I'm going to try the Emax 1408 2300kv on a Volador3, but I'm thinking of trying those BFPV 1805 1500kv on the Volador35. Both will be 6S, either 550 or 650 Lipos. For me, i'd rather have a slightly more hardy frame since I still have a penchant for slamming them into the ground from time to time. Also weight isn't really a thing.

(18-Jun-2024, 01:54 AM)mstc Wrote: Volador is a pretty heavy frame, I have 1604 motors on mine (190g dry) and definitely not the thrust-to-weight or agility of 1404 builds as I also need to fly a larger battery. On as 4S 850 I might squeeze out nearly six minutes cruising, whereas on the 1404s its pretty easy to get 8 minutes or more on a much smaller battery. For comparison a 1404 setup like the Babyhawk O3 is 160g and Crux/Scythe would be around 100-120g.

For an all aluminum frame, I imagine it would be quite heavy and probably a larger motor would be more suited, but probably not easy to get good flight times especially if you want to do aggressive flying. Also wouldn't the aluminum bend in a crash?

Hi mstc,

The more information that I gather, I am leaning towards trying the 1408's first. 
Since I already have several 4 inch quads running 1404 motors and pretty much 
have a "feel" for them, the 1408's might be just the incremental step up that I am 
looking for without injecting too many differences. Plus, I want to run both 3S 
(which is my default, standard) and 4S (as an interesting test) batteries.

Regarding aluminum frames. You know, a 1 meter length of the aluminum bar 
stock that I am using for the arms can be bent with bare hands if you hold it 
on the ends, however, a 3 inch length of the same stuff is almost impossible to 
bend without tools. So, in a 2.5 inch quad, I really don't think that it will bend. 
The possibility is greater in a 3.5 inch since the arms are a bit longer. Still, pretty 
short length. Plus, to bend this bar stock the forces have to line up along the 
length wise axis and be pretty strong. So Yes, this is one of the "tests"; to see 
how well the frame survives crashes. 

As for weight, the first 2.5 inch prototype came in at 33.3 grams complete with 
minimal skeletonization (holes to reduce weight). On the one hand, it is a tad bit 
heavy for a 2.5 inch frame, sort of. But less than any whooped frame in that size. 
So, I am calling it middle ground. The next 2.5 inch frame will have some material 
removed from the arms to reduce weight even at the risk of decreasing the strength. 
I think that I can get the weight below 30 grams. If so, then I will consider that 
pretty good.

Now, if I can get a 3.5 inch version that is close to 30 grams that survives crashes, 
then I will think that the aluminum frame project is a success.

Yeah, the edges are not finished off very good and the holes might not be perfect, 
but that wasn't a big concern for me at this point. I need to see how well these 
frames work. The following is the first 2.5 inch prototype:



Additional info HERE. 

NOTE: The camera mounts are Armattan Tadpole Aluminum Cam Braces. I happen to like
these camera mounts, however, any camera mount can be used.

By the way, the frame pictured was sent to LemonyLeprosy, so you might see a build form
him using this frame. 

Later, iFly  

It seems your aluminum frame is not that heavy. If you can keep it below 40g, I think 1404 motors would still work nicely. For example the GEPRC Smart 35 is a 50g frame and happily runs 1404 motors. 1408 motors as you probably know, are twice the stator volume, so basically double the motor size. If you are running the motor at the top end most of the flight (like racing) then you may get some advantages with the 1408, but maybe something like a 1505 would be a better match for extra power but still keeping it light and efficient? But if you already have the 1408s on hand, then certainly try them out. I have some 1408s on several 4" builds and they do quite well there, but give 5 minute or less flight time depending on the battery used.
It will be interesting to see how the 3.5" flies, I wonder if aluminum will have more or less resonance than CF?

I got to fly my twigxl yesterday with the 3” gemfan props it original came with .(removed the 3.5” Avans). Much more agile, controllable.. and not as “floaty”.. motors are stock (v1 version of this bnf).. 5.5-6 minutes on a 650 4s ..

(18-Jun-2024, 01:01 PM)mstc Wrote: It seems your aluminum frame is not that heavy. If you can keep it below 40g, I think 1404 motors would still work nicely. For example the GEPRC Smart 35 is a 50g frame and happily runs 1404 motors. 1408 motors as you probably know, are twice the stator volume, so basically double the motor size. If you are running the motor at the top end most of the flight (like racing) then you may get some advantages with the 1408, but maybe something like a 1505 would be a better match for extra power but still keeping it light and efficient? But if you already have the 1408s on hand, then certainly try them out. I have some 1408s  on several 4" builds and they do quite well there, but give 5 minute or less flight time depending on the battery used.
It will be interesting to see how the 3.5" flies, I wonder if aluminum will have more or less resonance than CF?

Hi mstc,

 I don't have 1408s. 

I know the 1404s make good cruiser motors, but I was looking for motors 
that might provide the performance that an Acro Stunt pilot might like. 

Yeah, you are probably right. I think that I have some 1404 in the parts bin.
I might also have some BrotherHobby 1504.5 3950Kv motors as I have used 
them in both 4 inch and 5 inch builds. These are very smooth and good for
cruising. I would wonder if they had enough punch for a stunt pilot. 

I will likely place a part order before I do the build, so I am contemplating
whether or not I need motors in different sizes, specifically, ones that give
a bit more acceleration. 

Thank you for all of your effort. 

Later, iFly