Here I go on another forum

[Helibus]

Hi all -- lots of helpful info on intoFPV.  I've been lurking for a few months....

I managed to retire early back in 2012.  At the time, one of my goals was to fly collective pitch RC, something I always wanted to do but never had the time to learn.  The Helibus moniker comes from 1600+ posts in the Helifreak forum where I participated mostly in the Blade 130x and 300x subcategories while those were active. 

Getting CP figured out was great, but my older eyes didn't seem to handle orientation well.  Then there was the fear of crashing and spending time, money, and eyestrain repairing.  On top of that, our yard and the neighborhood park I used to fly at are now in designated no-fly zones. 

3D printing got a lot of my attention after CP helicopters.  I go by the Printbus moniker on the 3dprintboard forum and Thingiverse.  Anyone interested in gory detail can peruse my printer build thread at MakerFarm 8" i3v Prusa build by Printbus.  I found 3d printing to provide a unique combination of electronics, microcontrollers, mechanics, and materials science to futz with.  

I've always looked at multicopters as something "too easy to fly", but a Christmas book on building a quadcopter piqued my interest.  I had no idea on all the flight controller, frame, and what not options that are out there.  Rather than build a 450 class or even a 250 class racer that I'd rarely be able to fly, I've opted to put together a 110mm brushed FPV quad that I can mostly use as a house flyer.  I wanted to 3d print the frame, but wanted to have the design source so I could tweak away.  Ended up starting to develop my own in openSCAD and now I'm just a few more slow boats away from having all the parts from overseas.  

Watch for at least a build summary in the brushed micro subcategory.  Well, assuming it flies.  

Kevin B.

[sloscotty]

Welcome Kevin!   Nice to have another OpenSCAD fanatic around!  (My thingiverse designs).  I'll be happy to see you around in the Micro and 3D Printing forums here - good to have you!

[Grisha0]

Welcome Kevin,
it will fly one way or the other... it is always matter of assumptions... how long do you want it to keep in the air... and then... building the big enough catapult/trebuchet

[Helibus]

Welcome Kevin!   Nice to have another OpenSCAD fanatic around!  (My thingiverse designs).  I'll be happy to see you around in the Micro and 3D Printing forums here - good to have you!

Nice quad you've got on Thingiverse.  I hadn't seen it.  I wouldn't say I'm a fanatic about openSCAD, but it works for me and the engineering approach my brain seems to like.  There are days though where I struggle with "man, what I want to do is simple, but how do I come up with the math behind it?".  I'm already up to about 800 lines in the openSCAD script for my frame, but I *do* comment extensively. EDIT: Well, and the script does include models to view the installed components like fc, motors, aio, etc. That adds a bit.

Welcome Kevin,
it will fly one way or the other... it is always matter of assumptions... how long do you want it to keep in the air... and then... building the big enough catapult/trebuchet

 
Good point!

[fftunes]

Welcome, nice to see heli people

I also still have two 300x and other helis but ever since flying fpv quads they've been nothing but collecting dust...
Well actually the 300x was flying once in between, but the quads made me fly much higher rates so i'd need to completely re-tune all my helis to feel comfortable on the sticks again.

[Helibus]

I think my main heli flying risk would be cutting the throttle stick instead of using throttle hold. I've been playing around with a NanoQX and I try to still use throttle hold with it, but I've noticed I'm using it less and less as time goes by.

My initial plan was to build something along the lines of a 250 quad that would reuse my 3s 1350mAh batteries from the 300x, but as suggested I grew to realize that just didn't make as much sense as something smaller.

I have to admit that quadcopters, at least the brushed variety, are a wonder of simplicity compared to the 130x or 300x. I somewhat laughed when I realized all I'd likely ever need for NanoQX spare parts were props and a couple of motors, compared to the dozens of parts and $$$ needed to handle the "what now" scenarios of especially the 130x.

[fftunes]

Funny that i just went the other way around back then when i started helis... first was a bit of Phoenix RC sim training to learn heli basics, then i got the nanoQX for a "reality check". After that i felt confident enough to fly the 300x as my first heli, and all was good.

But i recommend keeping the habit of the throttle hold switch - it comes into play again once you start using "airmode", means on more capable quads it's common to keep motors spinning at lowest throttle to basically keep full control at "zero throttle". Throttle hold (in multirotor terms arm/disarm) is then the only way to stop motors, and the fastest way to prevent damage from props hitting things.

You can set up the nanoQX like that as well, just give it a bit of throttle idle-up mixed in by throttle hold switch. Don't get rid of that habit, it's a good one.

[Helibus]

That's a good idea. Thanks.

[Oscar]

I think a Tiny Whoop or some other brushed quadcopter would be a good starting point, they are relatively safer, and hassle free. They don't break easily in crashes
However these are normally fly well indoor, they can't handle the wind!
If you are looking for more powerful solution that you can fly outdoor, check out the new little brushless such as the FuriousFPV Moskito70, i have been flying it and it's fun and pretty strong against crashes.

[Helibus]

Yeah, I thought about something like a TinyWhoop, but it sounded like you're pretty much stuck with a short flight duration. I'd also read that they're more stable moving at a clip than hovering. For now, I plan to do a lot of hovering and low-speed flight while I get my feet wet with FPV.

A Whoop is still a definite possibility as another build, especially if I can't stop crashing into things. I've also already been glancing at some of the micro brushless stuff. I've been amazed at some of the small brushless builds. I'm regretting having planted so many dang trees in the back yard when we bought the house 30 years ago. All I can pretty much do there is circuits around the tree trunks, but it's at least something. I've taken the NanoQX outside on mild days - I sort of enjoy a bit of breeze. On some windy days I used to take the 130X to the park just as a training exercise.

Everything but the motors are now in hand...

[Helibus]

...But i recommend keeping the habit of the throttle hold switch - it comes into play again once you start using "airmode", means on more capable quads it's common to keep motors spinning at lowest throttle to basically keep full control at "zero throttle". Throttle hold (in multirotor terms arm/disarm) is then the only way to stop motors, and the fastest way to prevent damage from props hitting things.

You can set up the nanoQX like that as well, just give it a bit of throttle idle-up mixed in by throttle hold switch. Don't get rid of that habit, it's a good one.

Bah. Looks like I need to rethink my TX setup.  I'm currently stuck with a DX6i. I had recently thought about getting a Taranis, but the budget I limit myself to for hobbies said I could go with either a new TX or delve into FPV a bit, but for now, not both. 

This really isn't an issue for the NanoQX. I'm already flying it with a heli type model in the TX where the throttle hold setup should work.  You lose a channel dedicated for what would be rotor pitch in the heli model type, but that's fine for the QX. For the new quad I'll put together as soon as I have motors, I had set up an acro type model hoping that I could eventually leverage all six channels from the DX6i.  Looks like you lose the throttle hold function in the acro model type, and it wasn't obvious I could fake it with a mix setup. 

I do like the idea of retaining the throttle hold function and being forced to use it.   Looks like I'll be doing without that 6th channel for a while.

[fftunes]

I do like the idea of retaining the throttle hold function and being forced to use it.   Looks like I'll be doing without that 6th channel for a while.

Did the same back then with my nano and the old DX6i, and now i'm still using heli models all the time in the newer DX6g2. Imho heli model offers much better functionality (expo, throttle curves etc. per flightmode, hold-switch & 3-way switch => easy setup for 4 flightmodes on 1 channel).

By making the pitch curves flat lines i could stil use them to control something independent of throttle stick, but it's not really needed as 1 channel is usually enough to communicate flightmodes and stuff to the flight controller (disarm, arm, airmode, blackbox logging is all controlled by channel 5).

[Helibus]

Well, before someone else points it out, I'll admit I was being a bit dense about the DX6i Heli model type. All I need to do to regain the channel lost to rotor pitch is to define a pitch curve of say 0% at all throttle positions for NORM and some other value at all throttle positions for STUNT. As long as I'm not using the FMODE switch for D/R Combi or something, that makes that channel somewhat usable. I just need to careful (or creative) on what I've got the pitch curve set to for HOLD, since activating throttle hold will put that on the channel instead of the FMODE NORM/STUNT setting. I also realized that in the Heli model type, the Gyro switch defaults to 50% when off and 50% when on. That's pretty helpful. That's now set for 0% and 100% as well.

So, I think I'm where I wanted to get to for now. I'm seeing cleanflight on the new quad showing me two AUX channels under switch control. DX6i model defined for Heli type, with THRO CUT enabled for zero-throttle arming, and the low end of the NORM and STUNT throttle curves set for something like 15% so that the blades are spinning any time the quad is armed and throttle hold is off, just as it is on the 130x and 300x.