Starting a new thread to show what I'm working on. I'm building a new Octocopter of my own design. The goal is to use it for Aerial Photography, lifting a mid-weight camera such as a Sony Nex5. It will of course be using Arducopter for control. ;)
I started off researching the various kits on the market, and starting getting analysis paralysis. I looked at all the options such as Droidworx AD8, Cinestar, CarbonCore, and SteadiDrone. But I just wasn't happy with the design on them, particularly for the price they ask. Combined with the fact that I can be pretty frugal, and have a strong DIY ethic, I decided to just design my own.
The basis of the design relies on many of the Hobby King quadcopter parts. I liked the design of the motor mounts, they are very professional looking, even compared to some of the high end machines. And I liked that the boom mounts are blocks of aluminum instead of plastic. Very rigid. I also liked the look of the dome on their H.A.L. quad, but since they don't sell it seperately, I bought the whole kit, it's only $34, amazing! I might end up using the rest of it someday, who knows? So, I basically emptied out their stock of Talon parts, so if you need to fix your Talon quad and the parts are backordered... sorry!
Once that was settled, I set about designing the center frame. My design required a few things, namely I want all the wiring hidden. I don't want any spaghetti showing. Particularly with the ESC's, while still allowing cooling airflow. This required the center hub to be larger than is typical. I then needed a smaller subframe to house the avionics.
You can see these plates below. The larger one houses the HAL dome. You will notice the 3 blue anti-vibration grommets in the middle. This is the APM1 pattern. I did that just because. Maybe I'll use an APM1 as a stand along gimbal controller. The second plate had grommet mounting for an APM2. The final plate is the top plate, and has bolt patterns for the Ublox GPS and the magnetometer.
This next photos shows the avionics frame built up with an APM2 mounted. 25mm aluminum standoffs are used. I don't like the plastic standoffs typically used. They get loose, and lead to vibration. They also break easily. This structure ends up being quite rigid.
Here is the avionics frame mounted on top of the main frame. Yes, the main frame is HUGE. I actually don't see the point in having a tiny center frame, and then long arms. This seems like it just leads to flex, and doesn't leave you with any real estate to mount your avionics.
This photo shows one of my design features. I put some cutouts on the bottom frame for weight savings, and then made matching cutouts on the top frames. This creates some nice conduits to run wires neatly.
Here it is with the HAL dome mounted and one of the Talon arm mounts bolted in. I'm really happy with how stiff the assembly is already.
Here it is with one of the arms mounted. These are the short 220mm arms, I also got some of the 320mm arms. One may wonder how I'm going to get away with such short arms and 13" props.... Astute readers will know what I'm planning already. ;)
This last photo shows one of the ESC's in position. This is a Hobby King F-40A, it's somewhat larger than typical 20A units which is partially why the frame is so big.
That's it for now. I had the plates cut out of aluminum to start with because it's cost effective. If it all works out, I'll probably have it redone in carbon fiber plate for the weight savings. I was a little uncertain about the weight, but it looks like the frame will come in at 1070g all in aluminum. That's about 300g heavier than a Droidworx AD8, but not too bad. It will drop about 1-200g if redone in CF.
Thanks and send me a tracking number when you have it. Did they say when it should arrive?
I know you are very busy with the CF parts.
But could you PLEASE send me the aluminum parts in whatever condition next week ?
I would really like to have them here before the end of the year .
Everything else is already sitting here, complete new set of avionics including new APM 2.5 etc …. Plus I have 6 days allocated for the project …wouldn`t like to see them going to waste
With respect, HB:
I figured that Rob probably also has a job, a family, his own hobbies, etc... and that he's willing to take our money and increase his personal project size is really going above & beyond for me.
Because of that, I've decided that for my own sanity I needed to keep my projects going - and am killing time playing with a cheap Hobbyking Talon (V1).
So that you don't get stuck without an octocopter project, or no project at all, I highly recommend just ordering something from Hobbyking (or elsewhere) so that you aren't stuck sans project!
It's not fair to lump expectations like that on Rob - he's not a web-store - he was goaded into doing this by us who wanted him to make us one too. :-)
HB, I wish I could, but they haven't even been cut yet. I'm sorry but I got really caught up in the CF pieces and I actually missed two days of work last week because I was sick and my daughter is really sick. Sorry, not to give a sob story, but it's just where I'm at. I will get right on it on Monday, and there's a chance I can still get it done by Friday.
What country are you in? I assume you want it for the Christmas holidays? I'm pretty sure there's still plenty of time.
Thanks for giving me the facts, and I am very sorry to read about you and your daughter being so sick.
So If you feel in any way that I put you under pressure, that was not my intention. So please accept my apology.
If you can get the parts sent by Friday or soon thereafter , that would be fantastic, I am so looking forward to compare it to my full-size octo ...
But please, put your health and your family first !
Btw, I am in Australia, you should have my address from my paypal transfer .
I hope you and your daughter`s health has improved.
Hi Rob, I just sent you an email about the shipping. Maybe my first message got caught by a spam filter? Just want to know if you have a tracking number so I can see where it's at.
This has been sent to Steve.
I believe I have 2 more CF kits ready to ship out, I just have to check who it is and figure out the final cost with shipping.
I just finished mostly bolting together the kit. I just have to stick the motors on the mounts yet. I'm pretty pleased with how well it came out. It looks wickid in black, and is good and stiff. I'm going to have to put together some kind of instructions or build tips.
One of the things I did with the kit was to include some riv-nuts for the canopy. Basically, if you use the HAL canopy, or whatever you are using, you can use these inserts to hold it down securely so you don't do what I did....
The holes for the canopy are still 3mm. I debated drilling them out and installing the riv nuts, but I wasn't sure if everybody would want these, so I decided not to. But if you ask, I can. It's super easy to do though. I'll get the drill bit size, but it's just a bit bigger than 3mm. Then insert the riv-nut, and just tap it lightly with a hammer to set it. They just sort of squish/wedge in. This isn't exactly the way you normally install these, but it seems to work fine on these aluminum ones.
So now you have permanently installed female threads in that bottom plate. Now when you mount your lid, you just have to put the red anodized aluminum 4-40 screws to hold it down. Real easy. And the red looks swanky! (I tell myself it's for positive identification of this critical flight fastener!) That's also what the 4 gold aluminum washers are for. (And you can tell people these are MIL Spec, for extra points, they really are! :)
I have been reading this thread with great interest. I am thinking of reproducing your design with some tweaks, so I have to thank you for all of the hard work you have put in to this design.
I have a question about props. I can't seem to find any 12x4.7 APC Pushers. I am not sure they even exist. In the absence of APCs, what do you recommend? It sounded like you were not super happy with the 12x3.8. Just curious about what you are planning on using.
Received my CF kit the other day. Everything looks great! I hope to have some pictures up of the build soon. Thanks Rob!
Yeah, I can't find those 12x4.7 either. I thought I had, but must have been mistaken.
After flying the 3.8's more, I think they'll be fine for the intent of the machine. I think a 12x4.7 would be better, but these will be OK in the absence of other options.
I cannot recommend any other props but the APC's. I have not found any which perform as well as the APC. Not that I've tried everything, but I didn't much like the no-name black plastic props. And I haven't heard many good things about Carbon Fiber props. And other guys that I have read, who have tried a LOT of props, even expensive ones, all come back to the APC.
I ended up getting CF props from FoxTech. Haven't tried them out but what bad things do you hear about CF props? Too stiff and may cause video problems? I've also seen some high end octos/hexes use wood props.
I've heard that they can break really easy. Even fail in flight. I dunno, just what I hear.