Newbie tries to build Elev-8

chasbearma

Haha! It is finally here! It was backordered at Christmas but it is finally here!

I've always wanted to build a flying machine. The wife and kids are out for the day, so I get to play with my boy toys...

They told me not to try this one first. (They being Servo mag, This one being Elev-8, FWIW.) But I'm ambitious. I read the articles, and looked over the diagrams. Because I have a middle class mindset, I already have a wide variety of tools. I have a few bucks so I can pick up a few things as needed (as long as I use the credit card the wife doesn't know about). And an above average IQ of 101 (too bad it is utilized in software, not hardware). What, I ask, could possibly go wrong?

Of course as a "freshman" I have yet to learn the list of things I don't yet know. While it is possible someone will learn something from this, it is far more likely that belly laughs will commence from those who have experience. I don't care, have a laugh at my expense! I'm having fun, too!

First tip from a n00b: Buy a lot of stuff. If an expert will spend $1200, you'll spend more (50%? 100%?). Bought the Elev-8. Bought the crash pack. Bought the hex upgrade. The optimist says "my flying minion will be 50% more powerful". The pessimist says "well, at least you have spare parts". (Take a guess which thing I'll do with stuff in the hex upgrade box... the answer will not be long in coming!)

First steps: put bullet connectors and shrink tube on everything. I think I got it, but it took me 4 hours instead of the 20 minutes it would take a pro. And, with the Metcal I picked up used on eBay, which makes anyone capable of making good solder joints. Was very easy to do, and the connections are quite good, but somehow the time just drained away!

Put loctite on the motor set screws. Cross-threaded/stripped one of the twelve. Not looking good for the hex-rotor..., more likely to be parts. But of course you already guessed that. At least for now! I can always order another upgrade kit...

Didn't try to build a power distribution doodad. Bought one instead. (Actually two.. one with six, and one with just 4. You know, in case I lose parts and end up with a quadrotor. In case.) Bought, because time without kiddos in the house is precious, not to waste on mere wiring. Likewise used the Turnigy ESC programmer. Maybe even met the 10 minute time budget the experts expected on that part.

Now on to the mechanicals. (And the laughing.) I started to put a rotor boom together. Sandwiched it all and started adding screws. Guess what - the 4 motor holes don't form a square! Turned the motor a quarter turn so the holes would line up, though it caused some stress on the leads. Then the bullet connectors hit one of the screws that goes through the boom. Then it dawned on me... the bottom motor mount was simply upside down. Flip it and the holes align, the wires go straight in the tube, no conflict with the bullet connectors. Easy peasy.

Well, except for the one boom where the aluminum tube extends too far past the screws and hits the motor. (I have a picture that proves they were NOT all the same.) That one, I figure, I will either hacksaw or hit with the grinder in the garage. (Probably first the saw, then the grinder...) More realistically, it will sit this round out, along with the motor with the repaired set screw, as I fly a quadrotor instead of hex. Still got 5 good booms... the hexrotor can wait!

One other tip for other n00bs - if you are screwing 2 things together, drill out holes in a top layer that are small enough to cause cross-threading (or any other conflicts in threading) for the bottom layer.

That's where I sit now, still finishing motor booms, and putting the hub together. Further updates as events warrant. Don't take it for whining - I'm really having a grand time here!

If I ever do complete this, trust me I will make it a true minion in my army. You know, because that's all about software :-) Haha!

(Dear moderator, if this should be in a more specific forum, please advise / move it.)

~Chuck

PS. I'll get through this, if it's the last thing I do. Or, more likely, build it and never really fly it. Stay tuned.,,

chasbearma

Another thought for n00bs:
I was told to get a few crashes out of your system on cheap Smile, before you crash the elev-8.
Sounds good to me.
Crash 60 bucks worth of s107g (which buys 2 or 3 plus crash parts) instead of the killer flying robot. Sounds good. Bonus: my nephew and daughter love them. But these el-cheapo things fly by IR, so they are indoor only, and won't even take commands if they are near a 100W (equivalent) CFL. My advice: Buy an RF one if there are CFLs in your best (biggest) flying space.

Ken Gracey

Hello chasbearma,

Welcome to the forums, and welcome to the Flight Club!

Sounds like you're getting a fine start. Let's take care of the boom problems that we must have created - sounds like one was a different length. Well, now that you've broken into your HEX Upgrade kit we must immediately make that kit complete again. Occasionally, we can and do make mistakes. We've now put a QA/QC process in place for the machined parts to prevent this from happening again.

Please drop me a message via e-mail with your shipping and we'll replace that boom. We shall also get you in the air and keep you there for the long term. You're starting a really exciting hobby and it will be truly rewarding.

Sincerely,

Ken Gracey

chasbearma

Thanks for the encouragement, Ken. But no need to send spare parts. (If we aren't making mistakes, we aren't learning, I figure.) I do occasionally forget how soft aluminum is (compared to C++ code), and with a few seconds on the grinder it is the right length now (wish I could use that thing in my day job...). A hex rotor is still not out of the question. Yet. Until I make that next big mistake.

Booms assembled, and look plausible. Time to put the center together, tie the ESCs on, and so on. by far the most fun I've had all day. Could take me the rest of the month at my pace, but still a good time.

chasbearma

Quick note - it takes four checks on the check tape to make it around the boom. Wasted a few on overlap because I didn't know that. But no big deal. I'm banking on the LED tape to really spice it up.

chasbearma

Article says, to avoid powering the Hoverfly with slightly competing voltages, cut the power / BEC / red pins from all but one ESC. (Makes total sense, even to a software guy.) And suggests doing it to servo extension cables to minimise risk of damage to the ESC wires. I did spring for the servo extension cables. Then opted not to use them. A gentle lift on the plastic with a teeny tiny flathead screwdriver plus a gentle pull on the wire, and they slip right out. Then I use my daughter's favorite color of electrical tape to keep it from touching anything, and keeping it near the original connector. On one hand, I don't have anything that flies yet, so don't trust me. On the other, ESCs aren't that expensive, and if this n00b didn't obviously break his, maybe they generally withstand this treatment.

dmagnus

I would strongly suggest getting a Blade MqX quad. I don't know what kind of radio you have, but if you get the suggested Spektrum Dx8, it will bind directly to the $139 version of the MqX. This little quad is good for flying both inside and outside. I just had mine outside yesterday learning to do flips. If you set up your transmitter with different dual rates it is either easy enough for a kid to fly or ultra responsive for things like flips. All very good training for your $1000 ELEV-8. Also the MqX is nearly indestructible, I can't count the number of times I've run mine into walls, table legs, the refrigerator indoors and trees outside. I even crashed it from about 15 feet in the air when I was learning how to do flips. And it's still going strong. Another benefit. With the Dx8 you can set up multiple models in it and use the same radio for them. Right now I have my ELEV-8, MqX and Prop Boe Bot all availalble at the flip of the selector. Best $139 I ever spent.

chasbearma

Got an hour or two to work on this now that the rest of the family is asleep. Basic mechanical shape is there. But I am wondering about small stuff, like how much torque is appropriate for putting a 4-40 screw into a nylon standoff in this situation? Finger tight? Times two? Use loctite of some sort? No big deal yet... still have to wire the thing, cleanly. And add (balanced) props. That spin the proper direction.

Was also thinking ahead, in a dreamy sort of way, about how to tell (in software, autonomously) if this thing is moving or not. Outdoors, I can probably use GPS. If 10s of feet is good enough, anyway There are accelerometers for changes in movement, but I don't think they'll accurately tell if the thing is slowly drifting at a constant speed. Indoors I can probably ping))), or use IR, and this might even help me from crashing into the ground outside. No go if 100 ft in the air, in the sunshine, though. Pressure-based altimiters, at least the ones in digital watches, show remarkable sensitivity to changes of a few feet in still conditions, but are off by hundreds of feet if you are hiking up a mountain in the wind (resulting in a bunch of air that wants to be in the same place as the mountain, causing higher pressure / lower elevation reading). I assume houses have a similar effect.

So, partly by accident, I was talking to someone today who knows a bit about computer vision. And I asked his opinion, with high hopes that I could get some tidbits. After all, the optical computer mouse costs ten bucks, senses motion (and direction) quite well, runs for days on a small battery, and has been around for >10 years. Captures 1000s of frames a second with a small, low-res camera. Maybe there's a lesson here... Well:
1. That mouse has the advantage that it lights the surface in a particular way
2. The mouse sees things that are very close / fixed distance, so the velocity is easier to establish than from distant targets.
And, unrelated:
3. If you want to auto-land, consider a pink target. Very rare color out in the wild.

Like I said, mostly a daydream. This thing isn't going anywhere until the props are on, and that's not happening until after I change a poopy diaper right about now :-P But it does cause me to ask: I've seen a lot of camera suggestions for sending video back to the operator... but what is the best kind of camera for onboard processing (like looking for a pink area below the robot, which has GPS'd to within 20 ft of where it is supposed to be)?

chasbearma

Minor assembly note - poke out any little bits of plastic that are stuck in the holes *before* you have all three hands engaged in holding parts and tools :-)

SRLM

You might look for the phrase "optical flow". It's pretty much what you describe.

Duane Degn

chasbearma, I've tried to list links to many of the ELEV-8 threads in post #10 of my index. There's likely information there that could help you with your ELEV-8 setup.

Cats92

Hello,

ELEV 8 is a nice multi copter but not easy to fly for a beginner , it moves very quickly and the propellers are dangerous while running.

I quite agree with dmagnus : buy a small quadcopter (the Mqx is best because it uses the DX8 like the ELEV 8.
You can also fly a Ladybird or a Hobbyking Q bot). These small quacopters crash without damage and cost around 100 $.

And meet people flying copters, they are always ready to help and give good advices.

Have fun !

dmagnus

Agree wholeheartedly re: meeting others who fly, especially copters and quads. And, please, unless you live in a large airplane hangar or huge warehouse, don't fly the ELEV-8 in the house - you are just begging for disaster.
I have enough of a challenge flying my Mqx in the house (I have a small house). But I'm learning and even was able to fly from one end of the house to the other and land on a tv table top. :cool:

W9GFO

dmagnus wrote: »

And, please, unless you live in a large airplane hangar or huge warehouse, don't fly the ELEV-8 in the house - you are just begging for disaster.

What about the shop?

Incidentally, my very first flight of an RC helicopter was in a hangar at Andersen Air Force Base in Guam. It was (still is I suppose) an eleven pound gasoline powered heli (17 years, zero crashes). I had training sticks with wiffle balls on the ends. I chose to fly inside a hangar due to the ever present trade winds. Quite nerve racking. The best thing I did for learning to fly was to ditch those stupid training sticks and get to flying it outside. Okay, well the best thing was spending time in a simulator but other than that - I think training sticks are stupid.

dmagnus

You're a better pilot than I am! Actually, I did get mine off the ground in my little work area in the Man Cave. About 5' X 5' with an 8 foot ceiling. Managed to get it about 3' up and hovered, then chickened out and put er down. Went outside and managed to run it into the deck railing and broke my first prop (of many). Go figure...

JasonDorie

Never fly in the house. Fly in someone else's house, or better still, an office.

chasbearma

Well, it is all put together, props spinning smoothly, and all that... blowing the plans off the table with the prop wash rather fun. I just need to attach the radio. Looks plausible, but I guess you can't be sure until it flies.

Things learned:
Shouldn't have pulled out the BEC pins until after I set the rotation directions with the servo tester. Oh well, I put one back, finished setting the directions, and pulled it again. Each and every one of the ESCs was originally spinning the wrong direction, at odds of 16:1 against. Yet surprising nobody.
ESC music is amusing for 15 seconds or so.

Thanks to CowboyCoder for the tip about black screws that look an awful lot alike. Prevented an almost certain mistake.

Now that it is all put together, it does look quite intimidating. I admit once admonished not to fly it in the house, my mind wandered to thoughts of demolishing all this Christmas Smile we've got stored in here but haven't used in years, robot style. Well, more likely to hurt the robot than anything else at this stage, so first test flight will be in the baseball field across the street. To the dismay of those hoping for a funny "told you so" video.

@SRLM - optical flow is exactly what I was looking for. And someone has already done it. Using a sensor adapted from a computer mouse. Looks very fun to try.

JasonDorie

The Parrot drones use a down-facing camera to track the ground to maintain positional stability without GPS. It wouldn't be trivial code to write, and would very likely be well outside the ability of the Prop to handle. Prop2 might be up to it, but comparing frame buffers needs a bit of RAM to work with. It's also easier when the CPU has SIMD instructions.

bfmorgan

This is my first post to the forum and thanks for having a knowledgeable group. Earlier in this thread it mentioned a power bus for connection negative and positives from the ESC to the battery. They said not to gang them together but use some sort of bus connector so that each wire could be easily removed as needed. It was implied that these bus bars or distribution connectors were purchased.

I have looked at all the R/C sites and cannot seem to find any of these for sale. Any ideas where I can get these?

I'm new to R/C and just bought an ELEV-8 with the HEX add-on. I'm an computer engineer with a lot of electronics background.

Thanks in advance and I'm really excited to get this ELEV-8 up and flying.

JasonDorie

Something like this would work: (Google search "Terminal Block")

http://www.google.com/shopping/product/13843179578661839274?q=terminal%20block&hl=en&pws=0&bav=on.2,or.r_qf.&bvm=bv.43287494,d.aWc&biw=1198&bih=821&sa=X&ei=gW1CUY7LJ8abyQGj_YCABA&ved=0CIoBEPMCMAM

Duane Degn

I've seen the motors wires joined together several different ways.

Besides the terminal blocks, I've seen a bunch of wires joined together on one side with connectors on the the other.

I used two hexagonal pieces of PCB to join six connectors together.

Here's a picture of my setup.



All the negative connectors were soldered to one PCB and all the positive connectors soldered to the other. I used bare copper wire and solder wick to reinforce the connections both mechanically and electrically. I insulated it with Polymorph.

Since I already had a bunch of batteries with Dean's connectors I used these same connectors on the ELEV-8. I considered switching connectors but I found I liked Dean's better than the connectors that came with the ELEV-8. I think this may be just because I'm used to the Dean's connectors. (BTW, HobbyKing's "T" connectors work with the Dean's and IMO are easier to use. And the HK version are a lot less expensive.)

The above was originally posted in this thread about setting up the radio on the ELEV-8

Make sure and take a look at the list of ELEV-8 links mentioned on post #11 above.

bfmorgan

But of course, back to basics (Radio Shack, etc.). I was restricting my thinking to using the types of connectors shipped with the ELEV-8 kit.

This will work.

Thanks,

chasbearma

Well, as I mentioned earlier in the thread, I am all about spending a few extra bucks to save time (a.k.a. cheating). So while I was waiting for the elev-8 to ship, I bought a few things, including a few power distribution boards. I think the one I ended up using was probably from hobby king, part 9171000033. It is perfectly compatible with the bullet connectors that come with the Elev-8, and with the battery connectors, and has a handy-dandy pins for a low battery alarm! And get this -- the holes in the corners of the board actually line up with the inner-most holes in the quad plate, so I just took a little off the stand-offs to make room for it to sit in the stack upside-down (connector side down) just above the ESCs. Almost too easy.

I am too lazy to take the 4-port out of the middle of the quadrotor at this time, but I also got an 8-port version of the board. Here's a pic of that one. You can easily see the mounting holes, the bullet connector ports, and if you look closely, the pins for the battery alarm.

Bottom of the picture is a different approach - just wires soldered together. Would consider using on the hex rotor. Maybe. Looking at the hex plate, it doesn't have the same holes as the quad, but I bet I could make them in a few minutes and put the 8-port in there... so still not 100% sure what I'll do when I'm ready to upgrade...

chasbearma

It flies! I did take a prop to the shin and lose my bowl of jelly beans when I accidentally bumped the stick, but at least now I know it works. (Time to get that prop balancer out again, sigh.)

Next set of "tips" that many other people could have told me, if I'd have listened more carefully:
1. Set the fail safes to cut off. I set mine to low throttle, thinking it would soften the crash on landings, but what it really does is make it a menace if the transmitter fails. Like say if, in a panic at seeing jelly beans skittering to and fro, you hit the transmitter power switch. (Man, it takes a while for that thing to boot up again to tell the elev-8 to cut it out...)
2. Don't use a random "servo tester" to calibrate the ESCs. If that's all it took, they could do it at the factory and be done. No, this is an opportunity for the ESC to learn about the radio you actually have, so use that one. (Somewhat miraculously though, the Hoverfly is what the ESC actually hears from, but calibrating with the radio works.) My copter was not doing anything after it armed; the ESCs would just sit there and beep the motors. Recalibrating fixed it in no time.
3. You have to use the "prior version" of the Hoverfly setup program. If you even want to; I think I didn't change anything after the firmware upgrade program.

It seems to me, as an inexperienced person, that the instructions available for the physical build of the bot are quite extensive and easy to follow. Much more knowledge is assumed on the part of the reader with regard to the RC aspect, getting power to the radio receiver (I soldered up a cable to power it from one of the ESCs). But got through it, and would still suggest this kit / project / endeavor to anyone willing to put in the time, money, and effort. You would be doing a lot of reading, at least I did. I didn't mind (half daydreaming most of the time), though I did end up with pieces of incompatible advice I think as I sort of took a mix and match from a few sets of build instructions/reports. But I think I learned more doing it that way.

Next to try it outside, though it is supposed to snow again. Then, to puzzle out how to get a camera on here and make a vid. Got just the subject in mind.