Lessons Learned: Quadcopters

Lesson One: Order lots of extra parts!

So, with some research, and far too much excitement, I put together a plan to build a quadcopter together.  I had some idea of what i wanted it to be, and made my first order.  With little hesitation, I put together an order that seemed to me, quite sufficient.  Those of you that have experience with this might see the order as a little light and ill informed, and I soon discovered you'd be right.

My First Order:

1x  Hobbyking X550 Glass Fiber Quadcopter Frame 550mm = $19.53
1x  HobbyKing Multi-Rotor Control Board V2.1 (Atmega168PA) = $14.95
1x  10CM Male to Male Servo Lead (JR) 26AWG (10pcs/set) = $4.00
1x  USBasp AVR Programming Device for ATMEL proccessors = $4.75
4x  D2822/17 Brushless Outrunner 1100kv = $31.00
2x  8040 SF Props 2pc Standard Rotation/2 pc RH Rotation (Black) = $5.18
2x  8040 SF Props 2pc Standard Rotation/2 pc RH Rotation (Red) = $5.18
4x #HK-SS18A/6456 Hobbyking SS Series 15-18A ESC = $18.45

Once I got my order, I quickly started putting it together and soon found that the inexpensive ESC were not sufficient and lacked the programming needed to make the proper adjustments needed for a Quadcopter (in particular, throttle travel). 

I also found that I should have ordered spare parts.  I really thought I'd be ok in this aspect, being that I've been flying RC for over 10 years now.  But my lack of flying ability was not the issue at all, merely the lack of building experience in the multicopter realm.

After quite a few hours of setup and a realization that I had made a bad decision on the ESC's, I quickly did some research and found the new MultiStar ESC's from Hobbyking.  They were designed for MultiRotors and fit the bill quite nicely.  I also ordered a few extra things to make the install and set up a little easier (programming card and breakout cable).

Second Order:

1x  5.6mm x 14mm M3 Nylon Threaded Spacer (10pc) = $1.57
1x  M3 Nylon Nut (10pcs/bag) = $0.60
1x  XT60 to 4 X 3.5mm bullet Multistar ESC Power Breakout Cable = $2.90
4x  Turnigy Multistar 20 Amp Multi-rotor Brushless ESC 2-4S = $35.20
1x  Turnigy Multistar ESC Programming Card = $3.77

Still however, I made a critical mistake.  I only ordered 4 ESC's.  Thinking that I was sure to get it right this time, I didn't think to order a spare.  Boy was I wrong.  During programming, I plugged one of the ESC's in backwards and fried it.  Once again, I was short one ESC and couldn't finish the Quad.

Third Order:

2x  Turnigy Multistar 20 Amp Multi-rotor Brushless ESC 2-4S = $17.68
2x  M3x8 Nylon Screws (10pcs/bag) = $1.34
1x  5.6mm x 21mm M3 Nylon Threaded Spacer (10pc) = $1.78
1x  Hobbyking X550 Hardware Package (complete) = $2.97

This time, I put 2 ESC's on the order so that I would have a spare (along with a few spare parts).  Knowing by now, that I would need it.  Luckily, I got everything together and got all motors spinning.

This brings me to lesson two.

Lesson Two: Not all firmware are created equal

After watching a few video's by Josh Bixler, I was confident that I could pull this off.  I programmed my flight controller to x formation using the suggested firmware and figured I'd be fine.  Little did I know that the KK firmware I tried wouldn't spool motor 4 up till half throttle.  After going back to Josh's video, I noticed the option to load custom Firmware.  I then downloaded the suggested file from HK for my board, loaded it, and everything worked great!  I finally had it in the air and got a few flights under my belt.  Which brings me to lesson three.

Lesson Three: Point of Failure

The multistar esc's and breakout cables are great in the aspect that all i have to do is plug it all in.  I made some extensions for the motor wires so that i could tuck all the ESC's up against the board, which makes for a much cleaner look.  All worked great, and I was having a blast... Right up until one of the ESC wires came unplugged and I lost a motor.  One of the bullet plugs came undone mostly due to a previously ignored broken ziptie.  I soon found out what happens when a quad looses a motor.  It flips over on its back.  

That crash landed me with 3 broken props and two bent shafts.  I did however, figured out a way to solve the issue of plugs coming undone.  I initially thought to tape them all around the joint, but tape makes a mess and doesn't look clean enough for my liking.  Luckily I ordered a bunch of shrink tube on one of my HK orders, so now I am putting a short piece of shrink on every bullet connector.  This will still allow me to make changes to it down the road if needed.

As for the bent motor shafts, that leads me to lesson four.

Lesson Four:  Know what your buying!

This one isn't near as critical, but I may have done it differently if I'd only known.  The motors I bought are great, and have great performance, but parts aren't readily available.  The motor shafts are 3.17mm diameter (or 1/8", which is strange for a Chinese motor), so the shaft is not easy to find.  My suggestion would be this, either buy a motor with cheap shafts, or find motor that you don't mind chucking if you bend a shaft.  It's amazing how much information is out there on quadcopters, and Flitetest.com has been a great jump start for those getting into it.

So that's my list of lesson's learned so far.  I'm sure there will be tons more to come, but hopefully I won't have to learn them the hard way!