Pulley Advice

Postby philstar on Thu 26/May/16 4:08pm

I bought a ceiling mounted washing line, but the cord hangs down form the middle of it. so i bout some pulley s to diver the cord to the wall. it is out side and exposed to salt spray from the sea so i bought stainless.

these have made it harder to pull up the washing line
I think the problem is that the pulleys have added drag into the system as they don't have bearings (or even bushes) just a pulley rotating on a rivet .

I was thinking if i greased the pulleys it might help, but getting grease into the axle is a problem as the is minimal room between the housing and the pulley.

Image

any suggestions on how to improve the situation?
philstar
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"misanthropic"
Member for: 11 years 9 months

Re: Pulley Advice

Postby OliverBendix on Thu 26/May/16 4:28pm

Visit a chandlers, or beg a friendly yachtie for a nice spare block? Yacht gear is pretty salt proof and the more expensive stuff runs on nice smooth roller bearings. Can cost $$ tho - worse than bike parts.
OliverBendix
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"Punter"
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Re: Pulley Advice

Postby danose on Thu 26/May/16 4:50pm

you probably don't even NEED a pulley for that application (unless the washing line is really heavy) - you could just drill a hole in the wall, glue this in and run the rope directly thru it

http://www.gearshop.co.nz/products/sing ... nchor-10mm

that over-kill pulley is most likely not rotating at all (since it's 'bearing' will be spec'd for some crazy big load), so your rope is just sliding around it - a smaller radius (and hence less contact area) will be much less drag.
danose
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Re: Pulley Advice

Postby Sims on Thu 26/May/16 4:56pm

You need a double pulley system to halve the effective effort required.
Sims
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Re: Pulley Advice

Postby ape on Thu 26/May/16 5:23pm

If you're keen to use that pulley and really want to grease it, there's always the option of grinding the end off the rivet and replacing it with a stainless bolt with an unthreaded shank long enough that threads are out of the way (and a nyloc or double nuts)

If you're not that enthused by the idea of pulling it apart, you may be able to fit a needle in there to drip a little oil on the axle.

Also, a bit of wear could loosen things up a bit.... splice a loop of rope through it, wrap it around a drill chuck and spin it for a couple of minutes.

but yeah, aside from that, as mentioned before, good pulleys aren't cheap.
ape
Member for: 13 years 5 months

Re: Pulley Advice

Postby philstar on Thu 26/May/16 5:30pm

Sims wrote:You need a double pulley system to halve the effective effort required.


tried that, the extra drag from the pulleys made it harder to pull :(
philstar
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"misanthropic"
Member for: 11 years 9 months

Re: Pulley Advice

Postby philstar on Thu 26/May/16 5:34pm

ape wrote:Also, a bit of wear could loosen things up a bit.... splice a loop of rope through it, wrap it around a drill chuck and spin it for a couple of minutes.
.


might give this a go :)
philstar
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"misanthropic"
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Re: Pulley Advice

Postby Dougal on Thu 26/May/16 5:39pm

Is it rope that doesn't like bending to that radius?

Get some smoother cord and try it. I have the same pulley (but even lower quality) and it survived a bigger pull than I expected (pulling an engine-less vehicle up a slightly sloping driveway into a garage). I planned to drill it out for bearings and bolts if/when it broke. But it hasn't.
Dougal
Member for: 14 years 7 months

Re: Pulley Advice

Postby philstar on Thu 26/May/16 6:21pm

Dougal wrote:Is it rope that doesn't like bending to that radius?

Get some smoother cord and try it. I have the same pulley (but even lower quality) and it survived a bigger pull than I expected (pulling an engine-less vehicle up a slightly sloping driveway into a garage). I planned to drill it out for bearings and bolts if/when it broke. But it hasn't.


it is 3 or 4 mm paracord/utility so bending radius is no problem

I got my spring balance out and measured the load (with mostly empty line), ~4kg (+/-1kg) without extra pulleys, 6 kg with, and when i put in a quad (there is already a double) it says at 6kg, so i think the drage is like a constant amount of force or something.
philstar
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"misanthropic"
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Re: Pulley Advice

Postby happybaboon on Thu 26/May/16 6:46pm

You could immerse it in an oil or a warmed grease.

However any time you change the angle of a force there's going to be some resistance. I bet with a pulley such as the one described much of the movement isn't even, er, pulleyed. It's just going to be rope sliding through an angle... And that means friction.
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Re: Pulley Advice

Postby pokey on Thu 26/May/16 8:03pm

philstar wrote:II was thinking if i greased the pulleys it might help, but getting grease into the axle is a problem as the is minimal room between the housing and the pulley.


You want a wick in lube like Inox MX3 or motorcycle chain lube that uses a solvent (which evaporates) to transport the lube into the tightest spaces, Wurth HHS 2000 is great if you know someone in the automotive trade.
pokey
Member for: 1 year 11 months

Re: Pulley Advice

Postby philstar on Thu 26/May/16 8:16pm

do you think i can get grease through a hypodermic needle?

I work in a hospital so that type of thin is handy :)
philstar
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"misanthropic"
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Re: Pulley Advice

Postby happybaboon on Thu 26/May/16 8:24pm

Yeah easy get a 16g/14g needle and a luer lock syringe. No worries.

Most greases would go through 18g slowly as well.
happybaboon
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Re: Pulley Advice

Postby philstar on Thu 26/May/16 8:51pm

happybaboon wrote:Yeah easy get a 16g/14g needle and a luer lock syringe. No worries.

Most greases would go through 18g slowly as well.


dame the 18 gauge 1.2mm (blunt fill) needle wont fit between the pulley and the edge :(

the next smallest is a 0.8 mm
philstar
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"misanthropic"
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Re: Pulley Advice

Postby happybaboon on Thu 26/May/16 8:56pm

Many greases would fit through that. If not, warm them.
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