i flew 3,5" on two different builds and like them both alot. while there arent much 3,5inch props, i like the hq 3520x3 alot. i use it on 1306 and 1105, tiny motors can spin them very well. i will explore it more. 
i like to get your attention on that size and get your about your thoughts

I mainly fly 3”, but I also have a 4” that I like. 5” is too big to fly here. 3.5” would fit nicely between my 2 preferred sizes.

I just bought a few sets of Hq and Gemfan 3520 props to try on my 4" Micro Reverb (1306) and 4" Micro Alien with 1606 motors. I hope it will work well like yours. Also bought some Gemfan Huricane 4520 to try on my ultra light 5".

3.5 inch, very interesting; should work nice on a 4 inch frame which is pretty much 
my "pet" frame size. Most of my builds are on 4 inch frames.  What I like about the 
4 inch frame size is that it will handle a wide variety of props including 3 inch props
with prop guards. At this point in time, the 4 inch is overall the best size frame for
me.

To answer the question: 3.5" will you try?
Answer:   YES

my favorite rotorsize overall is, maybe was, 4inch too. i like the availebility of half of an inch different sized props :-)
4,5inch is on my list :-) that might match well for my 1806 and 2004 motors :-) the high 3150kv of the bh vy might be well for something between.

the hq3520 gives awesome response and acceleration on my 1306 4000kv emax on about 130g buildweight with some 650-850mah 4s batteries, maybe the most responsive settup i own.
awaiting to hear your impressions jasper :-) 1606 sounds very nice too, will be intressting if the 1606 can provide its power benefits on that low pitch in comparison.

Hi Bat,

How do you like the EMAX 1306 motors?

in general they are nice powerfull and versatile, flew them from 3-4inch. they are high kv for 4s, i burned one on 4inch, im nut fully sure about lifetime... but as i use it not to gently, they already look acceptable.
the emax rs1306b is overall a nice motor, not sure how the price is all around the world on them, maybe value for money could be a bit better. power and weight let me choose it, i would buy a replacement if i brun another one; guess that counts as i like them alot :-)
i didnt use them for flighttime but i didnt recognize anything bad, it might give good flighttime either if flown gently on 4inch (maybe 4,5inch)

Hi Bat,

Thanks. You know, I am always experimenting with motors and props. My thing is getting the most
Fly Time. Thanks Again.

I’m ordering Evan simitar 3.5” blades for my Betafpv 3 twig.. the new version comes with them. And they will fit. It issue.. It’s a great flying rig on 4s with 3”.. the 3.5” props are the same design as the Evan Rush 2.5” on the Tinyhawk freestyle and those perform great..

maybe a 1304 would be great on 3,5inch for flighttime, the high stator of 6 might not be a benefit, maybe on a high prop pitch but there isnt any rotor of that kind.
overall 1105 or 1204 could be more of a sweetspot than 13xx, 1105 spin the hq pretty nice. my buildweight is 60g and it is under 100g with battery, maybe higher weight might change the need to bigger motor for efficiency.

(12-Mar-2022, 02:04 AM)hugnosed_bat Wrote: my favorite rotorsize overall is, maybe was, 4inch too. i like the availebility of half of an inch different sized props :-)
4,5inch is on my list :-) that might match well for my 1806 and 2004 motors :-) the high 3150kv of the bh vy might be well for something between.

the hq3520 gives awesome response and acceleration on my 1306 4000kv emax on about 130g buildweight with some 650-850mah 4s batteries, maybe the most responsive settup i own.
awaiting to hear your impressions jasper :-) 1606 sounds very nice too, will be intressting if the 1606 can provide its power benefits on that low pitch in comparison.

I need a new Emax 1306 motor for my 4" Micro Reverb so I could only test the Gemfan 3520 on Emax 1606 Micro Alien 4" today.  Very good impression so far. Smooth and  very responsive. 

I was using Hq 4x3x3 before and I actually prefer the Hq 3520 as the Micro Akien is now less floaty and I could be much more aggressive on the throttle close to the ground or object. No extra flight time but then I found the same with many different propa with thses super notchy Emax 1606. Not a fan of this Emax 1606.

Now I expect good things from the 3520 with the 4" Micro Reverd /RS 1306, a quad I have struggled to get a grip with since I build it. Hopefully  i will get it up in the air in a few days time. I will try Hq 3520 too eventually as HQ ishould be more durable than the Gemfan Hurricane props in general.


And the other  Gemfan 4525 is fantastic on  5" Micro Apex with 2203 motors (250g dry). I was using Gemfan 5125 before but I think I will get a few more sets to mix it up. Less floaty when I throw the quad around , confident enough to be aggressive with the throttle for proximity flying. I don't find  the power too lacking with the smaller props. It's actually easier to transition from traditional 5" with freestyle. .

I have been flying over 2000 packs on 3.5" props during the last year (because it's the best size to fly in my backyard) and I love the throw you have when you use proper motors (1505,1408,1606) on it while still keeping the low end control for tighter sections!
I designed a frame (TTQ35) to be able to fly acrobatic with a (full) Vista in small spaces and it changed the way I can integrate flying in my daily live.

I been getting a number of questions if any of my frames are 3.5". Given the stark difference I found between 2 and 2.5, I've since been giving this a lot of consideration. I may make Sohei arms that are 3.5.

(25-Apr-2022, 11:15 PM)the.ronin Wrote: I may make Sohei arms that are 3.5.

Yes! Do it!

I've been extremely happy and pleased with my Crux35 build  (108g dry, 163g loaded).  I get up to 10-mins cruising on a 525mAh 4S battery (55g).

Frame:...........Happymodel Crux35....................$  20
Motors:...........Happymodel EX1404-3500KV.......$  32
Props:.............Gemfan Hurricane 3520..............$   8
Camera:..........Caddx Nebula Pro Nano..............$  68
VTX:...............Caddx Vista (naked)...................$106
VTX antenna:..GEPRC Momoda 85mm Antenna..$  11
FC/ESC AIO:....JHEMCU GHF420AIO-20A...........$  55
Receiver:.........TBS Crossfire Nano Rx...............$  30
Rx antenna:......RUSHFPV Micro T-Antenna........$    3
LED lights:........HGLRC Race Wire LED's............$    6
TOTAL...........................................................$339