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Old Feb 12, 2013, 05:51 PM
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Quote:
Originally Posted by BJM-Maxx View Post
I think your post is very much on topic. I am curious how you made the graph.
I'm flying with this controller https://groups.google.com/d/msg/phoe...k/fHG2YCuajhsJ

It logs all the data from the flight. Pretty fun for doing this kind of analysis. More playing here https://groups.google.com/d/msg/phoe...o/8uJrkUelQSUJ
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Last edited by peabody124; Feb 12, 2013 at 05:52 PM. Reason: I accidentally a letter
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Old Feb 12, 2013, 06:00 PM
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>>Sorry, that's almost OT but I had the data up and saw your post.<<

I like hard data like those. Now help us interpret them.
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Old Feb 12, 2013, 06:01 PM
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Quote:
Originally Posted by mattchase View Post
I don't think any discussion of vibrations is off topic for us. Plus if we can narrow the worst vibes down to specific frequencies then maybe that will help dictate what type of isolation material would work best.

Besides the graphs are pretty to look at. In a scientific way of course.
I agree! More of these hard data will help us isolate better.
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Old Feb 12, 2013, 06:05 PM
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The main interpretation of that data would be that _most_ of the time the dominant frequencies do not shift around, but they do occasionally. However, I wouldn't want to claim the results will be the same under:

1) more aggressive flight
2) at the gimbal after the vibration isolation
3) with a large frame (this one is a very light frame running 8" props)

Also it hasn't merged yet but Kenn has written some nice code that can runs this in real time on CC3D / FlyingF3 so once that is merged in people using Tau Labs on those those as a gimbal controller will be able to get hard numbers on the affects of various damping materials - which will probably be of more interest to you guys.
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Old Feb 12, 2013, 07:00 PM
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So I would hazard to guess that there are three frequencies of primary interest. In no particular order. The motor rpm at hover, the blade passing frequency, and resonance of an arm if you plucked it like a tuning fork and let it vibrate. Harmonics and beat frequencies would be next.

In Peabody's data, seeing a peak at 75 Hz corresponds to 4500 rpm, is that the hover rpm? Next, a peak at 140 Hz, was the prop a two blade?

Dan
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Old Feb 14, 2013, 10:37 AM
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Joined Dec 2010
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Rusty,

Can you custom drill some motor mounts for me? Im making my self a couple of the brushless gimbal controllers and wanted to piece together a gimbal. Anywho ill shoot you an email.
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Old Feb 14, 2013, 10:12 PM
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Hi Seismic,

Following this thread for a long time & impressed with the discussions.

I want this type of mount for DSLR. Can you do that?
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Old Feb 15, 2013, 01:47 AM
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Quote:
Originally Posted by joshidharmesh View Post
Hi Seismic,

Following this thread for a long time & impressed with the discussions.

I want this type of mount for DSLR. Can you do that?
Yes you can but you have to do your homework. Jcmonty is taking up his Canon T2i in the air with this gimbal. His footage looks really good.

I have been taking my Panasonic GH2 up in the air occasionally. It works fine.

That said you have to choose your servo properly. A heavier payload means a stronger servo because of inertia. Balancing the camera on the gimbal is a definitely requirement. I didn't balance mine and suffered the consequence. Not really bad footage but definitely not the best.

The gimbal itself is more than rigid enough for a medium size DSLR. If you plan to take up a heavy camera like the Canon 7D or 5D Mk 2 or 3 you need to plan to use 1/2" square tubing and top of the line servos.

The 10mm tubes are good to 700 grams to 800 grams camera plus lens.
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Old Feb 15, 2013, 02:13 PM
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First - thanks to Seismic and everyone else who's been sharing their experience on this thread.

I've just ordered the parts to build my first 'real' multirotor after a few weeks of practicing with a Blade MQX.

I'll be building with:
- Rusty UAP2 frame in Y6 configuration
- 13 inch arm and leg tubes
- UAP 8 Damper Kit
- Avroto 2814 & 30A ESC
- APC 12x3.8 slow flyer props
- And of course - UG-1 Full Kit 2-axis gimbal, 10mm tubing and UG-1 floating plate.
- I also just picked up a OP CC3D from the classifieds on here with bluetooth and spektrum adapter.

Most of this I gathered as good options from reading this and other threads.

I'll be carrying a GH3 with 20mm lens that weighs in at about 650g. Primary goal is shooting still photos with single operator and also some video but I'm not expecting the smoothest video from this rig at first, just good enough to practice my flying mostly.

What's the latest experience on servos that would fit my needs, I'd like to get a set ordered soon. I realize the 'best' is likely yet to be, but something that would be a good start for me?

Any other suggestions on what I'm going to need to make this kit work?

Thanks again for all the knowledge sharing.
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Old Feb 15, 2013, 04:31 PM
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Camera plate for GoPro, just big enough for NEX5

Quote:
Originally Posted by R_Lefebvre View Post
Nice! Could you dimension the total grip thickness, and locate the shutter button?

I have added the NEX-5 dimensions according to the 3D-Data from GrabCAD Ė someone with one of these cameras will have to check if necessary. I donít know if the nodal point is really of interest, seeing as perhaps 90% of the people in this thread probably donít need exact pan effects. Probably the mass-midpoint is more important, which I can add in if someone measures it out (with the 1mm lens).


So I would like to present a camera plate draft into the discussion, and am hoping for some helpful criticism:

I presume that most people with this kind of a gimbal want to mount something from GoPro HD size (170g incl. housing & battery) to NEX5 size (355g with 16mm lens & battery).
Heavier camera systems will need specialized servos. Brushless direct drive gimbal versions being developed probably canít handle anything more (hopefully I am wrong)

Camera plate for GoPro, just big enough for a NEX5:
*rubber-band mount slots for GoPro2 and GoPro2 3
*holes for NEX5 mounting (lens axis is not in line with the roll axis)

Plate thickness I do not want to specify, as this is dependant on material want or available.

I donít really understand why GoPro doesnít have a weight optimized ľ thread mount option.
Of course there is a Shapeways option, but my rubber-band slots donít allow a thread hole in front of the GoPro lensĖ I think on my next version I can improve on that.


EDIT: the 19.05mm (3/4") spacing is if you are using clamping blocks with 3/4" hole spacing. I will relase an updated PDF and DXF end of next week, so I can add in any features if there are suggestions.
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Old Feb 15, 2013, 07:56 PM
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Quote:
Originally Posted by SeismicCWave View Post

That said you have to choose your servo properly. A heavier payload means a stronger servo because of inertia. Balancing the camera on the gimbal is a definitely requirement. I didn't balance mine and suffered the consequence. Not really bad footage but definitely not the best.
Agree with you on the balance being necessary. After testing my one sided gimbal (unbalanced) for a couple of months no matter how strong the roll is it is always faster going down on the tilt mech side than coming up. Makes it tough to tune. On the bright side I will be installing a balance arm on my gimbal while I work with another gimbal controller on the SCW gimbal. For me it takes a 132g of weight opposite the tilt mech to balance the roll. That did surprise me but guess I was just thinking about the 62g servo and not the rest of it.
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Old Feb 15, 2013, 09:27 PM
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>>For me it takes a 132g of weight opposite the tilt mech to balance the roll. That did surprise me but guess I was just thinking about the 62g servo and not the rest of it.<<

Wow!! That's some weight. I think I am going to start making my gimbals larger again and try to see if I can shift the camera to balance. I am doing pretty well with the Sony NEX series. The battery on the camera tends to balance out the tilt servo weight.
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Old Feb 15, 2013, 09:33 PM
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follows a video with various scenes using rusticwave gimbal. I'd like opinions

http://www.youtube.com/watch?feature...&v=IBR1Nk7z-UE
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Old Feb 16, 2013, 01:29 AM
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Quote:
Originally Posted by Rasec View Post
follows a video with various scenes using rusticwave gimbal. I'd like opinions

http://www.youtube.com/watch?feature...&v=IBR1Nk7z-UE
Nice work and great video!!! What controller and servos are you using? I can see a tiny bit of roll twitch. Are you using a "Pug bar"?
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Old Feb 16, 2013, 06:55 AM
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Quote:
Originally Posted by SeismicCWave View Post
>>For me it takes a 132g of weight opposite the tilt mech to balance the roll. That did surprise me but guess I was just thinking about the 62g servo and not the rest of it.<<

Wow!! That's some weight. I think I am going to start making my gimbals larger again and try to see if I can shift the camera to balance. I am doing pretty well with the Sony NEX series. The battery on the camera tends to balance out the tilt servo weight.
What I did was offset the gimbal on the roll servo. . . It did 2 things: centered the lens on the roll axis and got the balance set nicely. . I'll try to get y'all a pic in a bit.
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