Large Pulleys

[lxskllr]

I messed up a couple of my large pulleys yesterday. Not sure exactly what happened, but I think they clashed in a MA system when I wasn't paying attention. Bent the cheekplates a little, and gouged the sheaves leaving rough edges. On careful inspection, I think they'll be fine. I'll smooth out the gouges with a file, and double check clearances with rope to make sure the cheek bends won't affect it, but it looks like minimal capacity loss with the damage.

These are both big CMI pulleys. I was looking online to see about replacing them. The CMI outlet store has a few models that look interesting, from the same ones I damaged, to slightly bigger models, with bearing/bushing options. I'm thinking about getting a couple more for when I want to be absolutely sure I get the stated capacity. The ones I have are perforated stainless, 3" aluminum sheave with bushings, and 16k# mbs, ⅝" rope capacity.

The question(finally!) - What do you all use pulleys for? I bought the ones I have specifically for setting up redirects and Zdrags, and didn't have a clear goal otherwise. Any other uses that would influence a purchase decision? Bigger sheaves? Slightly higher weight capacity? Something worth doubling the weight of what I have?

 

[flushcut]

Pulleys are nice for MA systems because of the bearings reducing friction. Blocks are the work horse, heavy loads, and abuse.

 

[lxskllr]

Which ones do you like here?

Clearance & Factory Seconds

cmigearusa.com

The ones I messed up are the RP-105-CS. They're nice pulleys, and don't weigh a ton. Going up in size doubles the weight, and adds 4k# to the capacity. Is that a worthwhile tradeoff, or stick to what I have? I could also get the same thing, but with a 4" sheave. Is that amazingly better than 3"?

 

[flushcut]

I like any of the stainless models 5/8” capacity.
You can take the pulleys apart and press out any damage with a hydraulic press and resemble.

 

[Treeaddict]

Which ones do you like here?

Clearance & Factory Seconds

cmigearusa.com

The ones I messed up are the RP-105-CS. They're nice pulleys, and don't weigh a ton. Going up in size doubles the weight, and adds 4k# to the capacity. Is that a worthwhile tradeoff, or stick to what I have? I could also get the same thing, but with a 4" sheave. Is that amazingly better than 3"?

I like all of them 🤣

 

[theTreeSpyder]

the candy store (d)effect !

Pulley is super tool, only limited by yo imagination !!!!
Larger sheave to axle ratio is same internal frictions, but more leverage over them
>>and easier on rope bend, especially in stiff lines
But heavier and not as 'discreet' to carry, store, thread thru etc.
redirect truck pull as mule instead of bustin'butt
>>what the axle don't carry the azzhole does......
>>same as say when CoG is not over axle on a hand truck..
.
Can also float pulley (send new guy for sky hook while you work)
and use as lift , increase speed or force(not both at once) etc.

 

[SeanKroll]

We're you pulling with a truck to create enough force to damage the pulleys when they clashed?

 

[lxskllr]

Yes, it was a truck pull, and I wasn't paying attention to the pulley's position. Since this thread was made, I filed the burrs off the sheaves and decided the cheek damage wasn't bad enough to worry about. I may still get more pulleys, but it doesn't feel urgent.

 

[SeanKroll]

Pics always help, for the future.

 

[flushcut]

Pics or it didn’t happen. Lol

 

[Tree09]

I've been looking too for getting going on my projects again (I'm gonna be ordering some rope for what i need now on some of my projects), if you're doing truck pulls some heavier blocks are really nice, as is some wire rope. I found wire rope around 1.50 a foot for 3/8" 6x37 wire core galvanized, the 5" wire rope blocks were around 65 a piece for galvanized ones rated to 4.5 ton, and i even found the blocks on Amazon. The 4" blocks were only 40 bucks and they did 3/8 rope, the 5" does 1/2". They're solid steel, the cheekplates completely hide the roller bearing sheave (with a grease zerk). Blocks like that can stand up to the abuse and although heavy, they roll beautifully even with regular rope. The wire rope will also take abuse like no other, and a 3/8 line is good for a 1.5 ton wll, 1/2 is 2.5 ton. You can store it on a spool, throw it in the truck bed, and roll it out when you want. Get a pipe to fit in the middle of the spool and your hitch receiver, and when you put it back on just lay it straight and reel it in keeping tension to make lie right, maybe dragging something light to help supply tension if it's fighting you.

I even found one with a hook on Amazon, only 2 ton but with a 6" sheave and 1/2" wire rope capacity for $27. It's got a hook rather than a built in shackle connection but those would work too, and I'm probably gonna pick up a few of them myself for the log trailer and chipper cranes i built. The rope I'm getting is some blue moon for hopefully starting climbing again (my rrp still slips so I'm hoping the slightly fatter rope won't), some 1/2" double braid for the chipper, and maybe even some 5/8 for the log trailer and for some rigging rope. It's generic double braid, but for my purposes will be more than fine.

DIRBUY Snatch Block - 2 Ton WLL - Snatch Block with Hook for 1/2 inch Wire Rope, 6 inch Sheave https://a.co/d/gdqAyN0

 

[SeanKroll]

Didn't know you could put chain on a wire rope or synthetic rope sheeve.

Do sheeves has different profiles for metal versus synthetic rope?

I have a wire rope block that I think has a narrower groove in the sheeve.

 

[Kaveman]

Didn't know you could put chain on a wire rope or synthetic rope sheeve.

Do sheeves has different profiles for metal versus synthetic rope?

I have a wire rope block that I think has a narrower groove in the sheeve.

Wire rope has a tendency to gouge the working surface of the sleeve and can leave burrs and such, therefore once a pully has been used on wire rope, that's all it should be used with.

Chain, not at all really, here's a chain pully from an old hoist, forgive the rust, its scrap, after all.

You can see the teeth that engage with the alternating links.

 

[Tree09]

The narrow groove in the middle is for sailboats, at the top of the mast. When raising the halyard to raise the sail, sailors used to use wire rope because of the zero stretch and low diameter, but would splice rope to the wire so they could use a capstan winch. With amsteel and other modern fibers this became unnecessary so it's not used that way anymore. The rope could go over the sheave, but then when the halyard was tight the wire would be there, hence the groove.

A pulley is a pulley, virtually zero difference between wire and rope. Some pulleys are designed for rope going flat, but those are usually high performance sailing blocks designed for amsteel. The caveat is that if the sheave has seen a bunch of wire, it may develop grooves and scratches from the use, some of which can be cleaned up with a file. The nice thing about the wire rope pulleys is that not only are they of a much heavier construction, they often are designed for grease so they tolerate constant outdoor use very well, and work very well. I wouldn't likely want to wrestle one in a tree because they're heavy, but they work great for other applications, and would be fine in a tree if needed. The logging ones are designed for much higher line speeds too, so the bearings really are nice.

Edit: the wire ones are designed for shock loading, aka how blocks for tree work are used, so i would make sure it had a bomber connection that couldn't work loose before using it like that.