robs660
Gold Member
Working on similar What size winch are you going to use?
cable operated dump trailer
- Thread starter Army grunt
- Start date
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robs660
Gold Member
Working on a similar trailer. What size winch are you going to use?
Army Grunt,
It is good to see that you found a good service dog. He/she should be a good friend for years. Hopefully you will have a productive time while still there and learning about each other.
I was thinking along the same line since Army Grunt first posted pictures of the build but I thought the 3:4 block and tackle might be able to handle it. I had no idea of the actual numbers involved.
I have been thinking of building something similar but using an 1800lbs boat winch. However I thought I would connect the cable to the scissor mechanism in the way shown in my Charlie Brown sketch. I thought of putting a pulley or something like that on the front edge of the dump box so the first 12-16" of the pull is almost straight up from having the winch mounted on a post. I was going to use 2:1 block and tackle. Any thoughts?
It is good to see that you found a good service dog. He/she should be a good friend for years. Hopefully you will have a productive time while still there and learning about each other.
I was thinking along the same line since Army Grunt first posted pictures of the build but I thought the 3:4 block and tackle might be able to handle it. I had no idea of the actual numbers involved.
I have been thinking of building something similar but using an 1800lbs boat winch. However I thought I would connect the cable to the scissor mechanism in the way shown in my Charlie Brown sketch. I thought of putting a pulley or something like that on the front edge of the dump box so the first 12-16" of the pull is almost straight up from having the winch mounted on a post. I was going to use 2:1 block and tackle. Any thoughts?
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LD1
Epic Contributor
That would be a lot better than a direct hook to the scissor and pulling in a straight line. I Acutally like that Idea a lot. It will help start the dump and open the scissors and then a much better angle is achieved before the scissors have to do all the work.
And if you plan on using a hand crank boat winch, you wont have to bend over as far to crank.
No real good way to figure the capacities without some measures though. You have to account for the measurments of the scissor mechanism itself, How long the cable is between the winch and scissor, measurments of where the contact point on the nose of the trailer is in relation to the scissor and winch, the angles of the line across that pulley, etc. Lots of variables. But that method will definatally take much less force than the previous mentioned idea.
OP
Army grunt
Platinum Member
easygo,when I first started planning this system the winch on a post was my first setup, my thinking was the cable would go around a pulley mounted on the front this would get the "start-dead pull".Than my Buddie said he would design a 3to2 block an tackle using 3" wheels. an we could power it with one of those inexpensive 12 volt winches from northern tool($50.00)So that's where we are at, the sizzors are not closed, they are at 15 degrease apart from start.It will be a few weeks till i get home to do more on it Ill post update then. later
Army Grunt
Army Grunt
LD1
Epic Contributor
So are you going to use the pully in the front to start the lift?? If so, I think you are going to need it.
I would still need to know the length of the scissor arms to accuratly calculate it, but assuming ~16" arm length and with the 15 degree open, roughly 13x more force is needed in a straight pull. So if you are using a 3000lb winch, (Not sure on the block and tackle but is a 3 to 2 a 5x's increase in pull??) if so, you would have 15000lbs avaliable. Divide that by 13 and you are looking at an upward dump force of only 1150lbs without the pully in the front of the trailer to start. If the scissor arms are shorter, this would be a little more, it the scissor arms are longer than 16", it woudl be even less force.
OP
Army grunt
Platinum Member
Time will tell.
Army Grunt
Army Grunt
Woohaa. I'm learning here big time. Thank you. :thumbsup:
I guess the shorter the scissors' arms the more power they produce. But also shorter arms would force the scissors back towards the aft hinges in order to achieve the same degree of lift thus increasing the power needed for said lift. :confused2: How can we win this? There is no arguing with math so something else have to give.
A former teacher of mine used to say: "Nothing is for ever except for math or a large boulder. But math will probably outlive any stone."
I can't wait for ArmyGrunt to get home and continue with his project.
LD1
Epic Contributor
The reason the shorter arms will give more power is because it isn't trying to lift the dump as far as fast.
What I mean by this is (These arent actual numbers, but just an example.) Say the arms are 15" long with said angle. If the winch pulls say 1", this will force the scissors open a given amount. It the same angles were used but said arms are longer, it is trying to open FARTHER with that same 1" of winch travel. If the arms are shorter, and the same angle used, The scissors will open less with that same 1" of winch line pull. So obviously it will be harder to lift a farther amoung with the same force applied for that 1".
The downcall is that shorter arms will give less overall dump angle.
I think the only way to win is with the pully at the front.
Just as it is getting to the point where it will stop helping the scissor, the scissor is already open far enough to not require a great deal of force to finish the job.
6thgpSF
Gold Member
ArmyGrunt,looks like a nice job so far.Is that saw mill yours?On a side note,I see you are a Nam VET.Welcome home.173Abn/VN here. russ
