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Opening a Roll Off Roof.

astro mick

By astro mick
in DIY Astronomer

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astro mick

astro mick

Posted
Posted

Hi.

Having now got a chronic Shoulder problem,i,m finding it quite difficult to draw back my Roll Off Roof,and it leaves me in more pain.

Can anyone point me to a Thread that deals with construting some sort of Winch,or indeed a motor operated mechanism,that would make life easier.

Would have to be a DIY,as i have,nt seen any commercial units out there for this.

Hope you can help.

Mick.

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SniffTheGlove

SniffTheGlove

Posted
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There are some sub £100 electrical reversible winches (Example is Machine Mart http://www.machinemart.co.uk/shop/product/details/clarke-ch2500b-250kg-electric-power-hoist )

Then you just need to put bungee cord at one end of the roof and then use the winch to open the roof (and the bungee stretches to give some friction) and then to close you put the winch into reverse and the bungee cord pull everything back closed (with the winch controlling the speed)

HTH

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pete_l

pete_l

Posted
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There are some sub £100 electrical reversible winches (Example is Machine Mart http://www.machinema...ric-power-hoist )

Then you just need to put bungee cord at one end of the roof and then use the winch to open the roof (and the bungee stretches to give some friction) and then to close you put the winch into reverse and the bungee cord pull everything back closed (with the winch controlling the speed)

HTH

You could even replace the bungee with a pulley system attached to some weights. By designing the pulleys for the correct mechanical advantage, the "drop" distance can be many times smaller than the distance your roof moves to open or close.
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Zakalwe

Zakalwe

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You could even replace the bungee with a pulley system attached to some weights. By designing the pulleys for the correct mechanical advantage, the "drop" distance can be many times smaller than the distance your roof moves to open or close.

The problem with that is that you either need a small weight and a very long drop( which might not be possible in a small obsy), or a very big weight and a small drop (big weights=big problems)

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Gina

Gina

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Are you sure this winch is actually reversible? I bought an electric winch several years ago thinking it was reversible - it wasn't, it just had a clutch to let the hoist cable wind out. This would not be suitable to push and pull the roll-off roof. I've considered motorising my roof using a loop of rope/cord/cable with a spring or bungee to provide tension and friction on the pulley/drum but it would have to have a reversible motor/gearbox. I'm not particularly bothered as the roof moves easily enough by hand but an automated system that closes the roof when it rains would be nice.

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pete_l

pete_l

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The problem with that is that you either need a small weight and a very long drop( which might not be possible in a small obsy), or a very big weight and a small drop (big weights=big problems)

Yes, I was thinking of a large weight and a short drop.

So if your pulley system had an MA of (say) 5 and your roof needed 20kg of force ('pollies for mixed units) to roll on/off, you could counterbalance that force with 100kg of weights (maybe on 2 separate pulleys, one on each side of the shed). Then your winch would need to supply the 20kgf to open the roof and another 20kgf to pull the weights up. But closing the roof would only require you to disengage the winch motor and apply a small amount of effort to overcome friction and unwind the winch's cable.

Since weightlifters' weights are quite cheap (but telescope counterweights are piggin' expensive :confused: ) you could get a set or two and add just enough weights to balance your particular roof.

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Zakalwe

Zakalwe

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Yes, I was thinking of a large weight and a short drop.

So if your pulley system had an MA of (say) 5 and your roof needed 20kg of force ('pollies for mixed units) to roll on/off, you could counterbalance that force with 100kg of weights (maybe on 2 separate pulleys, one on each side of the shed). Then your winch would need to supply the 20kgf to open the roof and another 20kgf to pull the weights up. But closing the roof would only require you to disengage the winch motor and apply a small amount of effort to overcome friction and unwind the winch's cable.

Since weightlifters' weights are quite cheap (but telescope counterweights are piggin' expensive :confused: ) you could get a set or two and add just enough weights to balance your particular roof.

The issue then becomes building the frame strong enough to handle 100Kg of weights hanging off it. I personally would want to get that wrong as 100Kg will do some damage if it drops on you!

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SniffTheGlove

SniffTheGlove

Posted
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Are you sure this winch is actually reversible? I bought an electric winch several years ago thinking it was reversible - it wasn't, it just had a clutch to let the hoist cable wind out. This would not be suitable to push and pull the roll-off roof. I've considered motorising my roof using a loop of rope/cord/cable with a spring or bungee to provide tension and friction on the pulley/drum but it would have to have a reversible motor/gearbox. I'm not particularly bothered as the roof moves easily enough by hand but an automated system that closes the roof when it rains would be nice.

Yes Gina, the one I linked to at MachineMart is motorised in both directions.

See the actual mfr webpage http://www.clarkeinternational.com/shop/product/details/clarke-250kg-power-winch-ch2500/path/hand-electric-winches

"The CH2500B also has a remote switch with power in & power out facility for safety and convenience."

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astro mick

astro mick

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Thanks everyone for some great ideas.I,m thinking that the Motor as described by the sailor on ebay might do the trick.

Perhaps if the motor is bolted to the inside top wall of the Obsy,and a strong eyebolt at the other side to the roof,it would be a simple case of running the cable to the eyebolt,then operating the winch to draw the roof off.

The problem would be closing the roof.You could install a second motor at the other side to do the same thing,or perhaps you install a pulley,so as to run the cable around the pulley back to the motor,and affix to a second eyebolt.

Can you see any flaws with this idea.

Mick.

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Zakalwe

Zakalwe

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Put a pulley on the end cross-spar of the runners that support the roof. When you want to open the roof, run the winch cable through the pulley and back to the roof. Wind the winch in to open.

Then when closing, hook the winch to the rear of the roof. Wind the winch in to close.

Simple and easy.

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astro mick

astro mick

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Hi Zak.

Could you elaborate a little more on your plan,i,m a bit simple in this department.

Are you talking about putting a pulley outside at the end of an outrigger,and if so you are pulling from one side only.Would,nt it be better to pull from the centre of the roof to distribute the pulling weight.

Ransu,thanks,and that looks like a nice set up,but i,m looking to-ward a motor operated winch.

Mick.

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The Sailor

The Sailor

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I am doing some roof maintenance, fibreglassing it, so I took the winch off, here is it's layout:

Plastic toolbox with the winch guide rollers outside.

The white plastic pieces on the winch are radiator pipe decorations, these seperate the two ropes, one in, one out. The hole in the winch is for the orignal wire rope.

Jim

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