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Old Oct 15, 2012, 02:27 PM
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>>Hmmm... I was hoping the MIBL's would have less geartrain backlash, and less deadband. Can you comment on that?<<

If you read back a few posts I commented about dead band and my lack of feel for the difference. As far as gear back lash this MIBL servo seems to have a lot less gear back lash than my other servos. especially compare to other metal gear servos.

The great things about something that works. You don't know that it is working right until you switch it to something that doesn't work.

The other issue I have is that I have it on the roll axis. Roll axis is a lot easier to tune than the tilt axis.

>>It's the same thing with multirotor frames. $1500 for 400g of lightweight ultra-strong Carbon Fiber, and then 600g of steel screws and flimsy plastic connectors to fasten it all together.<<

LOL how true.

>>I'd love to do a welded monocoque aluminum frame sometime. If I can get past the fear of crashing ( = total write-off) then I might do it sometime.<<

Yes, that can be a problem. However if you make it simple enough you can always make another one.

Now that the metal gimbal is working I may go back and revisit Blue Sky RC's plywood frame for the 1/2" square alum tube arms. I was really resistant to the idea before because of my prejudice on "metal". So I was substituting all kinds of materials except for the square metal tubes. That's why I have so much lying around.

>>I was shopping for gimbals, ready to drop a chunk of change on one.<<

I was working with Andrey and testing a lot of his earlier prototypes. I have learned a lot about gimbal from those months.

>>Then I saw this great thread on multirotor forums where they're diagnosing a problem on an AV200 and they reveal what junk it is. Bunch of cut CF plate with flange bearings simply pressed in, not retained in any way.... The bottom camera mounting plate that has slots milled out of it is like a spring-board... Guys bolting blocks of 1/8" FR4 on top of the plate to stiffen it. Felt washers sandwiched in the joints to hold the bearings in place and dampen the free play, which then creates sticktion. What a nightmare.<<

Unfortunately companies have over head and need to make a living and therefore profits. So that pretty much put them behind the power curve and they are forced to come up with "newer" and "improved" products all the time just to stay in the game. Some times being an "enthusiast" is more beneficial because the stake is not as high. So we can really think outside the box and test concept against conventional wisdom. That's where a lot of innovations can really happen.

>>A big part of the problem is everybody insisting on flying with a 2kg camera, and then wanting to save weight on the gimbal. I think the gimbal should weigh at least as much as the camera. How could it not?!<<

To a degree if you can do a light gimbal for a heavy camera if you use the mass of the camera as part of the gimbal. Then again "light weight" is only relative. I think you are right about the gimbal and camera weighing the same. You need at least a 300 grams gimbal for a 300 grams camera and so forth. That's actually a very good goal.
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Old Oct 15, 2012, 02:47 PM
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To a degree if you can do a light gimbal for a heavy camera if you use the mass of the camera as part of the gimbal. Then again "light weight" is only relative. I think you are right about the gimbal and camera weighing the same. You need at least a 300 grams gimbal for a 300 grams camera and so forth. That's actually a very good goal.
Yes, it would be nice to use the camera frame itself as part of the gimbal. You could basically eliminate the tilt tray completely if the camera body had some sort kind of support points on the two sides. But, we're stuck using cameras that are designed to be mounted on tripods.

It would be fun to try de-casing a camera, and putting the guts into a 3d printed housing...

I've also wanted to try 3D printing an exo-skeleton for a camera, for crash protection, and then you could implement tilt mounts on the side too.

Look at the AV200, it's 590g with servos, designed to support a 1000+g camera.

The only way you can pull that off, I think, is with a very expensive CNC cut gimbal (Zenmuse), or even more expensive carbon fiber monocoque gimbal ( PH Hero).

You're not going to get there with flat plate. A least if they used CNC cut aluminum bulkheads between the CF plates, that would really stiffen them up. But just using round aluminum spacers, you have a structure that is weak in twisting.
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Old Oct 15, 2012, 03:31 PM
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>>Yes, it would be nice to use the camera frame itself as part of the gimbal. You could basically eliminate the tilt tray completely if the camera body had some sort kind of support points on the two sides. But, we're stuck using cameras that are designed to be mounted on tripods.<<

It is but not anytime soon.

>>It would be fun to try de-casing a camera, and putting the guts into a 3d printed housing...<<

I took apart a couple of cameras before and no think you. I will never put it back together.

>>I've also wanted to try 3D printing an exo-skeleton for a camera, for crash protection, and then you could implement tilt mounts on the side too.<<

Actually that is very possible but we may have to pay a bit of penalty in weight.

>>Look at the AV200, it's 590g with servos, designed to support a 1000+g camera.<<

I don't like that design. Same with DJ Vegh's gimbal and the one from Turkey. It is extremely difficult to get the roll cage to move smoothly on the bearings without play. That's why I have decided to pay the price of a cantilever design and use a shaft for the roll axis.

>>The only way you can pull that off, I think, is with a very expensive CNC cut gimbal (Zenmuse), or even more expensive carbon fiber monocoque gimbal ( PH Hero).<<

The Zenmuse has a very rigid design with the cantilever roll axis. They also use metal. Their success is mostly because of the good motor on the servo and probably a very good controller.

>>You're not going to get there with flat plate. A least if they used CNC cut aluminum bulkheads between the CF plates, that would really stiffen them up. But just using round aluminum spacers, you have a structure that is weak in twisting.<<

That's where your exoskeleton design comes in real handy. A tube cage to encase the camera will be real nice. For that matter two tubes as camera tray like the Andrey's design is pretty stiff.

For a larger size Rusty is thinking about using a square tube and a small stiff plate for camera tray. That is super rigid. The only issue I have with that is the offset thumb screw location for the camera tripod hole. If the user uses a longer and/or heavier lens and off set the camera a bit back that should be a non-issue.
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Old Oct 15, 2012, 03:38 PM
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well, it is not cheap to develop a gimbal that works well. Seismic can tell you how much work was done to get ag550 to where it is and I am continuing to work on improvement. I have discussed lot of the issues and shared lot of test result with him over last few month. In many ways though, this thread is from what's been learned, since lot of the basic concept is same as what is in ag550. People can talk about lot of things, but creating a quality product at reasonable price is not easy even with all the knowledge. In general though, people don't mind paying reasonable price for something that works. Heck, most have enough issues with setup much less building them.

In all honesty, it is really rare for enthusiast to come up with usable end products. rarely focused enough or have resources to get through the challenges to go from ground up to finished products. but I have found that enthusiast can provide many good ideas, which is good thing too. why I don't mind sharing ideas.
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Old Oct 15, 2012, 03:44 PM
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My latest update on the gimbal tests. Video is uploading on YouTube right now and I will post a link once it is done.

It is done:

20121015 2 axis metal gimbal third test NEX 5 (2 min 8 sec)


BTW the video was captured with my old NEX 5 and not the NEX 5N. The 5N is in the ocean.

In the meantime the roll axis is as good as it gets. I have zero complaint on the roll.

I still have issues with the tilt axis. It is good enough for me but I am sure there are others that want the camera to "follow" so you cannot see the tilt movements.

Right now I don't know what it is. It may be because the external pot is creating too much servo travel and slowing down the servo speed. I am using a CC3D board as flight control and gimbal control (that in itself may be an issue). I can get the servo to follow for a short duration then it over shoots.

So my next test is to use a servo with either 180 degrees travel, 120 degrees travel and/or 90 degrees travel. Too bad all my servos now have external wires for the external pots. So I have to acquire more servos to test. That will take time because of money.

If eliminating external works I will gladly live with the reduced tilt travel. I figured I cannot have my cake and eat it too so I have to compromise a bit. The issues I foresee are these:

1) Tilt stabilization is just that a bit of active damping to eliminate and/or reduce tilt movements from wind gusts. As such, we may not be able to have tilt stabilization and 90 degree of travel or more. So I have to live with the reduced travel.

2) To work around we can plan our flight to either shoot oblique angle or plan view. Then we adjust the tilt angle prior to take off to serve the purpose.

3) Tilt stabilization is mostly useful only for shooting video. So a smaller tilt travel may not be much of an issue. Unless some one insist on rotating the camera for greater than 90 degree during one flight. That may very well be off the scope of this project anyway.

4) To accomodate the tilt stabilization and a greater than 90 degree of tilt travel, we may have to redesign the gimbal to use two servos. One servo to serve as stabilization and another one to use as tilt travel.

So those are my thoughts. You are welcome to add, subtract or ignore.

As far as the gimbal structure I believe that it is simple and definitely functional as the thread title said and I see no major reason to change the design right now. Maybe small refinement as time goes on with more people trying it out and coming up with innovations.

As far as gimbal controller, we are sorely lacking. I may just have to bite the bullet and go on the waiting list for a HoverFly.
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Old Oct 15, 2012, 03:58 PM
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>> it is not cheap to develop a gimbal that works well. Seismic can tell you how much work was done to get ag550 to where it is and I am continuing to work on improvement. <<

Oh yes! For those that don't know I have been working with Andrey from the beginning after he came back from his hiatus.

>> I have discussed lot of the issues and shared lot of test result with him over last few month.<<

We exchanged email almost every day to talk about our trials and tribulations.

>>In many ways though, this thread is from what's been learned, since lot of the basic concept is same as what is in ag550.<<

That is exactly what this thread is about. The spark really came when Andrey used a round aluminum for the vertical post on his gimbal. That planted the seed. I have testing most of Andrey's prototypes gimbals. I have enough parts from him to assemble many gimbals. Unfortunately a lot of the parts don't fit together because of the continue improvements on the design.

One day Andrey decided to use boom blocks as the building blocks for his camera tray. I have a lot of boom blocks from Rusty and Quadframe. So I started experimenting and that resulted in the manual tilt camera gimbal that Rusty has.

Then one day I was looking for a roll mechanism for a prototype Andrey gimbal. I decided to use some boom blocks. One thing led to another and you saw how I came up with the carbon tube frame at the beginning of this thread.

The pulleys and ratio is a direct result of Andrey's research.

Then Rusty threw in a monkey wrench by suggesting using 1/2" square aluminum tubes. I was dead set against it and continued with the carbon tube built.

Then I remembered Andrey using the 1/2" aluminum tube on his gimbal and figured the short section of metal will not increase the weight too much. Then the rest is history. Now Rusty has a prototype that is less than 500 grams with 10mm square aluminum tube. I think that is what I call innovation from collective ideas.

>> People can talk about lot of things, but creating a quality product at reasonable price is not easy even with all the knowledge.<<

Price and quality is directly proportional.
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Old Oct 15, 2012, 04:53 PM
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I do think thread like this is good for the community to share ideas. heck, I learn just by reading other threads all the time. but you also have to do lot of tests. I get best improvements when i do my own test. that is for sure and sometimes, I have to make time to test. sigh. never enough time to do everything. that is for sure.
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Old Oct 15, 2012, 05:57 PM
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In general though, people don't mind paying reasonable price for something that works. Heck, most have enough issues with setup much less building them.
I agree. I was ready to drop up to $1000 on a robust gimbal that performs well. But, nothing in the market satisfied me.

Same deal with frames, so I've just made my own design for an Octo.
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Old Oct 15, 2012, 06:51 PM
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Hansen, it sounds like you would benefit from the HF Gimbal's ability to change the servo acceleration.

My big reasons for wanting a gimbal:

1) Stabilization for windy situations - doesn't have to be perfectly smooth. I would just like the option to film with reasonable chance to get usuable footage when it's windy/gusty
2) Stable horizon (roll) - annoying when you are trying to take pictures (especially panoramas) and your roll is off.
3) Ability to command an tilt angle - ideally up to 90 degree down. Also annoying to have to land to adjust tilt.
4) 2nd person operation (eventually) - requiring a pan-axis option. This DIY gimbal should be easy enough to add the pan option to

I have been practicing a lot with the rusty/hansen static camera mount and my T2i. I have been getting usable footage almost every time I go up. Recently, I improved my isolator layout, added a few more fasteners to take out some slop, and centered the camera CG a bit more, almost ridding me of all wind and FFF induced bounce

I know that the ultimate goal would be a "zen-like" experience where it doesn't matter how you fly. However, I have been practicing flying smoothly, and I feel with my current setup + a decent gimbal, my footage and still quality will go up considerably.

Currently this "best" results that I personally have seen - when you throw the zen out of the comparison go like this:

1) Cinestar footage - caveat: most if not all of the videos I have seen were flown, filmed, and edited by real pros. I am not sure how much raw footage there is out there with those gimbals. Plus, a lot of those guys are now using the CX760 because of the BOSS stabilization.

2) AG550/AG700 w/CX760 (or equivalent) - caveat: this camera plays a big roll in smoothness. It's expensive unfortunately.

3) AG55/AG700 with NEX or similiar - getting better with recent releases. Love the fact that these guys are willing to fly aggressively to give worst-case scenario performance.

Another dark horse is the direct drive AV200 that coming out soon. The only test video that I have seen is on par with the zen, though not quite there. I have been in contact with Kim Attwell (owner), and they are going full-steam ahead on it right now. It's probably going to be out of my price range though, unfortunately.

Reason, I like this thread and the possibility of a Rusty kit is three-fold:
1) Relatively cheap. I am guessing sub 500 with good servos.
2) Will work nicely with my already setup isolator scheme. May have to adjust, but I know it works out already.
3) Highly adjustable for any camera I may want to try.
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Old Oct 15, 2012, 07:43 PM
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>> it sounds like you would benefit from the HF Gimbal's ability to change the servo acceleration.<<

I am almost certain that I will. I am just waiting for the right time to pull the trigger. In the meantime I am trying my best to tune the CC3D.

>>1) Stabilization for windy situations - doesn't have to be perfectly smooth. I would just like the option to film with reasonable chance to get usuable footage when it's windy/gusty<<

The AG550/700 and this metal gimbal will definitely do the job well.

>>2) Stable horizon (roll) - annoying when you are trying to take pictures (especially panoramas) and your roll is off.<<

Look at my latest video footage. The roll is definitely a non issue now.

>>3) Ability to command an tilt angle - ideally up to 90 degree down. Also annoying to have to land to adjust tilt.<<

I am still working on that. Once more people are playing with the better gimbals more ideas will come forward.

>>4) 2nd person operation (eventually) - requiring a pan-axis option. This DIY gimbal should be easy enough to add the pan option to<<

That is beyond my scope since I can't seem to have a consistent assistant to work my schedule.

I have been practicing a lot with the rusty/hansen static camera mount and my T2i. I have been getting usable footage almost every time I go up. Recently, I improved my isolator layout, added a few more fasteners to take out some slop, and centered the camera CG a bit more, almost ridding me of all wind and FFF induced bounce

>>1) Cinestar footage - caveat: most if not all of the videos I have seen were flown, filmed, and edited by real pros. I am not sure how much raw footage there is out there with those gimbals. Plus, a lot of those guys are now using the CX760 because of the BOSS stabilization.<<

The bulk of them are either stabilized with software or slowed down by shooting at 60 fps and play back at 30 fps or as you mentioned shot with a BOSS.

>>2) AG550/AG700 w/CX760 (or equivalent) - caveat: this camera plays a big roll in smoothness. It's expensive unfortunately.<<

Exactly, I have a BOSS also but using that to test the gimbal is not doing any good.

>>3) AG55/AG700 with NEX or similiar - getting better with recent releases. Love the fact that these guys are willing to fly aggressively to give worst-case scenario performance.<<

That's where I am at. The AG550 and 700 are definitely very capable as are these metal gimbals Rusty and I are testing. The whole idea is simply to make a gimbal with the highest rigidity. The rest will fall into place.

>>Another dark horse is the direct drive AV200 that coming out soon. The only test video that I have seen is on par with the zen, though not quite there. I have been in contact with Kim Attwell (owner), and they are going full-steam ahead on it right now. It's probably going to be out of my price range though, unfortunately.<<

I am still not sold on that design yet.

>>1) Relatively cheap. I am guessing sub 500 with good servos.<<

Exactly the whole point of this thread. You build a good rigid gimbal at a reasonable cost then you spend as much as you want on the servos.

>>3) Highly adjustable for any camera I may want to try.<<

That is turning out to be the case. As Rusty have it the gimbal is totally scalable.
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Old Oct 15, 2012, 08:13 PM
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I just completed the fourth test on the metal gimbal. The tuning is getting pretty close. I am still using only 5V on the servos and I intend to bump it up to 6V. That would smooth things out a little more. In the meantime the roll tuning is just fine in my opinion and the tilt tuning is also there. I reduced the servo travel as much as possible. I still get close to full vertical downward looking camera. Very close to 90 degrees. I purposely let the servo lag just a tad for now. By the time I up the voltage it will be just right. I can see a major reduction in tilt movement. I am not going to load this video because that just takes up space and it gets boring.

I am going to see if I can rig up a wire in front of the camera so you can see how much movement the camera is doing compare to the image you are seeing.

In the meantime if anyone is interested I am attaching a screen shot of the values on my Open Pilot GCS for the CC3D board. This is only for the gimbal control

I think the only one using the CC3D right now is Matt. Rusty will probably use his when he is ready to fly.
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Old Oct 15, 2012, 10:24 PM
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On my previous gimbal I had the roll axis pretty good as well, I think it was set at about 25. The pitch axis was decent but not great and I think it was at about 70, like you I was just trying to get a very small / subtle amount of movement out of it. Once I get my hexa back together I will give your numbers a try and see how they do.

Also, the reason you still have so much range on the pitch axis with manual control is thanks to the settings under Advanced Settings (control), which let you manually override the limits of the stabilization settings. I know you probably already know that, just sharing for those who didn't.
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Old Oct 15, 2012, 10:55 PM
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Originally Posted by mattchase View Post
Also, the reason you still have so much range on the pitch axis with manual control is thanks to the settings under Advanced Settings (control), which let you manually override the limits of the stabilization settings. I know you probably already know that, just sharing for those who didn't.
Thanks for the heads up. I need to explore a bit more. I am thinking about getting the latest software to try. Sounded like it is working. I really want to fix the mixing value issue so I don't accidentally screw up.

New video is uploading right now. It is pretty neat.
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Old Oct 15, 2012, 11:05 PM
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Seimsec what happened to you NEZ 5N?
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Old Oct 15, 2012, 11:17 PM
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Ok ladies and gentlemen. Here is test number 5:

20121015 2 axis metal gimbal test 5 (1 min 58 sec)


Some one suggested earlier that I put something in front of the camera to reference the position of the frame. So I put a ball with carbon rod. It worked pretty well I think.
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