Why aren't there any smaller X8s?

Vermiform

Member
I'm wondering why we don't see any smaller (300-500 size) X8 multirotors. Does a smaller build get less efficient on an X8?
 

Motopreserve

Drone Enthusiast
I think one reason is that the smaller the build, the smaller the prop. While the added motor/props provides more lift - the added weight of 8 motors/ESCs may end up working against the thrust benefits.

Smaller quads and hex configurations seem to be able to handle the payloads required of them without taxing the build with unnecessary weight.

Of course the redundancy is a benefit to the X8 configuration. If that offsets the weight and added cost - could be a cool concept to test.
 

Bartman

Welcome to MultiRotorForums.com!!
Smaller quads and hex configurations seem to be able to handle the payloads required of them without taxing the build with unnecessary weight.

the bigger heli's seem to have more $$$ invested in them and they are more likely to be out operating for hire....both points would make redundancy and survivability worth the extra complexity and small efficiency loss. smaller helis carrying smaller, less valuable loads do fine with four motors like Scott said.

that would be my take on it. if you want a small heli that does great in the wind though then I'd still suggest a coaxial quad.
 

Vermiform

Member
I'm about to pull the trigger on some more cheap motors for my "knockaround" S500 quad. I have two of these, one with T-motors and best of everything else, and one with HK cheap stuff. I'm gonna turn the knockaround into a proof of concept and see how it flies as an X8. My goals are 1) redundancy and 2) more lift/flight time.

What I'm now trying to sort out is if I can still use the same 3S Batts or if I need something with more c-rating....or even 4S......
 

Vermiform

Member
I want to add that the main purpose for these quads is aerial video. I'm semi-concerned about introducing more vibration to the platform and also about airflow disturbing the gimbal. However, the S500 has upswept arms so I am hoping much the added airflow will be directed away from the cam. We'll see. I'll start a build thread when the parts get here, unless someone here talks me out of throwing money at this. You have 3 hours.....LOL.
 

Motopreserve

Drone Enthusiast
As @Bartman mentioned, there will be the efficiency loss due to the coaxial setup. So if flight time is a major concern, you may be working against that goal with the X8 config. You would have the redundancy though.

I like the idea - and I'd be interested to see how it turns out.
 



Old Man

Active Member
The 3DR X-8 has worked flawlessly for me for well over a year at a size of ~530mm. No vibration issues for gimbal served video at all. Flight time between the X-8 and the similarly sized 3DR quad is roughly the same with the battery sizes called for. Both can lift well over 800 grams of payload without significantly impacting the flight time. Those two MR's is where I got to learn the difference in wind stability between an X-8 and a quad since both use very similar frames, the same motors, props, and ESC's, and close to each other in dimension.

So why no smaller X-8's? Perhaps it's because companies don't think they can obtain enough profit from them due to a smaller target group?
 


jinly

Member

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Old Man

Active Member
Awesome! Please elaborate.

Since I am not an engineer of any sort I have to pose questions instead of providing empirical data. What I found was the X8 was more stable in any amount of wind, and could fly stably in more wind than the quad. The two frames are only about 10mm different in size.

Using the same equipment on both I wonder if the better performance with the X8 is due to an increase in weight, the doubling in power, or having an ability to generate more thrust response at any given "corner" for the conditions encountered? I really don't have the answer but when there's any wind above 5 to 7 mph my choice is the X8 every time. The quad will always be more "tippy".
 
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Vermiform

Member
Thanks Old Man.

My HK motors and afro ESCs are sitting on my kitchen table waiting to be opened. Hopefully I'll get some build time in tonight after church or tomorrow after school. Can't wait to fire up the soldering iron!
 

jinly

Member
Thanks Old Man.

My HK motors and afro ESCs are sitting on my kitchen table waiting to be opened. Hopefully I'll get some build time in tonight after church or tomorrow after school. Can't wait to fire up the soldering iron!


yes , this x8 was a quadcopter in the beginning. I had a prop break off in mid flight ( about 300 ft. in the air). It dropped like a rock. crashed through a maple tree and luckliy the only parts that broke off was the landing gear and the gimbal. the hood that covers the top saved all my electronic gear. (like a crash helmet). I advise you get one. TheX8 Octorotor came about because I wanted "Redundancy." It will fly with one or two motors losing power or props. I have tested this concept on take offs and in flight. I never want to worry about a failure like before. It's twice as heavy as the Quad (9.7 pounds AUW). Flies in the wind MUCH better and the yaw and vertical climb is tremendous. I would always recommend an X8 over a flat Octo. For many reasons that would fill this thread ha ha ha . Good luck on your build! Fly On Brother!
 

Vermiform

Member
I think my main goal is redundancy here. I don't mind eating a gopro or a gimbal now and then but I'm scared shitless of it coming down and hurting someone or damaging someone's property.

With the extra lift I'm also thinking about adding a Connex.
 

cootertwo

Member
Got my new hex flying, still in tuning stage. Yes, I put a Naza Lite on it for giggles. I counted 38 solder points!
GOPR0033_zpsz28sa23d.jpg

The rest of my overly cluttered living room, work space. Yes, I'm single, and luv it! How many quads can you count. (there are 9 visible)
GOPR0037_zps9vyvfmuk.jpg
 

jinly

Member
I think my main goal is redundancy here. I don't mind eating a gopro or a gimbal now and then but I'm scared shitless of it coming down and hurting someone or damaging someone's property.

With the extra lift I'm also thinking about adding a Connex.


Yes a ten pound weight falling from the sky can seriously hurt or destroys someone or something. I live out in the country and have acreage for a backyard, so I only fly here. I think the only thing I did was scare a bunch of squirrels in that tree. Which also belonged to me. ha ha
 

jinly

Member
Got my new hex flying, still in tuning stage. Yes, I put a Naza Lite on it for giggles. I counted 38 solder points!
GOPR0033_zpsz28sa23d.jpg

The rest of my overly cluttered living room, work space. Yes, I'm single, and luv it! How many quads can you count. (there are 9 visible)
GOPR0037_zps9vyvfmuk.jpg
Nice!!! Yes nice gander of Quads...I happen to own my own business which has a workshop in it. I tend to build there,,,I'm married and Wife likes this stuff in a workshop...Soldering can make a mess.. not to mention I burned a hole in her linen tablecloth.. My space is looking cluttered, I love building these things!!!Looks like you do too.
 

Vermiform

Member
Yes a ten pound weight falling from the sky can seriously hurt or destroys someone or something. I live out in the country and have acreage for a backyard, so I only fly here. I think the only thing I did was scare a bunch of squirrels in that tree. Which also belonged to me. ha ha

Me too. My closest neighbor is a cow.
 


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