This is a spare parts shelf build. I picked up the frame from Cyclone FPV for $12, everything else is gonna be bits that I already have on my shelf.

When I first unboxed this frame, I thought I was missing the actual frame. I couldn’t figure out how it went together. I had to reach out to Cyclone FPV to see if I was missing something.

Tarek took the time to make me a build video, and I gotta say, that is some incredible customer support for a $12 frame that he sold at cost:



Okay, so now I know how the frame goes together!

What bits do I have to put in it?
Seems like it requires a 16x16 stack. In that size, I’ve got 2 f3 stacks, an f411 stack, another f3 stack… 

JHEMCU f411 it is. I was planning on using that f411 to rebuild my Roma F1, but I think that F1 actually needs a 20x20- I think the GnarlyFPV SubAtomic frame I have fits a 16x16. If this build fails then the f411 will go in the subatomic. I’ve got a ridiculously overrated 20x20 that should fit in the F1. Maybe I’ve got that backwards and the subatomic takes a 20x20 and the F1 takes a 16x16. Whatever.

Maybe I should have started this build at 2 drinks instead of 3 (or 4… or whatever. It’s a holiday. )

Motors… I think it’s gonna be Flywoo Robo 1204 RB 5150kv. Little big, and I’ve got some 11xx options, but we’ll see how these do. Guess this will be a 3s build. I’ve burned out 3 of these motors on 4s, so I know they can’t handle that.

Started assembly. Couldn’t figure out how to actually mount the stack. It appears that I have to directly solder it to the frame. Soldered motor connections, used some 18g wire to bridge the power connections to the board…

Dude, this is looking sketchy AF. Especially since the tpu battery strap seems to just connect on the other side of the board without actually going through any part of the frame. I feel like one hard landing and I’m going to break all of my motor connections and my power connections.

Maybe I’m building this wrong.

I also don’t have any jst connectors in the right size, so I’m gonna hafta figure that out or figure out how to route my wires around the ducts to my esc.

I could remove the connectors, but they’re going through some pretty tiny holes- doesn’t give me a whole lot to work with for my motor wires, and the way the ducts connect to the frame doesn’t give me a good option for running my motor wires straight to my esc. I’m real tempted to say screw it and use a soldering iron to make some indents in the ducts to run my motor wires.

Dude, I feel like I’m starting all over as a newbie on this build.

I’ll make it work, even if I have to take a drill to the ducts to make a hole for my motor wires!

Yeah, this isn’t turning out to be nice and clean…

I haven’t destroyed anything yet.

It'll be a learning experience. Enjoy it and savour the moment.

Though that FC does look sketch. Is it a FC or is the frame built into it. Looks random as anything.

That’s the esc soldered onto the frame via the motor connectors and the power connectors. I don’t really like it, but, it does overlap a bit on the top and the tpu battery strap that bolts below it overlaps the frame from below, so I guess in theory it’ll work?

Pretty sure I do have some appropriate connectors for the motors in one of my parts bins. I was looking in my quad stuff for them last night- I should have been looking in my electronicals. Pretty sure they’re buried under some resistors or other random bits.

My intention with this guy was to use it to practice some acro stuffs inside my shop, but honestly, I don’t think it could handle multiple hard crashes- the motors don’t even bolt to the frame, they just bolt into the prop guards that are attached to the frame with a few small screws. I’ma finish this build and try it out, but I have a feeling it won’t stay assembled for long before I cannibalize it for parts.

For my inside acro practicing, I think I’m much better off rebuilding my Diatone Roma F1. It was my first “pick all of my own bits” quad build but it never got much flight time, so I eventually repurposed its stack and motors. Short flight won’t be a problem when I’m constantly smashing it into the cement floor.

I’ll definitely enjoy the build regardless- I love the building and figuring out of things just as much as I love the flying.

"I’ll definitely enjoy the build regardless- I love the building and figuring out of things just as much as I love the flying."

WOT He SAID!

Watching with baited breath mate, that's a unique frame you've got there!

Hi Lemony,

Yes, that is a very unique and interesting frame. I do believe that you are right about
the durability. A hard crash on one of the "whoops" will likely break the frame at the
points where the whoop is bolted on. Be careful with that fence (ha, ha). 

I am assuming the motor connectors are the standard JST 1.25 3 pin, correct?
Did you find some?  If yes, great. If not, maybe I can help you out there.

It will be fun watching this one come together. 

I’ve decided that this build post is going to be picture and information heavy. I’ve struggled to find what I need to know- I had to reach out to the retailer to figure out how the frame goes together and I had to watch the few YouTube videos that were available and try to screenshot and zoom in on the few times they turned it upside down to try to get an idea of what I’m doing.

To anyone that stumbles on this thread in the future, I hope it helps, but I can’t promise I know what I’m doing. I’ll give the best information that I can, but I can’t promise it’s accurate.

I’m also gonna include my thought process and frustrations. I’ve been fiddling with electronics and building circuit boards for three plus decades, and I’ve been building and flying quadcopters for a little over a year now- but y’know what? I still regularly screw up, connect the wrong thing to the thing, make a poor solder joint, destroy something, get completely lost, etc. For those of you just starting out- I screw up probably just as much as you do. I’ve learned to walk away for a bit when I need to, and I now have enough experience to be able to look back and figure out where I went wrong or how to fix the thing- you’ll get there too. And at least with quad related stuff, you’ve got a bunch of people here to help you figure it out if you can’t on your own.

These motor connectors fit cheap connectors that I bought from Amazon that are labeled JST SH. Pretty sure that’s not accurate. I think SH is 1mm pitch, and these are 1.25mm- so I think they may be Molex Pico Blade 1.25mm. The 4 pin buzzer and led connector fits the same pitch plug (1.25mm) in a 4 pin configuration. I’m not sure, I could be wrong.

Ignore my crappy soldering of the power connection from the esc to “frame” (the frame is really more of a glorified power distribution board.) Ideally I would have used the inside bit of some solid copper 18g to 16g wire instead of multi strand 18g wire that required me to use longer wire and snip the excess. I’m working with what I’ve got.

It’s difficult to use the terms I’m used to for this frame, so if I say, “frame”; I mean the PDB that the ducts mount to.

So, a 16x16 esc ever so slightly overlaps the top of the frame. It allows you just enough overlap for the esc to not be able to drop through the frame and for you to solder your esc’s motor tabs onto the frame.

Anyhow. For that 4 pin buzzer and led connector, I’ve decided that led=yellow, buzzer negative= green, 5v= red, and ground= black. That’s not important for you to know, but being able to reference this will help me in the future.
Wooohoo, I made a plug! Yay for progress.

This frame came with multiple bags of bits. A bunch of tiny screws for attaching the ducts to the frame and the canopy to the ducts, a bunch of screws that I think they expect me to use to attach my motors to the ducts, squishy spacers for the stack, 4 long stack screws, 7 nuts, and three screws that are slightly shorter than the motor screws. 4 of those nuts obviously go on the stack. I’m assuming those other 3 nuts attach to the 3 shorter screws, but I’m not quite sure where they go. Hopefully I’ll figure that out.

*If* I’m building this correctly, then the tpu bit that holds the battery strap hangs from my stack. Like, actually hangs from it- it only has 4 holes in a 16x16 pattern. I guess since the esc slightly overlaps the top and the tpu battery strap holder overlaps the bottom, it should be pretty solid?

I want some isolation on my flight controller, so I’m gonna use these purple gummy spacers I have left over from a different build to mount the FC. They’re the same length from board to board as the spacers this frame came with. I wouldn’t typically care about matching the length of stack spacers, but I’m hoping that they decided on that length because lifting up my FC to that height will allow me to actually access the USB port without removing a duct. Fingers crossed.

Used some UV glue to reinforce the usb jack.

Time to start soldering wires to the FC!

I’ve got my camera connector soldered up. If I haven’t mentioned it yet, I’m using a Caddx Ant nano, because I’ve got a bunch of them and they’re lightweight and have a decent quality image.

I’ve got my led & buzzer connector soldered.

Time to solder in my ELRS receiver!

Erm. Wait. This JHEMCU SI-F4 stack is an F411 flight controller so it should have two uarts.
I know that my ribbon connector to the vtx is using TX1 from the flight controller for IRC Tramp.

So I’m gonna need to use tx2/rx2 for my ELRS receiver… I’m only seeing an sbus pad on my FC, which I *think* will correspond to rx2. Did they not break out tx2 on this FC? Am I overlooking something? Is it inverted or not?

I can flash my ELRS rx to work either way, but I’m a pretty big fan of telemetry. I’m not a big enough fan to take the time to break out tx2 from the IC if it isn’t already routed to a pad.

I think this is it for tonight. Saturday night will be figuring out my rx wiring, flashing my rx with the appropriate firmware, hopefully maybe final assembly, flashing bluejay to my esc, flashing betaflight 4.3 to the flight controller, and fiddling with settings. I’d like to say that I’ll also get a maiden flight in, but it’s unlikely- I tend to use late afternoon and early evening to fly my working quads and fiddle with builds later in the night when it’s too late to properly, “send it”.

I’ll have to double check with proper lighting, but it looks like my yellow led wire needs to be resoldered- looks a little wonky.

Hi Lemony,
First, Good Job on the documentation.

I seem to recall somewhere that the ELRS wants to be on AUX1...so...
is that also TX1/RX1    

(02-Jun-2022, 12:38 PM)iFly4rotors Wrote: I seem to recall somewhere that the ELRS wants to be on AUX1...so...
is that also TX1/RX1    

ELRS wants arming to be a two position switch on AUX1 (channel 5) when you set up modes.

I’m still in the wiring phase, and trying to determine if they actually gave me a tx2 pad. If not, I can still hook up my receiver, I’ll just need only connect its tx to sbus and invert its output when I flash my receiver.

It will be interesting to see what you end up with. 

Before I start tracing pads to see if any correspond to tx2, can anyone confirm that I’m tracing from the correct pin?

It’s a stm32f411ceu6.

I *think* pin 12 (PA2) is what would correspond to tx2 (UART2 tx).
Anyone know if that is correct and if my markings on the attached picture are correct?

You have the correct pins, but in the wrong corner. Pins #1 and #48 are in the bottom left corner when the writing is facing the right way up. So it's the same pins but on the next corner anti-clockwise (bottom right when the writing is facing the right way up).

Awesome, thank you for the clarification!

When I attach my cheapy clip on macro lens to my phone and zoom in, I don’t even see a trace coming from pin 12.

So, I’m just going to assume that they did not bother to breakout tx2 on this FC, and I’m not going to bother tracing back any of the unknown pads. I’m just going to invert my receiver’s output so that I can just connect to the sbus pad to make my life easier, and forgo telemetry.

Just go with SBUS and make your life easy. On a small quad like this you don’t need much telemetry and just setup audio alerts for LQ etc on your radio.

You can direct solder a thin solid wire to the legs of the MCU and hot glue it but this might not be a strong connection during crashes.

For the skilled PCB repair experts they have another alternative using replacement solder lugs such as these: https://a.aliexpress.com/_mLfFm6W

Basically for a use case like yours it will mean creating our own broken out pads on the board.

Actually we can use this method to repair ripped off solder pads but its too involved. You also need additional tools such as a pcb microscope, uv light, pcb solder mask and epoxy.

I do not like to advocate such methods here since most members will not want to invest in such a pcb repair setup