An evolution of my D113, this one has a wheelbase of 124mm instead of 113mm. I was getting too much "dirty air" with 3 inch props on the old frame because the props were getting too close to the canopy. Punch-outs gave me some mad jello. But now with the larger wheelbase and custom canopy I'm happy to say the jello is gone. I also switched the props from the HQ T3x2 to the Gemfan 3018s and they feel great.

While I was increasing the wheelbase I decided to experiment with replaceable arms. Short answer: It works. However, replacing an arm is a pain and requires almost complete disassembly. It's also heavier.

My original intent with the Diamond series of frames was to experiment with freeing up the thrust between the motors and center of gravity. I was curious if additional stability or control could be achieved. In conclusion, I don't believe freeing up that area for thrust is doing anything special. However I do think that the weight being spread out more evenly is helping the overall feel in the air. Square frames like the Diatone Cube would probably offer a similar feel. It's also more robust than a single arm, but single arm designs lend much better toward replaceable arms.

This was my first go at designing a canopy and it turned out well. I'll be using this on other frames as well including a 4 inch ultralight that I'm building.

Other thoughts:

• 1104 motors are pretty small for 3in props. The quad might be a little bit faster with 2.5in tri-blades but I can't say for sure.
• It really needs 3s to fly well on account of using a bottom mounted battery due to balance issues (COG below prop line). Though I did get a few good 2s flights with some old GNB 550s. It helps that those particular batteries are so flat.
• The images show two different canopies. One is PETG, the other is TPU. I ended up going with the TPU (first few pics).
• Canopy is on Thingiverse: https://www.thingiverse.com/thing:4024637
• Frame isn't finalized yet. I'll make it available later.