Physics question: horizontal vs. vertical force
obieone
Posts: 5,077
Long story short, I'm trying to save my back, and am researching using a hand winch for lifting heavy items on to roofs. I read a disclaimer, that hand winches are NOT designed for lifting. Ideally, I should use a chain hoist, but that defeats the purpose, since most hoists weigh almost as much as the loads I'd be lifting(<120 lbs.). Which raises the question: Is there a formula for determining vertical vs. horizontal force.
TIA
TIA
I refuse to argue with idiots, because people can't tell the DIFFERENCE!
Post edited by obieone on
Comments
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force is force, no matter the vector.
I don't understand what force you're trying to calculate.design is where science and art break even. -
Based on the disclaimer, stating that the winch could not be used for lifting, I assumed that there must be a reason?
Example: If a (boat) winch was rated at 1.5T, it's structural integrity may be calculated for dragging, over a less resistant surface, then a direct lift.
Again, I'm assuming the disclaimer came from the manufacturer(engineer), and not someone (lawyer) working at Graingers?I refuse to argue with idiots, because people can't tell the DIFFERENCE! -
Get a roofer's ladder hoist or go old school and use an old masons pulley/rope rig. You'll fall asleep waiting for a winch to deliver the load. The simple answer is that the "no lifting" is a liability disclaimer, watch "The Gods Must Be Crazy" where a Land Rover hangs by it's winch from a tree. WWGrainger is a great place to pay the absolute highest prices, in my experience.
http://www.google.com/search?q=ladder+hoist&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=efSCUK_zBcnx0gGbpYCwDA&sqi=2&ved=0CD4QsAQ&biw=1280&bih=620 -
What would you mount the boat winch to because that would matter as much as the winch itself. That said, I've used the mast winch to hoist a 200 + pound person in a safety harness up the mast, a very common practice, without any issues. I have to tell you it's no where near as hairy on dry land as it is on the open water.....LOL
Be aware that winch failure is always a possibility, but so is a deck winch getting ripped out of the mount.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
The disclaimer is probably a Lawyer Label. Not designed with brakes and locks for lifting overhead or load safety factors.. Prevents liability on the manufacturer's part. Winches are designed for rolling or sliding loads.>
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>This message has been scanned by the NSA and found to be free of harmful intent.< -
Based on the disclaimer, stating that the winch could not be used for lifting, I assumed that there must be a reason?
Example: If a (boat) winch was rated at 1.5T, it's structural integrity may be calculated for dragging, over a less resistant surface, then a direct lift.
Again, I'm assuming the disclaimer came from the manufacturer(engineer), and not someone (lawyer) working at Graingers?
I see. So it's really not a question of force.
I don't know the regulations regarding mechanical winches and stated weights, but it would appear to me that as long as you don't exert a live (or shock) load exceeding 1.5T you would be good. Whether the load is dragged, or lifted, it shouldn't matter. I would suspect the the housing orientation and supplied mountings would be specific to horizontal applications.
One thing I can tell you is that the ANSI and OSHA requirements make creating lifting devices, and anything required for overhead lifting very expensive.design is where science and art break even. -
Hand winches are not designed for vertical lifting. The only way which you could accomplish the verticle lift is to add a pulley(s) to create a block and tackle. This will add extra drag, which puts more stress on the cable. By adding the pully, you will physically need less force to lift the load, but for each pully added, the cable will have aprx 10% more force added to the work load. Also those cables are designed to pull in a linear direction, and not around anything. The cable strands may not be ductile enough to handle and fail prematurely.
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There are hand winches that are designed for lifting. They usually have an automatic brake.
http://www.davidround.com/manualwinches.html -
There are hand winches that are designed for lifting. They usually have an automatic brake.
http://www.davidround.com/manualwinches.html
Thanks for the link. Now I can save my back without crossing paths with OSHA:eek:.
Thanks for everyones feedback.I refuse to argue with idiots, because people can't tell the DIFFERENCE! -
There are hand winches that are designed for lifting. They usually have an automatic brake.
http://www.davidround.com/manualwinches.htmlLoad capacity rated for single line pull. This equipment is not to be used for lifting or supporting people.
Make sure you know what you're doing. If something happens, it's your ****... -
Make sure you know what you're doing. If something happens, it's your ****...
Fear not good citizen:loneranger: The only thing this will be used for is tools and parts, going thru a roof hatch. The position I have to take over an open hatch is tearing up my back. I plan on over-sizing everything(marine grade cable, grade 8 bolts, etc.), to c.m.a.
I have to do something, or I'll be enrolled in a 'pain management' program petty soon.:sad:I refuse to argue with idiots, because people can't tell the DIFFERENCE!
