Quadcopter Builds

[Sigurthr]

Heh this thing zips around fast to me! My old heli moved at maybe 1ft/sec maximum, 8"/sec is more realistic. It would yaw slow as hell too, was like flying a dirigible, lol.


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[Speedy78]

They do have rc dirigibles that you can float around lol. Need to have almost still air. I have seen them inside stadiums at basketball games and whatnot floating around with cameras on them.

 

[Things]

The dropping while pitch/rolling can be fixed, but you need to be able to access the mixer on either the controller board, or the transmitter. Not sure a cheap TX would have a mixer though.

 

[Sigurthr]

Yeah, that's what I thought. It's not like a $50 quad is intended for superb flying anyway, lol. I'm having fun and developing my skills on it, so it is doing its job. Just one of those things I wish was easily researchable when looking into a quad.

 

[Things]

You'll find when you go to a larger quad they're a lot more stable, so learning to fly on a smaller one is great for getting your skills up. Of course the downside of a larger one is it hits harder when you crash

Should get my SK450 quad hopefully tomorrow, but it's pretty windy and will be for a while yet

 

[Sigurthr]

Oh nice I didn't realize you ordered a SK450! Let me know how it is!

Yeah, we're still in the heart of winter here, -35C outside every night and we have about 1meter of snow piled up everywhere. So it will be a few months at best before I get to fly my big quad, which I expect to arrive at the end of the month.

 

[Things]

Riiigghtt, where to start.

Well, I got the SK450 quad today, and, well, it's pretty bad ...

For a start, the really nice looking box has just been cut up and folded up inside out and used as the main packaging. I thought the idea was you could use it as a transport box? Oh well, minor thing ..

Took it out, stuck the props on, bound the TX/RX, and took it out for a fly. It flew like crap, honestly. While it flew and didn't oscillate, it was ssslooowww to respond, and loved just taking off in random directions, screw that!

They ship with the KK2.0 board, but it has pretty outdated firmware on it. I always use self level mode, so I decided to take the KK2.1 off my mini quad and try it on this. Didn't help at all, all the PID tuning I could do, it either oscillated badly, or didn't even respond to stick input.

So, failing that, I decided to flash the ESC's with SimonK firmware, and wow, what a difference that made! Did some simple PID tuning and the thing flies rock solid now.

Being multistar ESC's, and an "ARF" quad, I was thoroughly disappointed with it's performance out of the box, BUT, if you are able to re-flash the ESC's and KK board, it can be a pretty awesome, cheap quad.

I made a couple vids:





Such a shame that a simple software update would make this thing amazing right out of the box.

So yeah, out of the box, it's crap. With a bit of time and re-flashing the ESC's, it's perfect. Keep that in mind

 

[Speedy78]

Hmm. I am looking for a cheap quad i can do some 3d flying, or attempt lol, with. I may just go the kk2 rout and some wooden arms and body so I can can replace things cheap and quick.

 

[Things]

Some of the cheaper quads have a button on the TX that'll allow you to do a flip, but you'll want access to acro mode to do any 3D flying. Acro mode works a fair bit differently to the regular stabilize/self leveling mode, so make sure you have a nice big open area before you try it

ESC's used to be this pretty nice green colour, similar to the front arms, but had to cut the heatshrink off to re-flash them

 

[Sigurthr]

Set up my big quad today!

Charger: HobbyKing 6A 1S-6S w/ Balance Charge function (psu not included)

IFLY-4 by IdeaFly (radio system and battery not included)

It was a bitch to set up because my Tx and Rx did not come with any manuals! I managed to track down an English manual for the Tx online but there was no manual available for the Rx at all. The Rx came with a jumper cable that pulls a signal pin to ground, and I found references of it online being used on the BIND header, but no instructions about when it would be needed. So, I fiddled around with my Tx until I figured the basics of it out enough to use the Rx mapping program that my quad comes with to determine if the Rx was installed correctly. I also didn't know how or where the Rx gets its power from since this quad's FC doesn't have any power headers, so I wasn't sure it was going to work at all and was worried I might have needed to buy a Rx battery. Thankfully, it gets the power from the 5 channels, and the five channels line up exactly between FC and Rx! The Rx doesn't have the channels labeled by function either >.> . One absolutely great thing about this quad is that when hooked up to USB it powers the FC so you don't need a battery installed to do all the calibration and set up. It says that USB power isn't supposed to be able to start the motors, but if you accidentally enter the command to start the motors after you save your calibration while it is still plugged in, it apparently starts the motors! It gave me quite a scare but I had it on my workbench with all the props clear of obstruction. It was only able to spin the props at maybe 120rpm though so it wasn't in danger of taking off. I guess my PC can pump out some juice.

I don't have enough room indoors to fly this massive quad so I took it to the largest open space (about 1.5m^2) to do a basic powered function test to make sure all is well. After all, I didn't know which is the front or rear of the craft, lol, there's no markings! Luckily, again, my intuition was right and I assembled it correctly with the front oriented correctly. I took her up about 1ft and let her hover a few seconds. I trimmed a bit to get it to sit well, but the prop wash bouncing off the floor would maker her roam without aileron/elevator input, no biggie. I set her back down and powered off.

The charger also didn't have any manual, but it has so many fail-safes and diagnostics built in that I was able to safely figure it out. It works fantastically and is very accurate. My one complaint is that there is no active cooling and yet has a discharge function (both true discharge and storage discharge), which is a recipe for failure. I doubt I'll ever use the discharge function, but the storage function would be nifty. It is easy enough to run down a battery to 3.7V/cell and put it on a shelf though.

Btw, the ESCs on this IFLY-4 have built in heatsinks, which is an improvement not documented online. The on-DVD manual included with the quad is outdated in reference to the FC used in the quad; the quad has a newer and different looking FC and the orientation LEDs are different colors than in the manual.

Absolutely beautiful machine, I can't wait to give her a proper flight! I plan to eventually pick up a 6Ah cell, HD camera, and telemetry system when I can afford to.

@Things it is a shame that the out-of-the-box status of the SK450 is so poor. I was hoping for better, but now I am REALLY glad I spent the extra money and went with the IFLY-4 instead. I didn't do the full throttle response tests you showed since I don't know how to and didn't want to remove the props, but I did test the low throttle linearity and found it to be excellent, you can control the prop speed right down to a crawl and it seemed to be very responsive all around. The aileron/elevator controls on my Hubsan X4 are WAY spongy compared to this big quad.

 

[Things]

If it hovers well then you don't have to worry about the ESC's response, I wouldn't expect you'd have to re-flash anything to get it off the ground, being a complete product, vs the SK450 which is a more "hobby", I guess. I was disappointed with it out of the box too, but after flashing it flies bloody amazing.

Glad you're having fun though. Just be careful accidentally letting the motors spin up while powered from USB, as you could damage the flight controller or your USB ports

 

[Sigurthr]

Yeah I didn't intend to let it spin off USB but it took a bit to figure out how to disengage it. Doesn't appear any damage was done but I certainly don't intend to let it happen again.

I wish there was a more straight forward and easily accessible beginners guide for this hobby. Even with an electronics background a lot of info is esoteric thanks to prevalent use of abbreviations and initials for parts. For example trying to hook up the Rx and determine what all was needed I would have been lost without you guys's help. Searches turned up people saying something called a ubec or a Rx specific battery were needed, but obviously this isn't the case. I'm still not sure how the bind process works, unless the Rx I got came bound to the Tx I got as the bind button seemingly does nothing. Also what's the purpose of that jumper that is supposedly for binding? Lol.

Glad you've got it flying well finally. You going to attach a camera to it at some point? What's the flight time you're getting out of it now with the smaller props?

Btw, the problem I had where I was yawing when adjusting throttle is only on the hubsan remote. This Turnigy remote is awesome. Thanks for recommending it guys.


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[Things]

A BEC is a Battery Eliminator Circuit, does exactly what the name suggests and means you don't need a separate RX battery. Most ESC's come with BEC's built in, either a UBEC, which is just a linear regulator, or a SBEC, switching. ESC's labelled "OPTO" don't include a BEC at all.

The reason some people suggest a separate BEC is because Y6, X8, hex, octacopters etc can still operate even if one (or more) of the motors fail. If the ESC powering said motor fails, and you're powering everything off it, you don't have any redundancy. For a quad it doesn't matter, as any motor failing = it's coming down.

As for binding, you connect the little jumper lead into the BIND/BAT header, and power up the RX. Then, hold the bind button on the back of the 9x, and turn it on, from memory the red LED in the RX will stop blinking once it's bound. My 9x and it's receiver came pre-bound, but you'll need to do it for extra if you use them.

As for flight time, I'm not really sure. Definitely over 15 minutes though on the 5Ah packs.

Don't think I'll put any cameras on this one, the GPS loiter modes on the 3DR quad are a lot more camera and FPV friendly for a noob like me

 

[Sigurthr]

Ahh that makes sense now, thanks!!

So in a typical DIY quad/hex/oct build power runs from the battery to a/many ESC(s), and then to the flight electronics and receiver? That's very different from both my finished product quads which feature linear regulators on the flight controller. It just seems strange that hobbyist flight controllers don't have onboard power regulation and distribution systems and would rely on ESCs to provide power.

Thanks for the bind procedure!! I'll run through it just to be sure.

On the 9x Tx what's the three position toggle switch next to the right hand dual rate switch?


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[Things]

Ahh that makes sense now, thanks!!

So in a typical DIY quad/hex/oct build power runs from the battery to a/many ESC(s), and then to the flight electronics and receiver? That's very different from both my finished product quads which feature linear regulators on the flight controller. It just seems strange that hobbyist flight controllers don't have onboard power regulation and distribution systems and would rely on ESCs to provide power.


On the 9x Tx what's the three position toggle switch next to the right hand dual rate switch?

Well, no point adding additional power circuitry when you can just take it from the ESC's

The 9x is kind of designed around a regular plane transmitter, so some terminology is a bit different to heli/multicopters. For example, pitch is called elevators, roll is ailerons, and yaw is rudder. The 3pos switch is a gear switch, however all but the momentary switch top left can be configured for other purposes. For example I have the top left back toggle for triggering a camera, the 2pos toggle in front of that as a primary mode switch, the 3 pos as a secondary mode switch, and the pot on the front left for trimming etc. The momentary switch right back is called a trainer switch and can't be changed with the stock 9x firmware.

You may have noticed a little plug in the back of the TX near the bind button, that's a standard 3.5mm jack. You can actually connect 2 transmitters together, and if you hold that trainer switch, it allows the other transmitter to control the model, but as soon as you let go, you re-take control, it's a pretty nifty feature.

 

[Sigurthr]

My Tx only has one momentary switch marked Trn on the top right, I was wondering about that.

As for switches;
On the left is ele d/r, rud d/r, and thr cut. What does Thr Cut do? I can't seem to find it in the menus.

On the right is ail d/r, gear, aux 3 (3pos), Trn.

The FC firmware has Gear set to mode. I connected this to channel 5 on the Rx. Is this the 3 pos switch or the switch marked Gear? I ask because the FC firmware has Gear being 3position, lol.

In other words what switches do channels 5-9 correspond to, and where in the menus do you program them? I'm not sure but I think my FC is listening for gear signal on a channel not being used by the Tx as neither the 3pos or gear switches seem to do anything. If anything the 3pos switch has a very slight dual rate effect by observing the signal inputs via USB, but it's less than 10% gain over normal.


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