ToothFairy 5" Budget Rocket

By tehllama on May 11, 2018

14  844  2

Tooth Fairy - without the precious metals. Target weight of 333g AUW when equipped with an 850mAh 4S battery. This thing is an absolute rocket ship, provided I keep it out of trees. Still a solid race distance performer running 4S 1000mAh and 1300mAh packs depending on the track. Because of the light weight, it survives rough crashes extremely well, so it's a viable racer if your style is not very throttle-heavy.

It's possible to build one of these for $165 catching the right sales, which is absolutely insane for how good this performs. Spedix IS100 stack is the heart of this build, and also why the budget stayed brilliantly on track - RCX 2205 motors, Caddx F1, XM+, and go shred.

The biggest build advice I have is going to M2 20mm through-bolt mounting for the stack, and using 2x5mm silicone tubing (cut to size) as vibration isolating stack spacers. Much more survivable, lighter, and also cheaper.

For the full bling version of this build, I would run R6 2205's, Ori3 ESC2, TalonF4 FC, UnifyNano + MicroAXII, and either CRSF Nano or R-XSR. Still sub-$250 and you can hit 400g AUW with 6S 1000mAh packs and the 1750KV R6 motors.

I would recommend moving to newest generation Hyperlite 2205's, and soldering in an AXII Antenna onto the Spedix VTX if you're looking to make this a serious racing build, but those are all really minor adjustments. Similarly, if you can find the IS100 stack base (or want to run the HGLRC F440), the AKK FX3 or Aomway TX004 are great choices paired with an R-XSR Receiver running FPort, allowing you full smart audio control via LUA scripts. If you're trying to hit an insane weight target, going to 2204 motors and sticking with 850mAh batteries makes sense.

The Spedix IS100 DOES require you to solder bridge in four spots if you're using this configuration (run SBUS to Inverted RX1, run 5V to RX Input Voltage, run 5V to the VTX output, and I recommend running VBAT to the camera) - with that all sorted, it's great stuff.

Photos

Discussion

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Abonacci   Jun 25, 2018  

Hey wondering if you could help me . I'm having major trouble getting signal from my rxsr to recognize in bf on this board. Is rx1 the reciever port on the top picture ? it's not labeled on my board.  And question 2 is if I'm running my vtx/camera off the main wire lead pads and not the supplied plugs, is there still any need to jump those 2 v select pads ? Thanks again !

tehllama   Jun 25, 2018 

That image is off - the RX1 JST 3-pin comes out the 'left' side of the quad - but the first time I wired up my receiver I had the GND and SIGNAL pins backwards - it still powers up, binds, and does telemetry, but doesn't show up to the FC or do LUA scripts right. I'd check if that's the case.
If that is the solution - for posterity's sake, do let me know (here: https://www.rcgroups.com/forums/showthread.php?3048486-Spedix-IS100-AiO-Stack/page4#post39850347 ).
Good luck!

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