Wizz’s ZMR250SS (slim/short) mod

This is my first build and my second quad (I started with toy SYMA X5C) and Im still in a “begginer” level.

My goal was to build universal freestile quad with better range for some mountine downhill ower threes.

video:

my YT channel:
https://www.youtube.com/channel/UCNuXT1gGvqYWVAVrnR4uC2Q

Frame:
I started as many begginers with cheap ZMR250 / QAV250 bought as set with motors,esc, pdb and FC from aliexpress. It wasn’t great deal, as I most of the components was crap and I already replaced PDB MATEK XT60 clone to MATEK PDB XPW and FC ominibus F3 to Matek F722STD, motors (red bottom) still works correct as well as ESC on DSHOT600.

As original ZMR250 assembly looks uggly with lot of useles free space, i take saw and modify it acording my needs.
I made it “upside down” to correct centre of gravity with battery / gopro on top
First version was with 1200TVL camera on tilting servo, but there was only problem with that, and servos burned everityme, I replace it to fiexd one – Runcam micro eagle.

ESC/capactiors
I’m using ESC from bottom to protect from props and as I build this frame “upside down” ESCs are protected by frame size from bottom, anyway in first version of build I had even 470uF capacitors under the ESC, but than I found out that is not a good idea because I shorted one of them during crash.
Now im using one 2200uF capacitor inside frame for Lipo and separate 1000uF/6.3V for 5V (camera) and 1000uF/25V for 12V (VTX) so voltage is stale enough.
ESC are without heatsing, but i put thermal silicone pad between carbon arm and cover with heatshrink.

PDB
XT60 socked is fixed on rear side of frame, I have also “charging” wires with 100ohm resistor to prevent sparks on XT60 which I connect as firts to balancing connector and than connect battery to XT60. works pretty well, no sparks even with big capacitors, also It keeping balance lead in safe place.

VTX
as cheapo HLV VTX is crazy heater, i losing picture during first flight and get 90°C on static test, I made cooler as part of the frame.
as Fist I put thermal pad inside shielding plate (and also replace bigger shielding plate from wifi dongle) and than i made part of the frame from aluminium plate (SSD drive spacer) and screw some small heatsink on them. Ofcourse paint all to black. It sits exactly inside frame, Just VTX button was to high so I desolder it out as I fly alone only and no need to switch channels on place :smile:.

Partlist:

FrameQAV250 clone wizz short/slim modhttps://s.click.aliexpress.com/e/_d686anc20,5
FCMatek F7 F722-STDhttps://s.click.aliexpress.com/e/_d7UltOO29,79
ESC4x TTSRC ESC BLHeli-S 30Ahttps://s.click.aliexpress.com/e/_d9FeMqK21,5
VTXHLW 25MW-600MW 5.8G 48CHhttp://s.click.aliexpress.com/e/_dTwkGsg15
MotorEMAX RS2205 2300KVhttp://s.click.aliexpress.com/e/_d7or0co38,55
Props8 pair 5065 3 Blade Propeller https://s.click.aliexpress.com/e/_dVrWxVy4,34
CamRuncam Micro Eaglehttps://s.click.aliexpress.com/e/_dWmHqQE35
RXRadiolink R12DSMhttps://s.click.aliexpress.com/e/_s7wq9614,4
AntFOXEER Pagoda Pro 5,8 GHz 86mmhttps://s.click.aliexpress.com/e/_dV6M6DY7,42
LEDHGLRC 2-in-1https://s.click.aliexpress.com/e/_d83mNhM1,56
LIPOGaoneng GNB 14.8V 1500mAh 4S 120C/240C21,98
Soft20x M3 Flight controller standoffhttps://s.click.aliexpress.com/e/_dTEXEe65,65
HolderCNC XT60 Holderhttps://s.click.aliexpress.com/e/_d81elYE0,68
MatRC 3M 30mm x 1mhttps://s.click.aliexpress.com/e/_dYcW8O65,16
StrapRJX Kevlar Straps 200mmhttps://s.click.aliexpress.com/e/_dS7RPvM6,26

GEAR:

TXRadiolink AT9Shttps://s.click.aliexpress.com/e/_dY4VMdg65,34
TX LipoMOSEWORTH 3S 11.1v 2200mAh 25C RC Lipo https://s.click.aliexpress.com/e/_dSSZ5UE13,14
GoglesEachine EV200Dhttps://s.click.aliexpress.com/e/_dU2iisW242,93
Ant1FOXEER Pagoda Pro 5,8 GHz 86mmhttps://s.click.aliexpress.com/e/_dV6M6DY7,42
Ant2Foxeer 5.8GHz 8DBi  84.7 Degree Patch RHCPhttps://s.click.aliexpress.com/e/_dXijN7C12,47
ChargerDOTA D6 Dual Channel https://s.click.aliexpress.com/e/_dXTMEUQ76,79

Big Crash:
Lo qualityt VTX antenna which disconnect itself by vibration cause lost video – crash from around 100m to field and hits the rock.

  • All the main frame plates broken (No arm broken)
  • Runcam Micro eagle broken, PCB damaged, frame broken, lens lost
Alt Tag

  • Gopro Session 5 broken, Lens OK but can not control it, reacts on buttons but to late, make whatever it wants, not record, no connection to PC.

Corrective action an repair.
New frame concept for next build with using 3d Prints (still use ZMR250).
Tried to repair micro eagle with resolder broken chip but not helps – new runcam ordered.
Gopro dissasembled and did not find a failure, reflow not helps, so bought gopro with broken lens from ebay (30euro) and replaced PCB.
Total cost 90 eur.

Gallery:

update:12.6.2020 – working on update:

ZMReborn…

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