I recently received a 4” freestyle frame in my recent box from Cyclonefpv that I didn’t order (AlfaRC Fighter175). The frame looks fairly robust, I may soften the hard 90* edges…and I have parts just perfect for it that have been sitting waiting.. the motors are not my first choice, but they were free…I
I’m gonna be real curious as to how it handles, I love my THfreestyel2.5” and other 3”s I have.. they fly on rails compared to the 5” rigs that make me feel like they are “flying trucks”…
Here is the brake down..
frame- 4” AlfaRC Fighter175
Stack- Mamba f405 20x20
Camera-Caddx Ratel
Vtx-PandaRC 5805
Motors-Newbeedrone drone 1408 2400
Rx-TBS crossfire nano
Props- Avan scimitar(I LOVE these, I have them in 2.5,3,3.5 and now 4”) and Gemfan Hurricane
I’ll post some pics / weights when I’m done..
my props should be here tomorrow.. so I have got work to do..

Hi Rob,

I am really excited to see this build come together.

Personally, I really like a 4 inch quad. All of the ones that I have built fly really
well and cruise nice. A 4 inch frame has an advantage of also being able to
use 3 inch props with guards if the need arises. I have done this in the past.

Please add some pictures. Thanks. 

My only 4" is a bit of a bitsa, I bought a Diatone Roma 4" Freestyle (X) frame, and decided to transfer most of the bits from an EMax 250 (that was actually a 280). I moved it from FrSky to ELRS as I did it, but its still analogue atm.

So its a 4" 5", if that makes any sense.....................

You are using 1408/2400, mine's on 2205 2300's........... and you say your motors are not the first choice............. :-D

My 4 inch Katana-LR4 build is running  Brotherhobby VY-1504.5  3950kv motors.
The flight times range from 10 to 15 minutes on a GNB 3S 1100 mAh 67 gram 
battery. She is smooth and cruises extremely well. This one of my favorite 4 icnch
builds.

My Phantom-4X is sort of unusual in that it is built on a 2.5 inch Phantom frame
with arm overlay extensions that allow the use of 4 inch props. This build is 
running Flywoo NIN-1404 3750kv Dave_C edition V2 ultralight. Amazingly she
flies really well and gets 13-14 minutes from a GNB 3S 1100 mAh 67 gram battery.

My Ronin-MK1 ONE is my favorite 4 inch build. She is based on a RoninUAV frame,
is also running Flywoo NIN-1404 3750kv Dave_C edition V2 ultralight motors, has dry 
weight of 150 grams and gets over 15 minutes of fly time using a GNB 3S 1100 mAh 
67 gram battery. 

I will say that these are sub-250 gram cruisers and NOT Acro stunt quads so the motors 
that I used might be bit "small" for you. Still, my builds seem to have plenty of power
especially the Katana-4LR with the 1504.5 motors. They all cruise at about 20-25 percent
throttle so there is plenty left if I chose to use it. I just don't. 

By the way, what motor was (or is) your first choice ??

A 1408 motor has about 50 percent more stator volume than the 1504.5 motors and they
are a taller motor so should provide more power and better acceleration. 

If you already have the 1408's, then I would give them a try. 

Will you be using 4S or 6S battery ?? 

They were in a box (giveaway) from Bardwell.. I’ve never flown 1408s .. told they are great for “racing” and are “choppy” hard to tune….
We shall see..
Gonna fly it on 4s for the moment.. all my 6s lipos are like 1300… bricks

I’m a fan of 1408’s on 3”- great acceleration, even with high pitch props. I’d imagine they’d work well on 4” as well.

I’m looking forward to pictures of your free frame build.

Here are some pics, the camera mount with the top stand-off is a option.. there is another set that mounts flush with the top, I’m gonna see how the batteries fit before I decide which one I want to use

Nice! I like that little “anti battery ejection” bar.

Well… things were going REAL good, things fitting, even 3d printed a crossfire nano 20x20 holder.. can u see where my FIRST EFF-UP is??? Soldered they esc backwards.. no bid deal..
HOWEVER.. the second one was a rookie mistake..
I updated betaflight WITHOUT doing a cli backup… figured, it was a new stack, had never been installed.. no problem.. Righht??? WRONG!!!
DO NOT TRUST BF configurator “auto detect” in the firmware update!!!!
Let me back up.. before soldering the vtx, rx and camera.. I wanted to make sure the stack was “OK”..
I had tested the motors.. all were wrong direction except #4, so i make a mental note.. and figured.. “Hey, BF now has the motor direction / location wizard.. let’s see how well it works..”
I was fitting the rx.. and realized I was putting pressure on the usb, figured..”no-big”.. should be fine ..installed the rx, vtx, camera .. even checked in the goggles.. camera wasn’t upside down.. we’re good so far..
Updated the fc to 4.3.1.. only 3 tones when plugged in.. thought “maybe it’s bidirectional d-shot.. sure enough it showed nothing in the motors tab (no 150, 300, 600) .. so I check the boxes.. save and went to esc configurator.. and it would NOT read he ESCs ..
Bask fo betaflight, and see the battery voltage at 35v and ALL the fc LEDs were lit.. figured I broke something OR the wrong firmware got flashed..Buf since I didn’t make a cli backup I can’t go back and check the version..
So I went to my “back up”… pulled out All my mamba f4 405s .. plugged them into betaflight.. checked the firmware target and low and behold.. there were 2 different ones.. same fc.
So I tried the other (non auto detected”… and” BOOM, back in business” unfortunately I had unsoldered all my components to make sure nothing was bridged..
Two steps forward.. one step back..

ESC facing the wrong direction?

(20-Sep-2022, 10:28 PM)Lemonyleprosy Wrote: ESC facing the wrong direction?

That's my guess too. 180 degrees the wrong way...

EDIT: Yea, just looked again and you can see the motor numbers with #1 at top left instead of bottom right...

While the motor pads may not line up by default, I've had a couple builds where it made the most sense to mount it 180 to be able to get the capacitor in there and out of the way of other things. Changing the motor order is about the only time I fire up the CLI window, then again I guess that's not needed in 4.3 now.

Considering these things are their own cooling generators and how close the FC mounts, not sure an ESC upside down matters all that much either.

I added more.. I was cooking as I was editing… sorry

I was trying to figure out why I was getting 100% errors on my motors when I enable bidirectional d-shot.. I updated my ESCs.. but I updated BLHELI S .. NOT Bluejay..I’m guessing ..
I’ve been into this hobby for a bit, and I can EASILY see how pilots will get totally frustrated!!

Got it airborn / hover test..got a few “glitches”.. my tbs nano (brand new) no longer powers up.. no LEDs at all.. tried all the suggestions.. no luck. Also my eachine nano vtx won’t change .. I’m thinking it’s locked if I remember..
I’m gonna be updating that vtx anyway.. kinda pissed about the tbs nano.. it’s weird.. I was getting a solid green light just yesterday. The Ratel fits, not much “uptilt” may swap it out.. it will easily get me under 250 w/that 550 4s lipo

Nice Looking Build    GOOD JOB