My first attempt towards anything larger than a 5" quad and my first proper build thread on the forum. Not because I want to show off my build but because I will need constant advice from members who have experience with bigger quad builds.

One reason why I chose this build was because it has been proven to work on a 6s setup with a 30x30 FC + ESC stack which makes the build much more affordable.

My order from CMW arrived today which included:

- Macro Merica 9" frame
- Brother Hobby Avenger 2816-1050kv Motors
- HQ Prop MacroQuad 9x5x3 Tri-Blade 9" Carbon Reinforced props






Over the last few months I have been hoarding other components that I was planning to use for a future build but then decided this will be the best build for them:

- Rush FPV Rush Blade F722 / Rush Blade Super 60A 30x30 stack (with power filter board)
- Rush FPV Tank Solo 25-1000mW 5.8GHz VTX (with Lumenier AXII 2 antenna)
- Foxeer Predator V5 Mini 1000TVL
- Matek M8Q-CAN GPS Module w/ Compass, Barometer
- TBS Crossfire Nano (with Immortal-T antenna V2 - Extended)



My estimates are that the finished build will weigh around 850g (not including battery weight). I have no intentions to adhere to the 250g weight limits

CMW recommends a Tattu R-Line 5100mAh 95C 6S1P lipo for this build that weighs around 868g. Which is heavier than the dry weight of the built up quad.

However, I will be probably defer this till the end and in the meanwhile use a couple of Tattu R-Line 1800mah 95C 6S1P packs in parallel which should weigh under 600g combined and make the build overall 250g lighter.

I have AMASS AS150 connectors in the mail. I need to source some 10 gauge silicone wire and some other bits and pieces.

I also did not order the canopy because it does not fit the components I wish to use and thus I will be designing my own canopy (fingers crossed I can pull this off in FreeCAD) or I might just edit an existing design from thingiverse. This is going to take some time.

A lot needs to be done and I will be taking it slow with this build but I will keep posting updates to this build thread.

We don't get very many large quad builds of this size on the forum so I think it's going to be an interesting build thread. I'll be following it with interest 

Update 1: 

My attempt at trying to source 10 gauge silicone wire in Adelaide proved futile over the weekend as none of the hobby or electronic or electrical shops had any in-stock and so I will need to order some from one of the local RC parts suppliers in Sydney or Melbourne. Once I get this part sorted, I will start posting photos of the actual build.

I did manage to start looking at the frame and noticed there is not enough room to house the capacitors on the Rush filter board between the top and bottom plates (only 12 mm height) and decided I will mount these externally to the arms.

And so I started designing, remixing and printing some TPU (black TPU was all I had left) that took several hours of printing (my Ender 5 on a bowden setup prints TPU very very slowly). The parts look better in real life and is nothing I will lose sleep over :



On the canopy front I have not made much progress but I found a version on thingiverse similar to the Merica 5" canopies that Catalyst Machineworks sells on their website: https://www.thingiverse.com/thing:4878250/files



The mounting holes line up with the Merica 9" top plate mounting and the design looks sweet but it is designed for the Caddx Vista system and the author has only provided the final STL which is proving a huge pain to remix for the components (especially the Matek M8Q-CAN GPS Module that I want to embed in the canopy along with a Naked Gopro mount).

sub250g per arm xD not even that xD

how will you fly it? as a performer?

i would like to see 8s performance on a 9inch, get a view and impressions :-) two 4s 1800mah in parallel, small and lightweight :-) saw there is a 50a 3-8s rush 4in1 :-)
there is no option for 8s on your build? :-)

JB has one of these in a BNF version which he's planning to review, so that is probably worth watching out for. He showed it off on his live stream this evening. The time position link is below...

https://youtu.be/5Rpw7K-E7Yo?t=1370

(20-Jun-2021, 06:40 PM)hugnosed_bat Wrote: sub250g per arm xD not even that xD

how will you fly it? as a performer?

i would like to see 8s performance on a 9inch, get a view and impressions :-) two 4s 1800mah in parallel, small and lightweight :-) saw there is a 50a 3-8s rush 4in1 :-)
there is no option for 8s on your build? :-)

The dry weight of the frame (without any components) is 280g. I have blown the 250g limit before I even started the build

I plan on having this as a freestyle build rather than LR but it will have the M8Q-CAN in case I want to push into a bit of medium range.

The Avenger 2816-1050kv motors are only rated to 6s.

Furthermore, I had the Rush Analog FC /4in1 Super combo for a while now and the 4in1 ESC is only rated to 6s while the FC is rated to 8s.

I decided to use the Rush stack decided to use it on this build since Gal Kremer’s motor stand tests with 9” props on 6s shown an amp draw under 60amps at almost full throttle signal.

So I can’t stretch this to an 8s build in any way. (I did some research on 4in1 ESC's a while ago and there are no reliable 8s rated ones and for the few available there were not many real life examples of actually flying them on 8s). 

I do plan on using 2 x Tattu 6s 1800mah in parallel on the build.

i saw racerstar has a 60a 4in1 3-8s :-) i would like to try that

i tried to get some informations about the motor, 4-6s is the only info i got. no rotorsize suggestion or data on a small blade the voltage can be increased without issue :-) i thought there might be an option xD

2x 6s 1800mah sounds its going as nimble as a 9inch can go :-)

(20-Jun-2021, 10:46 PM)SnowLeopardFPV Wrote: JB has one of these in a BNF version which he's planning to review, so that is probably worth watching out for. He showed it off on his live stream this evening. The time position link is below...

https://youtu.be/5Rpw7K-E7Yo?t=1370

I am watching that stream right now. JB first showed it on a live stream a couple of weeks ago but now he seems to have flown it.

The BNF version costs $889 which includes a $179 assembly/setup fee I enjoy building and setting up stuff and I can use the $179 to buy parts for another quad

My total spend on this analog build so far (frame + components (- tpu parts - shipping - lipo)) is $610.

Let us not forget CMW is selling the BNF version with the Caddx Digital FPV system whereas my version is analog and so their prices for components are adjusted accordingly.

(21-Jun-2021, 12:16 AM)hugnosed_bat Wrote: i saw racerstar has a 60a 4in1 3-8s :-) i would like to try that

i tried to get some informations about the motor, 4-6s is the only info i got. no rotorsize suggestion or data on a small blade the voltage can be increased without issue :-) i thought there might be an option xD

2x 6s 1800mah sounds its going as nimble as a 9inch can go :-)

I have not seen long term reviews of people pushing a 4in1 ESC on 8s. Most on 8s and 12s seem to go the APD ESC route and these are very expensive for my taste buds.

I asked Brother Hobby for the motor test sheet and relevant data but they replied back with the following:

Quote:From: [email protected]
To: You

Mon 07/06/2021 10:10

Dear customer

We have no Avenger 2816 1050kv Motor test data for now.Sorry for this.

Thanks for contact BrotherHobby,we're happy to be at your service.
Best Regards
Service Center BrotherHobby
https://www.brotherhobby.com 
https://www.brotherhobbystore.com/ 

Gal Kremer has shared his motor test results here in this video:



2x 6s 1800mah is actually the lowest I want to go because I am afraid lower capacity lipos might sag under high throttle moves.

CMW recommends a Tattu 6s 5100mah lipo which weighs 868g. That is going to be heavier than the dry weight of the built quad. And the length of the lipo makes it look very awkward strapped to the bottom of the quad.

:-) they might still sag on midthrottle :-) but sag doesnt decrease the nimbleness in turns
i fly 4inch on 650mah 4s sometimes, it sags a lot, destroys the batteries over time; but its crazy nimble :-D

specs looks very good

(21-Jun-2021, 01:15 AM)hugnosed_bat Wrote: :-) they might still sag on midthrottle :-) but sag doesnt decrease the nimbleness in turns
i fly 4inch on 650mah 4s sometimes, it sags a lot, destroys the batteries over time; but its crazy nimble :-D

specs looks very good

I did some rough calculations based on the following formula:

Max Current Draw = Capacity (Ah) x C-Rating

Which is the case of a 6s 1800mah 95C lipo will be: 1.8 X 95 = 171 amps (so with 2 lipos in parallel I can get theoretically 342 amps since the voltage stays the same but the capacity doubles).

And based on Gal Kremer's motor tests, the motors top out at around 60 amps on 9" props which in a worst case scenario imagining all 4 motors demanding 60 amps would be 240 amps and this is still 70% of what the lipos are capable of delivering in parallel leaving 30% margin for safety. (This is assuming fully charged lipos but once voltage drops mid flight then the sag will be more noticeable).

I doubt I can even push this quad to its 50% limits in my usual flying spot.

I am building this now because depending on how things change in the hobby with 250g limits, we might not have such components available in the future if market trends change.

regulating the fpv market is the biggest risk for our hobby

(21-Jun-2021, 09:37 AM)hugnosed_bat Wrote: regulating the fpv market is the biggest risk for our hobby

Completely agree. With the regulations being enforced around the world, we might not have access to the broad range of components we have today at these competitive prices. Perhaps several components might completely disappear since there will be less demand or no market for them due to regulations.

(20-Jun-2021, 06:40 PM)hugnosed_bat Wrote: i would like to see 8s performance on a 9inch, get a view and impressions :-) two 4s 1800mah in parallel, small and lightweight :-)

Someone has already posted a video running the Merica 9” on 8S using APD 80amp ESC’s on 2 x 4S lipos in series to get 8S.

Update 2: I have been playing around with some test fits and measurements but my main focus since the previous update was coming up with some sort of a canopy design to incorporate the camera, Gopro Lite, GPS and VTX antenna. 

Tried to remix some canopy designs from thingiverse but I was not getting any good results. 

In the end, I took some inspiration form the GEPRC Sparrow or Leopard and the Dquad Obsession top cage designs (none of them seem to fit the mounting holes in the Merica 9 top plate which measures 45mm front to back and 42mm side to side) and so I started designing something in FreeCAD:



There will be 3 standoffs mounted horizontally to give the top frame some extra stability/rigidity which I have not shown in the model.

First glance I would call it ugly but then its functional

I will be printing the stuff in TPU but the design can also be used for cnc cutting into carbon fire or aluminium.