Jump to content



Photo

Ultra2 gimbal


  • Please log in to reply
12 replies to this topic

#1 Lars Erik

Lars Erik

    Advanced Member

  • Sustaining Members
  • 543 posts
  • Norway

Posted 09 November 2009 - 05:48 PM

Hi all,

just purchased brand new U2c. And had it for about 10 days, hasn't been out on a job yet. Only tested a few times with a small 1/2" camera and weight cage.

Today I did a 180 when the rig was on the docking stand and I noticed a very small clicking sound in the gimbal. When I returned the rig to its normal position it was off, fore/aft.

I did a new DB and did the same procedure, same result. I noticed the first joint of the gimbal seemed very loose. Is this the cause of it? The middle joint has some looseness also to the last gimbal joint.

I did a short video to demonstrate.



Hope someone can tell me this is something I can fix with the blue whale tool. As stated, the rig is brand new. :blink:


LE
  • 0

#2 Milos Kodemo

Milos Kodemo

    Member

  • Members
  • PipPip
  • 14 posts

Posted 09 November 2009 - 06:22 PM

Eric,

by the image in video you recorded and from I can see, the lower part of the yoke is not connected all the way to the straight part. On the straight part the threads have clear parts for the allen nut to come in and grip it firmly. If it is loose , and if you turn it it can make such a sound.
But , it should not have any effect on balance, I hope....
Try to turn that small allen nut all the way, stiffening the lower part of yoke to the upper.


excuse my english spelling

best regards

Milos Kodemo
  • 0

#3 Lars Erik

Lars Erik

    Advanced Member

  • Sustaining Members
  • 543 posts
  • Norway

Posted 09 November 2009 - 06:31 PM

Milos,

thanks,

the lower part of the yoke is now stiff. The click is still there, and so is the fore/aft problem...

I did a very, very precise balance. Left/right is fine, but also when I turn the rig 90 degrees while it's vertical, there is a change in the fore/aft also.


LE
  • 0

#4 Nitin Rao

Nitin Rao

    Advanced Member

  • Members
  • PipPipPip
  • 34 posts
  • India, mumbai

Posted 10 November 2009 - 12:22 AM

Hi Erik

I too have had a similar problem, its matter of just tightening the allen screw which is located just on the same moving part. Hope it solves ur problem. Since its a U2c steadicam u would have not had a remote so u could even reduce the space in between the part moving.
have fun flying the kit.
Cheers
Nitin Rao
  • 0

#5 Lars Erik

Lars Erik

    Advanced Member

  • Sustaining Members
  • 543 posts
  • Norway

Posted 10 November 2009 - 10:46 AM

I see I haven't been clear here. I wrote this late last night. So missed out the fact the I'm talking about a tilt movement, and I did a complete 360. It's just before the rig reaches the end of the 360 something shifts, most likely in the gimbal. Causing the rig to become off when it comes to fore/aft.
  • 0

#6 Steve Fracol SOC

Steve Fracol SOC

    Advanced Member

  • Sustaining Members
  • 148 posts
  • Thousand Oaks, CA

Posted 30 November 2009 - 02:14 AM

Lars,

I have had an original Ultra2 (not the c model) for nearly 4 years and have never had a single issue with mine. In fact mine has been totally bulletproof. Interesting. I wonder if it is a different gimbal than the original U2?

Your video link would not link for me for some reason. Can you email that link directly to me? steve@fracol.com

Hum...you say a fore and aft issue not a side to side...very interesting.
  • 0

#7 Lars Erik

Lars Erik

    Advanced Member

  • Sustaining Members
  • 543 posts
  • Norway

Posted 30 November 2009 - 02:39 PM

Hi Steve,

the rig is identical to the original U2. The only difference is that all the "goodies" are stripped from the c version. Like motorized stage and so forth.

I returned the rig to the company I bought it from. They checked it several times and found no problem.

I got it back and the problem I've had seemed to have gotten a lot better. So all apologies to Tiffen and the lot for the time they've spent on this.

There are still a couple of factors that are unclear to me.

1) a few times, not often, the rig will be off level, about 5 degrees, fore/aft after a tilt. I then correct it using the gimbal, no trim, and it stays at level. Why it acts like this I don't know.

2) There is still a "clunk" noise somewhere in the rig, most likely the gimbal. When I tilt it and the rig reaches about 60-70 degrees, the noise comes. According to the company I bought it from, they said this was normal according to Tiffen, as the bearings will shift if the rig is tilted. This may be, the thing is, my Archer doesn't do this. And if the U2 is supposed to do this, I would imagine the clunk noise would come closer to 180 degrees rather than only after 60-70 degrees?

Any thoughts?

PS! The video link is removed, as that problem is fixed.


LE
  • 0

#8 Jens Piotrowski SOC

Jens Piotrowski SOC

    Advanced Member

  • Sustaining Members
  • 1656 posts
  • Los Angeles, CA

Posted 30 November 2009 - 05:42 PM

check the topstage post connection. i had a problem on old master where the connection piece between the carbon post and topstage become lose and had to be re-glued. it made the same click/clunck sound when i shifted the weight/tilted......
  • 0

#9 Jerry Holway

Jerry Holway

    Advanced Member

  • Sustaining Members
  • 737 posts
  • Philadelphia

Posted 30 November 2009 - 06:33 PM

Lars-

Bearings should not be shifting. The only slight shift I know of (and it is intentional) is when you go from normally mounting the gimbal on the arm post to mounting it inverted with an F-bracket - not at all what you describe.

A place to check is under the fore-aft drive knob. I'm told that sometimes unintentional play gets in there (something is loose and needs to be re-tightened). A big tilt could shift the drive shaft to the end of its play, causing a shift of balance.

You can check if this is the cause without a camera on the rig; check if the stage will shift fore and aft slightly if you push on the "dovetail grabber."

Hope this helps.

Jerry
  • 0

#10 Lars Erik

Lars Erik

    Advanced Member

  • Sustaining Members
  • 543 posts
  • Norway

Posted 01 December 2009 - 04:38 AM

Lars-

Bearings should not be shifting. The only slight shift I know of (and it is intentional) is when you go from normally mounting the gimbal on the arm post to mounting it inverted with an F-bracket - not at all what you describe.

A place to check is under the fore-aft drive knob. I'm told that sometimes unintentional play gets in there (something is loose and needs to be re-tightened). A big tilt could shift the drive shaft to the end of its play, causing a shift of balance.

You can check if this is the cause without a camera on the rig; check if the stage will shift fore and aft slightly if you push on the "dovetail grabber."

Hope this helps.

Jerry


Hi Jerry.

I had this pinned down as the nr 1 cause at the start, as I've had similar problems with my Archer. I've tightened ALL screws that are accessible, same result.

When I try to push fore/aft, it might have a little play in it. But we're talking less than 1mm/0.039". Could this be the cause? I still suspect this to be the problem. According to Hofmann, they found nothing wrong, and they also stated that the "clunk" noise was normal. Something I found a bit strange, to say the least.

Only place I haven't checked is the fore/aft screw. Spoke to Robin T. at Tiffen UK, and he said I could try and unscrew the fore/aft screw and check if everything is 100% tight there. The thing is, I unscrewed the little safety screw out of the fore/afte adjustment screw, but the fore/aft adjustment screw wouldn't move. Afraid of damaging it, I never did try to take it off.

PS! Have moved the fore/aft all the forward and all the way back, so in theory, if it moves it should only move one way...right? But the noise it makes is identical to earlier...


Jens; how do you go about checking the top-stage connection, it's impossible to get to that connection. I did do a test by trying to move the top stage back forwards left right, but it seems to be hard rock solid there.

Lars E
  • 0

#11 RobinThwaites

RobinThwaites

    Advanced Member

  • Members
  • PipPipPip
  • 383 posts
  • Pinewood UK

Posted 01 December 2009 - 05:10 AM

Lars

I was under the impression that the noise occurred once the sled had passed the horizontal phase of its rotation which is why I suggested to Hofmann that it was not unheard of. This is the same as the small shift that Jerry is referring to when changing from high to low mode i.e. a small vertical shift of the post as the entire weight of the sled is transferred from one bearing face to the other.

However, if you have 1mm movement in the top stage is actually quite big and should be dealt with either in Sweden or by us.

Robin
  • 0

#12 Lars Erik

Lars Erik

    Advanced Member

  • Sustaining Members
  • 543 posts
  • Norway

Posted 01 December 2009 - 05:38 AM

Robin,

the shift is less than 1mm. It's not that I can see it very good, because the shift is so small. But I can feel and hear it. Does that make any sense?

Is this a case you can fix in the UK or does the rig need to be sent to the US?

LE
  • 0

#13 chris fawcett

chris fawcett

    Advanced Member

  • Sustaining Members
  • 1016 posts
  • Europe

Posted 01 December 2009 - 08:17 AM

Only place I haven't checked is the fore/aft screw. Spoke to Robin T. at Tiffen UK, and he said I could try and unscrew the fore/aft screw and check if everything is 100% tight there. The thing is, I unscrewed the little safety screw out of the fore/afte adjustment screw, but the fore/aft adjustment screw wouldn't move. Afraid of damaging it, I never did try to take it off.

L-E,
Assuming that your U2 stage is similar in construction to my A2 stage, you need to remove the grub screw, like you did, then take the rubber cap off the adjustment knob using a blade. Below this you'll see a hex nut. If it is loose, that might account for your noise. You'll need a VERY flat-nosed pair of pliers to reach it. Don't over tighten!

Good luck,

Chris
  • 0




Varizoom Follow Focus

Wireless Video Systems

GPI Pro Systems

Teradek

rebotnix Technologies

Omnishot Systems

BOXX

PLC - Bartech

Paralinx LLC

Boland Communications

Betz Tools for Stabilizers

IDX

Engineered Cinema Solutions

Media Blackout - Custom Cables and AKS

Ritter Battery

PLC Electronics Solutions

SkyDreams