tirsdag den 31. december 2013

MultiWii Pro controller

Being a newbie, it took quite a while to figure out the cabling required to make this all work, i originally had a Crius all in one Pro version 2.0 that i bought from unmannedtech.co.uk, the documentation was very sparse and much of it was DIY, so i ended up shorting the board as i fed voltage at a wrong connection and one of the copper threads burnt out, i eventually ordered a new one from rctimer.com

but that got stuck in the postal office somewhere in singapore, not wanting to wait another month i then ordered a HK MultiWii pro, i later repaired the broken board by soldering a wire between the burnt out circuit making the board usable again, and a month later the new Crius board arrived, so i now have flight controllers for three quads. In this section i will look at my cabling, as i mentioned i am no expert in this field, this is plain DIY and many things can be done differently, so let me know if thats the case.

As in the above picture the top section of the board is used to mount the motors and the Gimbal. Pin 44is the pitch of the gimbal and pin 45 is the roll of the gimbal. I only connected the signal cable of both gimbals as i am currently working a separate powering for the Gimbal to avoid brown outs, more on that later, i have not yet put shrink tube nor a pin connector still waiting for it to arrive.

Pins D2 through to PinD6 are used to connect the motors, if you are making a Hexacopter pins D7 and 8 would be used as well, but since this is a quad i am only using 2 to 6. Here i connected the signal cable from the ESC only, this has to be connected on the pin closest to the white arrow. Ok time for new year party back later

Ok happy new to you all, hope you all had a fantastic evening and a great party. Well mine was not to bad, though i left the partying out, the evening was great.

Pin 9 and 10 I used for connecting the HC-SR04 sonar distance sensor more on that later.
Connecting the motors on the copter all depends on what you are building in my case i have an X frame quad so i downloaded the manual from HK and got the setup from there.

I placed the quad in the flying direction with the arrow pointing forward and found the equivelant setup, so in my case D2 on the MultiWii board i placed the left front motor, D3 the back right motor, D4 the front right motor and D5 the back left motor. I only used the signal cable from each ESC as i used a seperate UBEC to power my system.

After i accidently shorted my ESC, I cut the positive and ground wire off leaving only the signal wire, the ESC still functions in powering and regulating the motor. 

On the otherside of the MultiWII pro, i connected the signal cables to my reciever.
here my story is the same as before i only need to connect the signal wire (most inner rail where the green cable is connected and not the + and ground rails as my reciever is also powered by my UBEC. The thing that i so far have learnt is that i had to search many sites and read many articles before finding out how to have it all down correctly, for instance my reciever uses the terminology "Throttle, Alieron, Elevator, Rudder", the Crius AIOP (all in one pro) uses the terminolgy "Throttle, Roll, Pitch and Yaw", now it actually took some time to find the out which was which, in actual fact for a moment i was wondering wether google had gone offline. Anyway for all of you, like me who can´t master the power of seaching in Google, Roll is Alieron, Pitch is Elevator and Yaw is Rudder, i later found out that the Alieron, elevator and rudder terminolgy is used for RC planes and the counter when building multi-rotors.

Back to the connecting the reciever and HK MultiWii, when i downloaded the official documentation off Hobbykings site i noticed a slight differance, i am not actually sure which revision my board is, but the official documentation states that the outer pin is the signal cable and the inner pin is the GND, this is not correct, the INNER rail is the signal, so just one more reason to gret confused. I connected my reciever with the corresponding cables. The top row on my reciever is the signal pins, my reciever is powered using a UBEC on the BATT/BIND this port i originally used to pair my reciever and transmitter, apart from that i use it to power the Rx, the middle rail has the + connection and the bottle rail has the GND.

Throttle on the signal pin of the reciever to A8 on the HK MultiWii
Alieron/roll on the signal pin of the reciever  A9 on the HK MultiWii
Elevator/Pitch on the signal pin of the reciever A10 on the HK MultWii
Rudd/Yaw on the signal pin of the reciever A11 on the HK multiWii

The Gear and the Aux1,  i believe i connected to get some extra functions out of my transmitter, but not sure have to check out why.

Well time for some live championshipcommentary Reading vs. Forest COYR
Halford does it again!!!

Hobbyking X650F Glass Fiber Quadcopter Frame

The zip tie around the frame was initially placed to hold the gimbal frame in place when i glued it together.

Hobbyking X650F Glass Fiber Quadcopter Frame 550mm, a great frame if you want to hide your cabling, I am a newbie at this stuff, but with this frame I was able to solder an extension cable on my ESC and feed them through the tube together with the LED all the wiring was then done under the frame of the X650F and the cables are visable as it is covered by the battery.

An idea i used was to take an old useless power supply from a PC and use the cables to extent the ESC, LED's and the yellow cables i used as signal wires from the MULTIWII pro down through the tube to the ESC.

I ran out of shrink tube so i had to use duct tape for some of the cabling, i ordered a box of assorted shrink tube from ebay, so patiently awaiting the package so i can redo the wiring. 

Mounted a gimbal, the left most wires but have to be redone as i plan on powering the gimbal on a separate battery to avoid brown-out, the first time i mounted the gimbal and connected it to the flight controller it caused the flight controller to lose power and restart due to the gimbal pulling to much power.

Three levels under the hood the bottom is the power distribution, you have to find a piece if plastic/plywood drill four holes equivelent to the holes in the power board. The plasticplywood has to then be mounted under the frame so you can tie the board down. I put M3 plastic screws through the bottom mounting the holding brackets, mounted the flight controller then tightened it down with plastic screws.

The plywood mounted at the bottom of the frame, so i was able to mount power distribution board on the first level, without this there would be no space for it.

Used some foam to tie down the GPS, bluetooth and the Rx/Tx glued the foam on to the frame, then put some glue on some of the chips and glued that to the foam, i am not an electrician and don´t really know about these kind of things but i avoided glueing the whole printboard, i was a bit worried that it could end up shorting the GPS, so for me glueing a few of the chips was enough to hold it in place.

The LED mounted around the frame, it actulally closes the gap so the wires under the frame are not visable, got the front and back with LEDs for directional purposes with red and blue LED from HK

The original product was a 12 dollar gimbal off HK, http://www.hobbyking.com/hobbyking/store/uh_viewItem.aspidProduct=36495, was a pain putting together the mounting holes were small and didn´t fit their counter parts, so had to pry the holes with a screwdriver.

Was a nuisance to put together, the mounting holes were small so they had to be remade using a screwdriver and pryed the holes a bit larger, then had to use a dab of superglue to make the whole thing stay stabil. After a while had to get rid of the top section of the camera holder as it restricted movement on the roll axis, the original gimbal could not pitch very much so i decided to reconstruct the gimbal, brought a park servo and mounted and glued it with the top section, used a set of pliers to cut a bit of the back section off, this could have been avoided if i had mounted the gimbal further back as there is a lot of space by the mount point, i further revised it (not shown in the picture) by stabilisig the back with a round gimbal mount. It is glued to the gimbal frame and the mount bracket is on the back section acting as a bearing.Look further done for more pictures of the bearing.

A generel weak spot on the Hobbyking X650F is the motor mount nut top right hand corner, it tends to give way, when the quad crashes thus eating its way into the carbon fiber, this is probably a good thing in some sense, if it didn´t give way, then could probably crack the frame, will try to place a washer between the frame and nut so at least it doesn´t wear out the carbon fiber. (tells you what a shitty pilot i am).


I cut the signal wire and mounted an extenseion through the tube, since i had shorted my ESC so they don´t supply power that i could use to power the MultiiWii pro board, i instead used a UBEC for that bit, the blue and the black cabel is the LED that i also extended and fed through the tube.

The ESC are fed through the holes at the bottom of the motor mount, then connected to the motor.

All the cables are then pushed into the space and zip tied together with the ESC at the bottom giving you a nice finish.

Mounting the Gimbal was done by using some foam glued to the X650F frame drilled two extra holes on the Gimbal frame and fed two Zip ties on either side, tightened them just enough so that i can remove it when not needing to use the Gimbal, so kind of slides on and off, it does tend to fall off during crashes but i will think of someway to take care of that.

As i mentioned earlier i used the round gimbal mount to act as a bearing on the back section of the Gimbal, this helps when carrying a camera and stabilizes the back gimbal in a neutral position. Have not yet tested its performance, but will probably be useless, but what the heck, it´s fun to make.