pulley for friction saver

Babberney

Babberney

Location
Austin, TX
I posted this somewhere a long time ago and can't find teh answer I got then. I've been using a FS made from a webbing strap, with a biner and a pulley. The CMI pulley I have is too small to allow my spliced rope to pass, so I have to use a rope with only one end spliced to install from the ground.

What kind (brand, model) of pulley do I need to have a wide enough opening for my splices to pass? I'm using NE Safety Blue 16-strand.

TIA,
Keith
 
The fixe is a bit bigger between cheek plates, unfortunetly we know it is not up to standards. Yates has one on there web site yatesgear.com They have a micro pulley that is a little bigger than a cmi. it also is rated and stamped at 35kn.
 
Since the pulley only makes up one side of the FS, doesn't it get by at half the rating? I have to be sure the TCC rules allow it, in addition to whether it is safe.

Tod, have you pulled a splice through the Wall pulley offered by Yates? not that I don't appreciate the suggestion, but "a little bit bigger" doesn't quite sell me.

thanks again,
k
 
I'm thinking that the Petzl micropulley is rated at 7000# and the axle pin is a threaded rod (¼"?)with locknuts on both ends, where the Fixe is a smaller pin that is pressed/rolled over on the ends. How about taking the pin and pulley from the micro and using it as the pin in an appropriate sized stainless clevis? This would give you the stronger pin and a larger area for the splice to pass.

When used in an RG type setup, the pulley would be supporting 100% of your weight so it would need a minimum of 5000# rating.
 
Help me out here.

I would worry about any modifications done to a pulley used for life support.

Is it the money or is it there one that has been tested for sale somewhere?

Please excuse me for being safety sheriff but I had to ask.

See you at the top^
 
Keith ,

you can still set the line with that type of pulley. Your rope would allready be in the pulley.Just make sure you pull the system far enough over the limb so that the weight of the line doesn't pull the system back over the limb before you pull the eye through the other ring or biner.

Also , just use a a larger pulley. I use a two inch CMI it gives me a bigger raidius and a little less friction.With out the core in the eye , it should pull through with no problem .

Greg
 
Dan,
Climbers routinely cut and modify their lifelines by splicing eyes (including removal of core strands), they modify B'fly saddles by cutting away the tie-in strap and replacing it with other rated hardware. What is the difference between that and combining the pin from a 7K pulley with a 7K rated stainless clevis?
On the surface, you raise a good point. On closer examination, it doesn't make much sense. I just assumed most here would make sure each component would have more than sufficient strength before hanging their life on it. I have not tried this configuration but would trust it once I found and put together the proper (life support rated) components.
 
Greg, I'm familiar with the installation technique you refer to, but I prefer the method illustrated by X-man's site because I don't have to pull up as much weight and (I think) there's less chance of things getting twisted, tangled, or otherwise unusable. Plus, it looks slicker to judges who aren't used to seeing such high-falutin' tricks (mostly in TX guys pull their rope up with no FS).

Good point about using a larger pulley, too. I get caught up in the aesthetics of things too much sometimes. I like the idea of a super compact system, and miss the obvious solution in an effort to achieve a questionable goal. Last year, it was my MT tails made from dbl-braid spliced rope. I wanted to show off my nice, new splice and failed to notice in time that these tails didn't run as fast as teh good old three-strand I was used to, so I missed the landing target in the work climb.

At least I can say I'm working out the bugs early this year.

thanks again to all,
k
 
I've tried installing the sheave from a cmi micro pulley and it works. I had to get an oil lite brass bushing with a ID of 5/16 and OD of 1/2. The only problem is that rope wont stay on the sheave. It can roll of to the sides. I can't seem to find a way to keep it inline. Does anyone know if this ever a problem with RG setup?

BigJon
 
Ok kieth , I didnt know if you knew about that option or not. I dont use it either...lol...Do you clip straight across to your throwline with your binner instead of pulling all the through the secoundary side ?

Flipping 16 footers...
Greg
 
Big Jon, the sheave in the RG is deeper than the CMI and doesn't allow the line to shift. also when I tried the pulley and clevis set-up w/friction saver the big ring would restrict the pulley from working because they were in direct contact. are you using it in the same set-up? i have been using the petzl fixie but will search out other pulleys thanks to some earlier posts.
 
Greg, yeah that's the main reason I went to a homemade FS, so I'd be able to open the biner instead of threading the whole line thru the ring in my old b'ham strap. Of course, it's also nice to be able to switch to different lengths without any real problems and to have a bigger bend radius. I broke down and ordered the Wall pulley suggested by Tod, and I hope by this weekend I'll know if it works. Otherwise, I guess I'll just move up to a bigger pulley since it looks like th Fixe is a no-go.

k
 
FYI

ANSI Z133.1 -2000

3.13 false crotch. A system used to support an arborist climbing line other than a natural crotch. A false crotch shall incorporate rings or a pulley, or some other device that will protect the system and/or arborist climbing line from damage or failure. Each component of the system shall have a minimum tensile strength of 5,000 pounds.
 
Re: pulley for friction saver--update

Well, I got the Wall pulley yesterday, and it was a bust. The max rope diam. is listed on the package at 11mm. Even if I wanted to push that, the splice is too big to pull through.

In the interim, I saw a couple of pulleys at REI that do work. They were both Petzl, both identical size. One was red with a plastic sheave, the other blue with aluminum. The red one was $21, the blue $45 or so.

Now, it's fairly obvious why the plastic one is cheaper, but I'm curious to hear any comments on whether I should avoid it. I'm pretty gentle on my gear generally, and we all know how much safety factor is built into the application I plan to use it for, so I'm leaning toward the cheaper item (which goes against my normal practice--I'd rather buy quality instead of quantity).

TIA,
Keith
 
Re: pulley for friction saver--update

"red with a plastic sheave"
You're not referring to the Petzl Oscillante are you, see
attachement ?
It is only rated at 18 kN as far as I know.

If it's another pulley and the rating is ok, I see no problem
with having a plastic sheave. I believe there is a plastic
sheave on the RopeGuide's pulley as well.
 

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Re: pulley for friction saver--update

No, this was model p102 or something like that--more like a 2" sheave, maybe bigger. It definitely meets ratings requirements, I just wonder how well the plastic would hold up over time.

k
 
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