My first quad - Electrohub w/angle arms!

[Micah]

Well, I'm coming back to the hobby. I maidened a plane for the first time in 15 years or so, and I finally got a quadcopter in the air as well. Things are falling into place nicely and I'm starting to question how I was away from this hobby for so long....

I feel like i'm making the finishing touches on my Electrohub build and I really wish I could have done a full build thread. For this I'm sorry, but I'll go ahead and post what I have and my experiences from now on.

Enter the quad:

I'm a pretty mechanical guy and I am no stranger to electronics and computers, so this all came pretty quick and easy for me, but I will say... piloting was the part I feared (and still fear). After getting this thing put together with the angle arms and to a point that I thought it was solid.. I finished it with the landing gear and took to the sky.

--My maiden flight--

I went to the local dairy (Alpenrose Dairy) that I've gotten permission to fly at, strapped a battery on, did a set of flight checks (Motor rotations, correct props, nuts on tight, battery charged, all plugs properly seated, etc). I then plugged it in, stood back, armed the craft and let her rip.

To my surprise, it lifted off the ground and hovered steadily... Even in a slight 5mph breeze it was unmoving. It hovered like it was mounted on a pole. Only until the wind gusts got above 5mph did I notice the stock PID's jerking it around. I decided to take it out and back... staying 4-6 feet off the ground, keeping the back to me. It worked great! A couple of gusts left me overcorrecting and I brought it to the ground a little hard a few times; breaking the landing gear off and consuming some more zip ties. I put two batteries through it and decided to stop while I was ahead. I more than understand the "one more time" aspect of flying and know you should listen to your gut.

Since then, I've taken it up a couple times... I got some really good starting PID's from this thread: http://flitetest.com/articles/angle-arm-mini-electrohub-build which I highly recommend for anybody making a quad like this.

I've only adjusted the yaw rates so far, and I love this thing. I'm still pumping milliamps through it and trying to get a natural feel on the sticks and in the sky with orientation before I strap the FPV gear on.. But, that said, I have mounted the FPV gear AND shortened the arms to the shortest possible length with my 8" props. This thing is mean looking and flies even better than it looks. I even ran a 4S 1.3 Nano-tech 45-90C battery on it.... that thing shoots up SO fast and hovers at about 35% throttle even with the FPV gear mounted. Still fun and snappy on 3S, but dang...

The only change since this last picture (to date) is the way I have the camera mounted and I shortened the antenna mast (yeah, made my own clover leaf/skew planars). I also got a clear acrylic case for the Naze32 from getfpv. It gave me a good platform to mount the video tx to, looks great, and I'm sure it adds a level of protection.

Once I get my chops up, I'll post a flight video. Until then, you'll just have to know that I am a horrible multirotor pilot, but I'm getting better. This weekend I plan on doing my FPV maiden. Wish me luck.

Now it's time for STATS:

****STATS*****

Motors: HT-450 (2028 - 1000ish kv) http://www.readytoflyquads.com/brushless-outrunner-hacker-style-20-28m
Props: GemFan 8045's
ESC's: Rotorgeeks 12A v4's Flashed to 13.1 BLHeli
Naze32: Full naze, OneShot125 enabled, running these pids: http://assets.flitetest.com/article_images/full/angle-arm-auto-pids-png_1425841228.jpg
Radio: FrSky Taranis Plus - D4R-II receiver + FAS-100 for voltage/current sensing
FPV: Using the Teleporter v4 setup from GetFPV with the included camera and 250mW FatShark transmitter. Home made clover leaf antenna+skew planar setup.

I'll add/change stats on this post as they do on the craft.

Hope you enjoyed,
Micah

 

[makattack]

Nice looking build and nice job with progressing so quickly! It has taken me a lot longer to get to the point where I will be able to fly FPV with my multirotors, but only because I finished my electrohub tricopter towards the end of last year, and haven't had much stick time. Was also waiting for the toughtilt before flying FPV, and it's now installed.

 

[Radflite]

Great build. I am still putting mine together.

Yours looks fantastic!

 

[Micah]

Nice looking build and nice job with progressing so quickly! It has taken me a lot longer to get to the point where I will be able to fly FPV with my multirotors, but only because I finished my electrohub tricopter towards the end of last year, and haven't had much stick time. Was also waiting for the toughtilt before flying FPV, and it's now installed.

Thanks! I actually purchased my electrohub as the tricopter w/tough tilt. So I have the mechanism sitting around. Eric Monroe convinced me to go quadcopter for my first one - touting that there were probably fewer points of failure and may be simpler to learn the basics of flight. I went to my local hardware store, picked up a couple lengths of 1/2" poplar and made the extra arm. My motors and ESC's already came in a set of 4, so it was kind of a no brainer for me.

Great build. I am still putting mine together.
Yours looks fantastic!

Thanks! Like I said, finishing touches. Hopefully it'll get even nicer in the coming weeks. I'll be sure to update this thread.

 

[Micah]

Okay, so I've been flying this thing a lot. Tuning the thing has been aggravating a bit, but I think I'm making progress. Turns out I needed to set my yaw_deadband and fix a constant yawing issue. Now that I have that all done there's one bit of notable progress I've made. So far, I've broken a few arms now... loads of props, but only a couple arms. At one point I was so eager to fly I couldn't wait for more angle brackets.. .so I put two more sets of the brackets on order and cut me some straight arms just to get me in the air. The flight characteristics were almost hard to get used to. The craft is slightly less predictable and it falls into it's own wash REALLY easy. That was something I took for granted with the angle arms.

ANYWAYS... Once the arms came in, I started doing some brainstorming.... My first set of angle arms was simply bolted together like it comes out of the package and it broke at the frame side bolds. Second set I ditched the bolts and glued it together... soaked the wood in super thin CA... It was rock solid, but broke at the joints where the two halfs meet - an imperfect joint with not enough surface area. I started cutting pieces of wood and creating a stong joint. Without making too intricate a cut and not being able to make arms long enough, I came out with a longer swept joint.... Then decided to find a way to make the cut more exact to get a better bond between the two halfs. Then it hit me.... why not cut this arm out of TWO pre-glued pieces. So I used medium CA and glued two 1/2" poplar pieces together.. side by side, clamped them together with the angle pieces against the two pieces and while clamped saturated the whole thing with thin CA. I then pulled it out of the vice so it didn't get permanently stuck. After getting thick CA pads on my fingers, I did a test fit of the motor mounts, accidentally glued one of the discs to it and went with it for the other three.

I wish I had done a full build up, maybe on the next set if these prove strong. At least I got to them before I painted them black. Here's what I have:

I'll let you know how they hold up!

 

[jipp]

you may have better results with simple tight bond II wood glue.. it will create a bond stronger than the wood. it really is better to use a wood glue to glue wood to wood together than super glue.. cheaper too.

yeah, iv notice lots of air frames are adding some lift in there arms these days. prop wash i could see that one benefit for sure.

your project looks good tho.. and more important it looks like you are making progress.

also it maybe cheaper to trace and copy them angle brackets.. be cheaper to make them your self i think than keep spending 15.00 a pop. but im frugal. heh.

chris.

 

[Micah]

you may have better results with simple tight bond II wood glue.. it will create a bond stronger than the wood. it really is better to use a wood glue to glue wood to wood together than super glue.. cheaper too.

yeah, iv notice lots of air frames are adding some lift in there arms these days. prop wash i could see that one benefit for sure.

your project looks good tho.. and more important it looks like you are making progress.

also it maybe cheaper to trace and copy them angle brackets.. be cheaper to make them your self i think than keep spending 15.00 a pop. but im frugal. heh.

chris.

The wood glue is a funny story... I got all of these glued together and thought "Hmm. I used to use wood glue for this....." then realized there was a bottle of it right next to me the entire time. Oops... Next set!

As far as the angle arms go, I don't really mind supporting flitetest. 10 bucks for a set of the brackets isn't much. I may eventually ditch them and do something of my own creation, but I'm not there yet and like I said... flitetest can have my money.

Thanks for the great suggestions... Keep posted and maybe the next set will have some woodglue.

I just got them painted black - so, I'll get them on the quad here in a little bit and post some new pictures.

 

[earthsciteach]

Congrats on having such a positive first experience! Tricopters are cool to a degree, but have some problems inherent to the design.

Personally, I like the brackets taking the impact of a crash. It saves booms and props. And, I don't mind supporting Flite Test and Eric at all, either. All of them are great guys!

 

[Micah]

Props are cheap. I actually just noticed as I was putting this thing back together......... One of my motors must have taken a pretty good hit and it's bottom bell is a bit warped/bent. It still spins so I did some banging on it and got it back into a shape. It works still, so I'm gonna get back in the air until the next hit finishes off that motor.... Then I'll be going tricopter out of necessity.

 

[Micah]

Got my arms on after painting them. Took this picture... Even got some flight time on it. Flies amazing as usual.