Basic design factors - help sought

[gb0wers]

Hi all, here are my first questions - hopefully somebody can enlighten me please?

I';m trying to put together a parts list for a quad and need a bit of help to understand some of the basics so I can make decisions on compromises.

This will be my first build although I have experience of flying fixed wing and a Hubsan X4.

What I';ll be trying to achieve with the first build is to hone my manual flying skills and then get into line of sight aerial photography / video using something like a Mobius. And I';d like to be able to add FPV capability. Ideally I';d like a flight time of 10 minutes. And ideally maybe pop on a 200g compact digital camera - canon S95 or the like - but would accept shorter flight times for that. I';m thinking either 250mm or 400mm classes. Budget up to £200 excluding Mobius, FPV, LiPo / charger / radio control Tx+Rx.

I already have three LiPo sizes and I don';t really want to have to get another. I have 3S1000 mAh, 3S2200 mAh and 4S2700 mAh and charging capability.

So, the questions:

First, how is "performance" described for a quad? Lifting capacity? Flight duration? Top speed? Other?
I';d like to have the ability to spec up a machine and have some understanding of its likely performance on paper.

What are the basic design rules? For example as how many watts per pound (or Kg) are required for a quad? And pros / cons of spinning big propellers slowly vs small props fast in the context of a quad? Are there better places to go for propeller performance data? http://www.apcprop.com/v/downloads/PERFILES_WEB/datalist.asp
Anything else relevant that I haven';t asked?

I know I could just copy somebody else';s configuration, but I';d like to understand this stuff in the way i understand fixed wing.

Cheers

Graham

[Hands0n]

To start with you could make good use of an online resources called eCalc to play around with various configurations to get a feel for what the different parts do in a specific configuration. I';d suggest to Google for it or search this forum for a link as I';m not at a PC.

The free version is a bit basic. The £0.99p paid version contains specific makes and models of components. Worth subscribing of you';re getting into design and build

Sent from my Nexus 5 using Tapatalk

[gb0wers]

Thanks Hands0n, I hadn';t found that. Graham

[Hands0n]

Here you go Graham: http://www.ecalc.ch/

For Multi-Rotor the specific URL is : http://www.ecalc.ch/xcoptercalc.php?ecalc&lang=en

Enjoy