Whats your prediction for next year?

[theGreenOrange]

I'm not sure what part you are missing so let me lay out my evidence. If you design a 4" frame with a stacked camera similar to the 180mm 5" designs, you can without a doubt, at a minimum, reduce the frame to 165mm [edit: 155 really, oops]. Then add in the savings from 30.5mm stack to 20mm stack and that gets you to about 160mm [edit: likely less].

Then factor in the reduced dead weight in the form of stack weight, wire weight for motors and battery pigtail, etc, etc... That is what efficiency is made of my friend. Maybe you won't believe until you start seeing 4" quads winning 5" class races, but prepare yourself mentally. It is coming. Micro CCD cameras are a big help too.

 

[CheFPV]

I'm not sure what part you are missing so let me lay out my evidence. If you design a 4" frame with a stacked camera similar to the 180mm 5" designs, you can without a doubt, at a minimum, reduce the frame to 165mm. Then add in the savings from 30.5mm stack to 20mm stack and that gets you to about 160mm.

Then factor in the reduced dead weight in the form of stack weight, wire weight for motors and battery pigtail, etc, etc... That is what efficiency is made of my friend. Maybe you won't believe until you start seeing 4" quads winning 5" class races, but prepare yourself mentally. It is coming. Micro CCD cameras are a big help too.

I'll take an ultra light, built with all those same light 20x20 and micro cams, 5" 190'ish mm frame and destroy that 4" you think is coming that has about 4 choices in props, none of which are any good.

But again, could be wrong. I am basing my info on experience and knowledge of what actual frame companies are making and working on behind the scenes. Surely I only have a sliver of the whole pie though.

Good convo.

 

[theGreenOrange]

The only problem there is that the biggest 20mm ESCs right now are 25A (maybe I saw a 28A) and that really isn't enough for 5" props in my opinion. It will be interesting to see what happens. I like the 5" ultralights like the floss as well. But this thread is about the future and floss is yesterday's news. 4" monocoque quads are the future!

 

[CheFPV]

The only problem there is that the biggest 20mm ESCs right now are 25A (maybe I saw a 28A) and that really isn't enough for 5" props in my opinion. It will be interesting to see what happens. I like the 5" ultralights like the floss as well. But this thread is about the future and floss is yesterday's news. 4" monocoque quads are the future!

you dont need 4 in 1 esc. Ill take 4 small 25-30a escs all day. I dont even run any 35a escs. Unnecessary completely. 20-30a esc Burst 60-75a and is plenty for even the fastest racers. Ask them, I think less than 30% run 35a esc or higher. We have even found that lower Amp escs have a faster signal pulse due to less components its being ran through and lower resistance.

 

[theGreenOrange]

Again, these are old problems. Dshot D1200 fixes the ESC issue. And if you don't run a 4in1 you don't get twig arms and you aren't ultralight. Both are the future: aero (or stick) arms and ultralight builds. Arms won't be wide enough for ESCs anymore, they already aren't.

 

[theGreenOrange]

Also, the 20mm ESC's do not burst nearly as high as the 30.5mm ones. A 20mm 25A ESC will likely have a 30A burst. Maybe 35A tops.

 

[VirtueViolater]

4" props need approximately 4.5" of clearance between motors, this does not accoutn for a 1.5-2" gap for camera and or removing props from camera view. Due to this, designs would need radical redesign to allow for much less than 180mm design of a frame and then you would have to change geometry of the motor positions and that leads to other issues.

4" motor and prop combos have not been in R&D at all compared to other sizes, this coupled again with many frames in thew 190-210mm range (I have a 5" 190 Bee Rotor Thunderbolt) that run 5" props due to small pod designs and other design attributes, 4" is just not going to be logical when a 190 size 5" can destroy it in every way and a 130-150 3" can make it look silly in half the weight and much less cost as well as small battery.

youre right I could be wrong though.

The only problem there is that the biggest 20mm ESCs right now are 25A (maybe I saw a 28A) and that really isn't enough for 5" props in my opinion. It will be interesting to see what happens. I like the 5" ultralights like the floss as well. But this thread is about the future and floss is yesterday's news. 4" monocoque quads are the future!

Raceflight is coming out with a 20x20 aio esc rated at 30a next week, it may even be able to handle more, cant remember for sure. Imo, an ultralight 5" may be unbeatable by anything. Check out Brian (BBrain), he's running the raceflight skinnykid ultra light 5", it's unreal

 

[VirtueViolater]

Only 4-n 1's will be dshot ready next year, as much as i like individual esc's myself, they are going away
4n1's are also sbus through pins. Digital protocal is the big thing next year. Also, raceflight is coming out with a new digital protocal

 

[VirtueViolater]

All these issues are only race related anyway, freestyle doesnt need any of these improvements as a little weight seems to help and speed isnt an issue

 

[theGreenOrange]

If the 20mm ESCs do get strong enough for 5" props, the 4" will lose most of the advantage that is shaping up.

 

[VirtueViolater]

If the 20mm ESCs do get strong enough for 5" props, the 4" will lose most of the advantage that is shaping up.

They are coming next week, you'll see

 

[theGreenOrange]

They are coming next week, you'll see

30A still may not be enough if they only burst to 35A before they explode. We will have to wait for some testing I think before we know.

 

[CheFPV]

You surely can and many people do put small spedix and emax escs on twig arms in tpu mounts. You also can stack them inside some frames quite easily. The point I was making is still true. For any 4" build you can throw out there I assure you a 5" build can be made to be much higher in performance. Otherwise you already would have seen guys like Brian Morris make the jump. PS I have had this convo with Brian, Envy, and Sed Hendo before and we all left the 4" talk and opted for 3" and 5"....

 

[VirtueViolater]

30A still may not be enough if they only burst to 35A before they explode. We will have to wait for some testing I think before we know.

Some are already running the rf 20x20 w 5"

 

[CheFPV]

Hahahaha burst to 35a? 12a ESCs burst to 35a.

Most ESCs can burst to 200% or more of their rated Amps.

This is a big misconception by new users that 20a ESCs can't handle heavy loads.

Conrad and many others fly 20a still.

Amp draw is not as heavy as most would make you think for 98% of pilots.

 

[theGreenOrange]

Some are already running the rf 20x20 w 5"

But at what power/weight ratio? My point is that right now, 4" has just gained the advantage in power/weight ratio.

@CheFPV This has only occurred in the last month or two, so it has not trickled down to results and adoption by racers yet. But unless the 20mm ESC's can really handle a 5" tri-blade prop, they won't gain back their previous advantage. I wonder how it would go today if you have those conversations again and see what they say now (if they have a recent 4" ultralight build).

 

[theGreenOrange]

Hahahaha burst to 35a? 12a ESCs burst to 35a.

Most ESCs can burst to 200% or more of their rated Amps.

This is a big misconception by new users that 20a ESCs can't handle heavy loads.

Conrad and many others fly 20a still.

Amp draw is not as heavy as most would make you think for 98% of pilots.

I am talking about rated burst current, which you can compare between product lines. The 25A 20mm ESCs have a rated burst of 30A. That is low, even for a rated burst. The 30.5mm parts have a much higher rated burst, usually 150% of rated continuous current.

 

[theGreenOrange]

Oh, and @CheFPV, I am not new. I have a degree in Electrical Engineering and built my first RC vehicle in about 1988. I have been using mosfet ESC's since the Novak on my RC-10 and Losi buggies.

 

[VirtueViolater]

I'm running blheli s 20a esc's on my Johnny Cash build. There's a big difference between 20a and 30a on these motors
can also run 50c paks w/ 20a, no puffing. They puff on 30a esc's

 

[CheFPV]

Yes INDEED!!!! This is something that is not expected. Most builders think they need limitless current available. Anyway. I prefer a 20-25a esc. Good info!