Slammed 4" custom deadcat

By virtual_stephen on Oct 23, 2021

6  172  4

Started with an cheap AlfaRC Mini LR4 cos it had thick arms and could handle larger motors.

Slammed the top deck down to 15mm by swapping standoffs, Vista unit is a tight fit and rigidity is improved. Frame comes with stupid "folding arms" which means the arms are loose and move during flight. Solved with tights screws and superglue. Frame is rigid and doesn't move now.

Experimented with the new Runcam MIPI, ok but grainy image - moved to Runcam Phoenix HD and the larger lens seems to help reduce graininess. Room enough for a capacitor behind the camera too. Camera is at a fixed 45-50 degree angle which is perfect for me.

2004 motors on a 4" mean plenty of power, but with an unusual KV of 3100 I wasn't seeing enough pop on 4S but 6S was too much - I settled on GNB's excellent new 700Mah serious of lipos which come in 5S with XT30. Perfect! Still seeing current peaks of 70A+ and the plug is holding up fine when backed up with a short run of solid 14AWG.

Resultant quad is perfect for what I wanted - to fly without a GoPro camera but with bags of power and good-enough DVR to share if I feel like it. This quad is for the fun of flying, with no props in view, 190g dry weight and plenty of power with agility too. Cruise speed is good and flips and rolls are tight.

Betafight was used, the 4.3 master branch, and I was able to push PIDs pretty high here. The thicker arms and slammed design work well to keep vibrations low.

Note that I did use sliders for the filters - but recent configurator builds are showing some bugs with filter sliders.



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Philm0   Apr 20, 2022  

Would love to see some flight footage!

virtual_stephen   Apr 21, 2022 

Thanks for your interest, I'll dig out some flight footage. Managed to fry an ESC in a crash so haven't got recent footage but here's some that I recorded when comparing antennas:   Nov 20, 2021  

can you post your PIDs / Filters? i have a few 4in builds - I used betafpv 2004 3000kv motors, but cant get a good tune. tried different FC/ESC combos to no avail. Micro Apex 4 and QAV-S mini 4 - both reported to be solid frames.

virtual_stephen   Nov 20, 2021 

I'll add a couple of photos to the post. Can't seem to add the pictures into my reply - they just vanish.

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