Oh yeah, I remember feeling uneasy when I put M2 screws into the stack holes as well. Pretty sure I 3D printed some TPU washers to stuff in there to give them more stuff to grab onto. Sorted the sag with a scaled motor limit of 80%. Still feels super floaty when I'm trying to control altitude. How's yours in that regard?

(13-Oct-2023, 07:54 PM)Suros Wrote: Oh yeah, I remember feeling uneasy when I put M2 screws into the stack holes as well. Pretty sure I 3D printed some TPU washers to stuff in there to give them more stuff to grab onto. Sorted the sag with a scaled motor limit of 80%. Still feels super floaty when I'm trying to control altitude. How's yours in that regard?

I have not had a chance to fly the 2105 motors. On the 1804's though it felt good no major sag issues on 850mah 4s but I just wanted a little more punch. I never had any issues keeping altitude, but on all my builds I always find my hover point, determine what throttle percent is and set that value to throttle mid then change the expo to .5

Build is complete.  Got the GPS mounted and it comes in with AUW of a chuncky 320 grams.  I did a basement tune on it and it flew well initially in my back yard but decided to try a preset just for giggles under another profile.  I used the Betaflight Superfly preset for 4" quads and used the online calculator to get a master multiplier value based off motor KV.  My impression.... Blown away.  Super smooth, very responsive, no prop wash or jello.. Love this tune.  so far it flies great and smoothness wise it flies just like my Apex 5" But...

I wanted a little bit more punch over the 1804's and got more than I bargained for lol.  This thing is like a little rocket ship.  In any of my other quads a quick blip of the throttle gives me enough altituted to do a flip or roll and stay at the same altitude.  A quick blip of the throttle in this thing and I am 25 feet above the trees, I have to admit it makes me giggle with joy.  Even though it has very good low throttle resolution and is very easy to fly I think I need to dial back throttle a bit. I scaled throttle to 90% and need to do another test flight but I suspect that might give it the feel I am looking for.  I am already running fairly low pitch props (4023) and offerings are not that great for 4".  Flight time is only about 2:30 flying it hard, which is "ok" but would like at least 3-3:30.  I am going to see if any of the guys local to me have any XT30 1100-1300mah 4s batteries to see if that gives more flight time and less punchy throttle but I have so many 4s 850 batteries I really want those to work. 

Seeing your results is making me think I should go for a motor swap. It's great that you've largely got what you were after.

(16-Oct-2023, 08:59 PM)Suros Wrote: Seeing your results is making me think I should go for a motor swap. It's great that you've largely got what you were after.

I left my Goggle SD card at home but I may pull some video from the VTX tonight and see if there is anything worth sharing lol

A guy walking his dog at the park approached me as I was packing up. He was like "Dude, I had no idea drones flew that fast, you must of hit at least 100mph. Is that an upgraded DJI?" We then talked FPV for a good 30 minutes and and he wrote down some links I gave him Sadly, my GPS was not locked so I didnt get any documented speed runs.

I'd certainly bet you could do >100 on that config. Was pushing 90 with my old setup, and you've certainly got more punch than I was working with.

Finally got the chance to fully rip some packs.  Everyone was thoroughly impressed to include myself but started out with some issues and learned some stuff.  So like mentioned the quad is silky smooth and low throttle resolution is amazing. The guys watching me fly said if they didn’t see it in person they would not believe it wasn’t a 5” Its so snappy!  But... using 850mah batteries I am only getting 2 minutes of flight time so I tried two scenarios.  

First, one of my flight buddies brought several GNB 1100mah batteries for me to try.  So I strapped one in, took off, did a flip, and screen went black.  Toasted two props in the process.  Strange, I retrieved it and tried another one of the batteries.  Same thing, as soon as I flipped the screen went black and I toasted two more props.  Strange because I had just done some short test flights with no issues the day prior.  Frustrated I strapped my homemade Y cabled 550mah batteries on and went back out.  No issues, the extra weight to tame it a bit coupled with the 1100mah capacity made it perfect to fly and got 3 min flight time.  Still snappy but not over the top.  This was the best combo.  So looking in my display I looked at max current draw and it was 120 amps lol.  My buddy’s batteries where only 60c!  The batteries I was running in parallel where 95c so totally makes sense I was getting a brown out.  I have since ordered some 1100mah 120/240c batteries.  

Second scenario, I used the 95c 850mah batteries but. I scaled the throttle to 90%.  Flight wise it is very similar to above I can feel that throttle is limited a bit flight time was 2:50 and on the display max current draw was 100 amps.  I bet if I set it to 95ish% it would probably be good but with 10% scaled throttle just almost getting 3 minutes.  If I set to 95% I bet that would drop to 2:30 and I really am hunting for 3 minutes.  
All said and done its super fun to fly and very smooth.  I think I will keep it : will try to get some footage together tonight.  

Here is the Video

https://youtu.be/OOFJDFpJQow?si=K_LuZEMwCtUKaHn2

It's nice seeing this build. I just realized today that I had a 4inch micro apex frame that I'd never built. Like you I'm trying to reuse what I already have, and I'm deciding between 1507 rcinpower m5 motors or I have some apex Toucan 1607 motors (both sets are 6s kv for 3-4")

What's your take on the right motor size?
Also did you wanna dell those 1804s? I'm thinking about using that size on a 3" x8 I'm building...

1804 is perfect size for light 4". About 120g

Ofcourse, 80g ultralight 4" using 1404 is bonkers crazy fun.

My biggest 4" is using 20g Axis 2204.5. Even though it hovers 20%, It feels useless and weak. The weight is a big drag.

Sorry for stating what seems obvious, but to confirm, the replacement 3 & 4 inch arms are interchange on these Apex 3 and 4 frames, correct?

Hi B4tn,

About the FC adapter. First, I am curious why you didn't make it so that the 
whoop board would be oriented correctly?  

I have purchased the TPU 20x20 square to 25.5x25.5 diagonal (whoop) 
adapters, but don't like them because they are too "squishy".  I used the 
one pictured below to mount a 20x20 VTX on top of a diagonal, whoop,
FC board. 



Currently, I use the 1/16 inch thick LEXAN plastic for such adapters. The LEXAN 
is easy to cut and drill. Plus, it is more rigid than the TPU adapters that I have tried. 

Anyway, just s thought. 

Later, iFly  

(31-Jan-2024, 09:26 PM)Green_Weedle Wrote: Sorry for stating what seems obvious, but to confirm, the replacement 3 & 4 inch arms are interchange on these Apex 3 and 4 frames, correct?

Yeah, that's right. I've done it to mine.