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#21 Malx

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Posted 11 October 2011 - 01:18 PM

Just found this: http://www.armokopte...c.php?f=3&t=477

Quite nice solution even though I find it a little hard to DIY. I would probably also not make the arms rectangular. (Round is of course the most effective but at least square would be better. ).

#22 z-axis

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Posted 11 October 2011 - 02:27 PM

I thought about this topic a lot during my first build (pics coming soon), but would like to share these design decisions:

- Removable booms become much easier if you can forget about using the ESC BEC. Instead of five wires, you only need two big ones and a small one for signal. Buy yourself a uBec like this one, stuff it into the central frame, and run your FC and reciver from it. Having three wires coming from each boom makes no sense to me from a design perspective if you only use one of the four wire trios for its BEC.
- Don't forget about LEDs. If you wil use LEDs for orientation or night flying, you can keep all five of those wires and repurpose the ESC BEC wires for powering your LED strips. I don't mean run 5V LEDs of your ESC BEC, I mean cut the wires from the BEC, connect LED strips to them, and connect the central ends to your 12V.

#23 jes1111

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Posted 11 October 2011 - 04:57 PM

Interestingly, the link I gave above leads to this one: https://picasaweb.go...012150332174722 - an image of a four-rotor flying machine with removable arms, dated 21 March, 2009. That predates Aeryon's application (14 May 2009), thus rendering their "invention" invalid. B) :D :rolleyes: :lol:
Jeremy

#24 Malx

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Posted 11 October 2011 - 05:15 PM

Interestingly, the link I gave above leads to this one: https://picasaweb.go...012150332174722 - an image of a four-rotor flying machine with removable arms, dated 21 March, 2009. That predates Aeryon's application (14 May 2009), thus rendering their "invention" invalid. B) :D :rolleyes: :lol:

Depends on whether the new (stupid) American patent law applies backwards in time... (Now it first patented instead of first invented)
But as I mentioned before, their patent is invalid on many points. It's just a question on having enough money to defend yourself. The problem is if you loose you will need to pay their lawyer costs as well (which can be millions) and you can loose on small technical details that has nothing to do with the case.
(Big Swedish inventor was overrunned by american court because he had filed the case in the wrong "name", himself instead of his personal company with only him as owner and employee. The court skipped to even check the case, forbid him to file it again in the right name and he had to pay millions to the other company...)

I thought about this topic a lot during my first build (pics coming soon), but would like to share these design decisions:

- Removable booms become much easier if you can forget about using the ESC BEC. Instead of five wires, you only need two big ones and a small one for signal. Buy yourself a uBec like this one, stuff it into the central frame, and run your FC and reciver from it. Having three wires coming from each boom makes no sense to me from a design perspective if you only use one of the four wire trios for its BEC.
- Don't forget about LEDs. If you wil use LEDs for orientation or night flying, you can keep all five of those wires and repurpose the ESC BEC wires for powering your LED strips. I don't mean run 5V LEDs of your ESC BEC, I mean cut the wires from the BEC, connect LED strips to them, and connect the central ends to your 12V.

Yepp, that is one of the ideas I'm checking and that I probably will use on my heavy Y6. A seperate BEC should be used any way. But there is some drawbacks as well, you most likely need to put the ESC:s on the outside of the arms making the multi more sensitive for water as an example.. I'm also a fan of using the inside of the arms for cables.

#25 z-axis

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Posted 11 October 2011 - 06:00 PM

Also, many of you probably know this, but the MultiWiiCopter SCARAB airframes all have centralized ESCs, tubular booms with the three motor wires runnning inside them, and the whole boom/motor combo is very easily removable by loosening the boom clamp screws and disconnecting the three bananna plugs. Very nice.

#26 Borneoben

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Posted 15 October 2011 - 08:00 AM

Hi Guys

I have also been thinking about how to make the booms easily removable with reliable electrical connections

Please see attached illustration of my idea.

Its based around Anderson PowerPoles. I am a big fan of these connectors
The power poles lock together side by side with a small Dovetail joint that is very stiff.
When two or more powerpoles are linked together like this they have some small holes that align allowing easy fixing to a surface.
You can connect as many power poles side by saide as you like.
You can also stack power poles on top of each other as well so you can have as many connections as you like.

Power poles are available in about 10 different colours so you can colour code all of your arms to make sure you reconnect in the correct location.

Draw backs are you would still need to loosen the boom clamps screws to remove a boom. (you could use wing nuts to make this a littl easier or use an electric screw driver with low torque setting?)
Another draw back is the size of the connectors they are a little bulky.
Each powerpole is roughly 25mm long and 8mm wide. My drawings show the asembly mounted on a 25mm diameter boom.

Pros are that all the components are avalable off the shelf

What do you guys think?

Ben

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#27 jbkappirossi

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Posted 26 December 2011 - 11:18 PM

hey guys, i was thinking two of detachable arms for my future build :) .

This was firstly my vision. Just use a XLR speaker connector and glue it in the tube.
The XLRs come in al 3,4,5,7 poles and the most apealing to me, they have hooks wich interlink the female to male connector.

then, on the outside a CF disk that fits tight over the tube with 2 wholes that fit right over the lip of the frame piece.
the spring keeps the disk in place and thus keeping the tailboom secure in place to.

I actualy was planning on doing this, but only if i can find a sponsor :P , because i don't have axis to a 2.5d cnc machine and the XLR plugs are pretty expensive.

its just a 15min skechup so you can see what i mean. :)

Posted Image
big one http://i.imgur.com/XcY0o.png

Edited by jbkappirossi, 26 December 2011 - 11:31 PM.


#28 r691175002

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Posted 27 December 2011 - 12:02 AM

I've seen an Aeryon quad in person and the detachable arms are absolutely wonderful. Its hard to explain, they use spring loaded pins pressed against flat pads so there is no risk of bending/shearing off pins in a crash. I almost want to compare it to BGA but those are not spring loaded.

The arms also snap on and off. This is different from sliding in and out because they disengage when a side force is applied instead of breaking. The amount of force required to remove an arm is such that I have never seen a scout break in a crash, the arms just pop off and can be re-attached in a few seconds.


I'd recommend checking out the patent, I'd love to copy the design but it looks very hard to replicate. I've noticed that most of the parts on the Aeryon quads are made on a 3d printer and the DIY type stuff is nowhere near the level of quality we would need.

http://www.google.co...epage&q&f=false

Edited by r691175002, 27 December 2011 - 12:08 AM.


#29 r691175002

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Posted 27 December 2011 - 12:11 AM

Hmm, I did some more research and it might actually be viable to mass produce these if you have a cnc mill + rotary table.

The spring loaded pins appear to be standard parts know as "pogo connectors": http://www.yokowoconnector.com/

The spring loaded ball bearings + sockets they use to hold the arms in place should be easy to replicate. You can get 15 10A pogo connectors for a few bucks on ebay: http://www.ebay.ca/i...=item3ca75c34f2

You really need a gold plated PCB with corresponding pads on the other side though.

Edited by r691175002, 27 December 2011 - 12:20 AM.


#30 jbkappirossi

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Posted 27 December 2011 - 05:14 AM

hmmm, didn't find that one yet, but my idea is different. i just take some already existing parts and put then together.
The whole point is, so that anyone can make it at home without the use of a hightech equipment like cnc ore lasercutter.

We shoud al put our'e heads together and make something for the community, because i havent seen anyone make this simple and affordable yet.

Well, we could always ask if the dev from the ''Aeryon quad'' aproves oure design. Or i ask HK, they don't care to clone.
But its not my intention to cloon, i haven't seen the Aeryon design ever, till now.

But I've got another bunch of great ideas, in my head. I wil see if i have some time and work them out the next weaks.

edit;

Also i wanted to show this unfinished model i was working on last weak. I just had nothing to do and started drawing, but it lead out to 20 hours. Not per definition ''detachable arms' but detachable sigments. :D

Posted Image

Edited by jbkappirossi, 27 December 2011 - 05:38 AM.


#31 Dado

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Posted 27 December 2011 - 07:27 AM

Bayonet Connector


brilliant, where could i buy these?



edit:

cool idea jbkappirossi, really cool looking too.

unfortunaly i don't have time to draw lately, detachable arms or motor moduls is cool stuff but im thinking why not make multirotor machine kinda like transformer, where you pull two sides of lets say quad, then the arms spread, one screw tighten and its RTF. Should take less parts.

when i get the time ill draw and render the animation, so far i was drawing different sollutions on paper and i think i got enough to start designing it in 3d.

here are some feature i've manage to achive.
Quad will be water and impact resistant, it will float on watter and fly on rainy conditions, only breakable part will be propeller or bended shaft. it will carry gopro and fpv camera, motor noise reduced too.

also it will have very good navigation lights with minimum of leds onboard and retractable landing gear for reduced drag for foward flight. weight is something ill have to see when i start calculating everything, im hopeing for 1kg fully loaded, 1kg should be enough for super stable behavior in wind.

my t2 frame is still under research, will post some render when i get time after NY i hope.

what if you need to do search and rescue while its raining, when its cruciel to aid imidietly.
http://www.youtube.com/watch?v=kYUpkPTcqPY&feature=related

Edited by Dadorcp, 27 December 2011 - 08:39 AM.


#32 Windbreaker

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Posted 27 December 2011 - 09:21 AM

I've been posting my progress on a quad, and the arms will be easily removed. The arms themselves have a round cross section but the ends are square...

... which gives us the answer as to how to fit a round peg into a square hole.

http://forums.openpi...r-from-scratch/

Just two turns on each socket bolt (four per arm) clamps the arm tightly enough to keep it from coming out. The bolts remain in place so there are no bolts to lose. Just make sure you have an Allen wrench handy.

The connectors will still be standard. Using Deans for power from the distribution buss to each ESC. I guess I should make plugs for the ESC control wires, too. That would eliminate having to plug directly into the CopterControl board everytime.

I plan to number each arm, along with the positions of each arm on the center plate, to make sure the right ESCs and props are in the right positions.

#33 jbkappirossi

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Posted 27 December 2011 - 08:51 PM

great idea windbreaker, but it also seems quite heavy?

Dadorcp.. as you stated already weight would be youre biggest enemy, because you wil need very strong ''and sophisticated'' hinges that probably have to be machined out of metal making them quite heavy and labor intensive to make.
But i can't wait what you are designing, im hoping a flying optimus. :lol:

i've been lookin' around the last couple off hours now and i found these connector which are used in vintage radio equiptment.
They also can handel the amps. but my questions what do these connectors weight? they look heavy ;) .

Posted Image
http://www.ebay.com/...=item27bf3e5833

edit;

Couldn't help myself,...just orderd a pare, because I have to know what they weigh. ^_^

Edited by jbkappirossi, 28 December 2011 - 02:14 AM.


#34 Piranha

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Posted 27 December 2011 - 09:52 PM

hey Malx one more interesting project from you!
I thought about attachable arms a lot and long time! There is no commercial avaliable connectors which can be used as is!
One more thought- to prevent problems with bad connection during vibrations one part of the connector(from frame side) must be dampened for example fixed on some kind of rubber pillow

#35 Breezemont

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Posted 27 December 2011 - 10:00 PM

,,,

Edited by Breezemont, 01 April 2012 - 03:00 AM.


#36 Piranha

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Posted 27 December 2011 - 10:51 PM

what is APP connectors?

#37 nick_a

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Posted 28 December 2011 - 04:29 AM

what is APP connectors?

Anderson Power Poles, very nice connector that i use myself

#38 Borneoben

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Posted 28 December 2011 - 04:35 AM

I like it. I'm working on a version of that myself.

I'm in the process of switching over completely to APP connectors instead of bullets/EC3's.
They are slightly heavier, ~2.8g per motor/esc combo but they are really easy to use and most importantly NO SOLDERING!!


Great!

Dont forget to show us your progress!

#39 naiiawah

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Posted 28 December 2011 - 04:52 AM

I'm in the process of switching over completely to APP connectors instead of bullets/EC3's.
They are slightly heavier, ~2.8g per motor/esc combo but they are really easy to use and most importantly NO SOLDERING!!

Just as an aside, Hams have been using PowerPoles for almost 2 decades now for the high power connections their radios need. While you can get away with just crimping, the "wisdom" in the Ham community is to solder them (with or without the crimping). Go with whatever works best for you though.

#40 Breezemont

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Posted 29 December 2011 - 08:29 PM

...

Edited by Breezemont, 01 April 2012 - 03:00 AM.