Always Wear Protection... And Other Stuff

Once I was almost finished building my Quad I started to think about all the dangers that might happen to it.  Like a scared parent I started imagining the dangers to my sweet little Quad that might be lurking just outside the door.  Um...  the most likely danger (other than being carried off by a big bird) is a crash.  The most likely cause of that crash would likely be Me.  Especially while I am trying to tune it and also learning to fly.

I was resigned to the fact my little guy was likely to crash and at my own hand.  Toward that end I had previously purchased some extra parts, just in case I "happened" to break them.  So, I had extra props and frame arms.  I thought about getting an extra motor and ESC but I assumed they would likely survive a crash.  So I though I was covered....  or was I? 

More specifically, was the most critical component on the Quad, the KK2 board safe from a crash?
I didn't have a spare and they are sometimes hard to get, due to backorders. Also, assuming they were in stock, I would have several weeks to wait until a new one was delivered.

So, the solution seemed to be.... Protection !!!   You should always wear...  I mean, "have" protection.
That was the thing I needed, some form of protection for the KK2.  If the Quad crashed on it's side or the bottom, the KK2 was pretty well protected, but if the Quad landed on it's top, the KK2 was a goner, most likely.

So, the solution was some kind of protection over the KK2 board, but what kind?  I have seen lots of people using Tupperware-like plastic bowls to cover their boards, but that limits access to the buttons on the KK2.  And since the mostly like time for a crash was during testing and turning, and me being lazy, I would likely leave the Tupperware cover off while testing.  Not a good thing.

Here were the criteria I came up with for protection for the KK2.

• The protection should always remain in place
• The protection should provide easy access to the buttons on the KK2
• The protection should allow the LCD screen and LED lights to be visible at all time
• The protection should absorb some of the shock of a top crash, not just pass it along to the Quad
• The protection should not weigh much or add a lot of wind resistance

Based on these criteria I came up with a very simple and cheap solution.  A kind of helmet to protect the KK2.  But the helmet that was completely open, made out of some kind of bars or rods.

When visiting my local hobby store I happened to see a cup by the cash register filled with plastic rods that were about 2 feet long and about an 1/8 inch in diameter.  They were flexible but strong enough to bend without kinking.  I asked the clerk what they were and how much they cost.  He said they were antenna tubes and they were $1 each.  Perfect...  I bought four of them.

In the photo below you can see my KK2 protective "helmet".

I doubled up two rods, taped their ends together and used zip ties to connect them to the frame arms, between the body and the ESCs. 

They had a nice bend and fit pretty well. 

Where the two rod components crossed above the KK2 I used two crossed zip ties to keep them in place. 

The whole thing weighs next to nothing, provides good protection, absorbs the shock of a crash and adds very little wind resistance.

Mission accomplished....

Next post: Putting a camera on the Quad...  Jello anyone???

Final Setups Before First Flight

Ok, we are almost ready to fly!!!   But first, we need to perform a number of setup activities to make sure our first flight is as successful as possible.

Assuming you have bound your receiver to your transmitter and have all the Quad components mounted and wired (in previous posts), it is time to do the initial configuration and setup of the KK2 board and it communication with your transmitter (via your receiver).

Here is a simple checklist of the various actions that need to be accomplished.  The order given is the order I used, yours may vary.

All of the following MUST BE DONE WITH PROPS OFF MOTORS

• Turn on receiver (make sure throttle is at zero) and then plug in battery leads to Quad
• Check that KK2 Board lights up and says "SAFE" at top
• Go to "Load Motor Layout" and load Quadcopter X (for X configuration)
• Go to "Receiver Test" and make sure all sticks are moving in correct direction (reverse if not)
• Use Sub-Trims in transmitter to set stick values to zero, as represented on Receiver Test screen
• Unplug battery and turn off transmitter
• Now we need to calibrate the ESCs - there is no longer a menu item on the KK2 Board for this
• It is easier if you get someone to help with this - BE SURE PROPS ARE OFF Motors
• Turn on transmitter then move throttle to max
• While holding down buttons 1 and 4 of KK2 have helper plug in battery
• After you hear beeps, reduce throttle to zero and listen for additional beeps
• Release buttons 1 and 4 and unplug battery and turn off transmitter
• Turn on transmitter (throttle at zero) and plug in battery
• KK2 should be in SAFE mode
• Move throttle/rudder stick on transmitter to bottom right and hold until KK2 beeps "ARMED"
• Slowly increase throttles (PROPS MUST BE OFF) and make sure each motor is turning in correct direction (refer to View Motor Layout screen in KK2 Menu if unsure of correct direction). Swap any two of the three motor leads if motor is turning in the wrong direction
• Make sure each motor starts turning at the same time as the others - if not see video
• Move throttle/rudder to bottom left and hold until KK2 beeps SAFE
• Place Quad on flat, level surface (use bubble level to confirm) and perform ACC Calibration in KK2
• Disconnect Battery and turn off transmitter.
• If all these steps were successful your KK2 board should be OK and is ready to be flashed with upgraded firmware - you should flash first because if board is defective return will be difficult if board has been flashed.

He is a great video from Frank that shows the above steps.  Frank used a slightly older version of the KK2 firmware so some of the menu text will be slightly different than yours.

Once you are sure you have a good KK2 board you will need to upgrade the firmware of the board, this is sometimes called "Flashing" the firmware.  The KK2 boards are delivered with version 1.2 firmware which does not have a functioning Self Level feature.  You don't want to fly with this version.  So you will need to Flash the new version (v1.6).

You will need the USBasp AVR Programmer for Atmel from Hobby King.  I ordered this when I placed my original parts order.

Once you have successfully updated the firmware you need to redo the previous setup, as the firmware upgrade wipes out all previous setting THIS  IS IMPORTANT - IF YOU DON'T GO THRU THE SETUP STEPS AFTER FLASHING, YOU WILL CRASH

Here is another great video from eluminerRC on flashing the KK2 board.  He is upgrading to version 1.5, which was the most current when he created his video, but version 1.6 is now available and should be used instead.

Before you perform the upgrade you must remove all the connections to the KK2 from the receiver and the ESCs (leave the beeper connected) - be sure to label them with a little piece of tape to make reconnection easier.  Failure to do this could damage the KK2 Board.

When the upgrade is successful and you have reattached all the connections from the KK2 to the receiver and the ESCs, you will need to redo the steps at the top of this post.  The upgrade has wiped out all previous entries to the KK2 so you will likely crash, since you will have an incorrect motor layout and other incorrect values. if you don't reset them.

Once you have completed all the above steps you will be ready to fly.

Next Post: Gonna Fly Now... 

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

Flashing and Other Fun Stuff

Not too much excitement right now...

At this point in time the Quad build has slowed to a crawl due to the ESC's.  After a lot of soul searching I decided it was best to bite the bullet and order four new Plush 30 Amp ESCs.  Unfortunately they were backordered when I ordered them several days ago and they are still backordered.  I had hoped I would get lucky and they would get them back in inventory right away but that doesn't seem meant to be.  I can find them at a few other vendors, but they are almost twice the price and since I have to buy four of them, and since I am basically a cheapskate, I will have to be patient and wait.

While I am waiting I have been making a little progress.  Yesteday I did some initial testing of the KK2 Flight Controller Board.  I powered it up using one of the ESCs I had.  I connected it to the receiver I plan to use, which is a Hobby King Orange RX 610 receiver.  The 610 receiver is a Spektrum DSM2 compatible receiver.  I have been using one of these receivers very successfully with my Dynam Hawk Sky RC Plane.

I bound the receiver to my Spektrum DX6I transmitter and connected a series of five male-to-male servo lead between the receiver and the KK2 board.  The KK2 board worked right off the bat with the receiver and I was able to run through a number of tests of the KK2 board as well as set up the transmitter for the Quad.  I had planned to wait until I had flown the Quad successfully before I flashed the KK2 board firmware to version 1.5.  But, being the impatient guy that I am, I decided to try a KK2 Flashdance.

Flashing (or updating the firmware on the KK2 board) requires a few things.  First you need a USBAsp AVR Programming device (a little circuit board and cable that provides the connection between the KK2 board and a computer).  You also need drivers for the Programming device as well as flashtool software.  Once you have all of that connected and working you need the actual new version of the firmware, developed by Kaptain Kuk, the creator of the KK (Kaptain Kuk, get it) 2 board.

I found a great video that does a wonderful job of providing a detailed video explaination of how to perform the flashing of the KK2 board.
Here it is (thanks to eluminerRC):