3S 2.5" Armattan Tadpole

By SquishinStix on Oct 15, 2020

15  843  4

UPDATE: After adding some 3D printed skids and a circular polarized antenna, the weight is up a bit, but worth it I think. I have also relocated the antennae to be coming off the rear arms towards the front which made a significant difference in how it free falls or glides through the air - those big zip ties hanging off the back really slowed it down quite a bit. I'm usually getting about 3 minutes of flight time, sometimes 4, using the RDQ Series 450mAh 3S packs.

Meet "Sebastian". This is my second build ever and I'm incredibly happy with it. My first solder experience came just about a month ago when I replaced a motor and flight controller on my iFlight Cidora SL5-E and after that I had the itch (and confidence) to build my own quad. I built "Leon" (Armattan Chameleon Build here) several weeks ago and it was so much fun that I immediately started planning my next build. I decided I wanted something smaller and primarily quieter so I could rip around my house without bothering my daughters napping or in school (my neighbors will appreciate it too I think). Also, my 5" is a little too much quad for my 1 acre of mixed woods, house, and lawn. Since my daughter named my Mavic Mini "Sampson", my Cidora SL5-E "Ferguson", and my Chameleon "Leon", I am sticking with the "ends in "N"" theme for this little fella as well. Last two pictures show the Tadpole next to and on top of the Chameleon. I actually think, when facing it backwards, it kind of looks like "Sebastian" the lobster from The Little Mermaid.

I chose the Tadpole frame because, frankly, it looks badass - it also matches my Chameleon very well and Armattan frames are built like a tank. Aside from the frame, it's a bit of a budget build. I got one of the cheapest 16x16 F4 stacks I could find and same goes for the motors, although I knew I would like EMAX ECOs already since I have them on my Chameleon.

In terms of the build, I wanted to try my hardest to make it super clean. It wasn't hard with a wireless stack (the flight controller, ESC, and VTX are all connected with pins - so cool!). The only wires are the motors, the receiver, and the camera. In fact, I'm a little annoyed about the camera wires because the FC doesn't have pads for the camera, it has a connector, and the wire harness that came with it is like 4" long and the distance from the FC to the back of the camera is only about 1/4". Right now I just have it twisted and bundled up in a ball behind the camera but I'd really like to direct solder to the FC or at least shorten the wires somehow. I hate to have to repin the wires into the connectors but maybe I could cut out a big section in the middle and just solder the wires together with a little heatshrink over them. Probably not worth it though.

This stack barely fits in this frame (thanks to someone on the RDQ Tadpole review that says it does though!). The screws were a bit too long in the back so I have some spacers on the underside of the bottom plate to effectively shorten them within the frame. I also had to trim down some of the gummie spacers a bit to make it all fit - but it fits beautifully and I'm glad because I don't know where I could have squeezed a separate VTX otherwise. Would have probably had to just stick it to the bottom of the top plate above the stack.

I flashed the ESC with JESC and am running BiDirectional DShot, DShot600, and RPM filtering. The quad flies like a dream. I'm running very low gyro filters and fairly high D gain - extremely hard to bring out propwash plus the motors stay cool. Must be a clean build!

The motor wires are heatshrinked, cut to the exact length necessary, and held to the arms with electrical tape. I had a lot of trouble soldering these little wires to the pads cleanly. In the end, everything works great but if you zoom in a lot, the joints aren't the prettiest. Oh well.

The battery leads are ziptied to the bottom plate and rear of the top plate for strain relief. Running the capacitor that came with stack (didn't notice the microfarad rating). Video feed is the cleanest of my quads though (even though they all have capacitors).

The R-XSR receiver was actually the hardest part of the build. Although the board is quite small, it has a comparitively enormous connector on it which I think is completely useless - why aren't the wires just direct soldered? Well, I cut off the plastic connector, desoldered the pins, and direct soldered the wires back to the board. The wires are only about 3/4" long now from where it's mounted to the FC. After I binded it to my radio, I heatshrinked the board and mounted it with VHB tape to the bottom plate between the stack and rear standoff. Antennae are ziptied and heatshrinked facing backwards on rear standoff. They look huge on this little guy but didn't want to shorten them just for aesthetics. Kind of looks like an insect now.

Coming from 5" builds with 800mW VTXs I was a little worried about this little 200mW VTX with a monopole antenna - figured I would try it but ultimately upgrade to a better antenna. However, I have been pleasantly surprised by the strength and quality of the FPV feed! In an open field at about 500' out the feed is flawless and still perfectly flyable when going behind stands of trees. At my house I can fly on the opposite side of the house (although it's ugly) without issue. Don't think I'll be upgrading the antenna after all. Plus the camera's feed is fantastic - easily my favorite of my three cameras. Can't believe such good looking footage is coming from this miniscule little Nano Racer.

The stack is all conformal coated (aka waterproofed), including all solder joints. My maiden flight with the Cidora ended in a gentle landing in wet grass that shorted a motor and the flight controller. Lesson learned.

I mount batteries with the lead in front, running over the top and connected to the quad's lead - I planned ahead and cut the quad lead to the right length so this just barely works with maybe 1/4" of wiggle room.

I've put about 10 packs through it so far, 3S 450mAh, and get 4 minute flight times bringing it down at 3.65v. The power is INSANE. On a full punchout it puts my 5" quads to shame. I just blip full throttle and the thing has moved 200' instantaneously. And the sound! I love it, so quiet, like a kickass bee flying around. One of my favorite things about this build is that it's just as much fun to fly as my 5" quads but the overall cost is a bit lower but more importantly the batteries are like $6 vs. $32 for the 6S monsters on my 5" builds. Right out the gate I snagged 6 packs and will probably grab 4 more on my next RDQ/GetFPV order. I dove straight into a 5" quad because the price difference for a good prebuilt 5" vs. 3" wasn't much, but I didn't factor the batteries in I guess! This little build has really opened the door for me to fly places I wouldn't have flown otherwise (like an empty field next to an occupied field for example, wouldn't have done that with my 5" quads).

I have some 3D-printed arm protectors and hard plastic skids coming next week.

Dry Weight: 88.3g
All Up Weight: 139.9g

I have gotten tons of excellent ideas and inspiration from other people's builds so I am excited to share my own work and I hope you enjoy it!

Photos

Part List

Frame

Armattan Tadpole 2.5" Micro Frame (26 builds)
Racedayquads.com
$33.99

Flight Controller

iFlight SucceX Micro F4 V1.5 (M3 Holes) Flight Tower System 16x16 Stack/Combo for CineBee (F4 FC, 12A 4in1 ESC, 25-200mW VTX) (4 builds)
Racedayquads.com
$39.99

Motors

4 x EMAX ECO 1106 6000Kv Micro Motor (3 builds)
Racedayquads.com
$47.96

Propellers

HQ Prop 2.5x2.5x3 Tri-Blade 2.5" Prop 4 Pack - Choose Your Color (21 builds)
Racedayquads.com
$1.60

FPV Camera

RunCam Racer Nano 2 1000TVL CMOS 4:3/16:9 PAL/NTSC FPV Camera 1.8 - Orange (13 builds)
Racedayquads.com
$31.99

Receiver

FrSky R-XSR 2.4GHz Micro ReceiverDefault Title (936 builds)
Racedayquads.com
$21.99

Batteries

RDQ Series 11.1V 3S 650mAh 80C LiPo Micro Battery - XT30 (8 builds)
Racedayquads.com
$14.99

Radio

FrSky Taranis X9 Lite RC Transmitter - Choose Your ColorWhite (17 builds)
Racedayquads.com
$89.99

Goggles

FXT VIPER V2 5.8GHz Diversity FPV Goggles w/ DVR (13 builds)
Getfpv.com
$170.99

HD Camera

RunCam 5 Orange 12MP 4:3 145°FOV 56g Ultra-light 4K HD FPV Camera for RC Drone (21 builds)
Banggood.com
$102.49

Battery Charger

HOTA D6 Pro 325W 15A 1-6S Dual Channel AC/DC Smart Charger w/ Wireless Cellphone Charging - Choose Your Color (55 builds)
Racedayquads.com
$117.99

Soldering Iron

LONOVE Soldering Iron Station Kit – 60W Solder Station 194℉-896℉ Adjustable Temperature, LED Display, Sleep Function, (2 builds)
Amazon.com
$49.99

Backpack

RDQ FPV Backpack w/ Optional Rain Fly (17 builds)
Racedayquads.com
$79.99
Show stores (4)

Discussion

Sign in to comment

Ifly@sgfpv   Dec 09, 2022  

do u think this motor can fly 4s?

feej   Jul 15, 2022  

Awesome build and really helpful write up/photos, thanks! Did you managed to fit a buzzer in there anywhere? I'm trying to work out if/how I can add one to my Tadpole :)

saahbs   Oct 18, 2020  

Very nice build - good points on the low battery costs of micro-quads. With this size class getting 15 packs and flying "entire afternoon" doesn't break the bank :)

DoubleJackOnTap   Oct 16, 2020  

Very nice!

Guides & Reviews

Jun 21, 2021

AirbladeUAV has done it again and this time they've brought long range to the 5" class! Based on the popular Transformer Mini, the new Transformer 5" Ultralight adopts a lot of the same design philosophies with larger props and more payload capacity. It can fly upwards of 20 minutes on a 4 cell Li-Ion battery pack and in ideal conditions it's got a range of over 4 to 5 miles. In this guide I'll walk..

Read more
Mar 04, 2021

With the release of the DJI FPV Drone cinematic FPV has become a lot more accessible, but you certainly don't want to crash a $750 drone! The QAV-CINE Freybott is a compact, lightweight cinematic FPV drone that can take a hit and keep going. It's a lot safer to fly indoors and around people. With a naked GoPro or the SMO 4k you can capture some great stabilized footage. In this guide I'll show you..

Read more