DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Stabilizers (Steadicam etc.) (https://www.dvinfo.net/forum/stabilizers-steadicam-etc/)
-   -   Newbie needs Stabilizer help! (https://www.dvinfo.net/forum/stabilizers-steadicam-etc/43172-newbie-needs-stabilizer-help.html)

Matthew Wilson April 18th, 2005 01:54 PM

Newbie needs Stabilizer help!
 
Hi all,
I just received a Magiqcam IIa about two weeks ago and have been starting to get my feet wet with the unit. In the short time I’ve been able to play with it, it has become clear that everything I’ve read about practice and sticking with it is true. I’ve been reading a lot of the posts and discussions about stabilizers here and looking at demo’s and such and I can now really appreciate the skill that’s required. I even got my wife to watch ER so she can see what really good Steadicam work is like. Now whatever we watch, she’s asking me, is that one? What’s that? How did they do that? Can’t watch anything the same anymore.

I also really appreciate the fact that so many of you are willing to spend your valuable time sharing and helping one another. I’ve gathered a lot of helpful info on stabilizers as wellas other topics from reading the discussions here. It’s really helped me to get a handle on some basic issues like getting my system rigged together so that it’s got pretty good static and dynamic balance. So now I was hoping (read that "begging") that some of you may be able to help me with some tips on actually flying the rig.

Since I got the dynamic balance working okay (though not as good as I think it should be) I think I’m getting a little better feel for it, but the one thing that is driving me crazy right now is that I’m getting a lot of “pogo-ing” up and down. I read some discussions where Charles Papert said that this was most likely operator error, but could also be due to friction in the arm. Can anyone shed some more light on this? Is there a specific technique that will help reduce or eliminate footsteps? I know practice is what is really needed, but I sort of feel like I’m in the dark as to what the proper technique I should be practicing is. I would love to find a workshop, but a recent one in my area got cancelled.

I do sort of suspect that friction may also be a part of it, since the pogo-ing seems to have gotten worse since I received the unit. What part of the arm would this be coming from? The manual for the Magiqcam says to lube it, but it does not tell you where or with what. I’ve got an email in to John about this. I also noticed some shake and jittering when running that didn’t seem to be there a week ago. Any suggestions would be greatly appreciated.

I’m flying an XL2 with several configurations. Mostly with a matte box and wireless, though with different lenses. I’ve tried different drop times. 2 to 2-1/2 seconds seems to work best for me right now. I’ve tried various settings for the arm springs and while it can make a difference to the overall feel, it doesn’t seem to make much difference to the pogo-ing effect.

Is Charles Papert’s training DVD available yet?

Thanks all,
Matt

Leigh Wanstead April 18th, 2005 04:04 PM

Hi Matt,

Can you post a demo video on internet to see what your problem is?

Regards
Leigh

Matthew Wilson April 18th, 2005 09:50 PM

Thanks Leigh - here are a couple short examples. They are short, but I think you can see what I'm talking about. The bouncing as was said before is most likely user error. Maybe I need to learn to walk again. Thanks for taking a look.

http://www.jewsfortruth.org/test-vid...ing-test-1.mov

http://www.jewsfortruth.org/test-vid...ds-w-shake.mov

Charles Papert April 19th, 2005 12:50 AM

Matt:

The first video looked quite good (in fact, very good, for 2 weeks into your stabilizer career!) The pogoing I'm seeing, which is slight, is probably a combination of the arm and what you are doing with it. I would recommend "de-tuning" your arm (let some of the spring force out of it) so that both sections tend to hang a bit below horizontal, so you have to hold it up a little with your arms. Understand that the design of the Magiqcam arm is not the same as a "pro" rig, which it isn't going to be for the money, and so it will present a bit more bounce. Detuning will help with this. A smoother step, a la the "handheld shuffle" will help also. A bit more force with the hand that is resting on the gimbal handle (not the post) to maintain the height of the system is another way through this.

The second video is more troubling. You are experiencing vibration in your rig somewhere. Lift the rig off the dock without vest and arm, and give it a little shake. See if you can isolate which component is exhibiting a bit of play. Could be in the camera mounting; make sure it is tight to the top stage; if you see it lifting off the top slightly, stick a wedge or two in there to shim it up to remove the play. Make sure all of the lockable parts in the sled are good and tight.

Haven't made the video yet, but I'm hoping in the next few months...stay tuned.

Matthew Wilson April 19th, 2005 10:28 AM

Thank you Charles for the quick reply. I'll try your suggestions and see if that improves the bouncing at all. It's not so bad when objects are not very close to the lens, but I've got some tight interior stuff I need to do in the near future and that could be a problem.

What is the major difference in arms between the lower end systems and the more pro rigs? Is there a major design difference or is it components and tolerances etc.? I had seen you mention non-linear versus linear designs, but I haven't found the explanation of what the differences are?

As far as the vibration goes, I think I've located the source. Unforntunately, it does not look good. The i.d. of the gimbal bearing post appears to be aorund 10 mils larger than the o.d. of the sled post. The gimbal fastens to the post on the lower end via a friction clamp. When the clamp is tightened, there is still play between the horizontal gimbal bearing and the sled post at the top of the gimbal. I think this is also why I'm not able to get the dynamic balance setup as good as it should be. When the gimbal clamp is tight, it causes the post to sit slightly offset where it meets the horizontal bearing. Anyway, a picture is worth a million words here. Maybe you could take a look at this and tell me what you think?


http://www.jewsfortruth.org/test-video/gimbal-play.mov

Anyone else with a Magiqcam see this problem? Is this how they are all made?

I tried placing a piece of aluminum tape on the post as a shim. It actually takes up about 80 percent of the play; however, I now can't seem to get it into dynamic balance again. Kind of frustrating. Any suggestions?

Much appreciated,
Matt

Charles King April 19th, 2005 12:53 PM

Matt, I'm sorry to hear. Judging by that small clip of your gimbal, i'll say you have a problem! Yep, sorry to say but that gimbal, AKA bearing should not have any gap. That will defeat and will definately hamper your operation.

Now that is probably why you are expericing some of your problems. That is no good. It seems John is not being particularly careful on these parts. The gimbal makes up about almost 50% of the stability of the stabilizer, why doesn't he take more care?

Matthew Wilson April 19th, 2005 02:15 PM

Thanks for taking a look Charles. I think you have confirmed my worst fear.
Is there a standard diameter for the post or gimbal tube? I've seen 1.5 inches somewhere, but obviously there has to be a a small difference in the two parts so that they can slide together, but I would think 1 to 2 mils would be more appropriate. Is that how other units are made?

Charles King April 19th, 2005 02:25 PM

Quote:

Originally Posted by Matthew Wilson
Thanks for taking a look Charles. I think you have confirmed my worst fear.
Is there a standard diameter for the post or gimbal tube? I've seen 1.5 inches somewhere, but obviously there has to be a a small difference in the two parts so that they can slide together, but I would think 1 to 2 mils would be more appropriate. Is that how other units are made?


...it will depend on the inner diameter of the actual gimbal being used. Are you planning on exchanging it for a new one or rebuilding the post? I suggest sending it back but judging by what I've been reading about the bad rep others have been having I would be very hesitate. I know one person who has been having bad luck is Ed. I think you've read his thread. Any way, What are you willing to do? first question?

Leigh Wanstead April 19th, 2005 03:01 PM

Quote:

Originally Posted by Charles King
Matt, I'm sorry to hear. Judging by that small clip of your gimbal, i'll say you have a problem! Yep, sorry to say but that gimbal, AKA bearing should not have any gap. That will defeat and will definately hamper your operation.

Now that is probably why you are expericing some of your problems. That is no good. It seems John is not being particularly careful on these parts. The gimbal makes up about almost 50% of the stability of the stabilizer, why doesn't he take more care?

I watched the gimbal video too. I agree with Charles King that bearing should not have any gap. I think that you better return back to the seller at least that you have one year warranty.

Regards
Leigh

Matthew Wilson April 19th, 2005 03:42 PM

I've sent John an email regarding the issue and called over there but apparently he's at NAB, so I suspect I won't be hearing back from him too quickly. I think I read in someone's post that they are displaying a "new" Magiqcam model. Maybe it's got a correctly sized gimbal and post. I did read about all Ed's problems, but I kind of got the impression that some of it was resolved. Funny thing is, I have not seen any other comments with regard to this particular problem, which sort of makes me think that I might have got a "special" one, except that the two mating surfaces appear to be manufactured to that size and not machined by John, so I would think that all of his rigs would be that way. The unit is supposed to have a two year warranty, so I definitely want to get this problem resolved with the manufacturer.

As far as what I'm willing to do, well, so far I shimmed it with some aluminum tape and I'll see if that helps stop the shaking, but now I'm having trouble getting the thing into dynamic balance. I can get it in static balance easily, but if I rotate it 180 degrees, it drops out of balance. Seems that maybe the gimbal bearing is not truely aligned. In fact, I'm wondering if it wasn't aligned in combination with the tilt induced by the gap so that it can't be aligned when the tilt is removed! Besides Advil, any suggestions on dealing with this?

As always, comments and suggestions are much appreciated.

Ed Liew April 19th, 2005 08:49 PM

after reading your post, i checked my gimbal and it has the same problem. let me know if you have any luck getting john to reply. i'm not getting any.

i'm having the same pogoing effect flying the rig. have tried all the different setting but still have the problem. since i can't get it right, i concluded it must be my fault.

ed

Leigh Wanstead April 19th, 2005 09:38 PM

Quote:

Originally Posted by Ed Liew
after reading your post, i checked my gimbal and it has the same problem. let me know if you have any luck getting john to reply. i'm not getting any.

i'm having the same pogoing effect flying the rig. have tried all the different setting but still have the problem. since i can't get it right, i concluded it must be my fault.

ed

Hi ed,

I think there is no way that you can train yourself to overcome this gap problem while you are operating your stablizer. The only way to solve it is by removing that gap.

Regards
Leigh

Leigh Wanstead April 19th, 2005 09:45 PM

Quote:

Originally Posted by Matthew Wilson
What is the major difference in arms between the lower end systems and the more pro rigs? Is there a major design difference or is it components and tolerances etc.? I had seen you mention non-linear versus linear designs, but I haven't found the explanation of what the differences are?

Hi Matthew,

The major difference is how much weight the arm can handle. You will see significant price jump above some weight support range of the arm.

Regards
Leigh

Matthew Wilson April 20th, 2005 01:09 AM

Hey Ed,
Are you able to get the rig to balance properly? Try just taking a piece of tape and wrapping the post where the bearing sits. Iv'e used some thin aluminum foil tape and another 1 or 2 mil think plastic tape over that and now it fits pretty snug, but I think that the either the bottom of the gimbal is out of wack or the the bearing is not true, because I can't get a decent dynamic balance and I still get some jitter. The lower the gimbal (the longer the drop time) the worse it gets. Are you saying that John has not answered any of your emails lately?

The bounce is really difficult but I don't think it is related to the gimbal/post problem. I'm not sure how much of it has to do with the arm, but I think a lot of it has to do with my walking. Small shifts in weight and any little elevation change at the hip moves the camera. Maybe I need to try roller skates! Hey, anyone tried that? A human dolley with a stabilizer?

Leigh, I sort of have to believe it's more than just weight. I imagine tolerances and materials play an important role. Don't some of the higher end designs use cables and springs?

Does your rig have a sliding gimbal. Does it sit firm on the post?

thanks for the replies,
Matt

Leigh Wanstead April 20th, 2005 02:07 AM

Quote:

Originally Posted by Matthew Wilson
Leigh, I sort of have to believe it's more than just weight. I imagine tolerances and materials play an important role. Don't some of the higher end designs use cables and springs?

Hi Matthew,

You are right.

Precision engineering work is very important and that cost huge money. And I heard someone said that arm cost half of the package IIRC.

Regards
Leigh


All times are GMT -6. The time now is 02:59 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network