Ken/Cluso99/ W9GFO/JasonD's QuadCopter Build Log (updated info ELEV-8 + availability)

[Ken Gracey]

Nice picture Ken, very Christmassy.

Have you decided to stay with the round tubes?

Rich, yes. The round tubes are very light, plenty strong, and favored among our internal team (and more importantly, hopefully the community). I admit we're bucking the trend in this regard and hope that it works out. Usually the only round tubes I've seen are carbon fiber. We could use your photography skills at some point on this project BTW [hint hint]. I know what you're thinking "get me a kit and you've got a deal!".

Thanks,

Ken Gracey

[W9GFO]

Photography will happen, for sure.

I do agree that the round tubes look nicer, and it is a better shape for something that moves through the air.

[Cluso99]

The round tubes look nicer. The square tubes are easier for DIY, but will probably weigh quite a bit more although I am unsure this really matters. Only time will tell.

I do hope to finally get time to add the gyros into the code over the coming w/e.

[ratronic]

Ken back in post #145 you said you were making up only so many kits for the forum members. I would like to preorder your kit #3 from post #271. I have a trm/rcvr just need to get a battery. Is your kit comming with a connector for the battery side or do I need to order a battery with a particular connector?

[Ken Gracey]

Hey everybody,

Thought I'd better bring you current on where we are from a cost standpoint.Back in post #271 in this thread I discussed possible prices and packages. Since this is a totally open product, drawings and all, we should also be open about the costs. Everybody who buys an ELEV-8 should feel they're getting a fair deal, right? This is what I mentioned in post #271:

1. Airframe with mounting hardware (target price of around $100)
2. Airframe with mounting hardware, with motors, ESCs, props, wires, connectors (target price around $325)
3. Airframe with mounting hardware, with motors, ESCs, props, wires, connectors and Hoverfly SPORT (target price around $550)

I think #1 can happen without any difficulty. What I'm showing below in the graphic really describes #2 above, okay? We targeted $325 and you'll see from the draft bill of materials below I think our costs are somewhere around $166. This is what's not included in the $166 internal cost estimate shown below:

• Inbound shipping from China for HobbyKing parts; inbound shipping on all other pieces from other suppliers. Add 25% cost to all HobbyKing parts for shipping.
• Stocking, kitting, and parts procurement from Parallax staff. We pay California wages.
• Parts that are sent out to/from anodizing.
• Cost of lead times and cash expenditure for inventory that doesn't generate return instantly.
• Purchasing manager didn't have a chance to shop the Acetal Delrin yet, and it's expensive. That might go down.
• Heatshrink. Not sure of the best source to procure that. Got a tip?
• Issuing/receiving of internal work orders to transform raw material to finished goods. An administrative cost - not too consuming.
• Non-recurring engineering costs. Design, documentation, assembly costs to prepare pictures, video, etc. This is being done on free time from myself, Nick and Kevin since we couldn't justify it easily internally. You'll see that from the timestamp on our posts.

I imagine our complete costs (all burdened labor, materials, shipping) to assemble #2 are probably about $275 or so after including the above considerations. I think the $325 mark is entirely reasonable for #2 and that #3 could be offered for about what we guessed at $550. ELEV-8 just might pay for itself if enough are sold over the long term. Distributors won't be able to buy the kit because they would simply make it more expensive for you (ie, factory-direct sale only). And it can't have an opportunity cost once we get into manufacturing, meaning it must not occupy our staff when they could be doing more productive projects (and that we might run these parts in the evening). I want to be open with the numbers so customers understand how the price is calculated for ELEV-8 (and to provide some internal justification for being involved in this project). Also, somebody else might want to take over the project at some point.

Attachment 0Attachment 0

Please share your feedback on any points or concerns. I don't want to be in a vacuum.

Thanks,

Ken Gracey

[Ken Gracey]

Ken back in post #145 you said you were making up only so many kits for the forum members. I would like to preorder your kit #3 from post #271. I have a trm/rcvr just need to get a battery. Is your kit comming with a connector for the battery side or do I need to order a battery with a particular connector?

Gotcha, Dave. Consider it done.

The battery will use the EC-3 connector (not a dean, as they are too expensive).

Ken Gracey

[Ken Gracey]

Just so there's no confusion, we'll start this with the SPORT board and switch to the OPEN when it is available. If you buy a SPORT and then want the OPEN we'll figure out some kind of discount so you're not paying full price twice. The OPEN is in prototype stages now. The prototype area is for an accelerometer or GPS. Should be fun, right?

Ken Gracey

[Cluso99]

Wow that is an extremely keen price Ken!

Perhaps you should state the battery is not included, as it is often purchased at the same time as motors, escs, etc.

I am trying the velcro style straps from HobbyKing to fasten the battery.

I have noticed the "O" rings for the propsavers are snapping while just holding the propellors on (without use). I am a bit concerned about these in flight so I might see if I can buy some better quality Orings locally.

I have ordered larger 11x4.7 props as well as 3blade 8x4 (normal and counter-rotating). Hopefully I will get either Sat or Sun to try the gyro code.

[Dr_Acula]

That looks very nice. I'll pay more - $1000 or more for a 'flying for RC dummies' package. Or more specifically, "flying for people who are happy coding GPS waypoints into software but are not capable of gently landing a helicopter in a light breeze."

(My RC helicopter remains stuck in the top of a tree!)

I found this nifty video http://multirotor-news.com/2011/07/1...ion-hold-ever/

I presume you need a GPS to be able to do this? Set a 'home' point. Fly to waypoints that have been preprogrammed. Hover in windy conditions. And something not demonstrated in that video but which ought to be possible - return to the home point and then slowly descend if the batteries are running down.

I don't know how that would work out in the field - I guess a laptop and a USB cable and some simple software to code the waypoints?

[Cats92]

It seems very clear and nice.

I read that you are working on the documentation , pictures and videos. Its a key to get ELEV-8 flying nicely.

When do you hope to have a first draft ?


Jean Paul

[ratronic]

Thanks Ken. I've looked but didn't find the voltage? I found this battery which is an 11.1V. Maybe the voltage was discussed back in Clusso99's original thread?

[Cluso99]

I am pretty sure Kens motors are 11.1V. You would be better off with a higher 35C. Not sure how heavy 4000mAhr is compared to Kens. I have a pair of 1800mAhr IIRC which is really too low unless I use both.

[ratronic]

Thanks Clusso99.

[Cluso99]

I found that the prices were not much different for the higher 35C batteries. The 35C refers to the usage current. Remember we have 4 motors all chewing up significant current. Even higher values are possible but they tend to cost more.

I did find a calculator somewhere recently (try google) where you could put in your battery, motors and propellers and it would calculate the flight time.

[ratronic]

I would be interested in what Kens battery weighs in at?

[Cats92]

MORE IS NOT ALWAYS BETTER

My drone was spinning like a fool and I did not understand why.

I have put foam rubber between the central frame and the booms (as anti vibration)

Bad idea : the propellers were a bit tilted and not in the same plane.

Without this foam rubber it flys much better.

Jean Paul

[Ken Gracey]

Hey all,

While we wait for parts from HobbyKing to build our first 25 sets of ELEV-8 kits we have been preparing some SolidWorks drawings for you. These will be for any purpose you desire. We will provide DXFs, SolidWorks and any other native export we can easily produce. In the true spirit of open-source, you can do whatever you want with the drawings. You can even build your own quadcopter and sell them.

Ken Gracey

[Kye]

Nice to see this project almost complete!

[Ken Gracey]

Nice to see this project almost complete!

I concur - I've worked on this project nearly exclusive of my office time since it's a hard one to justify from a business perspective. Of course, my time is exactly that - my time! But if the office crew had it their way I'd be out selling products instead of flying quadcopters around.

[mindrobots]

A happy boss makes for happy workers!

{I like to think that anyway, then I can apply the corollary and picture my boss sharing the misery of my work life. }

I need to make sure Matt still has my shipping address so he can send me one of the first 25 for my future product predictions!