Over the last three years I have been monitoring the web for evidence of large, heavy lift, commercially capable systems, for loads in excess of 10Kg
As many of you may know, there are a lack of larger frames on the market, that can handle more than 10Kg.
Rimcopters can manage 40Kg loads, and more!!!
From my research, I have found that many "heavy lift" frames are lacking one thing or the other. Either they are too heavy, or they are not strong enough. In both cases the frames are made using "tube and plate" style assemblies.
Three years ago I began developing a new type of multirotor frame. The basic idea came from my experiments with Aluminum extruded tubing as a core frame...bike rims.
This may sound quaint, perhaps even a bit tacky...bike rims for Commercial sUAS and UAV's...
I admit, its easy to get the wrong idea... I am not out in the dump collecting old bike parts to make recycled cheap frames! Stick with me for a bit, and discover why I kept going with this idea, and where I ended up :)
First, let me say that I am not here to bash anyone... There are millions of dollars invested into various manufactured designs, and those dollars are worth protecting!
It is not my desire to obliterate others hard work! My goal here is simple : make the best multirotor possible ! The fact that what I have made is less expensive, and easy to buy and build... That it is made entirely of stock components... And can be reproduced in any part of the world may be concerning to some... I am only here to show that what I have made has value, is useful, and may help some of you in your goals.
Please, if you are offended, or don't have anything useful to add... Please refrain from offering any comments!
If you are an operator, and individual or company that see's value in the work, please contribute !!!
I do not sell frames, or systems... I learned that lesson!
I do not have a business, nor do I intend to create one... So relax! Just enjoy the ride, and take from it what you can... If you intend to take this idea, and make a business... Beware ! I will not tolerate it, and ultimately, it would be better to just ask me to use the design, and pay for that use.
Individuals, who would like to reproduce my results may do so, for their own use... Make one, use it, and prosper! However, if you intend to make them for commercial use... Please remember that this is my intellectual property... And I can and will protect it :)
Now, onto the good stuff
Rimcopter is a TYPE of multi rotor frame, not a brand. To be honest, I didn't even coin the phrase. The name simply denotes what it is... A multirotor made from bike rims.
WHY BIKE RIMS?
Thanks to 100+ yrs of production and development, the bike rim is lighter, stronger.. Less expensive than custom designed parts to do a similar job.
Tube and plate designs could never create the same strength to weight ratio's apparent in my designs, nor can the tube and plates adequately deal with Vibration and Deflection issues... The truth is, Tube and Plates could never be expected to hold the weight, and as a result of the design, they suffer from vibrations effects... Jello, lack of resolution, and over loaded flight controllers, trying desperately to over come the errors created due to motor deflections and stray vibrations!
Rimcopters are completely different. The flight controller and loads are completely isolated from the drive system. In addition, the strength to weight offered in the frame reduces the load to the motors substantially. The result is longer flights, with greater flight ability and performance... Without any complications from stray high frequency oscillations or motors moving all over the place...
When I say lighter, I mean MUCH lighter... In any given example, our frame design will be lighter. Sure, you can make a light tube and plate, however, it would never been strong enough to handle the loads!
AS an example, the 1000mm X8 Aluminum design, AUW of 1.2Kg including 30mm CF Landing gear (can take 200Lbs !!)
Y6 Carbon 900mm... 780g
In both cases the frames can take well over 150Lbs force, before ANY movement / deflection.
AS comparison, I can deflect the motors of a s900 with just two fingers... Less than 10Lbs force.
Too good to be true?
Not at all... The strength of this design is that ANYONE can produce one for them selves, and because of that, it is unlikely that any larger corporation will attempt to produce it.
So, you can see, its not marginally lighter... less than 1/2 the weight in many cases!
not slightly stronger... Exponentially stronger!
Not slightly less expensive... Frames can be made for as little as $75 - $150.
So then, what are you waiting for ?
Need a larger, stronger, less expensive frame ?
Of course you do!!!
What I can offer...Two formats ( X* and Y6 ) , in two sizes, from three materials ( carbon, aluminum or steel)
Welded, bonded, or bolted...
Brian - Where are you at with theses heavy lifting copters? They look very promising. I want to know more.
We use VulcanFrames in our builds. They sustain dozens of pounds.
Extract from their web site:
Here is an unedited photgraph taken at the end of a product shoot – the brick test!
In this picture the Hexa is supported on three arms only, at full 1200mm span… and sitting on top of the centre plates are 28kg of house bricks. It could have taken more had there been more bricks available.
I was wondering when Vulcan would pipe up about this post... I spoke with Vulcan developer more than a year back. The Vulcan is definately one of the better tube and plates out there, however, it is no where near as strong, or as light.
The real deal, rimcopter has exponentially less vibrations that arrive at the IMU. I am willing to prove this, I am also willing to demonstrate it to anyone, anytime they like.
Tubes and plates... fancy tubes... thick plates... it all adds up to the smae thing : Rimcopters are lighter, stronger, produce less vibration, and are WAAAAAY less expensive to produce, distribute, own.
I am interested in a comparison in vibrations between such a vulcan frame and one of yours. With hard data.
Trouble is, getting a Vulcan to test... At the same time, it would be great to have a Gryphon, a Skijib... any 1000mm + frame that is meant for larger loads, particularily loads that require sensitive IMU's.
My assertion is that the Rimcopter will be able to produce a cleaner image / point cloud, with less expensive hardware.
It would be a worthwhile project, to collect and test each of the contenders, and do an analysis of strenght, weight, cost, availibity.
I would be more than willing to lend one or more of my existing systems to such an effort.
Thing is... I have little to lose in such a test... I have a few grand invested in my machines, $50K or so... I can only wonder what Vulcan has spent to get going... So, to be fair, I would understand if they were not so interested in a direct comparison.
If I had millions at stake, I would simply ignore someone like me.... as long as possible :)
that time may be coming to a close
This copter is in development..
70 lb payload..
What motors are this?
I have to wonder - the forces on the arms are almost entirely vertical (plus torsional). Sideways-forces must be relatively insignificant.
Would there not be more efficiency gains to be had in principle, then, by (somehow) bracing the arms vertically rather than horizontally using the bike rims? (using a vertical centre-pole above, perhaps)
Also, I think, somewhere, I've seen 'ring-quads' (or octos) using an entire bike rim as the outer ring on which the motors are mounted.