. Secondly, I often find myself going to shops and asking for items that are considered ‘specialty’ items and so walk out empty handed. This happened a few years ago when I wanted a shoulder mount/frame for my DSLR and went to one of the biggest camera places where I live. They didn’t have any stock or parts. So, what does one do in that instance? You go online and wait weeks… This was where I thought I was.

IMG_6535.JPG.jpg?width=300As it turns out, radio controlled gear (although as slightly specialist as it is) is reasonably common and not too hard to get hold of. So, off I went to the local R/C hobby shop. I grabbed one of the cheapest but full featured radio control units available a Futaba F8 unit – which includes a receiver, and it also runs on AA batteries; a big bonus. (Some transmitters have interchangeable transmitter packs for various frequencies and things).

When I had these new components with me and a big kid grin on my face and a hole in my wallet (because I’d just paid for a radio and batteries a second time – thanks HK), I was able to continue the build process and get things going properly.

It had taken me at least a few weeks to get to this stage, so I made minor tweaks to the initial and suggested look. I added some black braided plastic to conceal the wires on the six arms.

As soon as I brought the batteries home, I discovered I had a problem. I had initially ordered the wrong part. My battery had a T (Deans) connector on it. My power module unit from 3DR had an XT60 connector on it. Fortunately for me, a gentleman on YouTube has made 4 videos outlining various phases in the configuration of how the APM works and what goes where. It’s a good thing I’d watched them all and remembered about the little jumper pin video, as this was what saved my day. (https://www.youtube.com/watch?v=TFCmUuvcH04)

This basically meant I had to use the little jumper, because instead of using the 3DR power module, I'm now getting power from the ESCs to the APM. It's not a big issue, but just means the APM can't monitor the battery power and do an emergency landing if it runs out of juice.

The other videos in this mini series are also very good to give you enough information as well - Part 1, Part 2, Part 3 and Part 4.

One of the things I also did while waiting for parts and the construction phase was connecting the APM to my computer and loading the firmware required. After downloading the Mission Planner software, it was very easy to put the Hexacopter software on. There are plenty of tutorials out there about how to do this. I did however get excited to see the live telemetry data and the GPS signals coming through on my computer while the GPS module was connected. This was one of the main reasons for going down this OpenSource path.

When trawling through the wiki pages, also note that you are in the ArduCopter pages. The ArduPlane wiki pages are very quickly linked too as well and it's easy to mix up where you are. Most of the information is relevant, but at times it can be slightly conflicting.

For those wondering about how to connect the transmitter and other things, it's very easy.

 

IMG_6543.JPG.jpg?width=750The connections on paper.

 

IMG_6538.JPG.jpg?width=750Nearly finished.

 

IMG_6556.JPG.jpg?width=750What the radio transmitter IN connections look like up close.

 

IMG_6552.JPG.jpg?width=750Completed!

 

One thing you may notice is how I ended up connecting the ESCs to the APM. I went directly from and skipped using the distribution board because a few of the connections had broken and after doing a couple of tests with my multimeter, I wasn't totally satisfied with how it was working. It was easier to remove the soldered cables and go direct.

Thanks for reading. There is still more to come however. Stay tuned...

Read more…

A beginner's experience to the Copter world

My dad likes remote control cars. My brothers like remote control cars. I like them too. As a family, we grew up playing with train sets laid out on the family dinner table. As kids we also used to enjoy playing with a “Thunderloop Thriller AFX Slotcar Set” and making things out of Lego. The things that typical boys enjoyed playing with.

So where do I begin with this flying journey? How about this last Christmas. It was the year of… strangely enough remote control toys – yet again. Some years it’s been remote control 4WDs with over-sized tyres, other times, there have been noise making cars, or ones that only turn when you reverse them. Well, cheap infrared helicopters were in this Christmas. We flew them around, bounced them off walls, hit light fittings and dented couches until the batteries ran out, before we would charge them for 10 minutes, use the small charge stored in the capacitor and do it all again.

A few months ago I came across some quadcopters on the Internet. Mmmm… These looked like fun. I was so impressed that I looked on ebay and searched around and found a DJI Phantom Quadcopter for about $300 – well within budget. I thought, that looks like a good deal (because others of the same thing were over $600). As it turns out I got stitched up on eBay. But, PayPal came through for me in the end. (Thanks guys).

It’s a good thing it happened this way though. It started me on a journey to find out more about what these flying machines were really all about and the vast amount that are truly out there. I got my money back, and felt like I had received a bonus $300. Budget now doubled!

I write this not as someone who is an expert, but as someone who has gone from knowing nothing, to some who has watched videos, read up and who now knows a little more than the majority of my friends. Why is this so? Because none of my friends have a flying machine quite like I do.

It seemed to me there are several different types of flying machines around. To keep it simple, lets just use the word copter, as the generic term. There are several types of these copters around – all with a prefix to tell you how many propellers there are. I’m not going to be talking about planes, helicopters, wheeled devices or tanks as this hasn’t been the focus of my research.

So, the common ones are.

  • Tricopter – 3 blades
  • Quadracopter – 4 blades
  • Hexacopter – 6 Blades
  • Octocopter – 8 Blades

It took me a while to figure out, but the more blades you have – the greater lifting capacity you have – in a basic sense. I like photography and the odd hobby filming, so I thought a hexacopter would be a good start.

As I mentioned, there are many different types, and I’ll try and break it down a little. DIY open source kits which you put together yourself, or; closed source proprietary systems which are generally purchased in a ready to fly kit.

When I say drones/copters I’m not talking about military drones that cost a million dollars to fly, nor am I talking about a Cinestar 8 HL (or an Aus version), or the one used in a recent Top Gear Nile Special. I’m talking about a simple pro-sumer version with a minimum few features – such as GPS and waypoint controls. The ones you can get at a local electronic shop are the toy ones – these are not the ones I’m interested in.

The DJI unit I originally looked at is a proprietary system, though many people have modded them and done add-ons and hacked the frames to accomodate more things, but overall I felt these didn’t have the greater flexibility that their open source brothers have.

The OpenSource model however is a rather different beast. I somehow discovered it and found that there are many people out there all doing really cool things and I wanted to be a part of it. Why? Firstly, the OpenSource model is great because it’s a community collaborative thing, and updates are often regular. Secondly, the amount of people and active members I found at DIYDrones.com was massive. Theres’s a great source of material, and regular content.

There was a problem though. The more I looked at the different options, the more I got confused.

Many years ago, I remember looking at getting a satellite decoder box, because my house had a satellite dish on it. Why wouldn’t you? Free TV channels right? If you start looking up that kind of content of what to buy, how to find the right satellite you discover quickly that it’s a completely different language full of acronyms and words that are only in use in that field. Needless to say, I gave up.

Looking in to the world of these copters has been like that for me. I still don’t have a clue what half of the acronyms are that are dropped, and at the moment – I don’t really care. But, what I have found out, I’ve decided to share so that others won’t be confused like I was.

So, you want a flying copter but don’t know where to start? That was my position and you are not alone.

If you go down the DIY option, this image (source) (and many others like it) is probably one of the most helpful things you can have to understand the basics of what you need to get one working – at least of the electronics.

808846142_orig.jpg?width=800

Electronic Layout

Basically you need the following: (for a quadcopter)

  • 4 motors with blades
  • 4 Electronic speed controllers (ESC) for each of the motors
  • A battery
  • A radio receiver (and transmitter)
  • A “computer/brain” (I went with this leading model)
  • A frame and wires to hold it all together

Once I discovered this image, much of it made sense.

I looked at some of the stuff on HobbyKing (a website with many remote control items) and there were heaps of cheap options. I started looking at the frames. If I was going to have a copter, I wanted it to look good. The next problem was figuring out which models worked with what, how the ratings of motors worked, the size of the blades, the frame, the bla bla bla bla. I nearly gave up – again.

Instead, I started looking at kits that where ready to be built. This was more up my alley. The hard work was done, and I just had to put it together… As Jeremy Clarkson puts it “How hard could it be?” – yeah right…

I chose a Hexacopter from 3DRobotics with the full electronic kit. This saved me having to know what an ESC was, and what kind of rating a motor had. (I still don’t know what the specific motors are that they sent me. I just know they are blue and go really fast.)

The reason I chose to go with the OpenSource system, was community support There was software available, new firmware updates, it looked really good. I’d chosen the ArduPilot box and after searching on the DIYDrones website, I finally found what I was looking for. The final piece in the puzzle was all about batteries.

Do you remember when Linux first came out? I remember compiling kernels many years ago, and people saying, “Yeah, this is the future”. The future? Yeah…Whatever. Make it friendly and don’t make it crash on me. These days, it is much more stable and there are more than a few consumers using it.

This was where I found myself in the copter world; scratching my head and trying to figure out a bunch of information that everyone knew, or just assumed that was already known. This was probably one of the hardest things to understand. That and trolling through the massive amounts of forums posts. There was plenty of good help available however. My questions: Post 1. Post 2. Post 3

Now back to the batteries… If you are looking at buying a DIY drone, there are 2 things you aren’t told. Firstly, about a transmitter/receiver (and a charger) and secondly, what type of battery you will need.

The 3DR Hexacopter will easily handle/need a 3C 2200mAh 11.1V. What is all this? 3C means it has 3 cells. 3 parts of a battery that make up the 11.1 volts required. The 2200mAh value is how much power is in the battery for how long it will run. There is another value and that is how much punch it has, but a value of 30 will work fine. All up, a battery like this, you will get 7-8 minutes from it. (Yep, that’s all unfortunately). This is what they look like and the approximate price.

I’d like to say 2 things about when ordering parts from the Internet. My intention was to have a flying copter and be able to be proficient at flying so I can take aerial video. I made sure I ordered months in advance. The guys at 3DRobitics in the USA, I can not fault. I ordered on a Thursday/Friday night Australian time, and it arrived on the Tuesday. I also made an order from HobbyKing at the same time. I ordered batteries and a radio remote controller and receiver from them. I still haven’t received the package and it’s still sitting in Hong Kong (apparently) – and this was back in mid May, 2013. Now to be fair to them, it could be the mail service they use – SpeedPost.sg. Correct me if I’m wrong, and maybe my expectations are too high, but I would expect that when they say a package will be delivered within 3-6 days, that it will be.

You get what you pay for. If you want items, get them local or from trusted suppliers.

Needless to say, I discovered a nice little RC hobby shop up the road from me. They don’t specifically have much tri/quad/hex copter gear, however there is plenty of other equipment. They have batteries, chargers, transmitters and basically what I needed. I should have gone there in the first place. I’m a fan of supporting small businesses, especially specialty shops like this. Needless to say, the friendly staff are very helpful.
http://www.mildtowildrc.com.au/

On another note, I have found the story on 3DRobotics very interesting:
https://www.youtube.com/watch?v=n1E_CPxR3LA (watch the whole 5 videos)
https://www.youtube.com/watch?v=cwH7w1vOlIs (another one)

Part 2 of the building phase will come next.

Thanks! Let me know if this article has helped you in anyway.

Read more…