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.

Views: 81297

Reply to This

Replies to This Discussion

very nice.....

Is it as rigid as you hoped

cant wait....

The 1/16" CF plates are not as stiff as I had hoped by themselves, but when assembled into the frame, using the aluminum spacers, the structure is very stiff.

Rob, can I make a small addition to my order? I am probably going with the full length arms instead of overlapping the props. I don't mind the size and I don't think it will effect the camera view but anyway I would like to have the motor risers as an option. Can you add them to my order. Send me the final total when you have it so I can pp you the rest.

I noticed you are using bullet connectors on the motors. I stopped using those years ago after causing some crashes. Wasn't really the bullet connect but that they came poorly soldered. From then on I've been soldering direct even though it can be inconvenient. Maybe putting a shrink wrap over it after connected can help.

Rob, are you still using the H.A.L. landing gear or have you found something better? I didn't get any yet because it seemed the H.A.L. ones were too flimsy. Would be interested to know if you found anything better.

I am not using the HAL anymore, as I broke it.  I am just using the little carbon fiber "teeth" that come with the Talon motor mounts.  It's just temporary, just enough to keep the batteries off the ground.  I'm working on a design for combined landing gear and camera gimbal.

Which size arms are you going to use?  220mm?  Do you have them yet?  I actually bought a bunch to use but never used them.  I can sell them to you if you're interested, let me know.  Yes, I can include the motor risers in your order.  I'm planning on ordering the hardware today, I should get it tomorrow, then assemble your kit tomorrow night.  We'll have to figure out your shipping.

Yes, I've heard about the problems with bullets.  But they are convenient, and the Octo is resistant to a motor failure anyway. I also put one piece of shrink tube over both connectors after I get the direction sorted out.  So they can't come apart in flight.

Very nice in black Carbon Fiber! :) me like it!

Good job!

Did you get the gimbal kit from Rusty? I got mine the other day but haven't started on it yet. I will have to improvise some legs but looking forward to what you will create.

I got the extended arms. My first plan is to not over lap the props. I will be using the 12" CF props from fox tech that i indicated earlier here. Is it possible to use the 22cm arms without overlapping? I thought at first you were using 22cm but then was surprised to see that you had cut them in half. I just can't get it through my head, how big the center piece is until it's in my hands ;-)

So if 22cm will allow the props enough distance without overlapping then I might be interested because as it is with the 33cm it will be huge though not a problem. Let me know the price. Also I will need to give you my shipping address as it's not the same as the paypal billing.

I will do the same with my motor connections. Not worried as much with an octo and with the extra shrink-wrap is should be fine.

Ok everybody, I just received all the rest of the hardware to make these kits.  Well, the CF ones at least.  At this point I'm not quite sure how to proceed, the big question is around the shipping cost.  I really won't know how much until you tell me how you want them shipped.  Actually, I guess I can probably get the price online.  So just let me know what kind of service you're looking for.  I assume the addresses in the Paypal is correct?

F11Music, I'm hoping to ship yours first because of your time constraints.  It's probably going to have to be 1 or 2 day air which will be expensive.  Is that what you want to do?  You'll have to send me your address so I can try and get a price.  I'd like to ship yours tomorrow, but I have to get the quote, then you have to finish paying and then I can ship.

Also, on the hardware, originally I said $80, but I have come up with a slightly better system.  Basically I want to supply new threaded standoffs to replace the ones used with the Turnigy Talon arm mountings.  You all should have 2 20mm standoffs for each mount, but I have found they are really really soft (like the rest of the Turnigy alloy).  Mine are all buggered up from the crash and don't sit flat anymore.  I think the whole structure will be stiffer if I include industrial grade standoffs the same as the others I supply.

In addition to that, I've come up with what I think is a better system for mounting the canopy, so I don't have the same problem again...  Basically I'm going to install some riv-nuts into the bottom avionics plate in the 4 mounting locations.  Then include red anodized aluminum screws which you use to fasten down the canopy.

So if you want these upgrades, I have to charge $90 for the hardware.

I don't need the hardware. Post works for me what ever is easy for you

I got mine yesterday - began

Reply to Discussion

RSS

Groups

Season Two of the Trust Time Trial (T3) Contest 
A list of all T3 contests is here. The current round, the Vertical Horizontal one, is here

© 2020   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service