Hi Lemony, So you have eCalc ! I did not know that. SWEET. 

By the way, someone on here said that coax mounting loses 15% in thrust efficiency. I don't
know if that is accurate, but that is the only information that I have at this point.

I have been looking through my Parts Guide and comparing different motor options. At this point,
I think that there are three possibilities: 

1) A 2.5 inch frame Octocopter with 2.5 inch HQProp T63mm X 8 props.

2) A 4 inch frame with 3-3.5 inch with Turbine props; something like these HQProp Duct-85mm x 6.

3) A light 5 inch frame with 5 inch Turbine props like these HQProp 5x4x6.


I believe that the Turbine props produce the most thrust even though the smaller ones don't have a
pitch listed. The 5 inch 6-blade prop is a 4 pitch.

In any case, the frame weight will likely be about 40 grams or less. Plus, by my figuring, the
weight of the motors will also be about the same at about 15 grams per arm; that is one 15 gram
motor or two 7 gram motors...maybe a little more if I use larger motors with a 5 inch build.

By my very rough estimations, I am giving the 2.5 octo to be about a 4.25 inch prop equivalent.

I actually just found those 5 inch turbine props, so that likely will provide the best thrust; that 
might actually be the way to go. 

The thing about the 2.5 inch craft is that I was planning on making a custom frame from some
stiff foam that I have and cut out for "ducts"...more for protection and not getting hung up than
anything else. If I go open prop, then the 5 inch looks like the best option. 

Now for the retrieval mechanism....

Hi JSchubz, I kind of like the "claw" type mechanism, but not sure how to make it work.

I also like the magnet idea. Interestingly, I just got a bunch of magnets {from Amazon} for
use on a trailer lighting project, so I might experiment on the bench with them. If they appear
to be strong enough, well that might at least be an option. 

I am getting some interesting and promising ideas. I really appreciate the assistance from
members of the forum. 

Now, I will sleep on it    I do some of my best work while sleeping 

 

Whelp, my magnet test with the magnets I have on hand was a complete fail. If you'd like a good chuckle, watch my magnet test video below with sound to hear my commentary. I cut off the video before I started cursing.

So, my new suggestion is a combination of previous suggestions- some sort of a claw with a magnet to help you actually connect to the quad before you close the claw- because anything hanging down below your rescue quad is gonna be swinging all over the place, and you don't want any kind of hook that can catch on a limb before you get to your quad, and you want to make sure that you can close your claw on the quad.

Also, you're probably not gonna want the extra weight of wires running all the way down to your claw so it's gonna hafta be a two string system- the main string to lower the claw and a secondary string to close the claw. Two strings is gonna create a loop that could get caught up on branches, so I'm thinking two lightweight tubes taped or glued together for a foot or two to give you some clearance between your lines and the tree limbs.

Regarding eCalc- I'm comfortable enough with it now that I know how to adjust settings so that its output is very close to real life. However, I did find a limitation while helping Scott with his big cinewhoop- there is not (that I've found) a good way to take the additional thrust of ducts into account. I can add the weight of the ducts, but not the additional thrust. It worked out in his favor in that after accounting for the weight of the ducts, he ended up with a lower throttle hover point and slightly longer flight time. If you have to be inaccurate, it's much better to be under than over in this case.

I think you are significantly underestimating your weights so far- I still think that you are going to need much larger/heavier motors than you usually use, because you usually overprop your motors and run them at low throttle for efficiency- in this case you are going to need to keep your motors within their tolerances throughout your throttle range because as soon as you manage to attach to the quad you're trying to rescue, you're going to need your entire throttle range to lift and pull it- because you don't want to burn out a motor on your rescue-1 and end up losing a second quad.

All of the props that you mentioned do actually have their pitch available. I'll start plugging some numbers in this coming week to figure out what you can pull with each. Let me know what brand, cell count, and weight batteries you have available- it'll help narrow down options if you don't want to buy new batteries. If you're willing to go well over 250g, I've got a 6" frame and motors that I can send your way for free (it's way too big for me to fly on my property so I'm not going to use it)- but you're gonna need much higher amperage esc's than you typically use.

Edit- Also, my video is inverted. I had to fiddle with it to get it rotated correctly, and apparently during that process I made left right, and right left. Whatever. I’m not trying to be a professional, and my laptop isn’t capable of doing serious video editing, and I don’t care enough to go back and fix it.

Years ago I built a quad to drop a baited hook several hundred meters from the shore, I used one of these to drag out the line then release via a swivel threaded directly on the pin without the attachment. Worked well. Might be of interest for Rescue-1 mission abort.

https://www.horizonhobby.com/product/ser...LA405.html

I also had a dual cam, forward and down, so I could hover in a location and look directly down. There were small cam switcher boards that interface into an rc output like a servo and switch either of two cameras to the one video input.

Hi Roteron,

Thank You. That looks just like what I am looking for. Yes, the release is only a safety mechanism
in the event that Rescue-1 can't lift the quad or the line gets entangled. 

Yes, I have the same idea with the cameras; two: 1) a flight camera and 2) a stationary targeting
camera the is pointed straight down. I have seen those little camera switcher boards so that is what
I plan to used. You got a link???  Thanks.

I was Googling around for claws...

Not necessarily the place I would buy it from, but to give an idea, here ya go

https://www.walmart.com/ip/Techinal-Acry.../475704963

Here's a claw a kid made, that could perhaps be expanded on?

Cam switcher…

https://www.viflydrone.com/switcher.html

Hi Lemony,

Thanks for the video. I have just received my new magnets which appear to be super strong.
I will test them on one of my other quads, see how they work, and post my results, but 
probably not a video...well...maybe. I am still experimenting with Vimeo and AirVuz. I think
that I might like Vimeo best...just haven't take time to edit the videos. I use DaVinci Resolve
which is nice software for free, however, it is a bit complex and I forget how to use it between
edits. Ha, Ha, 

I am also thinking that the retrieval mechanism might have multiple components...maybe 
magnets and a fish net of some type. I will see what I can find.

Thanks in advance for the eCalc results...that will be very helpful.

Yes, you are correct, this build has a different focus and is out of my norm. I am working to
piece everything together correctly. I do realize that the motors will need to be a bit bigger
than I am used to and likely 5mm prop shaft. I also realize that I may need to deviate from
my normal AIO FCs, but I am will to use what is necessary. I am a "what-ever-it-takes" type
of guy especially in this particular situation. I will deviate to meet the goal if necessary. 

I definitely appreciate and would accept your offering of frame and motors. See you in PM.

Thank You Sooooo much.

Hi JSchubz,  

I like the claw idea. I might just buy that one or maybe build one myself. Thanks.

Hi Roteron,

Thanks for the info. That ViFly switcher looks just right...I will get a couple. Thanks.



I really appreciate all the help, guidance, and assistance. THANK YOU.

Well, the process of identifying and collecting parts has begun...

I have found the "claw" on AMAZON that JSchubz found at Walmart in Post #20 and
have it ordered, however, it will take about 3 weeks for it to arrive.

The DIY "claw" is very interesting, but would need to make it out of something other
than cardboard. So...Not sure whether I want to undertake that project.

I have also ordered an independent "drop" mechanism from AMAZON. 
What is nice about this one is that it has its own remote and is totally independent from 
the quad's system so, I don't have to worry about that and it is easily transferable 
as I work through prototypes.

The magnets that I have are NOT strong enough to hold the weight of one of my 4 inch
quads, so...if I do incorporate a magnet, it will have to be much stronger. Maybe the 
claw will work and I won't need any magnets. We will see. 

Also, I have ordered the ViFly camera switcher from AMAZON that Roteron listed in Post #21.

Thank You JSchubz and Roteron. Your help is very much appreciated.

(03-Apr-2022, 06:19 PM)iFly4rotors Wrote: Well, the process of identifying and collecting parts has begun...

I have found the "claw" on AMAZON that JSchubz found at Walmart in Post #20 and
have it ordered, however, it will take about 3 weeks for it to arrive.

The DIY "claw" is very interesting, but would need to make it out of something other
than cardboard. So...Not sure whether I want to undertake that project.

I have also ordered an independent "drop" mechanism from AMAZON. 
What is nice about this one is that it has its own remote and is totally independent from 
the quad's system so, I don't have to worry about that and it is easily transferable 
as I work through prototypes.

The magnets that I have are NOT strong enough to hold the weight of one of my 4 inch
quads, so...if I do incorporate a magnet, it will have to be much stronger. Maybe the 
claw will work and I won't need any magnets. We will see. 

Also, I have ordered the ViFly camera switcher from AMAZON that Roteron listed in Post #21.

Thank You JSchubz and Roteron. Your help is very much appreciated.

Man after you get this thing built you will be putting quads in trees on purpose, just so you'll be able to use this again

I'm betting it's gonna be a chunky one, I'm gonna guess pushing 1200+ grams AUW by the time it's built? Very rough guesstimate, but even just your 'accessories' are 500 grams easy, again, taking a WAG.

I can already picture this thing in my head, I think it's gonna be a monster! I picture those giant quad axle tow trucks that pull semi trucks out of embankments.

I'll see if I can do some digging on monster torque motors. I've seen YouTube videos where they're using load cells to check and verify the advertised numbers.

I also think many of the heavy lift cinequads use 5, 6, 8 bladed props. I know bi-blade is the most efficient, but are giga blade props better for torque? Have you decided on prop size yet? I know ''Nurk" put 3 inch props on 5 inch motors, but I think that was just for fun.

Waiting 3 weeks for Amazon is unheard of! I would have forgotten I ordered it by then. Don't laugh, I've done that, the addiction was real.

Keep it up, this will be an interesting build

Just a random thought just popped into my head, you may want to consider using Kevlar thread. It is incredibly strong for its size and mass. We used it in rockets, and not that it matters, it's basically fireproof.

Braided is the strongest, but may be a bit much, you're not lifting 700 pounds, nor deploying a parachute at 200mph. I know they make thread, I'll let you search Amazon for that lol. If not, places that deal in rocketry would carry it.

Hi JSchubz,

Well, I am now looking at a 6 inch frame with decent motors spinning these HQProp 5x4x6 turbine props. 
These ones have 6 blades and a 4 pitch being swung by 22xx or 23xx motors. 


I know one thing, it certainly will be over 250 grams. Some things are just going to be heavy.

Here is my guess so far:

6 inch frame = 60 grams
Motors with props 40 grams each = 160 grams
Electronics = 70 grams
Battery = 100-120 grams
Release Mechanism = 200 grams

Approximate total with "pick up" claw or mechanism = 610 grams.

I don't know how much that acrylic claw weighs, but I am not totally locked in to that device. 
So, let's add about 40 grams which bring the AUW including battery to about 650 grams.

Even though this is a "Heavy" build, I think that 650 grams is very reasonable. 

I am working to have a pull "load" of about 500 grams; 250 grams for the quad and 250 grams extra.

So, the total weight with quad in tow should come in at 1000 grams or less. 

Just my guess at this point in time. Let's see how close I am to the actual build.

Thanks.

Harry- The frame that will be on it's way to you sometime this week is from a Tyro119, and the motors are 2407 1850kv.
Frame with motors and the random GPS on an arm is 286g. Each motor on its own is 40.2g.

There are some ecalc results below. 
Things to keep in mind: This is ballpark guesses right now. I've gone with the Tyro119 manufacturers stated dry weight of 352.9g.
Depending on your electronics choices, (ie: 50a AIO, a smaller vtx) we can shave some grams off of that.
I've included an additional accessory weight of 350g (second camera, switch, retrieval mechanism, release mechanism, etc). This is just a wild guess on my part.

I tried putting in your 4s goldbat battery, and you ended up with less than a minute mixed flight time so that is out. If you want to see those results, pm me your email and I'll send it and higher quality pdf's of the pictures below.
You're going to need to go with a 6s high c rated battery.

The results below are with 2 different batteries:
750mah: https://pyrodrone.com/collections/6s-bat...y-jst-xt30
1000mah: https://pyrodrone.com/collections/6s-bat...v-drone-rc

And two different props:
5" 6 blade: https://pyrodrone.com/collections/5-inch...-carbonate
6" 3 blade: https://pyrodrone.com/collections/6-inch...oose-color

The best combination by far (so far) is the 6s 1000mah with the 6" 3 blade props.

If you're not familiar with eCalc, here are some things to keep in mind:
I currently have it set as quad weight w/o battery (meaning, dry weight). That means you can ignore the weight of the "controller" and the motors as you're reviewing things- it's only adding the weight of the battery and accessories to that 352.9.
The battery weight is per cell- if you multiply the weight I put in that field by 6, you'll have the actual battery weight.
Things to pay attention to: Flight times, temperature, and especially for this case, the column on the bottom right of page 2 of each settings results. In that column you'll see "add. Payload". This number is how much weight you can carry while keeping your throttle at 80% to still allow for maneuverability.

Something else to keep in mind is that those flight times and temps aren't taking that additional payload into consideration- It's only taking into account the AUW of the rescue quad with its retrieval mechanism and what not. As soon as you hook onto the quad you're rescuing and start pulling, and then lifting it out, you're going to start eating away at your battery power- you need to keep some in reserve, and you definitely need a high c rated battery because you're essentially going to be doing an extended throttle punch. That 1000mah I linked to above is 120c constant 240c burst, given weight, price, and c rating I think it might be your best bet if you don't want to get into much higher capacities. If you are willing, we can look at some 1300mah+.

Edit- you need to be looking at both the mixed flight time and the hover flight time. You’ll probably fall some where in between there. We can also start getting much more accurate once we know actual weights.
Also, I haven’t looked at 5s. Regardless, this bird is gonna need a much bigger battery than you’ll be able to use for future sub 250g builds.

Hi Lemony,

That Tyro119 frame looks pretty COOL       

Is 352.9 grams the dry weight that of the complete quad with props and everything??

At this point, I am afraid that I don't have enough data, however, as I get more
parts and start working with the components, the data will get closer and more
accurate. If is interesting that the 6" Tri-blades are coming out better than the
5" 6-blade Turbine style props. 

Today, I received the "Release" mechanism...
to my surprise it only weighs 25.8 grams with battery.

Add about 7 grams for that GPS.

Add about 14.3 grams for misc. stuff 

That brings the total dry weight to about 400 grams.

Let's add about 250 grams for a decent 6S battery and we have about 650 All Up Weight.

Add 250 grams for the Unsanctioned-1 and we get 900 grams total flight weight not counting
any additional "pull" to get it out of the branches. 

If we add just 100 grams for "pull" then we are at 1000 grams potential flight weight for calculations.

Consequently, I will need a battery that will provide the thrust to pull 1000 grams minimum and
provide at least 5 minutes of flight time. 

I think that plugging in 1000 grams as the dry quad weight, the calculations might get pretty close
to what I need.  Consider this GNB 6S 1400 mAh battery at 235 grams. 

Any chance Builds 1 though 12 are available for an intelligence gathering flight to assess visibility of Unsanctioned-1 and better understand what retrieval might look like?