No, I don't. But I've been running the Skyline without even powering up anything on the hexa, so I guess the problem is, as you say, on the stabilization board.
/Pär
Photohigher skyline rsgs
- Thread starter 1001 Copters
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No, I don't. But I've been running the Skyline without even powering up anything on the hexa, so I guess the problem is, as you say, on the stabilization board.
/Pär
ChrisViperM
Active Member
One place is here: http://www.aerialtechnology.com/shop/dji-z15-zenmuse/ ...in the product description....but you also could tell by closer looking at the Zenmuse. (stepper motors mostly have a "short" cylindrical shape) They are relatively cheap, verrrrrry fast and verrrry accurate and beat ANY servo in that regard, but they are not very powerful. The force they can produce is related to their size and the energy you put in, that's why there is the resrictions on the Zenmuse to be only used with certain cameras.
Some interesting reading about stepper motors in general: http://pcbheaven.com/wikipages/How_Stepper_Motors_Work/?p=0
Chris
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My understanding is that the Zenmuse is using brushless motors (of which stepper motors are one variant).
The problem with RC hobby servos (and the variance in suitability of different makes/models) is, IMO, less to do with the motor than the gearing and the feedback mechanism. Any gear system (which includes belt drive) has backlash - a "gap" in the system which is evident each time the motor reverses direction. But the feedback mechanism (usually a potentiometer) is (usually) attached to the output shaft of the servo. This means that the feedback mechanism will "see" the backlash as deviation from the target position and therefore command the motor to correct it. Also, if the camera is off balance it is able to "settle" to one side or the other when it should be stationary and, once again, the feedback mechanism will perceive that rotation as deviation from the target position and attempt to correct it. Hence: the infamous jitters. If there is gearing on both sides of the feedback mechanism then it gets even more complicated. Plus the programmed behaviour of the servo will vary how a given servo reacts to this situation, i.e. some will be more prone to jittering than others.
The obvious solution is to employ direct drive, i.e. connect the load directly to the output shaft of a motor. Bingo! - no backlash, so no jitters. But now the problem is available torque. Even a beefy 500W brushless motor will struggle to supply 0.5kg.cm of torque - equivalent to a tiny micro servo. Which is, I think, the reason for this restrictive behaviour from DJI - the system works brilliantly, but only if the mass/inertia of the load is low and it is perfectly balanced. It will be interesting to see how they can scale this performance up to bigger cameras.
There are other solutions: dual servos in an antagonistic arrangement (i.e. fighting each other slightly in order to "absorb" the backlash), harmonic drive (which has negligible backlash but isn't cheap) and complex anti-backlash gearing systems. I've heard (rumours?) that those sexy looking new PH gimbals use harmonic drive gearboxes.
Interestingly, the Skyline mimics a potentiometer, acting as the feedback mechanism to the connected servos. But, when applied to an AVxxx gimbal there is still gearing involved and therefore backlash. Add the general noisiness of the sensors and you've still got a problematic situation that will need to have the bad behaviour "tuned out" of it.
The problem with RC hobby servos (and the variance in suitability of different makes/models) is, IMO, less to do with the motor than the gearing and the feedback mechanism. Any gear system (which includes belt drive) has backlash - a "gap" in the system which is evident each time the motor reverses direction. But the feedback mechanism (usually a potentiometer) is (usually) attached to the output shaft of the servo. This means that the feedback mechanism will "see" the backlash as deviation from the target position and therefore command the motor to correct it. Also, if the camera is off balance it is able to "settle" to one side or the other when it should be stationary and, once again, the feedback mechanism will perceive that rotation as deviation from the target position and attempt to correct it. Hence: the infamous jitters. If there is gearing on both sides of the feedback mechanism then it gets even more complicated. Plus the programmed behaviour of the servo will vary how a given servo reacts to this situation, i.e. some will be more prone to jittering than others.
The obvious solution is to employ direct drive, i.e. connect the load directly to the output shaft of a motor. Bingo! - no backlash, so no jitters. But now the problem is available torque. Even a beefy 500W brushless motor will struggle to supply 0.5kg.cm of torque - equivalent to a tiny micro servo. Which is, I think, the reason for this restrictive behaviour from DJI - the system works brilliantly, but only if the mass/inertia of the load is low and it is perfectly balanced. It will be interesting to see how they can scale this performance up to bigger cameras.
There are other solutions: dual servos in an antagonistic arrangement (i.e. fighting each other slightly in order to "absorb" the backlash), harmonic drive (which has negligible backlash but isn't cheap) and complex anti-backlash gearing systems. I've heard (rumours?) that those sexy looking new PH gimbals use harmonic drive gearboxes.
Interestingly, the Skyline mimics a potentiometer, acting as the feedback mechanism to the connected servos. But, when applied to an AVxxx gimbal there is still gearing involved and therefore backlash. Add the general noisiness of the sensors and you've still got a problematic situation that will need to have the bad behaviour "tuned out" of it.
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They are direct drive torque motors that actually attenuate the sampled vibration as well as holding the desired angle within a magnetic field. Also it has a clutch drive. They do not step from one position to another but use a rotary encoder. Hence the low torque and the need for perfect balance. This technology has been around for many years now and is used on many mil. spec. devices from gun turrets to target designators. You can find similar examples to the Cineflex drive system on CNC multi axis machine centers. In appearance they look like a pancake T-Motor inside. Higher spec. ones have cross angled poles. It is however possible that DJI convert a stepper motor and just use the motor parts. usually 24 volt systems are employed.
I am currently working on one that uses flat piezo electric motors for a GoPro size mount.
I am currently working on one that uses flat piezo electric motors for a GoPro size mount.
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BorisS
Drone Enthusiast
This is a compilation of shots from a new mount we have co-developed with DJI-Innovations. The Cineron is the world's first fully-stabilized camera gimbal for Remote Control Helicopters.
can someone explain this to me. So DJI has the mounts for bigger cams based on similar technology ? The Hero 3000 equivilant ?
Boris
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I am not aware that they have anything yet, but all it would require is larger motors and more volts. As torque motors get more powerful they get very expensive and have a hollow shaft. The good news is that they are quite closely aligned in production techniques with pancake brushless motors that we already use. I would be surprised if DJI are not already working on that.
DST.Se make some very good gimbals that are mil. spec. They used to have a video that showed one of their own pan torque motors being assembled but they seem to have taken it down. It was hand wound and fairly simple.
DST.Se make some very good gimbals that are mil. spec. They used to have a video that showed one of their own pan torque motors being assembled but they seem to have taken it down. It was hand wound and fairly simple.
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ChrisViperM
Active Member
There is an interesting thread concerning this, especially the comment from Colin Guinn further down in the thread: http://rc.runryder.com/helicopter/t682687p1/
When facts are few bull**** abounds.
As you no doubt saw, I recently used a DJI Zen to complete a UN shoot from a Hughes 500. plenty of people will try to cash in on a cheap system if it works.
Plenty of Cineflex and other stuff around that DJI could have copied. Plenty of Mil.spec. stuff around also using the same technology. My first electronic camera mount was made from an obsolete laser target designator bought at a gov. surplus sale.
DST and a few others have been doing this for quite a few years. But at ten times the price of a Zen.
One of the main restrictions imposed by using this technology is that it infringes on John Doyles patents. Now held by Axis Technology. In most parts of the world, including Cyprus, there is also an imbargo on the import of certain components. It is technically illegal to use a Cineflex here because you can also find one on the front of an Apache.
As you no doubt saw, I recently used a DJI Zen to complete a UN shoot from a Hughes 500. plenty of people will try to cash in on a cheap system if it works.
Plenty of Cineflex and other stuff around that DJI could have copied. Plenty of Mil.spec. stuff around also using the same technology. My first electronic camera mount was made from an obsolete laser target designator bought at a gov. surplus sale.
DST and a few others have been doing this for quite a few years. But at ten times the price of a Zen.
One of the main restrictions imposed by using this technology is that it infringes on John Doyles patents. Now held by Axis Technology. In most parts of the world, including Cyprus, there is also an imbargo on the import of certain components. It is technically illegal to use a Cineflex here because you can also find one on the front of an Apache.
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adarsh_007
Member
WOW! This is great! Made to take the 5D and the epic is sweet! When'll this be available? I want one
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ChrisViperM
Active Member
But isn't it, that at the end of the day all of us couldn't care less who is using which technology and all the rest of the sad stories....I guess anyone of the competing systems will come out first with a workable solution, and that will be the guys who need a big parking space to accomodate the money delivery trucks.....
I'm seeing some horizon issues in that reel. Presumably sorted by now since they don't seeming to showing up on the Zenmuse?
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BorisS
Drone Enthusiast
Minimal horizon issue on the zenmuse after extensive panning around etc. But they are aware and addressing it.
I think we're all sitting quietly waiting for this weekends beta
Sent from my GT-I9300 using Tapatalk 2
+1 :encouragement:
adarsh_007
Member
I've got a AV200 with the skyline. I earlier had installed the 1.1.4 firmware and i was told to go back to the 1.1.3 firmware untill the the new one's out. Hence i flashed teh 1.1.3 firmware but still i dont have the pan after connecting how its supposed to. Am i doing anything wrong here?
I have the tilt and roll stabilisation.
But i have no control over the roll.
No control over the Pan.
How do i get the Pan? Is it ok if i connect the pan servo directly to the receiver instead of going thru the skyline? How're you guys dong it?
Regards,
Adarsh
I have the tilt and roll stabilisation.
But i have no control over the roll.
No control over the Pan.
How do i get the Pan? Is it ok if i connect the pan servo directly to the receiver instead of going thru the skyline? How're you guys dong it?
Regards,
Adarsh
