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Help: My Zephyr can no longer be dynamically balanced


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#1 Alan Rencher

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Posted 28 April 2013 - 11:50 PM

I noticed when I was on set yesterday that my Zephyr sled was no longer holding dynamic balance. I was able to get through the day with static balance, and I took my day off (today) to try to figure out where the problem was coming from.

 

I completely stripped the sled of all components, and proceded to do a quick-Mickey balance. I could not get it to balance properly. I can get it to do a side-to-side balance, but when i turn the post 180º (while still in horizontal), the sled spins back over to the other side, falling back into the initial static balance.

 

I checked with a straight edge to see if the post was bent, but it doesn't look like it is. What could be the problem?


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#2 Eric Fletcher S.O.C.

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Posted 29 April 2013 - 12:01 AM

gimbal issues 


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#3 Alan Rencher

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Posted 29 April 2013 - 12:19 AM

It does it even when the gimbal is not in play; when I balance the post horizontally on something. It's almost like the side-to-side of the sled is out of alignment. 


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#4 Eric Fletcher S.O.C.

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Posted 29 April 2013 - 12:42 AM

It does it even when the gimbal is not in play; when I balance the post horizontally on something. It's almost like the side-to-side of the sled is out of alignment. 

 

 

You answered your own question


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#5 Alan Rencher

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Posted 29 April 2013 - 12:43 AM

Well, Hopefully I can get a hold of someone at Tiffen in the morning.


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#6 chris fawcett

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Posted 29 April 2013 - 02:40 AM

Hi Alan,

 

Build the rig and balance it statically with a normal drop time, then rotate the post through 90 degrees, then 180 degrees, if the static balance goes off, your gimbal needs re-centering. Let us know so we can help you further.

 

All the best,

 

Chris


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#7 Alan Rencher

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Posted 29 April 2013 - 02:41 PM

Chris, I'm not having that issue. I had to take my Zephyr in for that problem whole it was still in warranty, and it was repaired for me. Someone has said that it's possible the the bottom stage may have rotated from zero. I'm going to check that once or company move is over.

Chris, do you know if the bottom stage cab be re-centered in the field?
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#8 chris fawcett

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Posted 29 April 2013 - 03:45 PM

Hi Alan,

 

Chances are your gimbal is OK, though it's hard to tell for sure without seeing it.

 

If the line from the monitor CG to the battery CG does not pass through the post, then it might be a little harder to DB, but that can hardly be the case for a Zephyr.

 

Where are you placing the camera CG relative to the post, and what is your drop time? Try camera CG 0.25" back from center, with a 2 second drop time, then balance below to see what happens.

 

All the best,


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#9 Eric Fletcher S.O.C.

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Posted 29 April 2013 - 04:37 PM

Hi Alan,
 
Chances are your gimbal is OK, though it's hard to tell for sure without seeing it.
 
If the line from the monitor CG to the battery CG does not pass through the post, then it might be a little harder to DB, but that can hardly be the case for a Zephyr.
 
Where are you placing the camera CG relative to the post, and what is your drop time? Try camera CG 0.25" back from center, with a 2 second drop time, then balance below to see what happens.


Why don't we first make sure the sled is in balance, then correctly balance just the sled. THEN lets add a camera (with the CG DIRECTLY above the post). Lets address the problem Chris not mask it


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#10 Alan Rencher

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Posted 29 April 2013 - 05:16 PM

I've completely stripped the sled (including monitor & batteries), and I've tried to balance the bottom stage with just the rear battery plate and a Merlin weight on the front. I placed the sled horizontally, balancing the rig by rolling the post over the dock. I active static balance with the two base posts parallel to the ground.

If I roll the post 180°, the sled will resist, spin 180°, and settle back to static balance.

Basically, no matter how I try to balance, the post will roll back and settle to one side.

I've also tried balancing with my monitor, batteries, etc and just a weight plate with the CG over the center of the post, and I get the same out of whack results.

This is really boning me on this job. Luckily, I haven't needed to be in perfect dynamic balance for any of these shots, but I'm on this job all week. I've tried contacting Dan Ikeda at Tiffen, but with no call back or email...

I was hoping to get a loaner while they take a look, but I have to get a hold of someone.
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#11 Brian Freesh

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Posted 29 April 2013 - 05:34 PM

This is really boning me on this job. Luckily, I haven't needed to be in perfect dynamic balance for any of these shots, but I'm on this job all week.

 

Last I knew, Dan was in Brazil.

 

Derek Hester: 818-567-7917

 

If he doesn't answer, you can try Kristi Davis at the front desk, maybe she can track him down for you: 818-675-7910

 

And if all else fails, maybe try Lyn Taylor 818-567-7918, he was able to help me when everyone was at NAB.

 

I so rarely need to be in dynamic balance, that's not the part that would worry me.  It's the idea of the rig potentially fighting my slower pans that would bother me. Best of luck!


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#12 Alan Rencher

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Posted 29 April 2013 - 06:30 PM

Thanks, Brian!
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#13 RonBaldwin

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Posted 29 April 2013 - 07:04 PM

I've tried contacting Dan Ikeda at Tiffen, but with no call back or email...

I was hoping to get a loaner while they take a look, but I have to get a hold of someone.

 

Alan...you are in LA.  You should have been at Tiffen beating on their door before lunch!  This is the kind of customer service bs that drives me crazy -- you are saying that nobody picked up the ph and could give you an answer?  No emergency number on the machine?  

 

Sorry to be blunt, but the harsh reality is that if the sled's balance issues are affecting your performance AT ALL, I'd start looking for a friend with a similar sled so you can finish the week with your reputation in tact -- even if it costs you out of pocket.  

 

Ron B


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#14 Brian Freesh

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Posted 29 April 2013 - 09:20 PM

Alan, did you get ahold of anyone? it may have been too late in the day by the time I gave you those #s. Also, they may not have Zephyr's for loan if they're not back from Brazil yet.

 

I need to run over there tomorrow morning anyway, Let me know if I can help you out while I am there. I'll be done there no later than 10:45, so catch me before that.

 

I also have one or two Zephyr owner contacts in LA. email me if you need them.


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#15 Alan Rencher

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Posted 29 April 2013 - 11:59 PM

Thanks Brian, I'll email you.
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