Sunday, May 19, 2013

Quadcopter Build : Power harness & frame

After a long wait another large box showed up from HobbyKing, It was the main one I was waiting for. It had silicon wire, connectors, heat shrink, Transmitter, Servo leads, KK2 board and other bits to make up to the full weight for shipping.  Luck would have it that it showed up on a Friday, which meant I could get stuck into it that night.

During the week I purchased some organiser trays to hold all the bit that are starting to gather during the Quad build. Need to keep them separated from the other work going on in the garage.

Right time to kick this next part of the build off... First task was to get a work space, very limited in the garage at the moment ... well actually always. So the portable spray table was used. I placed my old work desk top on the table (Actually just a door), worked perfectly. I then laid out the parts and tools required.  

I set the iPad but to capture some time lapsed footage of the evenings progress, unfortunately i forgot to full charge and only got half the build ...Doh.

 All the new bits laid out and getting sorted.

First step mount the motors, that required the mount plates screwed on and then zip tied to the booms, I realised that I didn't have any thread-lock  so only used 2 zip-ties to hold them in place until I can get some thread-lock and apply to all the mount screws.

With four zip-ties holding them in-place the motors are very securely attached to the booms.

I was getting a sore back working on such a low work desk ... so a little improvisation was required. I used a some speaker stands and my hotrod seat from the Ratty-T build as a seat ... work perfectly for this old man.

I now need to work out where the ESC were going to ne mounted and work out the wire lengths I needed.

Wires cut and the end trimmed ready for pre-soldering.

Using my new supa-dupa soldering iron I made quick work of soldering on the 3.5mm bullet connectors. After waiting all this time for the shipment I realised that I did not order enough ... grrr. That changed how I wanted to wire up the power harness. But I will change it one I get some more and have a few flight under my belt.

One end fully complete, only 11 more to do.

All wire now have 3.5 female bullet ends to connect to the motors.

The next job was to add bullet connectors to both the ESC and the other end of the wires. I wanted the ability tio easily remove and swap items in the quad, however since I didn't order enough I decided to splice the wires and when I get more connectors I can change that later.

Splicing and soldering, before heat shrinking.

The ESC also required connectors soldered on the power leads to connect to the power distribution board. Below is the finished power harness, and the test fitting in the frame.

A quick comparison to the SM450 sized frame.

The next build task was to create plate to cover the power harness and mount the receiver and kk2 board. Using balsa wood I made two rails 12mm wide and 8mm high.

I then cut the top plate out of balsa wood and covered the full length of the frame. The width was correct as the frame width was based on 100mm wide ply and balsa.

The rails were then CA glued to the top plate, they were shorter to allow a gap either end to allow the routing of the power harness to the motors.

The top plate sitting on the frame, you can see the small gap either end to allow for the power wires.

 Next I zip-tied the power harness in to the frame, I then did a lot of test fits of the top plate to see where I needed to add extra strength to the balsa-wood.

On the underside and center I added another rail so that rested on the frames main center cross member and cut notches to allow for the power wires that went over the top. I also added in some popsicle sticks at either end and also in the middle for where the nylon screws would be if use those to mount the KK2 board. 

 On the top side I added popsicle stick on the edges where I planned to have zip-ties holding the top plate on. I did not want the balsa-wood crushed. A couple of holes were cut for the ESC controller leads.

Getting ready to zip-tie don the top plate.

One end zip-tied down and you can see the power leads out the gap and the double thin zip-ties used to hold the top plate in place.

Connected up the power leads to the motors and zip-tied them in-place to give a nice tidy look.

A mock up with the KK2 and receiver sitting approximately where they will be mounted. Very happy so  far with the nice tidy layout and having most of the wire harness hidden.

During the weekend I also got Phoenix4Rc and the TX9 playing together to do some flight simulator practice. Which only proved that Im a crap flyer and need a lot of practice.

 One of the other items I got from Hobbyking was the ATMEL programmer that is used to update firmware. The KK2 board was shipped with version 1.2 and the latest and recommended version is 1.5. After watching a few good youtube videos It was a simple task to up date the boards firmware to 1.5.

While it was powered on it gave me a change to look at the menu structure and settings.

Here is the time lapse video that didn't quite work out ..


I am now waiting on other packages to arrive before the build can continue, the main one is the batteries.