Hi guys,
New to the forum, new to RC and new to UAVs - the trifecta! I have some very low beginner level questions - I'd really like some advice please.
I'm planning on building an all-purpose, versatile airframe which I'll be able to replicate for several different drones for a range of applications, from aerial photography or surveillance through to environmental sensing and carrying light to medium sized payloads.
I've been doing a lot of online research, and have found two airframe options which I think seem very lightweight and most promising so far - one is a CF/Al octocopter with 8 arms, the other is the same but with 4 arms (two motors per arm):
http://www.riseaboveaerials.com.au/...671/vulcan-skyhook-octocopter-frame-kit-900mm
http://www.riseaboveaerials.com.au/#!product/prd1/716736621/vulcan-skyhook-x8-frame-kit-900mm
I've also been playing around with eCalc to determine an appropriate combination of ESC, motor, battery setup and props - the best setup I've been able to achieve so far is in the attached screenshot.
View attachment 14315
Here are my questions...
1. I'm working on the basis that I want as light a frame as possible, so that the majority of the weight is in the batteries, therefore hopefully balancing increased weight with increased flight time. So I'm leaning towards the 4-arm, 8 motor octocopter at this point. Would there be any advantage at all in going for the 8 arm octocopter instead? I read somewhere that you lose about 30% efficiency by combining two motors to one arm, but the 4-arm option is roughly 30% lighter than the 8-arm option. Unfortunately eCalc doesn't seem to have an option for simulating doubled-up motors - can anyone give me an expert opinion on this?
2. Which would be more stable/reliable in the event of a motor failure - a 4-arm x 8-motor frame, or an 8-arm x 8-motor frame?
3. Are there any other pros and cons for these two options?
4. Both of these frames are 900mm diameter, but are also available in 1200mm diameter. The 1200mm diameter frames are of course heavier - is there any advantage to a wider diameter frame which might outweigh (so to speak) the disadvantage of the additional weight?
And going a little further...
5. Are there any differential GPS systems commercially available, or even better RTK systems? Is anyone aware of anyone who has successfully set up an RTK system with a mobile base station - eg. a car/ute mounted base station? Is this even physically possible?
6. Would it be possible to set up a UAV base station which charges the UAV by induction loops (ie no wires & plugs - no human intervention)? Has anyone successfully done this or seen this done before?
Thanks for taking the time to read this far. I'm sure some of these questions will be fairly dumb ones - like I said, brand new to RC and UAVs. I really appreciate any help anyone can give me.
Cheers
Gareth
New to the forum, new to RC and new to UAVs - the trifecta! I have some very low beginner level questions - I'd really like some advice please.
I'm planning on building an all-purpose, versatile airframe which I'll be able to replicate for several different drones for a range of applications, from aerial photography or surveillance through to environmental sensing and carrying light to medium sized payloads.
I've been doing a lot of online research, and have found two airframe options which I think seem very lightweight and most promising so far - one is a CF/Al octocopter with 8 arms, the other is the same but with 4 arms (two motors per arm):
http://www.riseaboveaerials.com.au/...671/vulcan-skyhook-octocopter-frame-kit-900mm
http://www.riseaboveaerials.com.au/#!product/prd1/716736621/vulcan-skyhook-x8-frame-kit-900mm
I've also been playing around with eCalc to determine an appropriate combination of ESC, motor, battery setup and props - the best setup I've been able to achieve so far is in the attached screenshot.
View attachment 14315
Here are my questions...
1. I'm working on the basis that I want as light a frame as possible, so that the majority of the weight is in the batteries, therefore hopefully balancing increased weight with increased flight time. So I'm leaning towards the 4-arm, 8 motor octocopter at this point. Would there be any advantage at all in going for the 8 arm octocopter instead? I read somewhere that you lose about 30% efficiency by combining two motors to one arm, but the 4-arm option is roughly 30% lighter than the 8-arm option. Unfortunately eCalc doesn't seem to have an option for simulating doubled-up motors - can anyone give me an expert opinion on this?
2. Which would be more stable/reliable in the event of a motor failure - a 4-arm x 8-motor frame, or an 8-arm x 8-motor frame?
3. Are there any other pros and cons for these two options?
4. Both of these frames are 900mm diameter, but are also available in 1200mm diameter. The 1200mm diameter frames are of course heavier - is there any advantage to a wider diameter frame which might outweigh (so to speak) the disadvantage of the additional weight?
And going a little further...
5. Are there any differential GPS systems commercially available, or even better RTK systems? Is anyone aware of anyone who has successfully set up an RTK system with a mobile base station - eg. a car/ute mounted base station? Is this even physically possible?
6. Would it be possible to set up a UAV base station which charges the UAV by induction loops (ie no wires & plugs - no human intervention)? Has anyone successfully done this or seen this done before?
Thanks for taking the time to read this far. I'm sure some of these questions will be fairly dumb ones - like I said, brand new to RC and UAVs. I really appreciate any help anyone can give me.
Cheers
Gareth
