Lessons Learned: Quadcopters

by spencer | November 5, 2012 | (22) Posted in Projects

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!

 


 

COMMENTS

cururu on November 6, 2012
Great article! I wish I had read your article 3 months ago! I have been through almost the same situations! Now I think I learned the lessons that you are teaching you here. Keep posting your experiences!

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spencer on November 7, 2012
That's why I'm sharing it. I hope others can learn from me rather than learning the hard way.
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cururu on November 8, 2012
By the way Spencer, how did you solve the bent shaft issue?
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spencer on November 11, 2012
I was able to find the right shaft on eBay, but it another thing I have to wait two weeks for being that it ships from china. The shafts are being a pain to remove, but with the right equipment I should be able to get them out.
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LanMark on November 6, 2012
Building quads is very addictive for me.. I am on my fourth frame now. :) But the way I see it is I am on V2 for the two quads that I have... I have one large aerial photography quad and a small one for FPV and exploration.
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spencer on November 7, 2012
I'm really enjoying it. I'm just getting over the learning hump and wanted to share what I've learn up to this point. Thanks for all the input.
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kenton on November 6, 2012
Thanks for posting this...I'm looking into building one come spring, and this will certainly be helpful!
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spencer on November 7, 2012
Glad I could help. Your welcome to pick my brain of what little quad information it may have.
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Cyberdactyl on November 11, 2012
I'm building a tri-copter and quad. Discovered once you have the peripheral components, radio, chargers, batteries, miscellaneous build stuff, etc. building a second flyer is maybe 15% more.

As to your post, I'm right there with you. Took me three orders as well to get all the stuff.
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dadi3 on November 6, 2012
Nice. I'm also making build thread about quad.
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Mirabile Visu on November 6, 2012
Valuable information for me prior to my HobbyKing order. Excellent.
Thank you.
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Beerpig on December 20, 2012
Great post.I am seriously thinking of putting a quad together myself but was always put off by the fact that i am only very new to the hobby(i only have a bixler 2 and am learning to fly it)and was worried about the flight board being to complicated.But might as well jump in with both feet.Only one way to learn lol
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PewPewPew on December 18, 2012
Thanks for this info.
My plan was to buy the sk450 frame, 2822/17 1000kv motors like yours, SS 18-20A ESC from hobbyking (only 4 of them).
I already have a KK2.0 board, 5x 1550mah 3s 20C lipo's and 6x 8x4 props.

So now i know not to buy those ESC's and buy 5 instead of 4.

I was wondering if anyone knows if the card-programmable ESC's (SS 18-20A)http://www.hobbyking.com/hobbyking/store/__6548__Hobbyking_SS_Series_18_20A_ESC_card_programmable_.html are better, or should I buy others?

I was really hoping to keep the price (frame+esc+motors+some small extras) under 100$ but that seems to be impossible :)

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spencer on December 19, 2012
$100 is a hard one to hit. Good luck with it, but I'd suggest not skimping where you can. If I had to do it again, I would put a good $250 into it and get it done right the first time. One slow speed control, a little cheaper flight controller, and an inexpensive motor may cost you the $100 you may have saved. But then again, you might get lucky.

The esc your looking at may work, but i'd still suggest a plush, multistar or a simon k flashed esc. I have found a few of those preflashed from various shops.
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PewPewPew on December 20, 2012
Ok thanks for the reply. I'm going for 5 Multistar 15A esc's. They should be ok but I orderr a spare one anyway. The motors seem to be very good as I haven't seen any negative comments on them, so I'll take 4 of those. I will still use my kk2.0 board or my kk blackboard, but I think the 2.0 will be the easiest for me. For the 100$ I meant frame+motors+esc and then some little extras :) Grtz
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LanMark on November 6, 2012
lol.. yeah I have found that building a quad copter is like me plumbing.. I never get everything I need in the first trip to the store and end up going back again and again.

The long waits on orders from distributors on the other side of the planet (HobbyKing) has made me find local distributors for most stuff... I like waiting 3 days or part of a week.. not so much on the 22+ days.
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Adrianm1972 on September 10, 2013
FYI, 3.17mm shafts are 1/8". You can find replacement shafts in your LHS. They are hinge pins for most off road r/c cars. Many have an e-clip on the end. Just cut it to size, grind a flat on the shaft for the motor bell set screw, use some blue lock tite and you are good to go!
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spencer on September 20, 2013
Thank you for adding that. I have since learned that, but hadn't updated the article. Ah, the things we learn the hard way.
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Lessons Learned: Quadcopters