DIY H4 home made frame

See the DIY frame in action, no tweeking done on the FC, flown by one of my students who is a complete novice and has no experience with quadcopters.

You might also want to read this article on the CC3D

Well was a bit bored so I decided to make a home made frame and see how it faired compared to buying a Ebay frame. So I went to the local hardware store and purchased a piece of 15mm x 15mm square wood measuring 2 meters in length. The length was a bit overkill, but could not find a shorter length, so i guess the rest will be used to repair the arms, when it eventually breaks. I also purchased a small square plastic box that is used by electricians to mount and combine electrical wires

 

Bought this cheap mounting plate

 

Measured and drilled four holes for the mounting plate used four plastic bolts and fastened the mounting plate with plastic nuts.

 

Mounted 4 plastic bolts at the top of the mount and tighten with a thin plastic screw. The screw will act as a stand-off.

 

Slotted the power distribution board on the mounting plate

 

used 4 plastic stand-offs to fasten the board and drilled four holes at the bottom for the power cables to the ESC´s.

 

Soldered the main power cables to the PDB,There is a small switch under the board which enables the power to be switched on/off. The board worked on its maiden flight but suddenly cut off and i could not reinitiate any 12 volts, i did not test why, but simply resolved the issue by resoldering and connecting the main power cables to one of the + and - from the ESC's, bypassing the on/off switch and making the 12 volts live at all times. This PDB is not sold with a manual so the Internet and common sense was the way i had to go by setting it up.

 

Soldered a JST XH connector to the LED pins, this will deliver 12 volts to the LED light strip that I will mount at a later stage.

 

I then soldered 4 positive and 4 negative wires using each corner and fed the wires through the holes in the housing. These wires will be later hooked up to four ESC's on the quad.

 

The ESC's power cables are now done, was a bit of a hassle as the soldering plates on the PDB are small and close together, make sure to check that your cables are not shorting.

 

Powering the CC3D can be done in two ways, I chose to use a UBEC, I soldered the + and - to the second LED pins/pads. The UBEC will convert the 12v from the PDB to 5v for the CC3D. The second method of powering the CC3D is by using the BEC on the ESC and plugging it directly to one of the motor pins on the CC3D.

 Method 1. using the UBEC, The + and - wire leads from the UBEC

 

 Plug it into motor channel 1, remember to get the polarity right + is the middle rail, - is the bottom rail closest to the edge of the board and the top rail is the signal cable to the ESC.

 

Method 2. Using the BEC from the ESC. Simply power the CC3D using the BEC of the ESC. It plugs into the one of motor channel, giving the CC3D the required 5v.

 

Mounted the CC3D and tightened it down with 4 plastic bolts.

Cut two sleeves and fed the signal cables to the CC3D.

 

 

Mount the cable for the reciever port, this will later connect to the radio reciever.

The cable for the main port, if you are going to be using other units like GPS, telemetry and so on. My setup is not using additional units, so this cable was removed.

  

Solder a female 3.5 mm banana plug on each of the power cables for the ESC's and cover it with shink tube  

 

Drill four holes in each corner of the housing, this will be used to mount the housing on the frame.
At this point you now have a almost ready to fly housing that can be removed on the fly and be used on another unit without too much hassle. Stage 1 done.

Building the frame.

 Cut two pieces of wood mine were 41.5 cm, try to keep the edges as straight as possible.

 

Drill two holes on each shaft, making sure that there is equal space on both sides. The more centered the housing is the better the center of gravity.

 

Using 25mm bolts mount the housing on the frame.

 

Tighten the screws firmly. 

 

To stop the frame from flexing too much, you will need to cut out and mount an adequate plate, using some thin light weight hobby wood. I used som Carbon that i had left over from a hobbyking H4. I cut the frame and drilled the necessary holes and tied it all together. if you don´t have an old frame, find something that is light weight. The length of the plate can be much shorter. Make sure to check the flex on the frame.

 

The top side. 

 

Both bottom flex plates mounted

 

Cut two more pieces of wood, They will make the arms.

 

Again measure an drill two holes, making sure that the arm is bang in the middle. You are going to need a top plate to stabilize the arm.

 

Mount the second arm in the same manor as the first. 

 

Make a flex plate for the top. 

 

Mount four motor mounts and a motor, one on each arm.

 

Connect each ESC to one of the power outlets from the housing, and feed the signal cable from the ESC up though the sleeve in to the housing 

 

Solder a header pin on to the signal cables or you can make your own header pins if you have the required tools

 

Mount the four signal wires from the motors accordingly

 

Mount the cables from the reciever port to the reciever.

 

Had to cut the lid of the housing as the wires stuck to far up. Anyways, not entirely done, the cabling needs to be done properly, for now the unit is ready for testing.

HP SimonK 30A ESC Brushless Speed Controller BEC 2A for F450 F550 Multicopter

Well these two ESC´s just arrived in through the door, thought i would give you a quick review.
The specifications for this ESC are as follows:

Highest efficiency 100% N-FET design.
No low voltage cutoff.
No over temp cutoff.
Super high refresh rate, no buffering of the input signal, resulting in more than 490Hz response rate.
16KHz motor frequency, giving fastest response of the motor, and quietest operation as well (no 8KHz squeal).
Super simple, foolproof operation! Nothing to program other than the throttle range.

ESC Specs:
Cont. current: 30A
Max. current: 35A
Input Voltage: 2-4S lipo / 4-12 cell Ni-MH/Ni-Cd
BEC: 5V 2A (Linear mode）
Size: 55x26x8mm (length 145mm including power cable)

Weight: ~22g

 

Very neatly made.

 

It has a printed manual with safety precautions and product specifications and a wiring diagram, which is actually a + in my book, many of these cheap ebay ESC´s are often sent without.

 

The ESC output has three 3,5mm female banana plugs, so you will at least need to have the male version to finish off your wiring. 

 

I hooked Both ESC´s to my home made test bench and they both fired up. 

 

This is where i needed some expert advice so my Co-editor Sebastian helped me do a test of a Turnigy multistar 20Amp esc and compare it to the 30Amp ebay esc. This is not a very precise test but it gives an indication of how effecient it it. Using an Iphone program AKlite. You need both motors running at the Same RPM, place your phone on the table next to your setup, use the same battery and motor to do the test. In theory the battery should be fully charged in both tests. Then you rev up each motor, to the same meter reading on the graph of the AKlite, this will indicate that the motors are spinning at roughly the same RPM. Now you can compare both readings from the Watt meter. In this case the Ebay ESC ran the same amperage as the more expensive Turnigy, but drew slightly less watts at low RPM. Need to put a prop on and test again under load to see if it is still more efficient. Under load the Ebay esc was even more efficient, but again, this is a very rough test and not very accurate.

Open Pilot CC3D

WOW, what a board this is, totally amazed at the simplicity in configuration and the flying ability, this leaves the KK2 standing. Was hearing quite a lot about the Open Pilot CC3D flight controller, so I decided to order one off Ebay. The one I puchased was a rip off version, backengineered off the original and reproduced at halv the cost. I tend to refrain from buying expensive stuff like FC's on Ebay, because one never know what you might get. But in this case the FC was very cheap, so if did turn out to be useless, then what the heck. The CC3D I purchased cost 11 dollars from this supplier.

Shipping was very fast, took around 10 days and all was good to go. I was planning on changing my Cruis AIOP ver2.0, seeing as i have never been able to PID tune it properly. Mounting the FC was simple. The hardest bit about it was converting the mounting holes, the Crius is much wider 50mm x 50mm compared to 35x35mm for the CC3D. I saw a very cheap mounting plate at under 2 dollars, it fits the 50x50mm on the bottom plate, has vibration pads, the top plate is smaller and fits the 35x35mm of the CC3D, The Talon frame which i was mounting it on has only mounting holes for a 50x50mm mount, but seeing as i intitially thought that the CC3D was just for testing fun I refrained from purchasing more accessories. I ended up building a wooden mount and after that was done, the board was mounted and ready in under 10 minutes.

 

The CC3D form factorcompared to the Crius.

The software Open Pilot GSC for configuring the flight controller is one of best flight controller software I have seen, simple, clean, user friendly, well designed and very informative, very difficult to get anything wrong, everthing from the automatic flashing of the firmware, quad setup, motor calibration and radio setup, took about 15 minutes, I won´t  get into how it is all done, but this guy has done a whole series on the CC3D, watch all 8 series and you will have all the infomation you require to set it up. Despite the software setup being simple, it still gives you the ability to dig down into tweeking at a more advanced level. Like I said am no expert so initially I stuck with the more simple. The quad flew with the default PID values. I then followed this youtube tutorial on in air PID tuning and this was PID tuned in a breeze.

My flying skills have picked up some what after using the selflevel of the KK2, so thinking that i was in selflevel/Stabilize mode, I lifted off, what i did not know was that i actually had reveresed my channel five and was flying in rate/manual/acro mode and wow it was almost tuned in, Prior to this i had never flown in rate/manual/acro mode before, but with this board it was a breeze, very responsive and was just cool to fly. So if you have been stuck the KK2 for a while, this board could take you to the next level, the KK2 was fun to fly, but now it is soon time for real action. You can of coarse buy this board from some official sites, and i would suggest that you buy it from hobbyking or another certified retailer.
Open Pilot have stopped manufactering and selling the cc3d board, so you will mainly just find clones on the net, these clones are of varying quality. Mine died after a couple of days and greenshop333 was very quick to offer a refund, so would not hesitate to use him again for the same board and hopefully the next will be of better quality.

 Very neat compared to my other builds, four motor wires and a power cable. from a UBEC. You can buy a casing for more protection.

 I have connected my 3dr telemetry to the board through the main port, so no need for an USB cable. The cable is supplied with the CC3D .

I used the main port on the right, as it is  configured pr. default for telemtry at the baudrate of 57600. The Pinouts are as shown below.

On the back of the 3dr there is a set of equivelent pinouts. 

Connect 5v/VCC from the CC3D to the 3dr.

Connect GND to GND

Connect TX on the CC3D to RX on the 3dr

Connect RX on the CC3D to the TX on the 3dr

It should  work without the need of configuring the 3dr radio, but you might run into some issues.

I initially followed this tutorial  to setup the 3dr, but this did not work, It suggests to change the Mavlink to Raw Data. When i changed it back to Mavlink and saved I got the connection. You are able to change the baudrate if need be, using the 3dr software. When you connect the CC3D software using the 3dr radio, it can take 30-40 seconds before it fully initiates the software. So be a bit patient.

 

 Connection to the radio is done through the receiver port, with a supplied cable, no need for soldering. Its a simple as plug in both ends, Does however require to read the online manual to get the corret ports. The software will confirm if you got it all right and reversing of the channels is also done through the software. The software is very illustrative and easy to use.

Pros: Very very cheap, compared to the KK2.

Small form factor gives you more space usually where it is always cramped.

Cabling is done neatly, with the 3 provided cables.

Software is illustrative and simple more tweeking available compared to the KK2.

Very responsive and fun to fly.

Has autolevel function for beginners.

Can mount a 3dr unit for cableless configuration.

Can mount a bluetooth radio for cableless config.

Can mount a GPS to show long/lat on FPV screen.

Ratittude mode: Rattitude mode will give you more response as you feed stick input in; when you return the stick to Center, you're back in attitude mode. 

PID tuning is very easy on this board.

Cons: Board size, have to convert from a lager form factor 50mm to 35mm if you are not running on a 250 frame size.

Configuration requires a PC compared to the KK2.

Only basic support for GPS for OSD displaying long/lat though its big brother CC3D revo does support all these functions.

No altitude hold or mission planning.

Led Light Strip 3S 11.1V Controller Remote Control For Quadcopter

Ok thought i would post this quick guide on how to make LED lights for your quad.
You can see the partly finished product in action her

You need to purchase this LED controller off of Ebay, they cost a mere 5 dollars
LED Light Strip Controller

The unit consists of a balancer male housing for the connecting the battery balancer plug for powering the unit with the required amount of power. It has four JST plugs for connecting the LED strips and a header pin wire for connecting the unit to your transmitter. 

They are available for different battery cells, I have 3S batteries, so the link corresponds to my battery type.

You will need some 12 volt LED Strips. They are purchased in different lengths and colours. Note: There are two versions, a non-waterproof and a waterproof version. The waterproof version is a bit harder to work with as i requires that you remove/cut the rubber lining protecting the LED from getting moist. Cut a strip corresponding to the lenth needed. You need to cut it just before the copper pad as you need to solder your 12 volts power here.

Grab a sharp hobby knife and gently cut a groove in the rubber lining, be careful not to cut too deep, as you might damage the  copper pad and render the strip useless. 

Put a bit of solder on the pads

Solder the positive and GND wire , pay attention to polarity, red goes on the line that says +12v 

once you are cover the wiring with some heat shrink.

I only used two LED stripes as i am still waiting for another colour to arrive so i can mount the last two stripes.

You can then test your unit by simply plugging the balancer plug into the unit and it should light up. But we more to do as we need to be able to change the lighting modes via the transmitter.

Plug the signal wire into a spare channel on your receiver, mine was plugged into channel 7.

I have a Tarnis plus, so i created a logical switch called L17, that defines the SD up button, L18 defines the middle SD button, L19 is not necessary as we are only using the up and middle button to change the mode, nevertheless it is there, but not in use.

On your receiver create two mixes, that correspond to the channel you plugged the header pin in the receiver. Notice the weight has been set to 41, the weight determines how fast the lights blink in the first blink sequence. Assign L17 in source and switch is set to SD up, my setup reads L16, so need to change that. The second mix under channel 7 should be set to source L18 and SD middle.

The mix should look like this. Power up the multi rotor and have the balancer plug in the Strip controller, flick SD in the middle position. The lights should start to blink, and the mode changes every time you flick the switch. I am no expert on radios so they could be an easier and simpler method of setting up the mix, so let me know if you do it differently.

DJI s900 with 3DR Pixhawk - wiring main components

Hey there!

It is time to perform the next steps in the build of a DJI s900 Spreading Wings hexacopter with a 3DR Pixhawk as flight controller.
First there were some hints for building up the frame itself. Second I showed you all my solution for mounting the Pixhawk with vibration dampening. In this part of my build log I want to show you what else I have mounted to my new hexacopter and how I wired it all up.

Here is an overview of the components I added to my setup prior to the first flight:

• AttoPilot 180A voltage/current sensor
• 5V 3A Hobbywing UBEC
• 5V 5A "Master BecBoy" (UBEC)
• 3DR GPS sensor (mine seems to be an u-blox NEO-7)
• FRSKY x8r - RC receiver 

Quite a bit of equipment and for sure not everything teh copter will have to carry in the future.

Let us start with the first part I added to the setup: 180A AttoPilot current and voltage sensor.
Why do I use this part instead of the 3DR Power Module that is already shipped with the Pixhawk? There are two advantages (or better two compelling reasons) and one disadvantage in using an AttoPilot. The disadvantage in using AttopPilot instead of the Power Module is that you don't have the integrated BEC of the PM (Power Module) for directly supplying the Pixhawk. That is also the reason why there are two dedicated BECs in the list above. But more on that later. The two compelling reasons why I have to use the AttoPilot are:

1. I am using 6S Lipos as battery for the copter and the 3DR PM is not able to handle the high voltage.
2. The s900 can theoretically draw 6 times 40A of current in peak (6 ESCs with 40A rating). That summs up to a wopping 240 Amps at 25V  (resulting in theorectical 6 KiloWatt max power comsumption! Thats like running 3 hairdryers in full power in parallel. Some really massive power) 

So in the end the 3DR power module would be fried two times with overvoltage and overcurrent (can only handle 60A with a Pixhawk).

The AttoPilot needs to be mounted in the current path of the battery to the power distribution of the s900 (built into the lower plate of the main frame assembly). A description for soldering the board to the battery cables is already on the wiki of Arducopter. The result of this work looks like the following at my copter:

As the AttoPilot sensor range has no built in BEC there comes the first BEC into the setup to combine both at the Pixhawk's PowerModule connector.
There are several information pages on the web were you can gather the wiring information, but for simplicity here is a complete wiring diagram with pinouts:

For this schematic I used the wrong BEC picture. Instead of the shown Hobbywing I used the BECBoy, because 3A is more than enough and 5A of the Hobbywing are better used for servos and so on on the Pixhwak's backward connectors rail.
So I hope this rough schematic makes it a bit easier to setup the battery sensing and the first part of a redundant power supply for the Pixhawk.
Speaking of redundat power supply for the Pixhawk lets have a look at the second BEC out of the above component list. The second BEC is connected in parallel to the same upper XT60 power port of the s900 lower center plate as the first (XT60 in center of picture).

The difference is that the "Hobbywing" BEC (forground of upper picture) is not connected to the Pixhawk's power module connector. Instead it is plugged to the input/output-connectors at the backside of the Pixhawk case (the one for connecting the ESCs of s900 frame). Pixhawk is intelligent enough to include an automatic internal failover when one of the power supplying BECs is failing. Impressive feature in my opinion!
Some more pictures for documentation of BEC mounting:

To finalize the redundant power setup of the copter there is an additional safety feature adviced by 3DR. They say there is a Zener diode required when you power the Pixhawk via the ESC/Servo-Rail. I added another personal touch to the Zener diode. A 1 Microfarad "elko" (tantalum capacitor) and a 22 Picofarad ceramic capacitor in parallel to the diode. The reasons are:

1. 1 uF Elko: buffering some current for bridging massive power consumptions on the ESC/Servo-connectors
2. 22 pF ceramic: filtering high frequency noise introduced by bad EMC of connected components. 

The schematic for my "protection, filtering and buffering"-plug is as follows:

The resulting, with heat shrinking tube covered and into a servo plug built, circuit looks like follows:

Output 1 to 6 are s900's ESCs; output 7 is occupied by Zener-Circuit; output 8 is used for 5A 5V Hobbywing BEC power connector.

So with the power circuitry finished, there is still the RC-receiver and the GPS left. The FRSKY X8R is mounted with "doubled sided sticky silicone tape" and some cable ties in upward position to the frame.

-----   Interjection  -----
I really really really love this sticky silicone tape. Have discovered it at the shop when buying the BECBoy supply. You should definetly try that stuff. Best double sided sticky tape for RC I have used. And silicone dampening! Definetly recommending!
-----   Interjection  -----

The two antennas are mounted in a 90 degree angle to the bottom of one carbon fiber tube and one of the aluminium plates of the frame. I know it is not the best decision to mount antennas to conduting (and so shielding) parts, but they are facng downwards and are only shielded in direction of the open sky were no signal is coming from. So I think it is going to be OK.

The 90 degree antenna mounting is for better signal reception and highly recommendet. And as my transmitter antenna als always in a horizontal position, both receiver antennas should also be in a (mostly) horizontal position.
Additionally you can see the Pixhawk safety switch on the last upper picture. I'm not really satisfied with the ziptied switch, but for now it will do. Couldn't drill such a big hole into integrity vital parts of the carbon fiber plates. If someone has a nice solution I'm thankful for hints.

The last component from my list is the GPS. I ordered a dedicated, additional mast from the great bay for mounting, because I do not like the DJI system. The DJI solution has to be glued together (what a nasty solution for a copter like this). And DJI also only includes the bottom folding part of the mount in the delivery. The mast and top mount are missing. So here is a picture of my mount:

Not perfect yet (mounting screws too long), but also OK. And if I have to buy additional parts for GPS I buy and mount the stuff I like. Last hint for GPS: I used countersunk screws and also countersunk my drill holes. So the screws nearly vanish in the top middle carbon plate and there is enough room left for Pixhawk and Pixhawk's top connectors. 

One last thing for wiring which is not on my upper list:
The order for connecting the six ESCs to the Pixhawk's outputs is as follows:

Pixhawk Motor-Out	S900 ESC
1	M6
2	M3
3	M2
4	M5
5	M1
6	M4

I used 4 servo connector wires already delivered with the s900 and adapted the signal wire order. I also adapted the order of the ground wires according to the above list. Not neccessary because all grounds are the same at Pixhawk side. Was in the mood for it :)
The resulting wires look like this:

My final comment on this blog entry:
Maybe you all have noticed that I often use mesh tubing for organizing many of my cables. In fact I always use mesh tubing at my s900 when I have to run two or more singla cables in parallel. This is for a nicer, more professional and organized look. But also for protecting my cables from possible wear out (rubbing). And a professional copter for such a pile of money has deserved that bit of detail.




  

So again we have finished another part of my build log. Hope you all liked it.

Next up will be the basic software setup of the Pixhawk and some words on "special twists" of the flight controller and frame combination. 
Maybe also some words about my initial PID tunings and the maiden flight ;)

Stay tuned and happy flying!