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Old Feb 06, 2013, 06:45 PM
Begin with end in mind...
power's Avatar
Eagle Lake, Minnesota
Joined Apr 2003
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Quote:
Originally Posted by jackerbes View Post
So what is the object to balancing? Is it to move the camera in and out and right and left until the weight is balanced. And did you have that there?

Jack
Hi Jack, I had the balance very close in the clip. As far as I understand this principle, the balancing is so the motor/motors have to work less to correct as they see direction from the control board. I would imagine any additional torque could be seen as lag and ultimately be seen on video footage.


Kenpilot, I really don't understand what you are saying?? Gears, servo drives, belts, and other mechanics are what this is eliminating. The videos in this thread as well as the DJI Zen clearly demonstrate how this type of setup functions. It is by far the smoothest video I have seen. I have yet to see the jitters you speak of.

Have you read the thread and watched the video samples??

Mike
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Old Feb 06, 2013, 07:14 PM
Make UAVs, not drones! ;-)
jazzboy's Avatar
Vancouver, BC Canada...eh!
Joined Feb 2010
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Motors + Gears = Servos...Servos = Bad
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Old Feb 06, 2013, 07:28 PM
checkout my Blog
otlski's Avatar
Joined Feb 2008
466 Posts
Quote:
Originally Posted by jackerbes View Post
So what is the object to balancing? Is it to move the camera in and out and right and left until the weight is balanced. And did you have that there?

Jack
Hi Jack,

I've put some work into providing the answer in my recently started blog. If you are interested, start at the first post (bottom of the page) and read the posts in chronological order.

http://www.rcgroups.com/forums/member.php?u=195984

Dan
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Old Feb 06, 2013, 07:35 PM
THE ЯUSSIANS ARE COMING!
rcposter's Avatar
United States, CA, SF
Joined Apr 2011
191 Posts
Quote:
Originally Posted by Kenpilot View Post
Why are those who are gifted in the art of engineering not considering a geared drive on these uber hyped brushless gimbals? My limited common sense tells me that there is NO WAY a brushless gimbal can exhibit smooth and accurate control unless there is a geared ( or more clearly a reduction drive) system involved in this magical new product.

Believe me, I hope my instinct is wrong here, as I'd love to replace my clunky and jittery low priced GP gimbals with several of these miracle solutions.

Every small brushless motor i own is jittery when moved within 180 degrees of center. I just do not get it!!!!!
I think this is why the Zenmuse uses a sort of stepper motors? I too am concerned that a big challenge here is overcoming the cogging of motors designed for high-RPM operation. Perhaps when some test videos which eschew fish eye lenses come down the pike, we will see how much of a problem this proves to be (or proves NOT to be).
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Old Feb 06, 2013, 07:47 PM
Don't disturb the pilot !!!
saucisse's Avatar
Canada, QC, Quebec
Joined Jun 2008
2,185 Posts
Did you check the videos in the very first post of this thread?? Looks good to me The key will be choosing the proper motor/custom winding so there is no jittering.

Quote:
Originally Posted by Kenpilot View Post
Why are those who are gifted in the art of engineering not considering a geared drive on these uber hyped brushless gimbals? My limited common sense tells me that there is NO WAY a brushless gimbal can exhibit smooth and accurate control unless there is a geared ( or more clearly a reduction drive) system involved in this magical new product.

Believe me, I hope my instinct is wrong here, as I'd love to replace my clunky and jittery low priced GP gimbals with several of these miracle solutions.

Every small brushless motor i own is jittery when moved within 180 degrees of center. I just do not get it!!!!!
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Old Feb 06, 2013, 09:13 PM
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ultrojo's Avatar
Malaysia, Johor, Johor Bahru
Joined Feb 2012
107 Posts
newbie question..

what motor specs can be used for alexmos gimbal controller ?
i have no idea about rewinding motor.

can we use any motor? or any spesific kv? or must rewind motor?

tq
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Old Feb 07, 2013, 01:24 AM
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Germany, NRW, Dusseldorf
Joined Jun 2010
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Quote:
Originally Posted by ultrojo View Post
newbie question..

what motor specs can be used for alexmos gimbal controller ?
i have no idea about rewinding motor.

can we use any motor? or any spesific kv? or must rewind motor?

tq
4 questions - 1 answer: read page #1 of this thread!
1 question for newbies: is this really asked too much?
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Old Feb 07, 2013, 02:49 AM
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Malaysia, Johor, Johor Bahru
Joined Feb 2012
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Quote:
Originally Posted by kinderkram View Post
4 questions - 1 answer: read page #1 of this thread!
1 question for newbies: is this really asked too much?
thanks kinderkram..
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Old Feb 07, 2013, 06:04 AM
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Joined May 2006
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Quote:
Originally Posted by jazzboy View Post
Motors + Gears = Servos...Servos = Bad
How about motors + belts?

Okay, let the magic continue. Not trying to rain on the dream parade, just a bit skeptical is all.

My money is ready to send once (if) they become available.
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Old Feb 07, 2013, 09:38 AM
E-Copter
Bricobrac's Avatar
Paris / Nice, France
Joined Aug 2002
2,091 Posts
Quote:
Originally Posted by rcposter View Post
I think this is why the Zenmuse uses a sort of stepper motors? I too am concerned that a big challenge here is overcoming the cogging of motors designed for high-RPM operation. Perhaps when some test videos which eschew fish eye lenses come down the pike, we will see how much of a problem this proves to be (or proves NOT to be).
Hi,

you are talking about harmonic drives maybe..
This is all the subject here : going direct drive, no more, no less, and do not forget that cogging with no current is a normal thing, the plan is to have a smooth control is all in the principle of the Alexmos controller ))) This is also why the winding forthat kind of motors ( direct drive for gimbal control)is different compared to " high speed" outrunners

Best regards,
Fabien
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Old Feb 07, 2013, 10:30 AM
Registered User
Moscow, Russia
Joined Jun 2006
307 Posts
Quote:
Originally Posted by rcposter View Post
I think this is why the Zenmuse uses a sort of stepper motors?
Who told you about magic stepper motors in Z15? There are brushless motors almost the same as all we are using in our models but more precise and specially developed for motion control
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Old Feb 07, 2013, 11:15 AM
Jack
USA, ME, Ellsworth
Joined May 2008
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The stepper motors used in machine tools, robotics, and many other controlled motion applications are quite different than our BLDC motors. They are often brushed, permanent magnet motors but they have encoders for contolling movement are are capable of much smaller steps (i.e., cogs) and with precise and controlled movements. And they bring with that a lot more bulk, weight, and cost.

Many of the best gimballed movement camera systems in use now use those kinds of motors but they are much bigger, heavier, and more expensive. Imagine that we are modeling the better systems at more affordable prices, just like do the airplanes and other flight platforms.

Browse some of the hardware here to see bigger gimbal systems and robotics components that are at the lower end as far as costs:

http://www.servocity.com/html/pan_ti...cessories.html

Jack
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Old Feb 07, 2013, 06:54 PM
E-Copter
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Paris / Nice, France
Joined Aug 2002
2,091 Posts
Hi,

better than words, here is a little video of one of our prototype motors with 0.20 mm wire ( and we are going down to 0.16 for production).

Small shakes are due to the fact i kept the sensor board in my fingers, and i used very high gains to " excite " voluntary the system ( p:30, i:0.30, i:12 ). Power at 50.

My Futaba BLS 451 servo has much more "steppy" behaviour and certainly not that speed ability lol !

The point is to have the right torque, right magnet pattern and winding with the right stator height.. Then from my tests i did not exceed 60 celsius on winding which is pretty good.

More videos next week, we start the motor production tuesday morning ( monday is final test and motor selection day at the factory).

We will ship 4 pre production motors to Jussi on tuesday for validation.

Best regards,
Fabien

PS: the shaft on the bottom was touching the adhesive tape and did not help the motor to spin free but well works fine anyway ))

Prototype motor tests for SimpleBGC controller (E-Copter / Viacopter / Flyduino) (1 min 6 sec)
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Old Feb 08, 2013, 12:17 AM
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DorianJ's Avatar
Freehold, USA
Joined Jan 2008
395 Posts
Quote:
Originally Posted by power View Post
If you guys are bored here is a clip of my Gopro brushless gimbal. I had some time waiting for the control board to be released as well as waiting for my .16 wire to show up so I designed my own gimbal.

I wanted to accommodate the Hero 2 as well as the Hero 3 so I tweaked some things and I think this will do. I was inspired by the design rendering that Fabien posted earlier in the thread. Since I had time, I made one to suit my needs. The motors in this clip do not have stators installed as I am waiting to rewind them. This gave me a chance to see how much of a chore balancing was going be. it is quite simple if the adjustment is there.

This is a one off personal project. No production.

Mike


https://vimeo.com/59103463
That video was actually very entertaining. I watch the whole video too
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Old Feb 08, 2013, 01:43 AM
E-Copter
Bricobrac's Avatar
Paris / Nice, France
Joined Aug 2002
2,091 Posts
Quote:
Originally Posted by power View Post
If you guys are bored here is a clip of my Gopro brushless gimbal. I had some time waiting for the control board to be released as well as waiting for my .16 wire to show up so I designed my own gimbal.

I wanted to accommodate the Hero 2 as well as the Hero 3 so I tweaked some things and I think this will do. I was inspired by the design rendering that Fabien posted earlier in the thread. Since I had time, I made one to suit my needs. The motors in this clip do not have stators installed as I am waiting to rewind them. This gave me a chance to see how much of a chore balancing was going be. it is quite simple if the adjustment is there.

This is a one off personal project. No production.

Mike


https://vimeo.com/59103463
Hi,

This is very nice work! Simple and effective
We are a bit complicated guys, i admit ( lol) ..
If you need 0.16 mm wire, i have a 4.9 KG 0.16 mm wire roll here, i proposed a trade to Jussi for a AQ6 board but...

Best regards,
Fabien
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