I did a video on the roma f35 um a couple weeks back, perhaps a little bit longer than that. I dont remember exactly, but you know these drones are both really similar in size and in terms of design and also in terms of motor choice but theres. Some pretty significant differences here in terms of um the choices theyve made and and ultimately happens with the flight performance. So the frame itself between these two are almost identical. The front the top plate is the same length. So in terms of the battery and everything like that should be the same, the only difference is that the f4 supports four inch propellers. The f35 supports three and a half inch propellers. So the motor to motor distance is a um, basically a difference of a half an inch or a quarter of an inch per propeller. So 158 millimeters for the f35 is the motor motor distance and then 174 millimeters for the f4. And then, if you look at the way the frames line up, if you line up this exactly right, you can see here with the f35 over the f4 there on the bottom, its just the arms are just a little bit longer to accommodate the four inch propeller And it turns out to be its a quarter of an inch long, which makes a lot of sense to make that propeller clear. Now i have the analog version for both of these uh same video transmitter same camera.

I did uh put some different receivers on these, so on the f35 i use the uh freesky, xm plus receiver and then on the f4 im using an express rs, 2.4 gigahertz receiver antenna here in the back, and i think this is the beta fpv receiver. In terms of weight, difference is not going to make that huge of a difference. So obviously the dji versions are going to weigh something else, but these are the analog versions. 20. Sorry this is uh 221.7 grams for the 3.5 inch and the 4 inch is coming in at 236.1 grams. Now. The other major difference here is the stack, which is the last thing uh i was going to get to. So let me go and pull these little covers off. The 35 comes with a you know: more of a standard 20 by 20, two board stack flight controller and esc. The four inch now comes with this new, all in one combined flight controller and esc in a single board, obviously to keep the weight a little bit lower theyre, both using the same uh, 20 220 3.5 motors, but different kvs. So these come in at 2200 kv for the 6s version on the 4 inch. This is also a 6s version for the 3.5 26 50kb, so the kv difference is pretty significant, 2650 versus 2200. Even though youre going up a half and im sorry its a half of an inch overall um from the three and a half inch to four inch propeller, i think that they reduced the kb a little bit too much.

In my opinion, im. Not sure why. I think that it could have gone to a little bit higher kv, but i think that they may have made that decision based on the fact that theyre using a single board here – and these are notoriously not very good – in handling voltage, spikes and large amounts of Current spikes and if you have this bigger motor on 6s youre, going to have more fluctuation, more variance in that voltage um with a higher kv motor. So i think they went a little bit conservative here and lowered the kv a bit more for to accommodate the single board, its 35 amps, whereas i think that on the three five perhaps they were overly aggressive, maybe 2650 might have been a little bit too high. Uh for even for a separate esc board, which is, i think, why you see a difference in performance, so you know um in terms of the. If, when you fly these, both on the lighter 550 milliamp hour battery, this is a sick. These are 6s. They you know they fly pretty well: okay, well, im, not gon na, say theyre, similar the, because the three five has a higher kv motor it the 550 the slider set. It flies pretty um. Well, its got a lot more um pop a lot more responsiveness. You know for the lightweight setup and the smaller battery um you put it on here. I was expecting it to be better, but it actually was not.

It actually had less performance even with the 550, even with a bigger prop, because i think the moto kb is a little bit too low. So, conversely, when you go to a bigger battery, which you know you, these guys can carry these like larger success virus. This is a 1056s, which is this is not a good battery. By the way, this is pretty old. Um weighs a lot more. So let me show you the difference in weight. I think also the weight differences will give you a different um uh characteristic in terms of the pitune. So 550 is Music, 102.4 grams and then the 1050 comes in at 190, 2.7 grams, so almost double the weight so im. Thinking that the ideal battery – probably for the f35, a little bit bigger than this – maybe like a 650 or 700 success and then on the four inch i think you can go – you can definitely go higher than the 550 im thinking like 750 800 850 somewhere in That range these are batteries i dont have so i was unfortunately not able to test this uh those scenarios because um yeah – i just i spent way too much money on batteries this year, so im just im, basically going to wait till next year. Before i buy any new batteries, uh yeah so im thinking that, based on my testing on these two batteries, you probably want something in between uh the ones i actually tested in in the stuff.

So, im not going to show you a ton of flight footage on this one, its the on the heavier battery. The four inch here with a lower kv motor is really the performance is sort of, not that not that real, not that really notable um compared to the 558 on 6s on the 35 or the three and a half inch model, so bottom line here is, i Think that they made a mistake on the motor keeping choice, but i think they did that to make sure that the all in one board survives im thinking that what they probably should do here is swap the stacks and bump up the kv in this one. So put this um all in one board here on the 30 on the on the f35, which will make it lighter and im thinking that this motor will probably be okay unless youre going to totally nuts on this one and then put the separate dual board stack. The separate flight controller and ac into the f4 and then increase the motor kv up to like say, 2450, and then i think their performance is going to be much more respectable. So again, you know, you know these are very similar in terms of size and prop size, but the when it comes down to the you know short the choices of the components you make in your build. In this case, i think theyve made some sort of odd choices here.

I like the performance on the 35 with this set up here, as you probably saw in that video. It flew really well, but i dont really like the performance on the f4 in comparison to the f35. You know again, this is this is still a nice quad. It flies. Okay. I think that the pigeon here is highly dependent on the weight, and i think that, on the lighter 550 air was very loose, not very locked in even on the 1050, it didnt seem super locked and i think the pitoun really just needs a lot of work On the f4, compared to the f35, f35 ive seen way more um locked in in terms of the pit tune so im thinking, they may have not done enough work on the on the pin tune in the f4. It needs a little bit more work and or they need a little bit more guidance in terms of the weight that youre carrying around. I think that they, i think in my opinion, i think that theyve pid tuned this for a pretty large battery, perhaps even bigger than the 1050, maybe like a 1300 6s plus the weight of like a gopro, maybe like a session five, which this thing is. This can definitely carry all that weight uh, but i think that when i looked at the numbers and compared to pigtunes im thinking, thats, probably what they were targeting but thats like um its gon na basically turns into this until, like a cruiser um, you know where Its gon na fly more locked in and not really give you very good, accurate performance.

But if you want acro performance, you probably want to go to the smaller battery like a 550. But in this case, like probably like a 650 750 with like a mount for like a cadex, peanut or insta360 co2, and then you get a nice little freestyle set up there with it. Obviously, youre gon na need an adjusted potoon for that. Okay, so thats pretty much it for the bottom line on these two guys um. You know, i think that it could. I think that the f4 needs a little bit more work, and i think that i would recommend going with a different, moto kb, but im thinking that, if theyre going with this all in one board, they probably cant, and they probably should be going for the dual Stack separate esc board in a higher kv motor thats. My recommendation on this model anyway uh any questions.

https://www.youtube.com/watch?v=8ZpdW9WW_JA