Thank you!
I know there are still improvements to be made, but time is running out and I decided to release this version of Tetra 3 before Tetra 2 Lite is completely forgotten. I would like to make other styles of drones.

What other frames do you have planned or would like to pursue? I would love to see more of your designs!

I have two prototype frames in work. One is a true-x quad frame (3-3.5") for double stack mounting, with tetrahedral construction for each of the four adjacent motor pairs. It is not as rigid as a simple Tetra frame, but it is easier to repair and has a lower CG. The other is a rather experimental frame that uses a servo to keep the battery in the horizontal position as it flies forward to reduce the aerodynamic drag. This is actually the second prototype. The first one flew well but was a bit fragile.

There are two other prototypes in abeyance, one for the Micro Hexa and one for the Tiny Octo. The motor layout is flat, but the footprint is smaller than a normal frame. Even though the motor layout is different from the regular hexagon or octagon, I found that they fly well if the motor mixer is set properly. These prototypes will be reconsidered after the above two projects.

That is absolutely incredibly my guy. What benefit does the first prototype have over the conventional toothpick platform? Still a pretty cool concept though while using similar tetrahedral construction from the smaller variants. I'm curious to see what that second prototype looks like. Seems like its focused on speed given you're prioritizing lowering drag.

very interesting work man! this is the exact reason why I follow you XD do you happen to have a YT channel where you showcase these frames? Would love to find more of your work if you have it on other platforms.

I think the ideal CG position for a multicopter is the center of thrust. Therefore, when I started my Tetra project I intended to mount two batteries connected in series under the upper arm, but this idea was abandoned because i realized it would be too cumbersome to prepare for each flight. Therefore, unless the battery is very light, the CG position is far from ideal. On the other hand, with current technology, the actual C-rate of LiPo batteries is rather better for larger ones. Therefor, in order to maximize thrust with the CG position close to the ideal potion, I think it would be a good option to build a long platform quad with a double stack configuration using the tetrahedral structure, if possible.

Lately, many people are building super fast quads with rocket style shells. I too like to fly fast, but I have no intention of participating in top speed races. I just want to enjoy more efficient high speed cruising without an aerodynamic shell.

I have only registered on YT, but not yet published. I am not very active on social media, so don't get your hopes up.

That version of the 2.5” Tetra kit was designed in response to requests received in messages on this site, and was only available for a short period of one month. It was actually the first prototype of the 2.5" Tetra, which I enjoyed flying with 1404 3800KV motors, but had strong frame resonance at 160-210Hz which still remained with the default filters. Since then I have been trying to improve it along with the 3" versions. Now finally released at Armattan productions, it is no longer lightweight. If you don't mind the 2.5g weight increase, the URL for the Tetra 25 (for 14mm wide camera) kit is https://armattanproductions.com/pages/kit_detail/3348.

I have already designed the first prototype of the 3.5” Tetra, but have not yet built it. I have to modify the design of braces, because the longer braces might have frame resonance at visible frequency (~100Hz), which is not acceptable for HD FPV. It will take time to release the 3.5” Tetra because I have another project. I hope to release it within 6 months.

If you wish, I would like to list the Tetra series on cncdrones.

glad i was able to get one of the prototype collector's edition! :) the version you built with the o4 lite looks great. 2.5g seems like a reasonable trade off for the increased durability. i built mine with 6000kv 1202.5 motors, 65g dry weight. no top end thrust to speak of, but it was great for gliding along like a little bird. i was flying it over a frigid winter sea so I didn't get a realistic impression of flight time -- it was about 5 minutes to 3.5v with 450mah HV 3s or 4s fighting a freezing wind. but i expect in warmer weather it would fly for longer. i may transfer the build over to this 3" version that you've built for the sake of comparison. personally i would love if the tetra series was on cncdrones. :) looking forward to the 3.5" tetra and whatever you come up with next!

Short motors are lighter, more efficient and probably have a longer life. My old 1202.5 11500KV motors (FPV Cycle) are scratchy but still work well. I built Tetra 25 with Amax 1504 6000KV motors (3S) which are pretty heavy (about 12g each) but work quite well with HQProp 63mmx8. Thanks.