Insider
A while back my buddy Clint Hild put a 6 pound ball on his Dualist and hovered it on 5s. That’s 2.7 kg, and we’ve been flying Black Magics at 1.2-1.4 kg with a 7” X8. So a 4” ducted quad can almost do the same job as a 7” octa??? That totally doesn’t make sense to me but it’s worth a try.
I have a few Dualists sitting around from a corporate event I did with Randy Slavin. I installed a new stack for 6s in one of them for a quick test. The 2206 2600kv Brother Hobby’s that were on it were meant for 4s, but for now I left them in. The original Dualist ducts were about 1mm thick, which seems a bit flimsy now that we’re going for an AUW of about 2.2kg. I increased the thickness to 3mm, which increased its weight from 36 to 45g, not a bad tradeoff.
I printed the ducts with Taulman 645, and with its extra thickness it held its shape really accurately, which in turn allowed me to trim props to a really tight tolerance.
So then it was time to toss 1kg of batteries on top and give it a hover.
With a 1050 6s it handled the weight no problem, around 45% hover. Time to start with a clean slate and draw up a dedicated Black Magic lifter.
The arms on the Dualist slip through the ducts on both sides, which means you have to slide on the duct and then install the motor. This is a pain for maintenance, so I made the inner opening a slot. Now you can take the duct on and off without de-soldering the motor. The original duct had screws threading directly into the 3d print. I didn’t think this would hold up with the increased weight, so I changed it to the trusted friction-fit-over-standoffs interface.
The Dualist ducts were a little less than 4” across, because I wanted to cut 4” props for the tightest possible interface. The boys asked me to make these take 4” props. You can cut down 5” or larger props for that super tight fit, or you can just drop in 4” bullnose props without the hassle of prop cutting.
I also gave them an angled cut at the bottom. The extended parts at the outside are meant to keep it from tipping too far on the ground, and I thought it looked kinda cool.
I like the Thicc’s cam mount system so I drew up a top plate that would work with it. Aside from that the rest of the frame was pretty straightforward, just an extended nose for the fpv cam.
The carbon arrived and it was kinda cool looking!
I moved the parts over and gave it an unladen maiden. It popped off the ground with barely any throttle and it was whisper quiet. DAL4040’s give a nice fit with no cutting.
With the city in lockdown the easiest way for me to get a test flight in is to fly at 4am on my street. I know it’s not the most responsible thing but I really don’t want to get arrested in a park. Here’s the maiden with an 1800 6s. Fully loaded down it’s LOUD. My wife and daughter could hear it from inside the apartment.
It flew ok at first, but it seemed to lose its tune after about 30 seconds. I know pids can be dependent on voltage, but the voltage wasn’t dropping THAT fast. I met up with Justin in Brooklyn to fly his Black Magic and the same thing happened.
This was a half spent battery, so it’s already into its wobbly phase, and the battery sagged out just as I was landing so I gave Justin’s camera yet another tumble. Also, the downdraft on this thing is incredible. 2.3kg of tight, focused thrust really blows the dirt around.
Now, as Betaflight has gotten better and more complex, I’ve gotten more and more out of touch with tuning. I’d just gotten a great tune for Thicc from Troy, so I just took a stab in the dark and threw those settings in, increasing roll and pitch P to 90 (because it’s wobbly!). I also updated to Betaflight 4.2 and dropped in the cinema settings. Finally I added a parallel harness so I could run two 1050’s. It’s not a ton more mAh but it’s worth a shot.
Magic! Way more stable, and no change in flight characteristics as voltage dropped. The Brother Hobby 2206 2600’s were getting pretty hot, so it was time to swap them out. I think 2300kv might be the sweet spot, but I’ve been on a recycling kick and the closest I’ve got lying around were some Xnova 2307 2000’s.
I biked out to Brooklyn on what turned out to be a hellishly windy day, so we weren’t able to get any decent Black Magic footage. But at least we have a quick clip of it with the right cam instead of my janky rubber band dummy weight situation. Talk about a flying camera, the whole thing isn’t much bigger than the Black Magic.
I added some expo to clean up my crappy piloting and it’s starting to look decent. Motors still warm but not as hot as the 2600’s.
So it’s flying well and I feel super confident with it. I’m getting 3 minutes with those dual 1050 6s’ at an AUW of 2.3kg. It’s always going to stink in the wind, but it should be able to do Squirt like things in still air. I wanted to see if it could pull off more acro moves like a split s, so I went to the park at dawn. Just my luck it was windy.
As you can see it flies quite a bit worse in the wind, and on my first half hearted gentle attempt at a split s (it’s scary to invert a 2.3kg with a lower power to weight ratio than the racing builds we’re spoiled on) the motors had a mild freakout on the descent. You can hear them trilling at the one minute mark.
Fincky suggested turning off air mode. I went back out there, and this time there was no wind. The big twitch at 9 seconds is a slip of the finger. The big wobble at 23 seconds is me dropping it to 0 throttle and the quad having no authority…‘cause air mode is off. I flew the rest of the battery without dropping the throttle to 0 again. With its weight and the ducts, it’s not very confidence inspiring on the dives, you can see me repeatedly picking up the nose early. But at least the motors didn’t freak out like before. I’ll have to test more to determine if air mode or the wind was the culprit. Aside from diving it did fly nicely.
And Then…
At this point the form factor of the frame itself was pretty much done. I’d sent frames to Gab and Fincky and neither were able to get a setup they were totally happy with. Meanwhile, other people saw the frame and asked for it, so I kept cutting more frames and sending them out. They got good results and posted on social media, which led to more frames getting sold, even though I’d yet to list it in the store.
I started working on a ducted Siccario and I stripped my Insider for its parts, and so I stopped experimenting with the Insider. It feels wrong to list a product when I personally haven’t built a perfect one and gotten a pro tune, but demand is getting to the point that I just need to put it in the store instead of treating it as a secret prototype only available via DM. If you’re interested I urge you to join the FPV Cinelifter Facebook page and chat with other users about motor choice and tune. It’s now in the store here.