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Spider Quad test flight

It was looking good with the FY-91Q control board until the Spider Quad dropped out of the sky (well maybe only about 1 foot off the ground). Looks like the 3mm Bunnings ply maybe wasn't up to the task. Easy fix though, I'll mount the motors directly to the aluminium c-channel. The wooden mounts are superfluous anyway.

 

Spider quad build

The motors, ESCs, and control board (FelyuTech FY-91Q) board are all mounted. Now I just need to connect them all.
Just mucking around with this control board while waiting for the DJI Naza to arrive.

Tricopter troubleshooting

Troubleshooting a tri copter

How to connect 4 ESCs to one LiPo battery (Make a power distribution board)

The first time I built a power distribution / wiring harness for a tri / quadcopter was back in December 2010 (http://fangin.com/blog/2010/12/07/tricopter-build-wiring-harness/) and I chose the most direct solution which was to solder all the cables together. I say "most direct solution" because in hindsight, it's not the simplest solution. The drawbacks of this solution include;

• It's more difficult to layout all the wires and get the lengths planned up front.
• Twisting the wire together and soldering 4 or 5 wires at one junction gets messy.
• I tried to link all the wires at one point (http://fangin.com/blog/wp-content/uploads/2010/12/1000000286-Large.jpg) to go into the battery which made it difficult to get the wire into the XT60 connector.

 

A neater, simpler and all round better solution is a power distribution board where a central, double sided PCB board (copper on both sides) is located centrally in relation to the ESCs / motors and all the wires connect back to this PCB.

What you'll need. 

1. PCB – Double sided.
2. Cutters
3. Red / Black Wire
4. Solder / Soldering iron
5. 20mm heatshrink tube.

 

• Cut a small board approximately 35 x 15 mm of the double sided PCB.

 

• Prepare the wires and board by soldering the ends of each wire and the board where the wires will go. You may want to consider orienting the wire to suit the layout of your multirotor. For example an X-Quad you may want to have four wires coming off the board in an X layout.

 

• Solder the wires to the board. Turn the board over and repeat for the other polarity wires.

 

• At this point you're almost ready to seal the board up with some heatshrink tube. Before you do! Use a continuity test on a multimeter to ensure 1) All the ground wires are connected and 2) There is no connection between the positive and ground planes.

• If you're worried about wires moving or foreign objects getting into the heatshrink, smother both sides of the board with glue from a hot glue gun. That will help keep the wires in the right place and prevent a short circuit between the two polarities should something conductive work it's way into the housing. 

 

• Now you can solder your favourite connectors at the end of each pair of wires. In the photo shown below I've used XT60 connectors on a harness made for a tricopter.

Proof the foamy quadcopter flies

Today was the first flight outside the confines of the garage. It was quite windy at the local oval making it fairly difficult to maintain stable flight. It's not meant to fly nicely, it's meant to look weird and fly weird and that's exactly what it does.

 

GoPro Time Lapse Setup

The problem: I want to record still images for a few hours with my GoPro camera using the suction cup mount and waterproof case but the battery is flat and I have to start recording in the next five minutes.

The solution: Drill out the side of the waterproof case where the USB cable would normally plug in. Now with the camera mounted in the non-waterproof case, on the suction cup, I can plug in the external power source usin a nano-tech 2650mAh battery. I know you can the skeleton housing with the sides cut out but a) I need a solution now, b) the skeleton housing costs just as much as the waterproof housing and c) Most of the stuff I do doesn't need a waterproof housing anyway. 

 

 

Turnigy Model Be Found

Going by the name of the Turnigy "Be Found" device, I get the impression it supposed to help you find your model if in the event of a mishap, it goes down somewhere hard to find. I've got a number of issues with this which I'll outline below. But then take a look at the website description (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=20578) and it describes it more as a pre-flight safety check device to audibly warn you if either your battery voltage is low or you lose the radio link during the pre-flight check you do before every flight (right – every flight).

From the website:

"This Handy unit will emit a loud beep if your receiver loses radio signal or when the voltage of your models radio system drops below 4v. Perfect for testing ground range of receivers and ensuring that your radio system has not dropped to an unsafe voltage before each flight."

 

Let's assume the low voltage part of it works (I'll have to assume because I didn't bother testing it), let's take a look at the worse case scenario where the model is lost in-flight and has to be retrieved in thick bush. Here are the drawbacks and why I reckon it won't work;

1. It didn't beep when I switched my Tx off. That's a pretty drawback as number one. Am I doing something wrong? Check the youTube video for how I tested.
2. Of all the models I've seen crash, the battery pack is quite often not connected to the receiver anymore (ie no power to the buzzer).
3. I reckon it introduces another likely point of failure. The in-line connector for the servo was a bit dicky and bent and the plastic cover stopped me from plugging it in properly the first time. 
4. If I have to rely on the low voltage buzzer to go off while I'm searching for a lost model, I could be waiting a while for the pack to drop below 4V.
5. Even as a pre-flight check device, if I'm standing 10-15 meters away from my model at a busy club field, and it did start beeping, I'm not convinced I'd hear it.

 

Overall, as a safety device, I don't think it adds much value and your radio setup is probably better off without another point of failure being introduced (even if it is only on one channel). This one is a Pass.

 

 

Using the HobbyKing servo tester to setup servo arms

Installing servos and getting the arms in the right position can be a pain if you haven't got around to setting up and connecting your transmitter yet. A servo tester like this one http://bit.ly/xUeoyB means you can find the centrepoint and test the throws all without the Tx. In the photos and videos below I've got three Hextronik HX5010 servos installed and pretty much centred without using any radio gear.

 

 

 

uReview – HobbyKing HK450 Tail Boom w/ Custom Laser Text

The purpose of the uReview (micro review) is to provide a short, sharp review of some RC products bought online. Often I've found product pictures are ok but there's no telling really what you're getting till you hold it in your hands. So the first candidate for a uReview is a fairly simple one, the HobbyKing HK450 Tail Boom w/ Custom Laser Text.

The "HobbyKing HK450 Tail Boom w/ Custom Laser Text" is potentially an alternative replacement part for my MWC quad arms. I say potential because thankfully I haven't needed to replace any booms on the MWC Quad yet. The MWC Quad booms are 12mm aluminium so the HK ones should be suitable. The photos below show;

• Outside diameter 11.98mm.
• Inside diameter 10.93mm.
• 1.05mm thickness.
• Length: 345.5mm.
• A 'Cold Blue' colour with white text.
• The text is etched on both sides of the boom.
• A small notch about 8.43mm at one end. I guess to hold it while the etching is done.
• Weight about 12grams. 
• Two Scratches / Dents.

Pretty much got what I expected. Disappointed with the ugly scratches and dents but for five bucks I'll put up with it.

Quad-Y-Copter (V-Tail) Specs

To answer a few questions about the specs of the Quad-Y-Copter (V-Tail) here are some details on the config;

Motors: All four are rctimer.com 750kV

http://www.rctimer.com/index.php?gOo=goods_details.dwt&goodsid=123&productname=

ESCs: Turnigy 30Amp. I haven't measured the current draw but I'm sure 30A is overkill. http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=2164&aff=257015

Props: 3 Bladed 9 x 5 regular and counter rotating. 

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=5250&aff=257015

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=5248&aff=257015

MultiWii Software 1.9 http://code.google.com/p/multiwii/downloads/list

Y4 Config as per http://www.multiwiicopter.com/pages/multiwiicopter-wiki

The frame is 12mm x 12mm Tassie Oak arms and 3mm ply. 

Inverted V-Tail arms at 20 degrees.

 

Custom mixing.

  #ifdef Y4

    motor[0] = PIDMIX(+0,+1, -1/2);      //REAR_R 

    motor[1] = PIDMIX(-1, -1, +1/5); //FRONT_R 

    motor[2] = PIDMIX(+0,+1, +1/2);      //REAR_L 

    motor[3] = PIDMIX(+1, -1, -1/5); //FRONT_L

  #endif