Wednesday, May 22, 2013

Almost Done - Mounting the Remaining Stuff

Just a bit of recap. 

I have tested all the equipment as it arrived and reordered a few items.

I built a static thrust test bench to use in the testing process, which is what prompted me to order new, higher capacity ESCs.

I had to chop off the shafts on the NTM 28-26 1200KV motors because I somehow managed to order the "normal" shaft version, rather than the "short shaft" version from Hobby King.

I mounted the motors on the frame arms and connected the arms to the body and mounted the ESCs to the arms and wired them by soldering on connectors to the motor side and direct soldering the power leads to the power distribution board.

So, we have motors and ESCs and wires and all that good stuff...   now we need a brain.  Well, I could probably use a new one too, but I meant for the Quad.  So it is time to mount the KK2 board.

The KK2 Flight Control Board, from Hobby King can be mounted a number of different ways. I chose to mount it on standoff because I just like the way it looks.  It is important that when you mount the board on standoffs that all the hardware be non-conductive.  So that is why I ordered nylon standoffs and screws when I ordered the other components.

I mounted the KK2 board on the top body board of the SK 450 frame.  That board is mounted to the board below it (the power distribution board) with standoffs also.  Unfortunately I followed what I thought was the obvious mounting sequence.  First mount the top body board, then the standoffs for the KK2 board and then mount the KK2 board on the standoff with the nylon screws.

Unfortunately that doesn't work very well since once you mount the top body board you can't easily attach the bottom standoff screws and even more critical - if you could you wouldn't be able to position the standoffs to match up with the KK2 holes.

So, the modified process was: remove the top body board.  Then mount the KK2 board to the nylon standoffs.  Then, and only then, mount the nylon standoff to the top board. Then it is easy to remount the top body board to the rest of the frame.  Easy Peasy, as our British friends say.

All that is left to do is run the servo wires from the ESC up to the KK2 board and plug them in.  Be sure, when you plug them in use the following order: Front Left motor to plug #1, Right Front to #2, Right Rear motor to #3 and Left Rear Motor to #4.  When plugging the servos leads to the KK2 Board the Ground/Negative/Black or Dark Brown wire should be toward the edge of the board. The Signal wire should be nearest the Display.

You next need to wire up the receiver. I am using an OrangeRX 610 receiver from Hobby King.  I used five 10cm male-to-male servo extensions to connect the receiver to the KK2 Board.  The same orientation applies here - Ground wire toward the nearest outside edge of the KK2 Board and the Signal wire closest to the Display.

When you get all that done, it should look something like this:


Here are a few more photos of the completed Quadcopter:





You will notice I added a battery strap and the battery, attached to the bottom body board.  I had hoped that one battery strap would be sufficient.  It turns our I actually needed two, on going the length of the battery and a second going across the middle.  With both of them, the battery is very secure.

So the Quadcopter construction is complete. There are still a number of setup and configuration steps needed but everything is pretty much together.  When I started the project I had estimated that the entire Quadcopter would have a flying weight (called AUW or All Up Weight) of 1,000 grams.
So, it is time for a weigh-in to see how close my estimate actually was.
Drum roll.......

Ta Da.....




And yes, the box was removed from the weight using the "Tare" function of the scale.

Next Post: Setup and Configuration


2 comments:

Anonymous said...

What size and pitch props are you using

Rick said...

Sorry for the delay in responding, the props are 8X4.5 SF from Hobby King