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Old Mar 17, 2010, 05:01 AM
Registered User
Tulcea Romania
Joined Mar 2010
203 Posts
Help!
Octocopter with folding arms on the cheap... need help

Hi everybody

This is my first post after reading a few hundred posts about multi rotor helis... I am a photographer and would like to build a rig to carry my camera (max 1.5kg payload) so I have opted for octocopter configuration. Usually octocopters are big and not easy to transport so I am planing on doing something with folding arms. I am on a tight budget so I am trying to reduce costs as much as I can please just help me out with ideas as I am full of information and... have a hard time putting it together. So here is what I had in mind...

What I want to use:
Octocopter structure with folding arms - like this one

The arms - I have studied a lot of options and carbon fibre seems to be the lightest but expensive... so I went to one of the china shops in my town and found these fishing rod tubes for 0.6 Euro a peace










These rods are light about 35 grams for 50 cm with diameter of 1.9cm at one end and 1.7cm at the other. They are tough and will not bend much... but they are thin... about 1mm or so. All good but the problem is they schread easily if you cut them and I don't think drilling a hole in them is a good idea. For this I had to find a solution that doesn't imply drilling so I came out with the idea of a clamp (that one I cut just for the idea it is not the final thing):












To hold the arm in position I am thinking at these pipe fixing clamps found in all plumber shops:








For motor mounts I will use the same type of metal clamps as I have no other viable solution. The main problem here is the conical structure of the tube that will not fit a standard motor mount.

For centre plate I want to use carbon fibre plate of 2.5mm as there is a guy here in Romania selling them 2.5x300x350mm 10 layers for 40 Euro/plate. Do you know a better offer?


Motors - I was thinking of buying some of the RCTimer motors for this task and I would like to know if anybody here can recommend one motor to work with the Mikrokopter system? - http://www.rctimer.com/index.php?app=goods&spec_id=159 I think this is a good choice as it is close to what MK is recommending... I will try to buy more of these so I have spare ones in case they fail.

For props I will go with some APC Slow Fly Prop 12 x 3.8SF or 12x4.7 for hover power. Do you think is worth going for larger ones? APC Slow Fly Prop 14 x 4.7SF? or is it overkill?

Any advice would be welcomed.

Please excuse the big pictures but better bigger than too small.
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Old Mar 18, 2010, 03:01 PM
Registered User
Tulcea Romania
Joined Mar 2010
203 Posts
Hmm... I see no one had any new ideas
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Old Mar 18, 2010, 03:28 PM
Free Tinker
chickenblender's Avatar
Augusta, GA
Joined Jan 2007
379 Posts
Wow, your tight budget is way different than my tight budget. This is way out of my league. One question I have is why build an octo since many smaller props are much less efficient than fewer large ones?
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Old Mar 18, 2010, 05:30 PM
The Dude
Smokytyrz's Avatar
Louisiana, USA
Joined Jan 2009
452 Posts
How small does it need to be? Something like this isn't that big:
http://www.nghobbies.com/cart/index....roducts_id=454
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Old Mar 19, 2010, 05:42 AM
Registered User
Tulcea Romania
Joined Mar 2010
203 Posts
Quote:
Originally Posted by chickenblender View Post
Wow, your tight budget is way different than my tight budget. This is way out of my league. One question I have is why build an octo since many smaller props are much less efficient than fewer large ones?

Well in reality there is no tight budget for such things ... maybe I should have said limited budget .

When you want to fly a SLR camera you have to think on safety too as the camera price can exceed the price of the whole setup. I think 8 propellers are ok for this project and don't forget that most of the quads and octos out there use 10" props while I intend to use 8 props 12 or 13" for hover power as I am not interested in acrobatics and agility just stability.

One of the main features is the folding arms as I will have to transport the rig. I could also build a 4 arms coax octo but all people say that coax-es are not so efficient and not so ergonomic as any unbalance on the ground will produce some broken props. Also the down facing motors are hard to handle as you can get cut by the props by trying to catch it.

This guy has build lots of multi rotors - http://plischka.at/MK9-Y6.html and he has some experience.

I might reconsider and try using the quadpower board but it has issues and no gps yet. Any ideas about a good quad folding frame?
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Old May 03, 2010, 03:48 AM
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Imagecatcher's Avatar
NSW Australia
Joined Mar 2010
245 Posts
My Folding Octo

I am in the same situation and have developed this

http://gallery.me.com/imagecatcher/100191
you might get some ideas.
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Old May 07, 2010, 02:46 PM
Registered User
Tulcea Romania
Joined Mar 2010
203 Posts
Quote:
Originally Posted by Imagecatcher View Post
I am in the same situation and have developed this

http://gallery.me.com/imagecatcher/100191
you might get some ideas.
Thanks for the pictures. You have a great idea there and you have put a lot of work in it. It looks great. What is the total wheight? And.. Does it fly?

In the end I think I will go with a coax okto as it is simpler and smaller. What do you think about the folding arms? Is there any inconvenience to it?
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Old May 08, 2010, 11:18 AM
Tri-Quad-Hexa-Octo-copters!!
United States, TX, San Antonio
Joined Feb 2007
14,446 Posts
I would suggest just making pinch mounts for the arms and then removing and unplugging as many as you need to for packing and portability. Keep it simple. A flat octo or hexa is more efficient and perrforms better.
Cheers,
Jim
Quadrocopter and Tricopter Mega Link Index
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Old Mar 24, 2014, 09:10 AM
Registered User
United States, FL, Gulf Breeze
Joined May 2006
575 Posts
You need to look at two links, there is NO way you can build something yourself to get something so sweet.

Cheep and super cheep that are top of the line in quality and durability.

http://www.rcgroups.com/forums/showthread.php?t=2054477

http://www.shop.aglhobbiesllc.com/UA...cto-Frame.html

I have study this for long time now and it does make sense to have a folding booms.
One has them and the other you would have to modify, but the components are cheep and high quality with lifetime warranty.

FU from foxtech has the market cornered with his K130 and is so cheep with the only large frame out there, could only compare it
to the very expencive DJI S100

Now as another option you could look at the tarot 960, seams to be a very popular unit for DLSR.

Stay with an octo.
Do not get anything that stacks one motor on top of anouther like that Y=6
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Last edited by gtxkid; Mar 24, 2014 at 09:20 AM.
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Old Apr 02, 2014, 01:30 PM
Registered User
Tulcea Romania
Joined Mar 2010
203 Posts
Quote:
Originally Posted by gtxkid View Post
You need to look at two links, there is NO way you can build something yourself to get something so sweet.

Cheep and super cheep that are top of the line in quality and durability.

http://www.rcgroups.com/forums/showthread.php?t=2054477

http://www.shop.aglhobbiesllc.com/UA...cto-Frame.html

I have study this for long time now and it does make sense to have a folding booms.
One has them and the other you would have to modify, but the components are cheep and high quality with lifetime warranty.

FU from foxtech has the market cornered with his K130 and is so cheep with the only large frame out there, could only compare it
to the very expencive DJI S100

Now as another option you could look at the tarot 960, seams to be a very popular unit for DLSR.

Stay with an octo.
Do not get anything that stacks one motor on top of anouther like that Y=6
Thanks for the reply but this post is so old... now I have build a few quads and I will stick to them. Check my other posts.

Cheers,

Daniel
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