Intro

Wanted something with protected props for indoor and playground flying.
I basically had another duplicate 2" 1103 quad that I wasn't overly happy with and decided to use its internals and build the pizzabox quad after stumbling over the twentyfour7 frame by jimbo_wa.

I had already looked at the dj-105 and rs90 in the past but never got around to build a successfull version of either even tho I printed the frames ages ago.
My target was 50g but I ended up at 55g which I find acceptable. As I have another quad at roughly that weight running the same props+motors I knew it would be speedy enough (especially for indoor).

Printing the frame

I experimented with various materials in the past, including Nylon, CF-Nylon, ABS, PLA, CF-PETG.
This time I opted for something new: PC-ABS (Polycarbonate-ABS).
Printing it worked fine as long as you use an enclosure and a heated bed (HOT at 110°).
I was printing at 280°C on glass and had no issue with adhesion after using a thin coat of hairspray and an ambient enclosure temperature of about 34°.
Glass has the added benefit of a super shiny finish :)

I had to use only one perimeter in order to get the infill perfect tho - anything more and there would be gaps in the print.

Cam Mount

The default frame called for 15mm standoffs and has a strange tilted plane to stick the cam on to - I wasn't very happy with that particulary as I was looking to use this quad indoors and outdoors requiring different angles for flying.

So I went ahead and designed a tiltable cam mount for the Turbowing cmos cams.
I shared that here: https://www.thingiverse.com/thing:2896804
I did end up using 20mm standoffs tho to allow for the tilting and the super_s f3 stack that I reused.

Challenges

During the build

If you want to run 2" props care must be taken with wiring and stack height. In my case the smaller fc on top of the stack is just fine to clear the gf 2" props.
On regular 20x20 stacks you will get issues.
Also make sure to get your wire management tight so the props don't cut anything loose.

I did have to extend the wires from the cam and vtx to wire everything up tho.

If you are wondering about the random use of m2 spacer under the motor screws, it is to make sure the longer m1.6 screws I was using aren't touching any of the windings.

The vtx03 on the other hand was no challenge at all as the frame has a recess designed to put the vtx in including a zip tie to secure the antenna (great job!).

After Maiden: Problems/Brownouts

After maiden the quad would fall out of the sky randomly with the escs rebooting - no mater how high the throttle.
I remembered researching this issue before as well as how the super_s stack only has a ~0.5a BEC.
After reducing the vtx output from 200mw to 25mw the brownouts were gone and everything worked as expected.
Based on my measurements I assume that up to 50mw should be fine :)

Maiden (pids not perfectly tuned)

Only did some quick adjustments on the pids as I had like 15 min. to test it.
Will also probably swap one motor that is dodgy (crashed the build I salvaged the motors from a bit in the past).

Tweaked PIDs indoor flying

Very happy with this after tweaking the pids some more

Conclusion

Overall I am pretty happy with this build. We will see how well it holds up in the future. I might replace the standoffs for aluminium ones (instead of the nylon ones) but I'll have to check what weight penalty that will be and how durable the nylon standoffs are first.

Updates

• Added a quick video from the maiden
• Swapped a motor that was a bit dodgy
• Routed the antennas differently to make for a flat and compact build. XM antenna now runs inside the frame at a 90° angle and the vtx is vertically zip tied to the standoff.