Autonomous paramotor for aerial filming

[Stefs Engineering]

Autonomous paramotor (Opale Hybrid 5.2)

Ey guys! This is my first real post (besides the "mandatory" introduction post)
and am excited to share my new project!

So I bought a wing from Opale almost 3 years ago, planning to build a cool camera
platform but unfortunately I did not find the time to actually build it. Untill now
that is! I decided with the new year that it is time to get this project started and
share my experiences along the way.

In a nutshell the goal:
"having a paramotor fly autonomous with a camera/gimbal attached for endurance flights"

So why a paramotor? There are a few reasons that inspired me:
- "cheap" for the size and payload capability
- Really compact when in storage or during transport
- Silent (well at least in comparison to multicopters)
- Efficient, there is not a lot of power needed compared to
multicopters (planes can be more efficient but also more
expensive and a lot bulkier in storage and during transport)


So the wing I bought back then is an Opale FOX RS 2.6:

This wing can be flown with winds up to 20 knots and 7 kg payload (please note that
this is in optimal conditions and according to the manufacturer)

About a year ago I made a concept of what the propulsion unit (or trike/backpack) could
look like. Here is a quick render I made of that:

There are a lot of things that I will change to this concept, the main changes are:
- Riser mounting points will be adjustable for easy CG adjustments
- Gimbal will become retractable (this will make it less likely
that it will be damaged during landings)
- The flightcontroller will be a Pixhawk mini instead of the larger version
- The airbags will be likely replaced for a landinggear
- I will use a 2 blade prop instead of the shown 3blade. (Xoar 18x10)

I ordered a couple of items yesterday and recieved most of it today in the mail

What I plan to use:
1x - Pixhawk mini controller (with current sensor, airspeed sensor and GPS)
1x - Plush 100A ESC
1x - YEP 20A BEC
1x - Aerodrive 5065 320Kv motor
1x - Xoar 18x10 propeller
2x - 6S 10.000 mAh battery
2x - TS700MG servo (weightshift steer)
2x - HK15138 servo (brake lines)
2x - 9gram servo (speedbar)
2x - 9gram servo (big ears)

Would you guys like to see the build in detail or would sharing the results suffice?

 

[Ricci]

Nice! Very interesting. Would like to see in Detail.

 

[Stefs Engineering]

Thanks! So here the second part I had somewhat prepared (I also share this build on a dutch forum)

So yesterday I installed SolidWorks 2018 and immediately started testing it out and find the
updates they made. I tought the best way to test it out was just to start experimenting with
parts of the paramotor. I am also happy that SW Visualize accepts my non quadro videocard, this
helps reduce the time required to render significantly! (20-40 seconds instead of 15 minutes)

These are a few initial renders that show what I have in mind for the propeller cage. I want it
to be made out of 6 arms and 6 ring segments that connect those arms.

Each of the arms is shaped somewhat like a propeller, the idea is that it will reduce the torque
effect of the propeller.

I also tried to make a render in visualize and that works quite nice!

 

[paulshort]

Wow this looks amazing. Cant wait to see the result

 

[Fluburtur]

Very nice CAD work, this looks pretty clean.
If I remember correctly Opale wings are rather expensive but the one you have is pretty big so it should be no problem, and I think it would be the first aircraft of its kind!

 

[Stefs Engineering]

Thanks for following along! After some thinking and feedback from other para rc flyers I decided to change things up a bit. I just bought a hybrid 5.2 wing to replace the fox RS. This should be a lot more docile and a better choice for the testing of the trike/gondola module.

It is expected to arrive tomorrow!

I allready recieved the hobbyking order so the motor, batteries, esc, bec and servo's are here now. I also recieved epoxy and glassfiber cloth that I want to use in combination with 3D printed parts (cover the printed parts to reinforce them)

 

[Fluburtur]

A friend of my dad built several paramotor trikes, this is one of them

I have no idea how that can help you but that thing can carry a lot of weight

 

[Stefs Engineering]

I'm not sure either but I do appriciate all the help and suggestions I get!

At the moment I'm working on making models of all the parts that will be used in this model. The idea behind that is that it will be easy to move things around and find the best placement of the components without the need of test rigs for that same purpose.

 

[Stefs Engineering]

Got quite a bit done working on the individual parts and trying out some layouts for the components. This is what I got to for now:

Not included in this render:
- Video transmitter
- Gimbal
- GPS
- Current sensor
- Airspeed sensor
- BEC

When I am happy with the layout I can start designing the frame that connects it all together

 

[Stefs Engineering]

Allright! The new wing just got delivered and took it out immediately to try to kite it. I also brought the FOX RS to compare and it's night and day when it comes to ease of launch. This should really help me a lot during the testing phases of the trike and after that the testing of the flightcontroller.

 

[CONNXT248]

This is a really cool concept! Can't wait to see it up and flying!

 

[Jetcrafter_2000]

This thing is crazy!!!
Looking gread and i hope the best for your projekt!

Looking forward to the maiden (and the video)!
Jetcrafter2000

 

[Stefs Engineering]

Thanks jetcrafter and connxt! I appriciate it


It was quite a bit of work but I managed to finish the 3D models of the propeller cage and motor mount.
For the first concept I will make the parts with my 3D printer and laminate with Glassfiber/epoxy for
additional strength.

Overview

Motor mount has air channels to keep the motor cool

And the individual parts the assembly is made out of. Each of these carbon parts is used 6 times.

 

[Stefs Engineering]

For those who are interested in a bit about how I designed the arms. In the screenshot below you can see a bit more (Basically I made a load of reference planes that I made sketches on and I connected those sketches with 3D sketches. After that I finished it with a loft extrude):

And for good measure a side view of the finished model. You can also see the motor mount here with the cooling slots.

The printer is allready busy making the first ring segments!

 

[Stefs Engineering]

The printer is hard at work, I am almost finished making the six ring segments.

On to some other progress I made yesterday evening, I made a concept version of the main frame that attaches all the components together. In this concept version my goal was to get a good idea of the rough shape. The next step is the so-called "DFM" (Design for Manufacturing) inwhere I optimise the design for manufacturing and assembly. In this case that means that I will split the frame up in roughly 10 pieces. Allthough it makes it a bit more complex, it will also make it a lot easier to make. Besides that, having more smaller pieces means that If I want to change something it is likely that I only need to change one small part instead of the entire frame (this also helps in case of damage caused by rough landings/crashes)

Concept render of the frame, I made it blue to make it stick out a bit more from the other parts.

The weather is still not that great but couldn't resist going out to take a few pictures of the wing:

 

[Stefs Engineering]

Today another day at high speed! Besides designing I also printed the 6 ring sections that connect to the ring arms. It took a while, almost 20 hours! The next step for these ring sections is preparing them for assembly (glueing together) and laminating with fiberglass/epoxy.

Here are most of the parts I am going to use for the trike. there are some servo's missing in this picture but of each type there is at least one. The other items are for example the printing filament and materials for the laminating.

And for the fun of it, a picture of the wings indoors. And I tought I had a big workbench! well not anymore I guess (the wings are not even halfway unfolded)

Tomorrow I will continue printing and finish the design of the centerframe.

 

[Stefs Engineering]

Before any really issues arise, a quick question:

While following along, did the experienced paramotor pilots here spot
possible issues or mistakes I made that I should fix or watch out for?​

I'm learning as the project is progressing so I have no illusion that everything will go perfect the first time.

 

[Stefs Engineering]

I got a suggestion on RCG and thought it may also be interesting here. So this is what I answered:

You are definately right that having the bulk of the weight low and the point where the risers connect high will give you more stability. Besides that, not having the vertical COG on the torque axis (motor axis in this case) will help a lot by itself.

I did consider this a bit but I agree that the offset should be a bit more. The main reason for the configuration that I showed in the renders is that I wanted the cleanest and least obstructed airflow to the propeller and working with a conventional setup you definately block a lot of the air. The result is that you get less efficiency out of the setup and besides that it will introduce more noise from the turbulent air going through the propeller.

I got curious and calculated the difference in obstructed propeller disc area:
Disc area: 1660cm2 - 24cm2 (propeller hub area excluded) = 1636cm2 (253 sq.in)

Concept version: 272cm2 (42 sq.in) 16.6% "blocked"
Conventional setup: 595cm2 (92 sq.in) 36.4% "blocked"

Ofcourse it is not as rigid as shown here, there is some airflow in the conventional setup because the backplate is not mounted within a few mm of the propeller. Same with the concept version I am working on now, it will have external covers that will help the airflow a lot, even when I increase the height of main body.

Here is a front view render that shows how little is obstructed at this moment:

And a render of the back with 2 additional batteries mounted (That I intend to do in the real model)

I will put it on the list though of things to take in consideration for the design I am sure I can change some things without having too much of a negative impact on efficiency .

 

[Fluburtur]

You could put some aerodynamic fuselage to provide cleaner airflow to the prop, with some NACA inlets it could look quite fancy

 

[agentkbl]

I second flubutur