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Update 11/28
11/29/2021 at 01:13 • 0 commentsTLDR:
1. Got all radio components
2. Settled on final airframe design
Details:
1. Working on implementation of the CRSF nano to my F405WING FC. UART1 didn't work but after some reading it seems that the move is to go with UART2, and run RC by Mavlink on the CRSF receiver.
2. settled on high-wing airframe. Seems easier to make, and much more slicked out for being a bigger airframe than the Talon. Only thing is that I will need a carbon rod or two. -
Crossfire Radio and HAM Licensing
11/17/2021 at 16:24 • 1 commentRecently, I received the first part for this project, a Crossfire radio system (thank you ECE depot at the U of M!). This is a long range radio link with up and down telemetry. This radio, unlike normal RC links (2.4GHz), operates on 900MHz (@ up to 2W, but that isn't legal even with a license). This band is classified as UHF. To operate in this band, you need an amateur radio license, specifically a technician class license.
Getting a HAM License is not the easiest, but definitely not the hardest. There is a ton of study materials out there. One of the ones I've liked so far is this one:
https://www.kb6nu.com/wp-content/uploads/2018/11/2018-no-nonsense-tech-study-guide-v1-1.pdf
Fairly straightforward language with plenty of sample questions in it. Another great place for finding questions is here:
This has the actual bank of test questions.
I personally have not taken the test yet, but I plan to in about a week or two. Until then, I will be starting airframe design, based on the Talon style frame.
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Initial Research
11/15/2021 at 17:02 • 0 commentsThis is the start of the project, and thus the start of the research phase. The first step here is to do a high level summary of this project.
What are the needs of this project?
- Flight Capable UAV
- Autonomous
- Telemetry link throughout flight
What are the wants of this project?
- Long flight time (30-45 minutes)
- Able to be broken down for easier transport
- Full FPV/camera integration
This gives a good idea of what has to happen. The next big step is deciding the UAV design. A good place to start is where I am familiar. While thinking of this, there are three main ideas that come to mind.
The first idea here is a "Talon" style UAV. This is a widely popular design in the world of small UAVs. It features a motor mounted on the tail, high wings, and a V-tail.
Pros:
- Already well known for being a good UAV design
- Fairly compact
- no long carbon rod based tails
Cons:
- Not as familiar with tail mounted engines
- Seems difficult to balance
The second idea is a "twin-boom" style plane. These are popular with slightly larger UAVs, and are characterized by two "booms" going out to the tail.
Pros:
- Easier to balance, can be done by adjusting tail length.
- Either dual rudder or inverted V-tail
- Easy to scale
Cons:
- Large carbon booms can be expensive
- Almost necessary to have landing gear
- harder to teardown
The final is a "high-wing" style plane. This is possibly the closest to a traditional aircraft. Features a motor facing backwards on a raised mount and a long boom tail. Can be either a T tail, V tail, or a standard tail.
Pros:
- Easy to balance
- Fairly simple
Cons:
- Long carbon boom tail
- Tail can be hard to support well
These are the options so far. I am partial to the Talon style right now, just for its lack of large carbon supports and its compactness. I plan to make a final airframe decision this week, and get the design started. I will update this log once I have an initial model either in Fusion 360 or SimplePlanes (which by the way I recommend for some rapid prototyping for aircraft).