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Jib arm with slider on end attached ( perpendicular) ?


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#1 TJ Marbois

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Posted 10 March 2012 - 07:48 PM

Hi

I've been imagining a jib arm but with slider attached to the end -- almost like this one:

http://www.straightshootr.com/

has anyone here set up a jib like this before? Imagine taking a nice quality slider ( motorized like DitoGear or Kessler slider ) -and attaching it for vertical moves ( up/down ) on the end of a jib arm thats locked just to rotate in one horizontal elevation.

Sort of a like this jibarm-----| ( and the | is the slider set perpendicular to the jib arm )

anyone try something like this? Any ideas what kind of mounts I would need to get that proper? or problems you foresee before I go trying?

cheers
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#2 robert duke

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Posted 11 March 2012 - 08:49 AM

why?

the jib arm gives vertical motion. the straight shooter allows the user to hide the arc of the jib with the slider. the jib would have to be able to carry the weight of the camera, head , and the slider. you would have to use one of the professional level jibs. (10lbs of camera, 15lbs of head, 15lbs of slider= 40lbs of payload) .

why not look at a zero gravity jib?

http://www.khill.com/prod03.htm

the slider on the end of the jib vertically would just limit your travel. you would lose lower end and upper end on the jib. it would mute the point of a small jib and limit the jib selection on longer jibs. The Jony jib only has a 30lb payload. the jimmy jib only has a 30lb payload (spec) at full stick. you dont gain anything using it vertically.

the chapman stinger jib and the straight shooter and a couple others use the slider effectively to mask the horizontal arc of the jib. the vertical slider would only increase the arc of the jib, think unwanted tracking in the horizontal plane.

again why? you lose and limit yourself more than you gain.
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#3 TJ Marbois

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Posted 11 March 2012 - 11:06 AM

why?

the jib arm gives vertical motion. the straight shooter allows the user to hide the arc of the jib with the slider. the jib would have to be able to carry the weight of the camera, head , and the slider. you would have to use one of the professional level jibs. (10lbs of camera, 15lbs of head, 15lbs of slider= 40lbs of payload) .

why not look at a zero gravity jib?

http://www.khill.com/prod03.htm

the slider on the end of the jib vertically would just limit your travel. you would lose lower end and upper end on the jib. it would mute the point of a small jib and limit the jib selection on longer jibs. The Jony jib only has a 30lb payload. the jimmy jib only has a 30lb payload (spec) at full stick. you dont gain anything using it vertically.

the chapman stinger jib and the straight shooter and a couple others use the slider effectively to mask the horizontal arc of the jib. the vertical slider would only increase the arc of the jib, think unwanted tracking in the horizontal plane.

again why? you lose and limit yourself more than you gain.


Ah ok so the zero gravity will do vertical with no arc? that was my intent - also I wanted controlled up/down with very fluid motion... Ive seen that out of hydraulic lifts only.... most jib arm motion Ive seen can get wiggly if not done absolutely spot on.... so my thought process was a jib locked horizontally ( 90 to the ground ) would let me rig a slider mounted sideways for vertical motion with a servo would let me do nice up down while just using the jib for rotation around an axis in the center... and I was thinking the camera is mounted to the slider so it could easily go low... the slider would nearly be touching the ground - I can set it there and let the servo lift it while I turn the rotation point on the jib... this gives for 2 axis moves with one axis being fully controlled by the servo ( fluid movement up like a hydraulic lift ) - and one rotation axis that I can move manually but with less potential for jiggle... its locked to a single plane in the rotation.....

but I'm sure this sounds like a round about way to get to my goal and it looks like the zero gravity handles that kind of stuff too.... ( keep in mind - Im looking for cheapest lightest and no truck needed to carry it there...I got a hatch back )

thanks again for the advice! its much appreciated...I will look into the zero gravity offering.
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#4 robert duke

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Posted 11 March 2012 - 08:08 PM

if you spend money on a jib, that is getting QUALITY jib it will have very little wiggle. JL fisher arms wiggle, chapman arms wiggle, even the elemac wiggles. It is all to what extent it wiggles. the more mass a crane, jib, slider, dolly has the less wiggle will be apparent. Again it is about Physics. An object is motion will remain in motion until acted upon by an outside force, and an object at rest will remain at rest until acted upon by an outside force. thusly without the math the more mass and thereby momentum/ the more inertia it takes to get in motion or change directions ( wiggle).

Spend more $ and the problem is solved. rent a grip truck with a proper dolly and it will cost you less in time and headache trying to invent a square wheel. you dont need to fit anything in a hatchback if you rent a grip truck.

It is unfortunate to think that you can achieve professional quality with less than professional gear. in order to save the $325 rental you want to spend $3600 ($200 dolly, $1500 jib, $700 tripod, $1200 slider). Only to find out it still isn't a workable solution. you could rent a dolly 10 times for the cost of your experiment.

Try as an experiment put 1lb on the end of a 6ft 1x3 and move it around. it wiggled. adding mass to the end of a jib with a slider only exacerbates the issue of wiggle.
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#5 TJ Marbois

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Posted 11 March 2012 - 08:34 PM

if you spend money on a jib, that is getting QUALITY jib it will have very little wiggle. JL fisher arms wiggle, chapman arms wiggle, even the elemac wiggles. It is all to what extent it wiggles. the more mass a crane, jib, slider, dolly has the less wiggle will be apparent. Again it is about Physics. An object is motion will remain in motion until acted upon by an outside force, and an object at rest will remain at rest until acted upon by an outside force. thusly without the math the more mass and thereby momentum/ the more inertia it takes to get in motion or change directions ( wiggle).

Spend more $ and the problem is solved. rent a grip truck with a proper dolly and it will cost you less in time and headache trying to invent a square wheel. you dont need to fit anything in a hatchback if you rent a grip truck.

It is unfortunate to think that you can achieve professional quality with less than professional gear. in order to save the $325 rental you want to spend $3600 ($200 dolly, $1500 jib, $700 tripod, $1200 slider). Only to find out it still isn't a workable solution. you could rent a dolly 10 times for the cost of your experiment.

Try as an experiment put 1lb on the end of a 6ft 1x3 and move it around. it wiggled. adding mass to the end of a jib with a slider only exacerbates the issue of wiggle.


Robert I hear you... I understand what you are telling me. ;) Im not discounting what you tell me...

however - I also want to let you know... experimenting and finding new things and new ways of doing something is part of who I am - I like to discover and I like to make mistakes because sometimes I find something that perhaps is useful or different than whats out there now.

Giant grip trucks and gear invented for film based cameras that weighed a lot more than the gear I have and gear I plan on using - is not necessarily the only answer for professional looking results...I don't discount your advice - in fact I appreciate it. I just believe that the gear is changing so rapidly...that the support gear is not in sync with the needs of a guy like me... ( and I have a totally different set of needs than a guy who needs grip truck ) - the film I want to shoot involves more intimate needs, smaller gear, lighter weight... more portable and flexible with the use.... Im going into a location that cannot bring a grip truck or a large crew... however I want to achieve certain types of shots... that I know are done on big gear as you say....

Im not trying to break the laws of physics...I understand that math ( quite well actually as Im an engineer by training ) -- however I know there are ways to achieve fluidity in motion that may be different to the ways done now...and that involve lighter gear 'possibly'...

I would hope you don't hold it against me too much to want to experiment and possibly discover something new.... just like a guy who jumped on a wheel chair and said - hey this will work.... or a guy who decided to tape the camera to his helmet before jumping off the bridge...:) Im just asking to see what people might say - and I actually appreciate their input.

However - I also feel the gear is different that what we've dealt with in the past and there is currently an evolution going on.... lighter gear is part of that... I feel like there must be a solution that still achieves smooth movements but with less mass and weight... these new sliders are a testament to that concept already... I feel like theres a next gen of jibs / dollies and more coming down the line that will hopefully also get back to capturing that smoothness of motion -- without bringing on all that weight.

Thats all Im thinking - and thats the reason why Im asking. Thanks for your expert insight.... I agree with you that what I asked was round about way to get a solution you already know is possible and done a certain way.... I just believe there are alternatives still yet worth exploring - which includes asking the experts like you what you already know and why.

Hope thats ok? :)
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#6 robert duke

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Posted 11 March 2012 - 08:56 PM

you asked for advise and I say save your money.


A small jib on a dolly will hide the arc by allowing the dolly to move in sync with the jib move.

If you are a trained engineer, then why not look at the physics involved. adding weight to the end of a stick adds the wiggle you are wanting to avoid.

yes the gear is lighter, but the physics of motion are the same. no matter how you want them to be.
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#7 TJ Marbois

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Posted 11 March 2012 - 09:08 PM

you asked for advise and I say save your money.


A small jib on a dolly will hide the arc by allowing the dolly to move in sync with the jib move.

If you are a trained engineer, then why not look at the physics involved. adding weight to the end of a stick adds the wiggle you are wanting to avoid.

yes the gear is lighter, but the physics of motion are the same. no matter how you want them to be.


yes I agree - and thank you for your advice... I'm now adjusting my search based on it and i do appreciate it. ( I ask lots of questions sometimes and Im sure some are stupid...but thats just me - I have a hard head and learn the hard way sometimes )

cheers!
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