Not necessarily true. Li-ion batteries are very similar to LiPo in there resistance to over voltage, under voltage, temperature, and almost everything else. The biggest difference is that a Li-ion need sub 2.75v-2.5v to get damaged where lipo is 3.2v- 3v. Also in a thermal runaway, a lipo will melt through their aluminum foil like case and light on fire. On the other hand a Li-ion will destroy itself, but it will never light on fire because of the metal case they are in.

The reason people often use a bms with a li-ion is that it actively monitors the battery which make them last longer makes it more idiot proof, and removes the need to have 16 Ballance wires that many 15s li-ion battery packs would need. This is the exact same reason why dji builds a bms into ever single of their drone batteries no matter if it is lipo or Li-ion.

Yeah! I'm working up a guide to how to build them, along with the STL files. I'll update here when they're available, as well as post in the brushless micros facebook group.

how is the progress? I really like your project!

I need to get on top of my projects! testing has been slower, it's been harder to find space/time to fly with everything shut down. I've been putting a bunch of time into developing the LFH6, just uploaded it here on thingiverse :)

It would be a great platform for a cinewhooop build, with a naked gopro on it.

I haven't decided if I'm just open-sourcing the plans, or free plans and also offering frames for sale, or what exactly. Either way, I'm just flying (and testing) it as much as life/weather allows. And I've already started playing around with a pod design for a nano-cam + naked H6 :)

That would be great. I also want to develop it, design a tpu prop guard for it. Much like the Cinerat frames tpu prop guard.

Want to move into Li-Ion cause Lipo batterys here cost so much.

Looking forward to your cinewhoop build in that frame

Can i ask whats the frames weight? without the tpu part

Thanks! I'd say these 1404 7000kv are likely the perfect motor spc for this quad, or at least getting really close. I'm finally getting nice smooth prop control through most flight situations. I haven't flown it in intense wind yet though. Peak thrust is limited more by battery then the motor, so I can't imagine larger motors would be of much benefit. I still have some question as to the best KV... if 5000-6000kv would be sufficent, or if there would be any benefit from something 8000-9000kv.

i know that the 7500kv motors ive run didn't like anything more than 2s voltage on a 2.5" prop. i would assume that with the voltages you're using that the higher kv would be better performance than a 5000kv motor. im trying to decide if im going to get a whoop next (spring is coming and the rain here will be constant for the next month or so. or to build a mutant 4 with a set of 1204 5000kv motors

Funny you ask about the 1108 motors... They're actually doing suprisingly well, performance is totally adequate, temps are fine, and overall flying nicely. But I'm having trouble getting that last bit of smoothness I need in the footage. So I have some xing 1404 7000kv showing up tomorrow that are getting swapped on, I'll see how they work out. The 18650 pack is 8.4v fully charged, and I aim to have it back on the ground around 5.8v.

thanks for the insight. i saw your build the other day and i instantly thought about getting a racer x mutant 4 with these motors. probably will keep with lipo batteries as im not as concerned about endurance. just good to know those motors can handle the 4"

It's coming along! The weather hasn't been so cooperative, but today's flight will get posted.

Lithium Ion cells come in a wide variety of chemestries, so I'm only really talking about the ones best suited to our needs (most the rest just suck). LiIon (Lithium Ion) packs more energy into less space then Lithium Polimer (LiPo), but also has higher internal resistance. Basically it's a lower C rating. So to make it work, the quad just has to be designed around sucking fewer amps, and keeping up prop RPM at low voltages. Essentially, the same stuff that lets modern Toothpick-type racers have stupid-fast acceleration for a couple minutes, means that even at half the thrust-to-weight this thing still rips around plenty quick for a long time shooting 4k footage :-)

Yup. I'm using a tiny LC filter supplying vbat to the camera. It will run 5-20v. The VTX and RX use 5v, and it all appears pretty tollerent of low voltage. I haven't actually found which component glitches first, I've had it in the air below 5.4v specificly testing to see what happens. I'm sure something was struggling, but nothing failed. With this quad, and other's I've flown with 18650, I aim to be back on the ground by 2.9v. At that voltage, everything seems to hum along fine.

Eventually I'm sure this size of quad will feature digital FPV. But right now, the Air Unit would dwarf this quad. It would have to be so much larger to fit it, it wouldn't be the same quad. However the Caddx Vista should fit ok directly over a Zeus AIO. When the frame goes open-source, if I don't design a camera pod for the Vista I hope/expet someone else will :)