Cinestar Dual Purpose (HeavyLift / Long Endurance) Build Log

[Carcara]

The main objective of this project is to build a dual purpose multirotor, able to fly heavy lift payloads for videography and lightweight cameras for aerial mapping.

We want to be able to fly different missions, with minimal part changes. To achieve this we decided to maintain the center frame (flight controller, power distribution board, battery packs) and change booms (with motor and ESCs at the end) when wanted. Open the case, get the center frame, choose booms and fly. This first part of the build consists of the heavy lift configuration, and parts for the long endurance config still need further research to be purchased. This build will have an A2 controller (because we have a spare one at the shop), but later will be changed for a Pixhawk, which is our preferred controller for aerial mapping).

Objectives:

- Small form factor when disassembled for ease of transport
- Quick-release arms
- One carrying case for both multirotor configurations
- Quick release system for different camera gimbals
- Heavy lift payload around 5kg (Red Epic + Light Lenses)
- Light weight payload: Sony A7R

Parts used for HL configuration:

- Cinestar 8 frame X-8 configuration
- Famoushobby 25mm metal boom clamps
- Catalyst Machineworks 500mm C25 quick release boom system
- Avroto AVL3520/520 motors
- Spyder 60A Opto ESCs
- Foxtech Supreme 1550 props
- DJI A2 Controller (later to be changed to Pixhawk)
- Ronin M Gimbal
- Foxtech FPV D130 dual landing gear
- Powerhungry PHS-10 distribution board
- Tattu 10A 6S battery packs

Parts used for Long Endurance configuration:

- Cinestar 8 frame X-4 configuration
- Catalyst Machineworks C25 quick release boom system
- KDE 7208XF-110 or Tmotor U8 100kv (to be decided)
- KDE Direct XF UAS 75A+ or Foxtech Multi-Pal OPTO 80A HV ESC (to be decided)
- KDE Direct 27.5" x 8.9 or Foxtech Supreme 2880 (to be decided)
- Pixhawk Controller
- Custom built Gimbal (for Sony A7R)
- Tattu 10A 12S battery packs
- Powerhungry PHS-10 distribution board

View attachment 26913

 

[Motopreserve]

That looks like it will be a hell of a rig.

Keep us updated. Look forward to seeing it come together.

 

[Carapau]

My only thoughts are that where the booms join together, there isnt a very deep join. This is a real weak spot I think, especially if carrying a heavy set up. The potential for movement in the arm and resonance is quite large I would say. When I had a v1 Gryphon Dynamics frame, there was terrible frame resonance on account of the folding arm joints not being solid enough. Funnily enough Gryphon, shortly after my aircraft crashed due to the resonance, released a joint reinforcement upgrade and then changed the join system all together.

 

[Carcara]

My only thoughts are that where the booms join together, there isnt a very deep join. This is a real weak spot I think, especially if carrying a heavy set up. The potential for movement in the arm and resonance is quite large I would say. When I had a v1 Gryphon Dynamics frame, there was terrible frame resonance on account of the folding arm joints not being solid enough. Funnily enough Gryphon, shortly after my aircraft crashed due to the resonance, released a joint reinforcement upgrade and then changed the join system all together.

Hello Carapau,

I too had some issues with more then one folding/quick-release arm systems at the past. Actually I have been researching for a long time and at the end I decided to try this one. I did some bench test and was impressed with the quality and stiffness of the system. That is the deepest joint I found on the market, and its very tight (at least when its new), and even kind of hard to pull them apart. After joining the 2 parts, you still have a clamp with adjustable tightness (really useful for future play) and a last lock to secure and prevent coming apart. This is definitely well made and thought out. But I think its a good idea to check for possible play on bullet connectors over time and change them if needed.

I performed 2 tests, one for vibration resistance and weight tolerance (they have a similar test on their website but I preferred to make my own test as well). For the vibration test I left the system running for almost half an hour to check possible play on screws and parts. It produced some heavy vibration, a lot more then we would expect on brushless motors, and at the end it was totally intact, with no play at all.

Take a look at the tests I did:

Vibration test:

Load test:

 

[Carcara]

That looks like it will be a hell of a rig.

Keep us updated. Look forward to seeing it come together.

Thanks Motorpreserved,

I will try and post pictures as the setup continues! Stay tuned.

 

[Carapau]

Carcara, good tests. Are you sure the flex in the arm is not happening at the joint? Looking at the video you took ie on the tripod mounted camera, it looks like the angle changes at the joint- it could of course be my bad laptop screen?

 

[Carcara]

Carcara, good tests. Are you sure the flex in the arm is not happening at the joint? Looking at the video you took ie on the tripod mounted camera, it looks like the angle changes at the joint- it could of course be my bad laptop screen?

Carapau,
let me try some more tests with a better set of lens and let's find out. Looking directly to it sure looks like the flex happens at the tubes and mostly at the plastic clamps holding the tube. With better lens and zoom we can try to go deeper on the joints. Let me get back to you.

 

[Carcara]

Carcara, good tests. Are you sure the flex in the arm is not happening at the joint? Looking at the video you took ie on the tripod mounted camera, it looks like the angle changes at the joint- it could of course be my bad laptop screen?

Carapau,
I made more tests, sorry the video ended up a little bit too long, but you can see more details about the mechanism. Note that at the end of the video I mention some movement, which will be eliminated once the boom is set up flush with the central plate's metal boom clamps. The plastic boom clamps I used for the test IMO are the weakest point that show any kind of flex. I might sound a bit boring or repetitive, but as I mentioned on an earlier post, I had problems before with other quick release solutions and I want to assure the next one will solve the problem (the possibility of taking the copter apart on a small factor is something worth the time on research IMO).
Let me hear your thoughts.

Joint test:

 

[Carapau]

That's great testing and for something like this project a wise thing to be doing! I am a bit suspicious of folding mechanisms as they can be real weaknesses in a frame although done well then of course they are excellent. I have seen a few people on here rush into building their rigs and believing that it will work only to see the aircraft plow into the ground (it has also happened to me). This is always painful to here about. So I dont intend to be negative about this but just want to see you be successful with it. The clamp looks solid enough although I am still suspicious of the depth of the join of the clamp- it seems to only be about a cm or 2 but your testing is doing a good job of determining if that is indeed a weakness or not.

 

[Carcara]

Starting the build. Put main parts on scale to have an idea of total weight before assembly.

Main Frame:
View attachment 26952

Motor Mounts:
View attachment 26953

Main Frame + Motor Mounts:
View attachment 26954

Booms:
View attachment 26959

Main Frame + Motor Mounts + Booms:
View attachment 26955

Main Frame + Motor Mounts + Booms + Battery Mounts:
View attachment 26956

Main Frame + Motor Mounts + Booms + Battery Mounts + Landing Gear:
View attachment 26957

 

[Carcara]

I sent an e-mail to the manufacturer of the C25 quick release system, asking about the optimum position for installing the booms at center frame. Below is his response. I thought it would be interesting to share for whom may be following the build. I sent him the following 2 pictures, and after that you can read his replies.

View attachment 26961 View attachment 26962

Response:
"The C25 is designed to be mounted up flush to the center hub of the craft (like picture 2). This keeps overall size of the detached hub smaller for travel.

Plus I noticed in your pull tests you had the couple rotated 90 degree from where its optimum orientation is. You want to mount it and pull it at 90 degree to where you had it. In other words the red clamp should not be facing straight up but rather parallel with your work bench. This will most likely stop that little bit of movement you saw where the interior coupling edge mates to the CF tube."

After that I asked about the optimum pressure one would apply to the main tube clamps...

Response:
"This is a little of a gray area to be honest. The reason is every carbon fiber tube manufacturer produces tubes with slightly different OD's. And the same manufacturer will produce two batches with two different OD's! The C25 will compress down to that OD. So the required position of the arm might be different from tube to tube.

BUT, as a general rule set the arm as in the picture. Or maybe even with the top of the arm horizontal for a nice tight fit. You can get a feel for what is correct after a while. Also, with the testing you did it will help you to know where that "sweet spot" is."

View attachment 26963

What a great customer support, that's all I can say. You should take a look at their instructions manual, amazing quality. Let's hope it works as expected.

 

[Motopreserve]

That's some nice CS. Glad to see they were able to point you in the right direction (pun intended) and you should now be good to go.

Keep the updates coming!

 

[CatalystMachine]

Hey we try! This stuff is our passion. We love it and want our customers to have success using our products. GREAT REVIEW!

 

[Carcara]

Hey we try! This stuff is our passion. We love it and want our customers to have success using our products. GREAT REVIEW!

Hi CatalystMachine, thanks for chiming in!

Here goes more pictures of the build:

View attachment 26986 View attachment 26987 View attachment 26988 View attachment 26989 View attachment 26990 View attachment 26991 View attachment 26992 View attachment 26993

 

[CatalystMachine]

Hi CatalystMachine, thanks for chiming in!

Here goes more pictures of the build:

View attachment 26986 View attachment 26987 View attachment 26988 View attachment 26989 View attachment 26990 View attachment 26991 View attachment 26992 View attachment 26993

Hi CatalystMachine, thanks for chiming in!

Here goes more pictures of the build:

View attachment 26986 View attachment 26987 View attachment 26988 View attachment 26989 View attachment 26990 View attachment 26991 View attachment 26992 View attachment 26993

Holly cow! That thing is looking nice! Curious what is the distance (in mm) from the motor shaft to the main clamp on the C25?

 

[Carcara]

More pics:

View attachment 26994 View attachment 26995 View attachment 26996 View attachment 26997 View attachment 26998 View attachment 26999 View attachment 27000 View attachment 27001

 

[Carcara]

Curious what is the distance (in mm) from the motor shaft to the main clamp on the C25?

345mm

View attachment 27002 View attachment 27003

 

[CatalystMachine]

345mm

View attachment 27002 View attachment 27003

Ok that is easy work for the coupling then and well within our rating. As the arm gets longer the same load results in more moment at the coupling joint.

You are A-OK.

 

[Vitaly]

Hi,
i think it's good engeneering experience, but in practice - there is no much utility. As you can see, no one uav-manifactuaring company in the world produce such dual-purpose drone. I think, there is two reasons for it:
1. Main reason: i don't think can be real necessity promptly take off RED, transform X8 to quadrocopter and quiqly start aerial mapping. Frankly speaking, i can't imagine such situation. Mayby i'm wrong?
2. Technical issue. I think, nowdays copter hardware is not so flexible to allow speedy transform from X8 heavyliter to light quad.
Anyway - good luck! And "stay hungry!"(c.)

 

[Carapau]

1. Main reason: i don't think can be real necessity promptly take off RED, transform X8 to quadrocopter and quiqly start aerial mapping. Frankly speaking, i can't imagine such situation. Mayby i'm wrong?

I do this all the time. One minute flying an Alexa Mini and the next doing some agricultural mapping. I use the same machine for both which is a bit overkill for the mapping- but it does the job perfectly.