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What happened if rocket scientists trying to get into film business...


Johannes Holweg

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I agree that a forklift can be a valuable tool (have used them several times), but a few things worry me about how the forklift was used in the first video.

 

First, there was no handhold for the op - not too bad because the forklift was not traveling and there was a grip. More worrisome was the lack of protection from the moving parts - it would be safer if there was a large sheet of plywood at the back of the platform being lifted, so the op or his cable could not get caught in the works. I could not tell how well the platform was secured to the forks, but that's a big concern - it should not be just a pallet being lifted by the forks.

 

At least it was a big forklift...

 

Seriously, if anyone is planning to use a forklift (and they can work great, as can other industrial machines), it's also essential to have great no, perfectly clear communication with the forklift operator, so that he understands that when the director says "faster faster closer closer" or something equally unsafe, the forklift op doesn't do that no matter what, and that he only does what you and he have agreed to do and worked out ahead of time safely, and his mind is on you the whole time, during rehearsals, going back to one, etc.

 

Jerry

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I could not tell how well the platform was secured to the forks, but that's a big concern - it should not be just a pallet being lifted by the forks.

 

It looks like a concrete block just balanced on the forks! This is an extremely bad idea as if the op or grip were to move to one side, past where the block sits on the fork, the whole thing could tip over. Not only would you have a serious fall in a rig, a massive concrete block would follow you to the ground.

 

The other issue with anything which is not actually connected to the forks is that most forklifts can tilt the boom or forks and if the driver pulled the wrong lever (which can be very easily done) the whole thing could be sent sliding off the front. I have used forklifts a fair bit including carrying people on properly designed platforms. What they do in this video is a seriously bad idea. However, they can be used to carry people safely. Most forklifts are smoother going down than up but can suffer from jerky starts and stops although some newer designs seem to be a lot smoother.

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Well, I think I can prove that it is safe!

 

Base on the video, and using the operator foot dimension as a measurement unit (1 foot).

The concrete is:

Width = 6ft

Length = 12ft

Height = 0.5ft

Density = 143 lb/cubic foot

The weight of the concrete will be; W = W * L * H * D

6x12x0.5 x143 = 5148Lbs = 2335Kg = 2.335 metric ton = 2.5 US ton

 

The pivot point is 1/4 of the length, to tip the concrete over that point the mass needed is 1287Lbs = 583.77Kg

Let assumes the grip is 400Lbs (!)

We will need a minimum of 4 400Lb grips standing at the edge to tip the concrete over.

 

Since the car is not moving.

The friction force is F = uN = uWg = 2335 x 9.8 x 0.5 = 11441.5N

to move it 1 meter in 1 second you need minimum of a force of 11441.5N

Chance that the concrete will slide out of the forks is quite small.

 

It looks unsafe, but it is safe.

The concrete is wide and heavy.

The forklift is relatively big.

The forks are wide apart.

And, best of all, weight is the main factor to keep thing bonding together.

 

Visually proof: as the op and grip walk, the concrete board stays still; no wobbling.

 

My only concern is the cable.

It might get stuck under the concrete!

Cheers,

Ken Nguyen.

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Well, I think I can prove that it is safe!

 

Base on the video, and using the operator foot dimension as a measurement unit (1 foot).

The concrete is:

Width = 6ft

Length = 12ft

Height = 0.5ft

Density = 143 lb/cubic foot

The weight of the concrete will be; W = W * L * H * D

6x12x0.5 x143 = 5148Lbs = 2335Kg = 2.335 metric ton = 2.5 US ton

 

 

I really don't think we should recommend this method. Besides, I think your calculations may be a little out, it certainly doesn't look 6ft wide for a start. Granted it will still be very heavy but and may be unlikely to topple but I'd still rather do it with the proper equipment.

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Another option ... not as high, but quite useful. I was testing it for a sequence inside a narrow corridor from a high angle looking down, tracking back with an actor and then down a flight of stairs (step off for the stairs :) ). Chapman makes this for the Hybrid Mark3.

post-8480-12807354432462_thumb.jpg

post-8480-12807354644223_thumb.jpg

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Chapman makes this for the Hybrid Mark3.

Looking good with your U2 Sanjay! Just curious, it looks as if you can adjust the positioning to the arm by 1' up or down? What other Chapman products will this work with, any cranes?

 

-Alfeo

 

Hey Alfeo,

It cannot be adjusted up and down in its current configuration. Its built to boom down till the platform is flush with the floor for easy step on and off. It should work with the Hustler, but I can't be certain. It definitely would not work with a PeeWee (tip hazard). The Chapman cranes are great for step on or off anyway, not sure you'd need this, although the built in safety cage is nice. The Hybrid also has a nice crane turret (not steadicam related) that can lift the operator on the nose on a crane style swivel turret along with the camera.

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