For some reason the 2.5" (or 65mm) size is just my favorite all-around size, despite there being very few options for frames and props. I'm mostly inspired by the excellent Tinyhawk 2 Freestyle, but the EMax vendor-lock-in makes it very hard to do more with that platform.

Enter the Tadpole 2.5: A lightweight frame from the wonderful folks at Armattan; tiny but still built to their high standards. It's not got a lot of space in the frame, but it's very well-designed. The default is to use a 16x16 stack, but I really, really hate that form-factor (everything is pin headers and pain). Fortunately they designed a 25mm whoop bracket which opens up a plethora of possibilities, what with all the new AIO boards out there. You could probably use a whoop board without the bracket if you don't stack anything on top since there's just two holes in the frame bottom for it. Cabling and soldering will likely be a bit of a challenge and it took me 2-3 tries to get everything worked-out exactly right.

The back-end is cramped a bit with a R9 receiver, capacitor, Foxeer lollipop vtx antenna, and mini 900mhz T-antenna. I routed the battery leads around the outside of the rear bracket and it just clears the rotors. It's not great but it all seems to work.

Lets talk motors. The 9x9 mount pattern is the 11xx standard, and most Xing c-clips fit just fine in it. Originally I built this with 1204s, but the battery life was garbage. The Xing 1105 4500kv motors fit the bill perfectly (and the colors are extremely fly). They have great battery life on 4s and pack more than enough punch to fly the whole rig and an insta 360 go. I love these motors! My only complaint is they only have 2 M2 holes for mounting props (I always use screws to t-mount the 1.5mm shaft props). I've had a set of motors that finally wore-out the holes so it'd be nice if there were 4, but it's a minor quibble.

For the main board I opted for a hakrc AIO because 20A for like $35 you can't go wrong. Who cares if it's just an F4? The only awkward part is soldering the negative battery lead is super close to the USB port. BUT since the outside of the USB is ground, it actually doesn't matter if you get a bit messy with the solder.

Video-wise I got a relatively OK flywoo VTX (with screw-locking u.fl connector) and a Runcam Racer 2 nano (eh, it's not great but it works). There's not a ton of clearance between the back of the camera and the front whoop mount, so be careful.

Overall I've got it at 156g with a 4s 450mah battery. This is a great power/weight ratio and a very suitable park flyer for dinking around playgrounds and other very non-serious locations. What's surprising is just how much lighter than the next size (an Armattan Gecko 3") which tops the scales at 300g.