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???

Gonna Fly Now... Maiden Flight of my SK450 Quadcopter

The day has finally arrived.  I have been waiting a long time for this moment.  Time to turn on the transmitter, plug in the battery and let my Quad take wings....   um... props  and fly.
I have tested, retested and tested again every possible thing I could test, check and confirm but now is the moment of truth.

The truth is, I think I am a little scared...  Scared for several reasons.  Will it actually fly?  Did I make some fatal mistake in the construction?  Was I wrong about the parts?  Would there be enough thrust to lift off?  Would there be too much thrust and the dang Quad will rocket off into the sky never to be seen again?  Will I be able to control it, since I have absolutely no Quad flying experience and very little helicopter or even RC plane experience?  All legitimate reasons to we a little nervous - and nervous I was.

So, time to head out to the back yard and give it a shot.  My other concern was my backyard has a bunch of bushes and buildings and trees so the only clear area I have is about 20 feet wide and about 10 feet deep.  Kind of tight for someone with no Quad flying experience.  The only good thing is the wind is very light.

Without further ado, here is the video of the maiden flight of my Quadcopter:

I do have to admit, this video was not the absolute first flight.  I did a number of short hops to check the configuration settings.  What I found out pretty quickly is that I needed to turn on Self Leveling or the Quads days were numbered.  So this video shows the first flight with the Self Leveling turned on.
My total flying time for all the hops was about 10 minutes, which I thought was great.  I had estimated my total flight time on a battery would only be about 6 minutes.

I was ecstatic, the dang thing flew and it actually flew pretty well, once I turned on Self Level.

For those of you that might be interested, my initial flights were using the default tuning values for the KK2 board under firmware version 1.5.

Roll & Pitch: P Gain=50 P Limit=100; I Gain=25 and I Limit=20
Yaw: P Gain=50 P Limit=20; I Gain=50 and I Limit=10
Self Level Settings: P Gain=100 P Limit=20 with ACC Trim Roll and Pitch both at 0

I had a very hard time controlling the Quad with Self Level turned off, it was just all over the place.  I suspect someone with good piloting skills would have had no trouble controlling it.  But with my "limited" Quad skills and my nervousness, I switched on the Self Level and was amazed how much easier it was to control.  I still had to make a lot of corrections with the sticks, but I could keep it in the air and in the same general location pretty easily.

All in all it was a very successful maiden flight.  I confirmed I had the right parts, put together properly so that even with my limited skills, I was able to fly the Quad. 

Next Post: Always Wear Protection (and other stuff).

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

"Arming" the Quadcopter

Now that the motors are mounted on the SK450 Quad Frame arms it is time to connect the arms to the body and also mount the ESCs in their final resting place.

As mentioned in a previous post, I purchased an optional Power Distribution Board (PDB) from Hobby King that replaces the middle support board in the body of the quad.  The Distribution Board provides an easy to connect mounting point for the main power lead (which connects to the battery) and the positive (red) and negative (black) power leads from each of the ESCs.  The battery lead is soldered on the bottom of the Power Distribution Board and the ESC leads solder on to the top.
Each of the four arms attach to the Power Distribution Board with four screws.

Once the four arms are attached to the top Power Distribution Board (PDB), I then mounted 4 nylon spacers to the top of the PDB which will be used to mount the top SK450 body board. 

With the basic structure of the Quad set, it is time to mount the ESCs to each of the four arms.  I decided to mount the ESCs on the top of the arms.  They could also have been mounted on the bottom of the arm, but I assumed they would be better protected on the top.

 

 With the ESC safely "zip tied" to the arm the power wires then need to be soldered to the + and - pads on the PDB. Because I chose to mount the ESCs on the top of the arms, the wires need to be reversed to connect to the appropriate pad.

I used a Kester Flux Pen to put some liquid flux on each of the pads before I tinned the pad, prior to solder the ESC wires.

Once the ESC connections were made I then mounted the bottom body board below the PDB.  Each of the arms has a built in spacer to provide the spacing between the PDB and the bottom board. The bottom board is where the battery gets attached.  I mounted bottom board with two screws (with the ever popular threadlock) on the bottom of each arm.

Once again I am including two fantastic videos from eluminerRC - he mounts his ESC with connectors on the power leads, but the process is similar:

Now we are making some progress and this mass of parts is starting to finally look like a Quadcopter. All that is left to do is mount the KK2 board and wire it to the ESCs and receiver.


Next Post: Mounting the KK2 Board

Let the Games Begin... Starting Actual Contruction of the Quadcopter

The moment has arrived.  All the ordering and waiting, and testing and ordering and waiting and more testing is finally behind me.  Now is the time to start the actual construction of the Quad.

First step: Mounting the motors

The for NTM 28-26 1200kv motors had been tested (previous post).  I also needed to cut the existing prop shaft that protrudes from the bottom of each motor (another previous post) so that the motor would fit onto the frame.  With these preparation tasks completed I am now ready to perform the final preparation step.  Each motor requires a prop adaptor be permanently mounted onto the top of the motor.  You can see the machine prop adapters sitting below the 3 motor in the photo (above).  These adaptors are mounted using three tiny metric screws.  A 2.0mm allen head driver is required to turn these tiny screws.

It is a little hard to see in the photo above, but this screw has a small drop of medium strength (blue colored) threadlock liquid.  Each screw, in the entire Quad, that screws into metal must have a drop of threadlock before screwing it in.  The threadlock (one brand is called "LockTite") keeps the screw from loosening due to vibration but will allow the screw to be removed if needed later.  Don't forget to do this important step.  Do not use the threadlock on any screws that screw into plastic.

Above are three of the motors with the prop adapters attached and ready to mount on the Quad arms.

The motors mount with small screws, that came with the prop adaptor kit for the motor, to a motor mounting ring, which is supplied with the frame.  The ring then mounts onto the actual frame arm.

While it is difficult to see in the photo above, the inner set of four holes are not exactly the same.  Two of the center mounting holes are slightly further away from the larger center hole, than the other two mounting holes.  The motors have a similar arrangement, so it is important to rotate the ring until the holes match the holes in the motor exactly.

Put in the four screw (with a drop of threadlock on each) and tighten in a crossing pattern.

Below is a picture of of a motor with the ring attached.

Next step is to mount the motor and ring onto the actual Quad arm.  The motor needs to be positioned so the holes line up and the wires are pointed in the direction of the center of the Quad.  Again each screw needs a drop of threadlock.

The final step in the motor mounting is to screw the landing gear leg onto the arm, below the motor.  The landing gear is mounted with two screws with a drop of threadlock on each screw.

Here is the green one.  I am not sure if I mentioned earlier that my Quad will have two white arms and two green arms.  This is to help determining orientation in the air.  The green are will be the front of the Quadcopter.  I order the green arms separately, they didn't come with the frame kit.

I had to repeat the motor mounting steps four times, one for each arm.  I took me longer to type all of this than it actually took to perform the steps.

Here is a short Youtube video from eluminerRC showing the steps:

Next Post: Mounting the arms to the body and mounting the ESCs to the arms.

Whoo Hooo !!! The Parts are Finally All Here

The mailman finally delivered the last of the parts (the replacement Plush 30 ESCs) I was waiting for.  It took the expected 2 weeks to arrive, although it always seems a lot longer.

Before I began the contruction of the Quad I wanted to be sure the new ESCs were all functioning properly.  The best way to do that was to use the Thrust Test Bench (see previous posts).
I mounted each of the ESCs and ran up the throttle to make sure each ESC would work and give me the full speed control range.  I also checked to make sure that the ESC didn't get warm.
One thing I confirmed was that my decision to use a terminal strip on the Thrust Bench was a great idea.  I was able to connect up each of the ESCs in seconds and didn't have to solder on any connectors to do the test. Just takes a small screwdriver.  Great time saver.  I purchased the terminal strips at Radio Shack.

Here is a picture of the terminal strip with an ESC mounted:

After I determined the ESC was functioning properly, while still connected to the Test Bench, I disconnected the servo lead from the Throttle control (servo tester) and plugged it into the Turnigy ESC programmer.  I then configured the ESC to the appropriate settings for multicopter use.

For use in a multicopter you want to change the battery type to Ni-XX.  This may seem strange, since you will be using a LiPo, but by changing the battery type to NI-XX you turn off the Low Voltage Cutoff (LVC) function.  If you were using the ESC in an airplane you would want the LVC on to protect you from over discharging your battery - but in a multicopter, if the LVC kicks in your Quad will crash.  So it is a trade off between killing your battery or your Quad.

In the case of the Plush series of ESC, for multicopter use, you also want to set the Timing Mode setting to High (the default is low).  This setting allows the ESC to respond faster to speed change requests from the flight control board.  Makes for a more responsive flight.

Here is a shot of the ESC programmer with the final settings:

Once I had all the ESCs tested and configured it was time to solder on some connectors.
The Plush ESCs come with no 3.5mm bullet connectors so you need to order those, which I did.
Since I will be connecting the "power side" red and black wires directly to the power distribution board by soldering, I didn't don't need connectors for that end.  But I do need 3 female 3.5mm bullet connectors for the "motor side" wires.  You also need some small heat shrink tube to cover the connector once the connector is soldered on.

Here are a few photos of that process - I used my new Weller WES51 Soldering Station:

First you cut the wires to the appropriate length and strip off some of the insulation (I use wirestrippers for that).

 

 

Then tin the exposed wire with solder

 

solder on the bullet connectors (tin the connectors first)

 

Put on the heat shrink tubing and heat it to shrink (I used a heat gun)

The four Plush 30 ESCs ready for installation.

Next post:  Mounting the motors.

Smokin'... Soldering on the battery connector

Well, I am finally starting the initial construction on the Quad.  While I don't plan to do too much until the ESCs finally arrive in a week or so, I did want to start the process.

One of the extra items I ordered for my Quad is a power distribution board.   This board replaces one of the boards provided with the Hobby King SK450 Quad Frame.  Having the power distribution board allows me to make all my solder connections for the power to the ESCs to the board, rather than having to kudge up some kind of spyder of wires.  Each of the four ESCs have a positive (red) and negative (black) power lead.  Each of these leads need to ultimately be connected to the LiPo battery.  To connect the four positive wires from the ESCs and the positive wire from the battery connector would normally require a messy soldering job which results in two big wads of wires, soldered together.  The power distribution boards makes connecting the power leads, easy, neat and structually strong.

Rather than making my own videos, I have been using the wonderful videos from eluminerRC on Youtube.  He has created a fantastic series of videos that exactly match the Quad I am building.
There are a couple of things he is doing differently than I am.  He rewired his ESCs with connectors on both ends - I won't be doing that.  He also is using black wires for all his power and motor connections - I won't be doing that either, since that makes it very easy to accidently reverse the polarity of one of the power connections - which could be dangerous.
I am also using different battery connectors - he is using a Deans connector, I am using a 4mm banana connector.

Here are a few pictures of my finished product:

You might notice in the first photo, my new soldering station.  I have been using the same cheapie Radio Shack soldering iron for the last 35 years.  I figured it was time for an upgrade.  So I found a great deal on Amazon.Com for a Weller WES51 analog soldering station.  It has a temperature controlled tip and heats up in under a minute from a cold start.

As soon as the ESC's arrive and have been tested, I will be soldering their power leads on to the reverse side of the power distribution board.  Once that is completed, I will be able to assemble the entire Quad, which hopefully will go together very quickly.

I still need to figure out some kind of a protective cover for my KK2 board...   Hmmm maybe the case bulk blank CD's come in will work.  They are made of tough, but pliable plastic and are semi transparent and have a easy to use locking mechanism.  I will be looking into that.

Chop... Chop... Chop... How to trim an RC Motor Shaft

Latest update...
I received my order from Hobby King for green frame arms and green props, to help with visual orientation when I am flying.  I should be able to spot the bright green front of the Quad.  At least I hope so.
Also, I just received a really nice Multicopter simulator called AeroSim RC.  It seems to be highly rated by multicopter fliers.  While it doesn't have the high res graphics of many current flight simulators it has a significant number of different types of multicopters (Quads, TRi'd Octo, Hex, etc) as well as a few helicopters and planes.  In addition to providing a good simulator it also has a training section.  It walks you through several different training scenarios to improve your flying.  I have tried a few so far and found it very useful.

Here is a video the provides some info on the product from an recent customer:

Now to the chopping...
When I ordered the four motors for my Quad from Hobby King, I "planned" to order the "short shaft" version of the NTM 28-16 1200Kv motors.  What I received was the "normal shaft" version,  which has a 1 inch 3mm shaft sticking out the bottom of the motor.  I don't need that shaft, since I will be using a prop adapter screwed to the other end of the motor.  And what is more important, the normal shaft won't allow me to be able to mount the motors in the frames, since they will hit the landing gear.  So, the only solution, short of sending them back to Hobby King, is shortening the shafts.

I used a piece of aluminum plate I purchased at a local hardware store, drilled a hole in it just big enough to push the shaft through.  The plates supports the shaft, acts as a barrier to metal filings and also conducts some of the heat away from the motor.  I used a Dremel tool with a large cutoff wheel to do the cutting.  It went very well and only took about 20 seconds per motor.  I wrapped the motors in aluminum foil during the cutting to keep metal filing from the cutting from getting into the motors and their super strong magnets.

Here is a video I found on YouTube of someone using a similar process to trim their motor shaft.  The major differences, I needed to trim a lot more off so the aluminum plate I used was only 1/16 inch thick.  Also, I wrapped the motor with foil before I started cutting, to protect the motor from the steel "saw dust" generated by the cutoff wheel.

Here is a link to the video LINK


Here is a few pictures from my chopping:

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):

Testing.... Testing...

Well, once again this post is not the post promised in the last post...  I think it is even better!!!

Today was testing day.  I was able to test all my motors, including Thrust tests.  I also did a preliminary test of the KK2 board.

Before I could do any testing I needed to make some cables for the Thrust Test Bench so that I could connect the ESC to the motor and the battery to the Test Bench.  I won't bore you with the details, other than, while I really like using the 4mm polarized banana plugs for connecting batteries, soldering them on is kind of frustrating.  The soldering part is easy, the problem is getting the metal part of the connector to snap into the plastic part of the connector.  If you get any solder on the outside of the metal barrel you will have a problem getting it back in the plastic connector shield.  Needless to say, I always manage to get solder on the outside of the connector.  So, then I have to get out a little file and try and remove the excess solder.  Not a lot of fun.

Anyway, I got a battery connector cable made for the Test Bench and also made up three wires with 3.5mm bullet connectors on one end so I could connect from my terminal strip to the motor.
This part was pretty easy, just solder on the connectors and put a piece of heat shrink over the exposed connector.  Easy Peasy as our Aussie friends say...

Below you will see a short video of a motor test, including Thrust measurements.  There is good news and bad news...  The good news - all the motors worked great.  The bad news...  They actually worked better than I had planned and gave me more thrust than estimated via eCalc.  I had expected about 600 grams of thrust at about 10 amps current draw.  I got that, but at about 70% throttle.  At full throttle, with a newly charged 3S battery I got 800 grams of thrust at 16 amps of current draw.
In subsequent tests I got about 760 grams at 15 amps since the battery was not fully charged.
This was bad news because the Electronic Speed Controls (ESCs) that I bought are rated at 18 amps and I am getting close to that rating at 16 amps.  I was hoping to have only about 10 amps at full throttle, which would have given my sufficient "head room" with an 18 amp ESC.  It's even "badder" news because currently Hobby King is out of bigger ESCs.  I would like to return the three unopened ESC and exchange them for 30 amp ESCs of the same brand, but they are completely out of stock.
Not sure what I will do now...

Here is the video I promised:

 

 

Here is the eCalc simulation estimates:

The other testing I did was plugging in the KK2 Flight Control Board to make sure it at least powers up and the buttons and sensors work.  That test went very well.  The KK2 board powered up as expected and I was able to move through all the menus and perform some preliminary sensor tests and configuration loads.  So, it appears the KK2 board it functioning A-OK.

So, lots of good news today.  Unfortunately I need to decide to go with the ESC's I have or wait until they get more in stock and then wait the 2 or 3 weeks to receive them from China.
At this point I am not sure what I will do...

Next Post:  Check back and see  :-)

Whoo Hoo !!! The Parts Have Arrived !!!

This is going to be a very short post...

The Mail Lady ? ...  Post Woman...  ?  whatever, rang the bell this evening and had me sign for a package.  Straight from it's 3 week journey, my Hobby King order has arrived from HongKong.  Amazingly, the package sat in the HongKong Post Office for over a week after Hobby King shipped it.  It only took 2 days to get from HongKong to here via the USPS.

I have checked that everything is there and that nothing looks damaged.  The next step will be to test out each electrical/electronic component and make sure they all work.  Also, I plan to weigh each item so I can better estimate the exact All Up Weight (AUW), the entire weight of the Quad when it flies.
I have estimated from the manufacturers data that the Quad should weigh approx 1,000 grams.  When I actually weigh each item I will have a better idea.  I will also weigh the completed Quad.

Hopefully tomorrow I will make a short video showing all the components spread out on a table so you can see exactly what I received.

That's all for now...

Next Post:  Look at the Goodies

Building the Thrust Test Bench - Part 1

The good news is I finally got some notification from Hobby King that my main order of parts for my Quadcopter has finally made it through the HongKong post office.  The tracking number finally shows up on the USPS website (the order is coming Air Parcel Post and will be delivered in the US by the US Post Office). Still now delivery date information.  I am guessing a couple of weeks...

While I am waiting for all the goodies to arrive I thought I would put together a simple structure to allow me to test my motors, ESC and Props when they finally arrive.  I wanted to test them for two reasons.  I wanted to be sure they weren't defective and even more importantly, I wanted to be sure that I ordered the correct items.  My Quad should end up weighing about 1,000 grams and I need about 2,000 grams of thrust for successful flight.  So, I need to be able to measure the thrust put out by my motor/prop combination.  That is why I needed to build the Test Bench...  Well, also it is because I am a geek and need to test stuff.

So, being cheap, I decided to use what I had laying around in the garage for the contruction.  I used scrap lumber and hardware.  I had previously purchased a nice scale for Ebay sales so I have that available.

The video below gives a quick description of the completed Thrust Test Bench structure.  Later I need to add a teminal strip, a wattmeter, throttle control and battery.  But for right now I wanted to show you how I built the structure.

This isn't a "Step-by-Step" how to video because I think you can figure out how I build it from the info in the video.  Not too exciting watching me cut lumber and screw in screws.

I still need to put a small spacer where the horizontal piece meets the scale. That will level the motor structure to the scale.  I will also need to place some weight on the base to keep the test bench from sliding on the table when in use.

Next Post: Quadcopter info

Oops... this isn't Building the Thrust Test Bench

Sorry everyone, I decided to slip in this post today since I have to go to the hardware store and buy a hinge before I can build the Thrust Test Bench.

Just a quick little update on where I am...

I had ordered all the parts, well, not quite true.  I forgot to order an extra set of arms for the Quad frame in bright green color and also bright green props.  Both are for the front of the Quad to help in orientation.  The normal arms are white and the props black.

Here is what the replacement arms look like:

The props are the same color, so I should be able to tell the front from the back (hopefully) a little better.
I placed the order this morning from HobbyKing in HongKong and this order is coming International Air Mail rather than Air Parcel Post like my big order.  We'll see which arrives first.

I also noticed something while reviewing my original order...  It appears I might have ordered the wrong motors - well kind of wrong.  They appear to be sending the same motor but not the "short shaft" version.  The motor I wanted basically has no prop shaft sticking out of the motor.  You have to screw on a prop adapter to the motor bell housing and the prop goes on that.  The motor it appears they are sending (can't tell for sure) has a shaft, which will be in the way.  So, if I do get the "wrong" motor I will need to cut off the shaft with my Dremel tool.  I will need to come up with a good way to make sure none of the metal "saw dust" from the cutting gets into the motors.  Remember the motor are stuffed with powerful magnets so any metal filings will get pulled into the motor by the magnets.
My plan is to tape up the openings and then wrap the entire motor in aluminum foil before cutting.
Hopefully I will receive the correct motor, but just in case, I will be ready.

I promise the next post will be: Building the Thrust Test Bench

Designing a Thrust Test Bench

One of my "Buyer Remorse" concerns is that the ESCs I ordered (Turnigy Plush 18A) won't have enough capacity for the combination of motor (NTM 28-26 1200Kv) and prop (8X4.5) that I also ordered.
I have searched the Internet for others using similar configurations but found in almost all cases they used a larger ESC (usually 30A).  When checking the specs provided with the motor it would appear that the motor/prop combo will draw no more than 10 amps at full throttle, so my 18A ESC should be plenty big enough...  or will it???

So, the only way to know for sure, short of building the Quad and seeing if it fails, is to test the components and develop some data.  To do that the motor has to be running with the prop on.  You also need some way of determining how much current the ESC is being asked to control.  In addition, it would be nice to measure the thrust provided by the motor/prop combo to see if it (with it other three brother motors) will have enough thrust to fly the Quad.  Most Quad gurus say that you need twice as much thrust as the Quad weighs for successful flight.  Based on my calculation my Quad should weigh about 1,000 grams (about 2.2 lbs) AUW (All Up Weight, the weight of the craft with everything installed, including the battery).  So, if my Quad weighs 1,000 grams I would need thrust of about 2,000 grams for good flight.  Since I have four motors, each one needs to generate at least 500 grams of thrust.  Based on info I have found I am expecting my motors to generate about 700 grams - but until I can test it, I won't know for sure.

Based on the info above, my test bench needs to be able to meaure the following:

• Motor Thrust at full throttle
• Maximum Current consummed at full throttle
• Voltage at full throttle (to calculate watts)
• Temperature of ESC and Motor during and after run

The bench also need to be able to support the motor as it runs and allow unrestricted airflow both in front and in back of the prop as it runs.  In addition, the bench should allow easy connection of motor, ESC and battery.  The bench also needs some way to control the speed of the motor (a throttle).

I found a great video on YouTube from the boys at FliteTest. They build exactly the Thrust Test Bench I think I need.  I will be stealing their design, with a few changes of my own...

To build the Thrust Test Bench I will need the following:

• 2X2 and 2X4 lumber
• A Hinge
• Corner Brackets
• Scale that reads in grams
• Watt Meter
• Terminal Block (to make connecting the ESC easy)
• Battery Connector
• Motor wire connector (3) (short wires with 3.5mm barrel connectors for easy motor connection to Terminal Block
• Servo Tester (to act as throttle - won't need to use transmitter)

Good news is I have everything I need other than the Hinge.

Here is my CAD drawing:

Next Post: Building the Thrust Test Bench

The Wait... And Some Buyers Remorse?

So, the order, actually the orders, have been placed.  I ended up ordering most of the stuff from the HobbyKing HongKong site but since I forgot a few items I ordered them (the ESC Programmer and the Servo Tester) from HobbyKings US warehouse.  I also ordered the battery from there since the shipping was much cheaper.

I finally got a delivery confirmation date from the US warehouse, actually from the USPS website.  The US order should be delivered sometime next week (about 2 weeks total).
I have no idea when the HongKong order will arrive - their "estimate" was 7-45 days (quite a range...).  So, I just have to be patient (hard to do) and wait.

When I was doing my research on the components to order for the Quad, I read a bunch of reviews for each of the items.  A funny thing about human nature,  during the excitment of creating the order you tend to place more credence on the good reviews and kind of gloss over the negative ones.  BUT...  after you place the order all of a sudden the negative review seem to scream out at you!!!

So, the ESC I ordered "might be too small" and burst into flames on first use and the motors I ordered might be "dead on arrival" or have the "bearing go out after 5 seconds of flight"!!!

Also upon closer checking of my actual order it looks like I may be receiving a different version of the motors than I thought I was getting.  I planned to order the NTM 28-26 1200KV (short shaft version).  When I look at my order, it looks like I might be getting the long shaft version.  Not sure what if any issues that might cause.  I suspect I may have to cut off the extended shaft (which will be pointing at the ground), if it gets in the way.  The motor has a prop adapter that mounts on the opposite end to the motor, so the shaft isn't needed.  So, I guess I will find out when I open the box.

To be sure the ESC, Motor and Prop combination will operate within their expected range (i.e. the ESC won't burst into flames).  I will need to do some static testing when the parts arrive.  I need to be able to connect a battery to the ESC/Motor combination and run it up to full throttle with the prop on.
That is the only way to know if the ESC is big enough and if I measure the thrust at the same time I will know if the motor/prop combination will provide enough thrust to fly the Quad.

To perform the tests mentioned above I will need something to mount the components to to be able to run the motor and measure the wattage used and thrust produced.  A Thrust Test Bench.

Next post: Designing a Thrust Test Bench

Placing the Order

When I decided to get a Quadcopter, a series of questions came to mind that needed to be answered before I could move forward.

1. Build or Buy?
2. What Size (and how are Quadcopters "sized")?
3. How much to spend?
4. Most importantly, how to get funding thru the "Finance Committee (i.e. My Wife)?

The deal breaker question is always, Number 4...   Oh wait...  my birthday is coming soon..   Check - Number 4 is done.

Number 3 kind of is controlled by Number 4 so I am guessing if I keep it under $250 or so, I will be safe.

Now for the more interesting questions.  Buy or Build?
I previously have built my own home computers.  I really like doing that because you can choose the components you want, rather than having to get whatever the manufacturer chooses.  Building a Quad seemed a lot like building a PC.  Figure out what parts you want and place the order(s).  Test out the parts when they arrive.  Putting the parts together is pretty easy and doesn't require much skill.  The last step can be the hardest.  Getting it to work with a new operating system and software.

I really liked building the PCs and have been very successful so check off Number 1 - I am going to Build! A Quad seems a lot like a PC - just bolt the parts together and away you go (at least I hope that will be how it works).

Final question - Number 2 - What size (and how are Quads measured).  After a little research it seems that the distance between the motor shafts is a commonly used measure.  That measurement is usually in millimeters (mm).  So if a Quad is called a "450" is measures about 450mm between diagonal motor shafts.  In watching lots of Internet videos it seemed to me that the 350-450mm range looked to be the "right" size for me.  Smaller Quads are fast and nimble but have limited space for add-ons like cameras, etc.  Biggger and I would have storage problems.  So for me, the 350-450 range seemed perfect.

I decided to order my stuff from HobbyKing.  They seem to have the biggest selection and usually have stuff in stock (or get new stock very quickly).  Waiting for it to be delivered from China is a bummer (who likes to wait?) but my Birthday was over a month away so that helps convince Finance Committee (see Number 4 above) that I am serious.

Here is what I decided to order and why:

• SK 450 Frame - Right size, seemed harder to break, ball in front will help orientation, priced well.
• NTM 28-26 1200KV motors - Recommended as good size for SK450, description praises high level of testing before shipping and rugged build quality
• Turnigy Plush 18A ESC - Plush has good reputation, doesn't required reflashing for Quad use - but will 18A be big enough???  This was the only size they had in stock...  Hmmm  I'll chance it.
• KK2 Flight Control Board - General agreement that this is great "starter" board - easy to program and flys great
• 8X4.5 Slow Fly Props - Again, recommended size
• Other misc stuff - Programmers for KK2 and ESCs; assorted hardware, 2650 3S LiPo, Battery strap, servo tester.

Secrets to ordering Quad parts...  remember that you have to order four each of a number of parts - 4 ESCs, 4 Motors, 4 Props (of two different types, Normal and Counter rotating), Needed connectors, times four. 4 prop adaptors.

The ordering process actually went pretty quickly.  Everything I wanted was in stock, other than a larger ESC, but I am hoping that my choice will be OK since the specs seem to only call for a 9A draw from my motor and prop/battery combo.

So I double check and triple check the stuff in my HobbyKing basket to make sure I have thought of everything...   Finally with conviction that I have everything, I hit the "OK" button to place the order.
Success !!!  Oh, crap I forgot to order different colored arms for the front of the Quad.  I also forgot to order a servo tester and different colored props for the front of the Quad for orientation...
Too late...

Next Post: The Wait...  And Buyers Remorse

Day 1: Who Am I and Why in the Heck am I doing a Blog?

Hello Blogosphere !!!  My name is Rick and I am an Addict...

First a Confession.   As of this moment in time I do not own a Quadcopter.  I have never owned a Quadcopter, never flown a Quadcopter and for that matter have never even seen one in person.
But, I have watched hundreds of Internet videos - enough for me to say... "I got to get me some of that".
So, last week I ordered a bunch of parts from Hobby King and will  be building my own Quadcopter.
And hopefully, once I get all the parts and get it working, I will be flying a Quadcopter.

So, this Blog is an attempt to document my addiction, from a noobie whose only exposure is a sniff of Quadcopters via the Internet, to becoming a full blown "monkey on the back" hooked user.

But first a little bit about me: 
I am a retired IT manager who worked for an international energy company.  I am in my early 60's, married, two grown kids and 3 fantastic grandkids.
I have been involved in RC planes and helicopters for only a year or two and have very limited flying skills in both.  Matter of fact, I still can't get my Blade 120 SR heli to do a decent hover for more than a few seconds.

My other aircraft are:

• Dynam Hawk Sky - I have flown this plane twice so far
  
• HobbyZone Champ - I have flown this plane 3 times
  
• Blade 120 SR Helicopter - I have flown it a number of times, but never very successfully. 
  
• Blade Scout - I have flown this many times indoors - too small to fly outdoors
  

I have been a licensed Amateur Radio Operation (Adanced Class) for over 40 years.  My other hobbies are:

• Photography
• Stock Investing/Trading
• Building the occasional home computer
• Juggling

So that is a little bit about me and why I have created this blog.  I hope to document the build and testing of my Quadcopter and post pictures and videos of the constructions and eventual flights.

Next Post: Placing the Order