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.
Replies
Ok, is there anybody else out there interested?
I have the first batch of 6 sold, and I have an additional order from Dave C which starts the next batch of 6. I think if I can get to 3, I might go for it all in one go.
HB, are you interested in upgrading to CF?
Hello. Im a little confused are you saying that coaxial props are less efficient than conventional single props?
regards Eddie
I have deposits from:
-Kevin Brown
-Doug B
-Jake Bayless
-John Kroening
F11, I'm holding the last spot for you, but I don't have your deposit yet.
And the pricing on the plates made in 1/16" 6061-T6 aluminum for main plates, and 0.050" for the avionics plates, provided as-cut on water jet (ie: some rough edges and cuts show a sand-blasted appearance as shown in the images) is $100. I will extend a price of $75 for the next week when the first batch goes in.
These do not have nearly as much batching problems as the CF, but I would like to see the interest for 1 week before placing the order.
In the future, if there is demand I will investigate finishing operations on these, such as deburring and anodizing.
Ok guys, I just finished putting together the BOM. The pricing is as follows:
- Premium Plate Kit. 1/16" Carbon Fiber Main plates (large) and 1/16" G-10/FR4 Avionics plates, CNC cut.
- $325
- Premium Hardware Kit. All non-Hobby King hardware necessary to assemble the basic frame. This is all SS or Aluminum hardware. No plastic or steel screws. To include solid copper washers for use as the power distribution bus, and plastic washers and screws to go with it. Also includes 4 vibration damping grommets, and plastic screws, nuts and washers for fastening the APM2 with the grommets.
- $100
- Motor Riser Kit. This includes the spacers necessary to do the overlapping props, and long screws. I also include short screws to replace the terrible Philips head screws included with the NTM motors. Screws provided are quality steel alloy hex socket flathead screws. The screw finish might not be quite what you're used to, because I plan to supply grade 10.9 hardware, and you don't always get the nice shiny black finish you have on cheap screws. The ones I have are a dull dark grey. This is in line with the more industrial philosophy being used.
-$30
However, for a limited time, I am going to offer these at a discount for early adopters. This is both as a thanks for your faith in me, and because... well you're taking a bit of a chance on this. You've seen the assembly, and some flight videos. The concept works, but I can't guarantee performance obviously. Also, I have no documentation... but as you can see, it's pretty straight forward. Basically, you're getting in at the beginning of this, and will be the first to see parts, at the same time I do. I noticed no problems with the aluminum frame, and the CF frame should be stiffer and stronger. Amazingly, the frame appears to have survived a quite incredible crash as you have seen.
So, I will offer the plate kit at $275, the hardware kit at $80, and the riser kit at $25.
"Hurry up folks, you know I can't do this all day!" ;)
I'm putting 5 kits up from the first batch. Please send a deposit of $200 to reserve your spot. This deposit is not refundable if you change your mind, unless I can sell the kit to somebody else at which point you would be refunded in full. The deposit is of course refundable if I fail to deliver.
If more than 5 people put deposits, and I get to 11 by early next week, then I will attempt to get the shop to cut more in this first batch. If I cannot do that, I will refund any excess deposits by the end of next week.
Kevin Brown, I know you expressed interest in getting 2 kits, but I would ask to please hold that at 1 for now. I will extend the lowered pricing on your second kit in the future. I will also extend the the lowered pricing to anybody on that list, if they do not make the first round. It only seems fair as you've shown interest, but this has sprung up quite suddenly.
You can send me a Paypal at robert.lefebvre@gmail.com.
Shipping will be extra. I'd like to be flexible here, as people in different countries have different requirements. Personally I prefer using the postal system, but I can do FedEx or UPS as well. DHL might be another option, but I'd like to try and keep the variability to a minimum.
I just got a quote back for production of the frames, the pricing looks pretty reasonable, I think. However, they still end up being a bit pricy due to the center plates being so large. I just have to put together the BOM and pricing on the hardware kits now. This is the parts other than Hobby King parts. So screws and spacers mostly.
Now here we have another choice. I use aluminum standoffs, they are far stronger than plastic, and avoid the use of mild steel screws (magnetism). But they are more expensive.
Would anybody really want to use plastic to save cost? I could do that. Again, maybe Econo hardware kit, plastic and mild steel. And then premium hardware kit with Aluminum and SS screws. I plan to offer the motor riser kit seperately, as some people will not do the overlapping design. There is no econo option here as these MUST be done with Aluminum spacers.
Oh, and I'm happy to report, if you look at the post-crash photos, the spacer system outlasted the motor mounts. The mounts are trashed, the spacers seem fine!
Went for a flight at the field today, and had a catastrophic failure. This was my fault, poor design/construction. Basically the canopy I was using was not fastened securely enough, flew off, and contacted the propellers. But it was flying great up until that point!
Any way, time to rebuilt. I actually think the electronics all survived, amazingly. I guess I'll have to get those CF parts cut.
I was thinking about trying to build a roll-cage instead of using these canopies, but I'm just not sure of the best way to fasten them? They would need some sort of aluminum block to mount onto the bottom avionics plates, which I don't really want to supply in the kit as I have no good way to make them. I still like the dome, I just need to find a better way to secure it.
I basically had used rubber grommets in the bottom plate, with screws in the dome that just pushed into the grommets. It's similar to how helicopter canopies are retained.
I change my preference to: Premium with CF base and G10 upper.
-
7
-
8
-
9
-
10
-
11
of 13 Next