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I built this homemade block and tackle. As it has been used more and more I notice the rope is wanting to unwind. In the top yellow rope you can see a certain amount of "looseness".
The other major sympton of the problem is when the block is let out, the whole thing wants to twist up terribly. I usually have to turn it four or five complete revolutions to straighten out the lines before connecting it to the load to lift.
Anybody got any ideas of what I can do to prevent both these problems in the future.
I could probably just buy new rope (3/8" poly), it isn't expensive. But, I want to prevent the problem in the future.
thanks
Poly is nasty. Use a heavy hemp or sisal rope.
You did a really nice job making that block and tackle. I think it deserves some quality rope. ;) I'm a real fan of block and tackle use. A good one is hard to find and often very expensive. Come-alongs are great, but I usually favor the block and tackle. I've had my share of tangled-up messes. The rope I've got on mine now has way too much stretch, be aware of that too.
I may completely loss all credibility here... or maybe not, but here goes...
You either used the wrong end of that rope, or went the wrong way around the block and tackle.
Seriously.
Really, seriously.
I've had a couple old salts (sailor types) tell me that rope like that has a natural way of winding. If you go the opposite way from that, it will untwist, just like it is in your picture. If you go the other way, the twist stays nice and tight.
At least that's what my sailing buddies tell me (and from what I recall when I had the boat, it was true, too. Altho I only had one rope that wasn't woven - ropes like that are hard on the hands)
A braided or plaited wrap rope might have less tendency to unwind. I've bought some at Home Depot that I use for kids' tree swings.
Well... You jumped in first and I was too chicken. But... nearly 40 years ago from my dim memories of Navy days I think I recall a Bos'n telling me the same thing. So, for what its worth, try reversing the way the whole rope goes (swap end for end) and thread the blocks the opposite way to see if there's a difference. I 'spect there will be.
Quote from: JavaMan on May 24, 2010, 07:13:20 PM
I may completely loss all credibility here... or maybe not, but here goes...
You either used the wrong end of that rope, or went the wrong way around the block and tackle.
Seriously.
Really, seriously.
I've had a couple old salts (sailor types) tell me that rope like that has a natural way of winding. If you go the opposite way from that, it will untwist, just like it is in your picture. If you go the other way, the twist stays nice and tight.
At least that's what my sailing buddies tell me (and from what I recall when I had the boat, it was true, too. Altho I only had one rope that wasn't woven - ropes like that are hard on the hands)
I have 10 years in the Merchant Marines and I can verify that.
This is also true with things like long extension cords. When you
try to coil them, you will find that they coil easily in one direction and not the other.
Bruce
thanks guys, I'll reverse it tomorrow and report back.
Whew!
I am relieved that others have had the same experience I have! For a minute there I was thinking I would look the fool d*
I had forgotten about extension cords, too - must be the price of getting old(er) ???
If you always coil your ropes and cords with a single butterfly loop coil, you won't have problems with twist.
Okay, I swapped ends on the rope and reversed the direction of wind around the wheels and it's working much better...thanks guys.
I also found out that 300 lbs is about the most I can lift with my 6 wheel block and tackle.
So that is why mine keeps twisting!!! Thanks for the tip!
I have a really heavy set with 3/4" sisal rope and it really is a great tool to have. I righted (straightened the load) a 20' truck box that was dangerously tilting to the side on a rollback wrecker with my block and tackle and then used it to slide the body off the wrecker. Before you all get too excited, that was me doing the hookups and two other 200 plus pound rope pullers helping me pull the tackle free end. We had to grunt but we got it done without a wreck.
w* to the forum.
We all like to share and learn from each other here.
Get some static line (not rope) from a marine shop. Ask for something like a sheet line...
Would it be possible for me to get the specs for that block and tackle? It looks really good, I've been trying to find a good one for awhile, but buying them is really expensive.
I'll post the specs with the following understanding:
.this block and tackle was NOT designed by a professional.
.it wasn't tested in any meaningful way, so I have no idea what any upper lifting limits are on the block or the rope.
.you understand and realize that building one like it is wholly at your own risk.
The side plates are 1/8" steel plate and are 3" wide x 6" tall. I bought the steel at a scrap yard, so no idea on it's specs.
The axles (4) are 1/2" bolts, grade 5 I think, secured with locknuts.
The steel wheels are 2.5" diameter and are rated for 700#.
There is a thin aluminum "horseshoe" which goes around the middle wheel in both blocks, purpose: to "channel" the rope and keep it from coming off the wheels, or rubbing excessively on adjacent ropes. You can see the horseshoe in the pic.
The oval lifting rings at top and bottom are 3/8" diameter and centered in the block with lots of 1/2" washers.
I've been happy with the block's performance over the last year or so. I started out with 100' of rope and eventually added 25' more. Now that I reversed rope ends and direction around the wheels the poly rope has tamed down a lot making using the block and tackle much easier. My max lift so far has been 300 lbs. I don't think I will exceed that in the future.
Be safe, don't ever get under a suspended load. Keep your cell phone (turned on) in your pocket if working alone.