(15-Jan-2021, 12:57 AM)Joshua_A Wrote: Hey ifly4rotors, are you still running 5” props?
I didn’t see 5” in the thrust tables, although I’d think you’ll get higher efficiency over 4”...
 And wow, your capacitor and your camera are the same wight!!!

I listed the 4 inch props, the 5 inch props are 3 grams more at 10 grams. They are still in the running, it sort of depends on if I end up using a manufactured frame or fabricate one myself; which is looking more like what I will do so that I can keep the weight down. If I do make my own frame, then it will be spaced for 5 inch props; no question. 

(15-Jan-2021, 01:06 AM)Krohsis Wrote: Joshua makes a good point.  With a 2s system why go with such a big cap?  I don't know if there is any weight savings, but you clearly could drop the cap voltage size by at least 10 if not 15 volts, perhap more given the low voltage of 2s.  Also, I don't remember the formula for caps and noise reduction vs voltage etc.  But there is a difference.  You may want to drop the capacitance to around 470ish.  Just a thought, not a big deal...

Yes, I probably could reduce the capacitor size which will shave a few grams. 

I guess I could lose the buzzer and hope that I don't lose the quad as well; ha, ah.   

Maybe swap the camera for a Caddx Ant and look for a lighter GPS   

I could shave off 1 gram by using my alternate FC, but then I lose the barometer.   Is it worth it    

Next thing you know, I will have a balsa wood frame 

What’s the BEC for?? Maybe you could try a much smaller cap wired to your VTX power in??

(15-Jan-2021, 04:15 PM)iFly4rotors Wrote: Next thing you know, I will have a balsa wood frame 

It’s funny you said that, because I was thinking a balsa wood frame might work fine (although fiberglass would be used as reinforcement)... hummmmmm

(15-Jan-2021, 05:40 PM)Joshua_A Wrote: What’s the BEC for?? Maybe you could try a much smaller cap wired to your VTX power in??

Hi Joshua,

The BEC is to provide separate power to the GPS for faster satellite fix. This is one of TMac's suggestions and the one I like best. The iFlight BEC that I am using weighs less than a gram...it doesn't even register on the scales so I will keep it.

Now, for some changes in the electronics package:
1) Use the HIFIONRC F7 flight controller instead of the iFlight Beast. This saves a gram but I lose the barometer. Oh Well.
2) Use a 470uf 16v (or maybe 25v) BEC that weighs less than a gram {doesn't register on the scales}.
3) Use an iFlight FPV GPS unit which only weighs 4.6 grams.
4) Switch to a Caddx Ant camera that weighs 2 grams
5) No Buzzer; I guess if I lose it, I just lose it. 

These changes bring the weight for the electronics down to 25.6 grams from 42 grams; a 16.4 gram reduction.
This brings the weight with motors and props down to 88.6  grams.

I am also considering nylon hardware.

I will simply have to fabricate a custom, light weight, frame. 

Yeah,  I need to order some parts and supplies. So, I will now be waiting on things to arrive. 

(16-Jan-2021, 02:33 PM)iFly4rotors Wrote: Hi Joshua,

The BEC is to provide separate power to the GPS for faster satellite fix. This is one of TMac's suggestions and the one I like best. The iFlight BEC that I am using weighs less than a gram...it doesn't even register on the scales so I will keep it.

Now, for some changes in the electronics package:
1) Use the HIFIONRC F7 flight controller instead of the iFlight Beast. This saves a gram but I lose the barometer. Oh Well.
2) Use a 470uf 16v (or maybe 25v) BEC that weighs less than a gram {doesn't register on the scales}.
3) Use an iFlight FPV GPS unit which only weighs 4.6 grams.
4) Switch to a Caddx Ant camera that weighs 2 grams
5) No Buzzer; I guess if I lose it, I just lose it. 

These changes bring the weight for the electronics down to 25.6 grams from 42 grams; a 16.4 gram reduction.
This brings the weight with motors and props down to 88.6  grams.

I am also considering nylon hardware.

I will simply have to fabricate a custom, light weight, frame. 

Yeah,  I need to order some parts and supplies. So, I will now be waiting on things to arrive. 

Wow, you dropped 16.4g, nice!!
Now we’re using the same parts for our builds , although I’m using a buzzer...
It’ll be cool to compare the aircrafts with each other, since there so close...
And I’m waiting for parts too...

I did this "weight diet" several times.

It looks easy - its not.

Most of the time, it makes build difficult and lose functionality - just to save 1g. Lose Lose.

Lots of little things you can do here and there, but ignoring elephant in the room.


The solution is obvious and simple. DJI already does it. Heck, all smartphones do it. Look at your MAtek GPS. Now imagine cramming that into your smartphone.

Integration.

AIO Whoop FC. Rember those extra 20/30mm boards. Remember many said it wont work. It does.

Now imagine DJI - who has $$$ - makes integrated FC/ESC with DJI digital and GPS and rx and everything.

No wires. Just antenna. Cable to camera. Thats it.
Well, they already do - its called Mavic.

(16-Jan-2021, 09:13 PM)romangpro Wrote: I did this "weight diet" several times.

It looks easy - its not.

Most of the time, it makes build difficult and lose functionality - just to save 1g. Lose Lose.

Lots of little things you can do here and there, but ignoring elephant in the room.


The solution is obvious and simple. DJI already does it. Heck, all smartphones do it. Look at your MAtek GPS. Now imagine cramming that into your smartphone.

Integration.

AIO Whoop FC. Rember those extra 20/30mm boards. Remember many said it wont work. It does.

Now imagine DJI - who has $$$ - makes integrated FC/ESC with DJI digital and GPS and rx and everything.

No wires. Just antenna. Cable to camera. Thats it.
Well, they already do - its called Mavic.

Well said, integrating all the needed components is definitely possible... and can be done on different levels.

I’ve seen the progression: individual ESCs with PBD and FC, 4/1 ESCs with FC And now AIOs... I wonder what’s next?

Well, the concept  of integration is sort of already done in the tiny whoop world, where the Rx receiver is integrated in the FC/ESC board. One tiny little single board Flight Control System. It is interesting that when "they" moved the whoop board out and up into larger craft, they took out the integrated Rx Receiver; Go Figure    

Oh, that's right...options...different receivers for different folks...short range, mid range, long range. 

Now, if you take one of these high power whoop boards and integrate TBS Crossfire circuitry, then you will have a "Grown Up" whoop board. 

Why not just include long range receiver circuitry into the bigger whoop boards {like maybe the iFlight Beast}; then you would have one board with everything except a video subsystem. This could then be an almost UNIVERAL board; put it in anything, everything, what ever you want.

Then, all that would be left would be to integrate some nice 800mW VTX circuitry and you have it ALL in one little whoop format board. 
Done 

So, where is it. 


Next, there is the body of the craft. How much does that thin plastic body of the DJI Mini weight ??  
Maybe I will use a lightweight plastic frame. 

Of course, you don't have to worry about crashing the DJI Mini...DJI won't let you...

With all of the automagic features, you barely have to fly it. Right 

(13-Jan-2021, 03:35 PM)Krohsis Wrote: So Harry, what are you using the BEC for?  

Also, given you can get lighter GPS pucks than the Matek, is it more important to you to have a Matek GPS or save a gram or 2?  And on the issue of weight savings, is lighter also the metric you look for or if you can stay under 250g, will performance/reliability be what you look for?  Will you go for the lightest components to carry a heavier batt?

Hey Krohsis, which GPS have you found that is light and reliable?  While the Matek GPS’s have served me well enough, they are just one option.

Hi Kaity,

I have a couple of iFlight GPS units coming; the listed weight is 4.59 grams. I vaguely remember {yeah, what memory} a YouTube reviewer that believed these to be rebranded Beitian units.  I purchased the iFlight GPS from AMAZSON for 19.99 (free shipping and 3 day delivery).

I could have saved $3.00 on the cost by purchasing the iFlight GPS from PyroDrone at 16.99, but I would have had to pay shipping and it would have taken about a week to get here. So, in the end, I think the cost is a wash {in fact I might have actually saved money} but I am getting them several days faster.

This is but one example of why I use AMAZON when I can. 
The product is the same, but the delivery is free and often much faster even if slightly higher price.

PyroDrone also sells a Flywoo GM8 Mini that sells for 12.99 and weighs 4.6 grams. This looks to be pretty much identical to the iFlight unit.
{you only get free shipping if the order is over $50.00, so I rarely buy small items unless I need a bunch of stuff}

These are the lightest GPS units that I could find.  

While waiting on Lexan sheets to arrive, I have been working on the frame design. After working on this for a while, I have decided to use a multi-part frame; I will use a set of light weight arms and bolt them onto main frame plates made from the Lexan. I realize that a unibody design would likely be lighter, however, the multi-part frame will expedite the process since I currently don't have the precision tools needed for motor mount holes nor anything to intricately cut the Lexan for arms and such. This approach will also allow me to experiment somewhat with the main fuselage frame plates. I will just know that the results that I get can likely be improved with a full Lexan unibody bottom frame plate. 

I really want to try the 1404.5 motors with 5 inch props first just to see what we get.

If the 5 inch props don't work out, then I will switch down to 4 inch props. 

Stay tuned ... 

Since the situation with LVC and 18650 Li-Ion batteries has come to light, 
I am now checking my FC boards that I have, but I don't think that any of them, 
including the BEAST has BLHeli_32, so that is a bummer. 

Since I definitely want to use 18650 Li-Ion batteries, I absolutely want the LVC turned OFF...
SO...I will likely need to get a new FC that has BLHeli_32 so that I can turn off the LVC. 

More information...

KaityLynn found BLHeli LVC information on Github.

I have read the entire article which seems to say that there is NO Low Voltage Cutoff in BLHeli_S and that any cutoff is a circumstance of the actual hardware whether implemented at the ESC level or the FC level and all depends on what and how the manufacturer decides to use and how to construct the boards.  

Interestingly, it seems to muddy the waters a bit.
 
Just because it has BLHeli_S does NOT imply that Low Voltage Cutoff has been implemented.
It simply means that you can not turn it off with software.  

Unless someone has tested and knows for sure, it is all a guessing game. 

What BLHeli_32 appears to offer is a method to turn off the LVC if it has been implemented.

I will also mention that the hardware "fix" illustrated may likely be specific to the particular board.
So, again, you would have to have intimate knowledge of the board, its circuitry, and how it was all implemented to really know how to approach that. That is WAY BEYOND what I am willing to undertake.

On the positive side, it doesn't mean the ESCs are limited just because they are using BLHeli_S firmware. 

Now, if the firmware is BLHeli_S.... we are back to... It Depends on the Board...Period. 

Take a DEEP breath...whew...

Since I have a brand new Flywoo GNF4 35A 16x16 stack V2.1 , it will be going in one of the builds. I will likely put it in the Phantom-X Upgrade (post # 70) and buy a new FC with BLHeli_32 on it for the Quest250-LR build. At this point, it is looking like it, too, might be a Flywoo board since they are leading the pack in this arena. 

I will now have to test each FC board type to see which ones appear to have Low Voltage Cutoff implemented. Of course, I will NOT be able to change it since they all use BLHeli_S firmware. 

Onward and Upward... stay tuned... 

Having done considerable more research and following some other threads, I now believe that the 2722kv motors will likely not really work with a 2S battery, so...I have decided to use Flywoo NIN 1404 4850kv motors instead of the Hyperlite 1404.5 2722kv motors for the Quest250-LR build. I think that the 1404 4850kv motors will spin the 5 inch props just fine since 1303 5000kv motors spin 4 inch props.

This is not eCalc or "real" math, just my mental extrapolation from flying my past builds.
 
Also, the 1404s are 2 grams lighter per motor than the 1404.5 motors; that will save 8 grams.

With this change the new projected dry weight is down to about 72 grams without a frame.
Using a 22 gram BrotherHobby Hyperbola frame {I already have this frame} the dry weight is coming  in about 94 grams.

If I can keep it less than 100 grams, that leaves a solid 150 grams for a battery; potentially a 3S 18650 3000 mAh pack. 

Now, we are talking. 

I think that's a solid plan iFly! The NIN 1404s should be able to spin a mild 5030 prop fine, but you'll likely run into power limits at high throttle. With a 2S or 3S Li-Ion pack, the current demands at high throttle will exceed what the batteries can provide. Not that you're the type to try full-power punchouts, but for safety I'd set a conservative throttle limit in Betaflight when you're running 5 inch props. If you use the GNB LiPos that can deliver much higher current, you'll hit the max power rating of the motors at high throttle potentially causing damage.

A 4" prop is a much better match for those motors, and eCalc actually shows higher efficiency, range, and performance with a 4024 biblade than with a 5030.

I guess the benefit of starting with a light 5" frame is that you can try both!