Hi there,

after working on frames based on carbon tubes for the last 3 years, this is the latest one of my designs. It's a TrueX design which is targeted for aggressive freestyle and racing / chasing. This build is only 4s, yet has a maximum thrust of over 4 kilos, while it's weight is only 190g (w/o battery). I needed to limit the motor output to 90%, otherwise when going full throttle the battery would drain way too quickly ^^.
And before you say "But tubular frames have issues with vibration and torsion!!" -> I added a blackbox log of GYRO_SCALED of a throttle ramp that you might find interesting :-) I've been optimizing tube-based frames for a few years to "solve" this issue by design.
The trick is to glue to rods into the 3d-printed parts using superglue or (better:) epoxide. That combined with a few design tweaks that i've learned over the years.
I plan to do a build tutorial video on my YT channel soon.

Regarding the frame:

The big benefits of this design:
1) you can build it at home with a 3d-printer and a simple saw (for cutting the carbon tubes)
2) the price for a frame is around 10$ (except the >8" versions, they are a bit over)

You can find this specific design here: https://www.thingiverse.com/thing:6165253
There is a TrueX, WideX and Deadcat version in many different sizes. You can find an overview here: https://www.eyeflydesigns.com/
Also there is a Discord where you'll get all the support needed for building your own: https://discord.gg/R6SYpZbgku
This TrueX-version is the easiest one to build, and i highly recomment going for this one as your first tubular build.
There also is a 3" version available - and i'm working on a 12" version right now ^^

Regarding the build itself:

This is a 4s build. I know that 6s is way more popular, but i dare you to try it out on 4s. The RCinpower 2104 3000kv are just crazy on 4s and 5" props. You have a great throttle authority throughout and it just flies amazing.
I'm using the DJI O3 system because... well, there is nothing comparable out there right now if you want best picture quality - and you're not super sensitive to latency (i do not notice it).
Now i know O3 isn't really a racing platform. However i'm just not really a racer. I'd love to build a strong canopy for it, but therefore your input much be much appreciated - what VTX and Cam should it support?

If you have any questions, hop on Discord :-)

Cheers,
Nic