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Old February 22nd, 2007, 10:25 PM   #1
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Bogen tripod for crane use: How can the specified weights be accurate?

Hi all. . .

I'm going to be buying a Kessler Crane (12/8 model) this week, but I'd like to save some significant money and use a currently owned tripod to support it. This is my tripod (Bogen 3051):

http://www.bhphotovideo.com/bnh/cont...ughType=search

The tripod is rated to hold 26 pounds, but I just put ALL of my weight on it (and I'm at least 185 pounds) and it didn't even begin to budge. Since a crane set up will weigh, at the very most, 80 pounds with all the weights, wouldn't I really be safe using this tripod on its lowest leg setting?

FYI, I'll be using a tricked-out HVX-200 (mattebox, follow focus, Nikon lens, Redrock M2) on the 12/8 Kessler Crane.

I just don't want to waste money on a crane that can clearly hold WAY MORE weight than I'll ever be putting on it.

Any thoughts?

Stephen
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Old February 23rd, 2007, 09:58 AM   #2
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Hi Stephen,

I've got the Bogen 3011 T-pod. I frequently put up to 30# extra weight (leg weights at center) in addition to Cam, Monitor and Aux Battery. I do this for stability in windy or certain other situations.

I've had no problems. That is very different than using a Crane system where the weight is extended way out from the T-Pod's center, even though that weight is "balanced". I would want a lot more heft (weight & leg strength) towards the T-Pod botom to suport that much top weight. The fact that that extended weight will be doing some swinging about, changes the force dynamics to the T-Pod legs. I think you might be able to modify some things to compensate, but not sure without trying.

By the way, I'm just down the street in Olathe. Since I'm accustomed to making modifications (see my posts & Pics), I'd be glad to work with you on it.

Harold

Last edited by Harold Schreiber; February 23rd, 2007 at 02:35 PM.
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Old February 23rd, 2007, 01:41 PM   #3
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Quote:
Originally Posted by Stephen Pruitt
wouldn't I really be safe using this tripod on its lowest leg setting?
Do really want to know if you would be "really safe" using the tripod on its lowest setting or are you just looking for some one to agree with your hopes.

If you are really interested in the safety factor You'll have to consider the risks involved. If there is an "oops!" will the equipment be the only thing damaged or are people at risk also. The further those tripod legs are spread apart, the greater risk of tripod failure.
What appears to be holding may be slowly sliding to catastrophic failure at a rate to slow to notice until it reaches a critical failure point. Did you consider a safety margin such as a 3:1 ratio?

Asking people who are not qualified to determine what's really safe is like asking someone who is not a firefighter is it safe to go in a burning building.
Allen W
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Old February 23rd, 2007, 01:46 PM   #4
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Quote:
Originally Posted by Stephen Pruitt
wouldn't I really be safe using this tripod on its lowest leg setting?
Do really want to know if you would be "really safe" using the tripod on its lowest setting or are you just looking for some one to agree with your hopes.

If you are really interested in the safety factor You'll have to consider the risks involved. If there is an "oops!" will the equipment be the only thing damaged or are people at risk also. The further those tripod legs are spread apart, the greater risk of tripod failure.
What appears to be holding may be slowly sliding to catastrophic failure at a rate to slow to notice until it reaches a critical failure point. Did you consider a safety margin such as a 3:1 ratio?

Asking people who are not qualified to determine what's really safe is like asking someone who is not a firefighter is it safe to go in a burning building.
I think that is a question that you really have to answer yourself. Personally I would go for the strongest base that I could afford; for safety reasons.
Allen W
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Old February 23rd, 2007, 01:49 PM   #5
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Thanks for the posts, Harold and Allen. . .

I don't want to modify the tripod because it belonged to my late father-in-law, so that's out. I don't really know what a proper safety/insurance factor on these crazy tripods is. The tripod is built like a you-know-what, so I'm just not certain what to do. I hate to spend $500 for yet another tripod. . . especially one that won't get used all that much (I expect the jib shots to be used somewhat infrequently in my projects), but perhaps that's the way I should go. . .

Thanks much.

Stephen
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Old February 23rd, 2007, 02:35 PM   #6
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Hi Stephen,

All the Mods I've created allow for the original piece of equipment to be returned to its stock condition. They are all "add ons" so to speak.

Allen's point on "safety" is well taken, and I had hoped was implicit in my prior discussion. In addition to equipment failure, you certainly do not want anyone or animals hurt either.

Harold
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Old May 7th, 2007, 10:39 AM   #7
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My belief is safety first. I just ordered a Skycrane Jr., and also have a Tripod that should "Handle" the weight. But I'm going to get one that's enough, and use it as a set. I'm in NYC, and will rent it out. It will pay for itself in no time.
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Old May 7th, 2007, 11:12 AM   #8
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There are a number of issues here. The tripod legs, and head (which I'm guessing is one of the Manfrotto/Vinten/Bogen badged models) are designed with a static load in mind. So the 26 pound statement doesn't really relate to being able to support just 26 pounds, they will have incorporated a safety factor too, to cope with a heavy camera suddenly moving down, or up, as happens when the load is unbalanced. The limiting factor is the 3/8" thread that attaches the central column to the head - so your carefully balanced jib is likely to be less of a problem, than a full size camera falling forward.

I have laying around in the workshop a very similar looking Manfrotto - no idea what the model is, but the weak link here is when the legs are wide at the base, and the height kept low. The telescopic small tubes take a lot of strain in this mode, and the thumbscrews don't have a lot of grip. If you do you weight test in this mode, you'll find one or more of the clamps fail with much more modest weights on top.

The telescopic main leg clamps seem pretty good to me.

So, If I wanted to use this tripod to support your 12ft arm, I would make a few small changes to the setup process. I would construct out of plywood, a base triangle, with cutouts for the tripod feet, and in the centre route out a circle that a piece of 2" tube could fit into. Set up the tripod and cut the tube so it connects to the bottom of the centre column - you may have to cut out three small tabs to make it fit snuggly. So all you do is arrange it so that the tube takes the vertical weight, and extend the legs to make it all sturdy. This will allow the weight of the jib arm, weights and payload to be taken straight down to the floor, with the legs downgraded to performing stability from toppling, not carrying the full payload.

I have a Vinten Dolphin crane which weighs enough to need two people to lift it, and it sits on a Vinten heavy duty tripod. I've never been that confident that the leg clamps would hold (they have never failed, but just a feeling) so I have made up three of these additional tubes for the three usual working heights I use. Over here, we call this a 'belt and braces' approach. (Would this be 'belt and suspenders'?)
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Old May 7th, 2007, 12:26 PM   #9
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Bogen "3051"

Hello Stephen,

Bob Jones here from Skycrane mini DV camera jibs.

Your tripod (Bogen "3051") is an ideal tripod for supporting the Kessler crane or any jib you should choose. I been recommending the Bogen "3051" exclusively for use with any model Skycrane up to and including the Skycrane Moonraker for over seven years. In that period of time I've not heard anyone say that it did not perform as expected. It is an extremely robust tripod and has many great features. Stephen, as you have mentioned it will support your body weight and remains rock solid. It is way under-rated as to its advertised capicity.

Cheers...
Bob Jones
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Old May 21st, 2007, 07:51 PM   #10
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A bit late but hopefully worth saying...

I'm currently trying to source a new tripod for a B.Hague J12 jib and all the bells and whistles. Anyone doing the same, or operating an existing tripod/ jib/ crane setup should be aware of this piece of info: from my Insurance Broker -

"A public liability claim for 3rd party personal injury OR a private claim (by you - er, me) for damaged equipment, may be declined cover in the event that any of the equipment giving rise to, or involved in such claim is/ was being used outside the safe operating parameters published by the manufacturer"

In short, if your rig weighs 88 pounds, and your 'pod is rated to 26 - DO NOT have an "incident" - it could be VERY EXPENSIVE indeed! Worse, you don't have to be 100% over the margin, 1 lb over is enough.

This is the reason that many of the supports in North America have more conservative ratings than elsewhere on the planet - they need a bigger safety margin as getting sued can get pretty expensive.

Worth thinking about next time you take that gigantic toy out to play.


Cheers,

Chris
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