Update

• I re-printed the frame with Fiberlogy PA12-CF filament. This filament is much more rigid. I'd like to try NylonX someday to see how it compares, but I don't have any. So far the fiberlogy filament is the best I've used for drone frames.
• I increased the motor output limit to 75% and swapped to Gemfan 3018 bi-blade props. (My motors are 4700kv, so this gives me ~3500kv). I found this combo to fly smoother. I also tried Gemfan 3016 tri-blades, but I liked the bi-blades better.
• The files are available on thingiverse now: https://www.thingiverse.com/thing:5982087

I had made a 3d printed 3in toothpick frame a while back, and it worked well, but I really didn't like having the props in view. I finally found some time to make some revisions. The main design is similar, but widened, with additional holes to attach the camera and vtx antenna TPU pieces.

I wish I was better with the 3d design stuff, but this is functional :)

Weight: ~105g dry (165g AUW w/4s 550mah)

I'm running this 3in build on 4s with 1404 motors, but this can be built many different ways.

I need to clean up the motor wires and secure the VTX antenna with a zip tie.

Notes:

• Printed using GF PP and TPU
• Uses m2 hardware for mounting the stack and m1.4 modified truss head screws for attaching the TPU parts and bottom cover
• I'm using HDZero, but this should fit anything that has a 25x25 mounting pattern. It may require adjustments to the height of the cover that goes over the middle though.
• You'll notice in the photos I have a power lead with 2 xt30 connectors. This is so I can re-use my 2s lipos I already have for my 2s whoop.
• I'm using XNova 1404 4700kv motors because they are what I had on hand, but that kv is too high. I have a throttle limit of 60% set (~2800kv). I like this amount of power/flight time. You can use higher kv motors at the cost of flight time due to more amp draw.
• I'm using the older version of the JHEMCU F411 AIO with 25a rated ESCs. At ~3000kv, this build doesn't pull many amps, though. It can't be more than 5-6 per motor, so 25a is overkill, but I think 20a+ is normal for AIOs that support 4s
• I'm getting ~6.5min flight time down to 3.65v in the OSD just cruising around with light acro. Lipos recover back to ~3.75v after a few mins.
• I had to use a usb cable with a long tip to reach the usb port on the FC because of the way the FC fits inside the frame. This frame was really designed for whoop-style FCs where the usb port points down, but it's hard to find those kinds of FCs that support 4s.
• I tried making the frame bigger and thicker for a 4in build, but it wasn't as good. At that size, it's hard to maintain the rigidity of the frame without making it super thick. The 3" size seems like a good balance of weight and toughness.

I'm going to work on getting the stl files uploaded to thingiverse in the coming days. Maybe someone can make some cooler looking TPU parts for it!