there are lots of type of VTOL UAVs that can be used for aerial mapping platforms, for my personal option, I like 4+1 configuration. Simply it is more reliable and more stable on dual batteries system.
there are many of 4+1 VTOL Mapping platform in the market, I can list more than 30 of them, here I am introduce you the full composite material VTOL platform-Swift VTOL.
here is the question, is it expensive to build?
it is not cheap to make a composite material frame for sure, it is time consuming and also master skill required..
The Swift Composite Material VTOL Mapping UAV is a high quality Vertical takeoff and Landing fixed wing UAV with a very safe,more high reliable and effcient features. It can take off on ground less than 1 square meter, and had 1.5-2 hours duration depends on its payload. We have tested the aerodynamics both on simulation software and real field test, it is designed so that the air provides the optimal upthrust with minimum resistance. It can takeoff with 6S batteries power instead of 12S, when it cruises, the current usage is between 8-10A, the power consumption of this plane is 140mAh/1km, and futhermore, it has large interior fuselage space, so it can carry large size of payload or large size of 18650 li ion batteries pack.
you can choose 5010 400kv motor with 17-18 inch foldable props and 60A 6S ESC for quad propulsion system. 3520 550kv with 1380 props and 60-80A HV ESC for fixed wing propulsion system. 6-7S 18650 22000-25000mah li ion pack for fixed wing and 6S 4500+ lipo for quad motors. It has been tested and approved that it has 2 hours 20 mins flight time with payload (720g) for mapping mission.
list of parts:
so the cost of building it by yourself is around 3500$ for the VTOL plant only, and you have to choose your own RC or GCS and data telemetry.
you should choose high C rate (100 above) 4500-5500 mAh Lipo battery for Quad motors.
and you can make your own 18650 22000mAh Li ion pack for fixed wing Batteries. or purchasing online like two of 18650 12500 6S Li ion.
In conclusion, building your own VTOL plane requires master experiences, it seems to be easy and does require detail oriented and fully understanding of VTOL Arduplane. I am sharing the pixhawk parameters here.
the last two videos:
Introduce to Swift VTOL: https://www.youtube.com/watch?v=iOWLLDdv8mI&t=3s
Easy to setup the Swift VTOL: https://youtu.be/-I93z-QhB1g