450 size x8. building, sharing, learning.

aerialdroning

aerialdroning

Member
of course i'd like to feed off information from others experience, but hopefully others can learn things as I build, share and discuss.

wanting to build an x8 for more durability in the wind (flying above the cliffs in bali most the time)
want it small for easy transport and hopefully backpacking up mountains with it

  1. looking to build around an f450 using upgraded centre plate from VGE
  2. arms from tbs so I can do the below to reduce motor vibes
  3. doubling up dampening tarot motor mounts
A friend has told me about ecalc.ch which I plan to use, but in the meantime I'd like to learn from others how all this works.

End of the day I suppose there are restrictions to how much the 450 centre plate can handle?

Well, I hope that makes sense for my first decent post on here. Looking forward to the next steps :).

Have just edited this and taken out the things I already found answers too so I don't waste peoples time. That ecalc is excellent! Almost figured out what motor/prop combo to go for.

I just need to know what the largest props are that I can swing on a flame wheel with a 450mm wheelbase.
 
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Bartman

Bartman

Welcome to MultiRotorForums.com!!
aerialdroning said:
A friend has told me about ecalc.ch which I plan to use, but in the meantime I'd like to learn from others how all this works.
Click to expand...

Aaron,
I start by making a list of everything that will be included in the build (frame, motors, props, ESC's, batteries, flight control system, misc fasteners/stuff, gimbal, camera, wireless video equipment, additional batteries if necessary, etc.) and then I try to assign an accurate weight to each item.

In the first run of the numbers you might have to guess a little as to which motors/props/etc. you'll be using so that you can do a first run of the weights but with a total weight you can then divide by the number of motors and that will be your hovering lift per motor.

Once I have a hovering lift value I go back to the data table for the motors I've chosen and look to see if I can use the props I've selected and have the motors turning in the 50 to 65% range while hovering for the given voltage I've chosen. If I'm a little off one way or the other then I look for a different motor or see about using a different prop. I also look to see if the current values for the motor are appropriate for the ESC's I'm planning to use.

The thing about this method is that once you're close the weights of stuff won't really change a whole lot as you swap out specific items, the total weight might go up or down a little when you insert values for a different motor/battery/whatever but you should be in the ballpark unless you really change something like 4S to 6S.

So you just work the numbers through a few iterations until you're close to the set-up that you had in mind to do the mission you're trying to accomplish.

The video in this post will explain it better and there's a sample motor data sheet for reference
http://multirotorforums.com/threads...i-a2-h3-3d-xy4-quad-build-with-a-twist.22207/
 
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eskil23

eskil23

Wikipedia Photographer
A 450 size airframe with a AUW of over 4 kg will be a real little power-pack.
A question though, how large props can you use with the TBE arms? The E600 comes with 12" props. If there is not enough room for 12" props, then you'll have to go for the E310.
 

Gary Seven

Gary Seven

Rocketman
Hello @aerialdroning. Just curious. How are you going to do power distribution with this arrangement? You can't actually use carbon fiber plates to do that, so are you just going to build a distribution harness?

Edit: Second question: What FC would you use on something like this?
 
Last edited by a moderator:

Gary Seven

Gary Seven

Rocketman
eskil23 said:
A 450 size airframe with a AUW of over 4 kg will be a real little power-pack.
A question though, how large props can you use with the TBE arms? The E600 comes with 12" props. If there is not enough room for 12" props, then you'll have to go for the E310.
Click to expand...
From the website the arms are spec'd at 330mm. Way more than enough for the E600 system, no?
 



aerialdroning

aerialdroning

Member
Bartman said:
Aaron,
I start by making a list of everything that will be included in the build (frame, motors, props, ESC's, batteries, flight control system, misc fasteners/stuff, gimbal, camera, wireless video equipment, additional batteries if necessary, etc.) and then I try to assign an accurate weight to each item.

In the first run of the numbers you might have to guess a little as to which motors/props/etc. you'll be using so that you can do a first run of the weights but with a total weight you can then divide by the number of motors and that will be your hovering lift per motor.

Once I have a hovering lift value I go back to the data table for the motors I've chosen and look to see if I can use the props I've selected and have the motors turning in the 50 to 65% range while hovering for the given voltage I've chosen. If I'm a little off one way or the other then I look for a different motor or see about using a different prop. I also look to see if the current values for the motor are appropriate for the ESC's I'm planning to use.

The thing about this method is that once you're close the weights of stuff won't really change a whole lot as you swap out specific items, the total weight might go up or down a little when you insert values for a different motor/battery/whatever but you should be in the ballpark unless you really change something like 4S to 6S.

So you just work the numbers through a few iterations until you're close to the set-up that you had in mind to do the mission you're trying to accomplish.

The video in this post will explain it better and there's a sample motor data sheet for reference
http://multirotorforums.com/threads...i-a2-h3-3d-xy4-quad-build-with-a-twist.22207/
Click to expand...

Hi there and thanks so much for your reply!

Well it's good to know that I'm on the right track. Have already in fact listed all that will be on there and after working my way through the e-calc I have a better idea of what motors to use - well so I thought until I watched the video you made in the link (very well done btw - gold!)

I say "so I thought" because I had just watched this video where the guy says you need to have double the thrust of the weight of the craft because the same thrust will mean you will equal the weight and not get off the ground. Double will mean you will equal the weight, but then add the same thrust again in able to hover at 50%. Check out the video and see what you think. With that said, using the Tiger motor MT 4008 (380's) with 13" props - ecalc said I could still add 2200 grams of payload. So maybe this double the thrust theory doesn't add up excuse the pun. However, interested to hear what others say about that!

Thanks for teaching me how to work out flight times! I love this forum already!

Aaron
 




aerialdroning

aerialdroning

Member
eskil23 said:
A 450 size airframe with a AUW of over 4 kg will be a real little power-pack.
A question though, how large props can you use with the TBE arms? The E600 comes with 12" props. If there is not enough room for 12" props, then you'll have to go for the E310.
Click to expand...
Yes good point, I am in the process of figuring all that out. Which poses a good question, thank you! On a flame wheel f450 keeping with eh 450mm wheel base, what are the largest props I can swing? Anyone know this?
 

Bartman

Bartman

Welcome to MultiRotorForums.com!!
aerialdroning said:
This one looks fairly decent too, any advantage for the mikrokopter board you think?
Click to expand...
i'm a big fan of the Voltair board, if you look around the site you'll see them in a few of my builds. the Mikrokopter one is just a little bit smaller making it better for smaller builds where there's less space.
i can measure standard motor span for an F450 if you'd like.
 


aerialdroning

aerialdroning

Member
Bartman said:
i'm a big fan of the Voltair board, if you look around the site you'll see them in a few of my builds. the Mikrokopter one is just a little bit smaller making it better for smaller builds where there's less space.
i can measure standard motor span for an F450 if you'd like.
Click to expand...
because this is my first build I'm going for easy and the voltair board looks easy! :)
love you to measure up!
now I'm trying to understand thrust etc. i think that the amount of grams of thrust that all 8 motors give at 50% power should equal the all up weight of the craft, then add 20% to make up for the coaxial arrangement and other miss-calculations of payload ... am i on the right track?
 


Bartman

Bartman

Welcome to MultiRotorForums.com!!
12 props on a frame the size of an F450 will be super overkill. even having eight 10" props will be a lot for what you can cram into the frame.
 

Bartman

Bartman

Welcome to MultiRotorForums.com!!
someone here built a few really trick coaxial quads, maybe it was @stevemaller ? there was an F450 coaxial quad and a phantom coaxial quad, they were very nicely done and worth taking a look at if you can find them in the archives
 


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