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Main Boards => The Bowyer's Bench => Topic started by: ColonelSandersLite on March 18, 2015, 10:57:00 PM
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So, how many of you are using a 2 pulley system vs a 1 pulley system? Your thoughts?
I'm considering trying double pulleys out soon for a few reasons, all of which revolve around the idea of halving the pull weight while doubling the travel.
The lower pull weight should reduce fatigue during the tillering process, making it easier to keep tillering for longer. Though part of me suspects that doubling the distance you need to pull the rope to get the same effect could be counterproductive in this regard. I would have to try it to form an actual opinion on validity.
Being easier to pull and having to pull twice as far for the same effect should make it easier to come to a specific draw distance and hold it steady, giving both a more accurate draw distance measurement and a more accurate poundage measurement.
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I've always used a single pulley. Never had a reason for a double, even when tillering a 95@30" yew ELB.
I like to be able to set the bow on the tree, hook up the rope, exercise the bow well and step back and look at and mark stiff and weak spots and not hold the bow at a static draw for more than a few seconds. It would take twice as long with a double pulley system I'd think.
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Never had a reason for more than one pulley. Seems to me the logistics of pulling 56-58" instead of 28-29" would be counter productive.
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One pulley. I don't draw the bow much past 40 pounds on the tree anyway.
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I have 4 pulleys.... all on the same shaft down by the floor :^)
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Originally posted by Bowjunkie:
I have 4 pulleys.... all on the same shaft down by the floor :^)
Doesn't count.
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I use a two pulley system and love it. It greatly reduces fatigue. I don't actually think I'm pulling the rope any farther now then I did with a one pulley system. I never really thought about it. I just now it is a lot easier for me.
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I use two pulleys, and like it.
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Originally posted by Robyn Hode:
I don't actually think I'm pulling the rope any farther now then I did with a one pulley system. I never really thought about it.
You are, it's basic physics. For every factor of mechanical advantage your pulley system yields (2 in this case), you must also multiply the distance traveled by the same. It's definitely possible to rig up a tillering tree that would increase this factor to 4 or even more, but that probably falls well past the point of diminishing returns.
Here's a simple primer:
http://www.explainthatstuff.com/pulleys.html
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Um, tillering is great exercise. If you fatigue from tillering, you need to do something about your upper body/cardio conditioning. You should also take the stairs and accept the parking spot the farthest from the door.
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Yeah, I like one pulley and never got tired while exercising the limbs, even on the heavy bows and I work em a lot. I often pull it, hold it with one hand, lean in, mark a spot needing work, and keep going. That might be impossible to do if I had to pull the string twice as far???
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one pulley-x2 wot Jon said
for me- if i needed more than a pulley, i might be questioning whether i could shoot the bow all day.
unless of course yunz real old, tired and hide out in Pa, then maybe two pulleys are ok :laughing:
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Originally posted by Bowjunkie:
I have 4 pulleys.... all on the same shaft down by the floor :^)
what do you use four pulleys for? I can see two, on for split finger, one for three under holds. even a third pulley if you wanted to look at a bow from both directions by flipping 180* in the cradle. why four? I need to improve my pulley. I hate the squeaky one I pilfered from an old extension ladder, but it works. is there such a thing as a pulley with bearings built in that I can just bolt the bottom of my tree?
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sailing shops will have "blocks"- sometimes called "snatch blocks' ( careful now :D :D )
that are designed to work under load- and have an attachment hook.
but the super system like BJ and Roy use- are two pillar blocks and a shaft with pulleys locked onto the shaft .
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Jamie I used two pillow blocks and a half inch steel shaft then used a regular pulley that I slide left or right for split or three under.
(http://i47.photobucket.com/albums/f165/ROY-CHRIS/pulley2_1.png) (http://s47.photobucket.com/user/ROY-CHRIS/media/pulley2_1.png.html)
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Here's my cheap a$$ way of doing it. I just slide the paracord to put the pulley inline with the bow shelf.
(http://i.imgur.com/AECZEgl.jpg)
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I use a single 1.5" pulley. But, I never use my tree for tillering so fatigue isn't an issue :)
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can I buy pillow blocks and keyed shafting at local hardware store or Tractor Supply or something? looks like an excellent set up. :thumbsup: better than what I have now, for sure.
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Yup.. I just bought a straight round 1/2" shaft, then ground a flat spot on it for my set screw on the pulley to affix it to the shaft. I just slide my one pulley left or right for split or three under tillering. Or you could use two pulleys.
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Jamie, mine looks like Roy's, but with 4 pulleys... simply so I don't have to move them each time. If I want to flip the bow and look at the other side, I just do it... takes seconds. The 2 outer pulleys are for split finger holds and the 2 inner are for 3 under.
I used a 1/2" piece of drill rod for the shaft. The shaft doesn't need a keyway broached in it. The pulleys are held to the shaft with allen head set screws.
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If you can't find them locally, you can get the pulleys and bearings on ****... I got the smallest pulleys I could with a 1/2" center hole so they would clear the wall without having to make pedestals for the bearings.
I didn't grind flats on the shaft, just tightened the allens, and they hold well, even on the hardened drill rod.
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"****" means the big auction site.
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thanks fellas. I'll be going after parts tomorrow. be nice to have a good pulley system after all these years.
Roy, did you have to bolt to the floor for clearance for the pulley?
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Yes. The pillow blocks sure make a smooth system. This is the top pulley with like a long U shaped mount on top, top pulley has ball bearings in it.
(http://i47.photobucket.com/albums/f165/ROY-CHRIS/IMG_7869.jpg) (http://s47.photobucket.com/user/ROY-CHRIS/media/IMG_7869.jpg.html)
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https://www.youtube.com/watch?v=lp49vxL-Sf4&list=UUBMjR2l-xfFufcLpkUpYYBQ
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Originally posted by John Scifres:
tillering is great exercise. If you fatigue from tillering...
If tillering is great exercise, you will fatigue from tillering, especially if you spend most of the day or most of a couple of days doing it. I have a bad lower back. Tillering is not an issue on its own, but it is an issue when mixed with other activities.
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Originally posted by J.F. Miller:
Originally posted by Bowjunkie:
I have 4 pulleys.... all on the same shaft down by the floor :^)
what do you use four pulleys for? I can see two, on for split finger, one for three under holds.[/b]
His setup has 2 for right handed bows and 2 for lefties. There's a pic in this thread: http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=012442;p=3
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On the subject of pulleys, for some reason, the hardware stores around here have horrible pulleys.
Home depot:
The pulleys where not straight in any way shape or form. The pins where in crooked on a lot of them, and the grooves for the rope where not centered or straight. This means you'll have problems with the rope sliding off the pulley. Just pure junk.
Ace hardware:
It says right on their pulleys that they are not rated to be used for lifting a load. I.E. they are not real pulleys.
Lowes:
Their pulleys seemed fine, except most of them have a problem with there being a big casting seam on the wheel which will make it chew through ropes. I opted for these as the lesser of evils, and just ground the seams smooth myself.
I have yet to check Mernards though.
So wtf? Where can you even get decent pulleys these days? Someone mentioned sailing shops, but there's not much call for those for us land locked state people.
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Not for left or right handed bows, Colonel... just so I can flip the bow around and view it from the other side.
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Those pulleys of mine, the ones in the picture in the thread you posted the link to, also had a couple of casting ridges that I had to clean up.
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ColonelSandersLite my fatigue is from lower back pain as well. I have three herniated disks in my lower back and find the two pulley system easier to use after working all day. I bought 2 inch pulleys from ACE hardware and haven't had any problems.
My two pulley set up is similar to Roy's. I set it up based on the instructions Terry Green posted here on TradGang under the Topic: How to Make a Tiller Tree - (Jeff Sheyn). You should be able to find it under Topic Archives >> How to - Resources >> How to Make a Tiller Tree - (Jeff Sheyn)
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Originally posted by Bowjunkie:
Those pulleys of mine, the ones in the picture in the thread you posted the link to, also had a couple of casting ridges that I had to clean up.
You too huh? I was tillering today. First time with that pulley I mentioned (I haven't done a 2 pulley setup yet). At first, everything was fine. After a little while, it started squeaking. Then it started more screeching with every pull. I took it apart and found out that they didn't even bother lubricating the dang thing at all except *maybe* a very light coating of wd-40 or something similar... Fortunately, I had some automotive bearing grease sitting around that quieted it down. What a pain in the ass though. So seriously, wtf is it with pulleys these days?
Originally posted by Bowjunkie:
Not for left or right handed bows, Colonel... just so I can flip the bow around and view it from the other side.
Oops :p .
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@Robyn Hode
Good to know it helps your back out. I'll definitely have to try it out on my next bow then. Won't get the chance on this one though. That basic layout is what I was thinking of as well. Here's the actual link for the convenience of anybody that reads this thread. http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=2;t=000016
As for ACE's pulleys, either your particular store is carrying some better stuff than mine or it's not rated for lifting. Even though the stuff I saw would probably work, I'm just not willing to buy from a company that won't stand by their product even a little bit. It's like buying a bow from a bowyer that says their bow is not rated to shoot arrows. Just... No...
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Google Petzl climbing pulleys
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My top pulley with the bearings in it is for a garage door cable. It's well constructed. My lower pulley is one that slides onto the shaft of an electric motor.