Designing Electric Dump On Trailer

[npalen]

I'm needing to come up with a power dump on my 4'x8' "monster" trailer used mainly for hauling lawn and garden residue to the local landfill. Been thinking about installing a 12 volt winch under the trailer to accomplish this in conjunction with the existing tilt feature on the trailer. Would mount the winch to the underside of the bed and behind the trailer's axle with the cable and hook extending up to the underside of the tongue at the front. Pulling the pin and letting the trailer tilt up (about 20 degrees) would then give the winch roughly a 16" lever arm measured between the cable and the tongue tilt pivot point which is about 17" ahead of the wheel centerline.

I've seen some of the homespun lifts that use a cylinder or jack mounted to the front of the trailer to tilt it but I want to get at least a 60 degree tilt to make sure it empties completely. When the pin has been pulled and the trailer tilted up the tail end will be resting on the ground. I'm thinking of a 3" or so diameter roller(s) mounted under the trailer at the tail end that would let the trailer bed move toward the pickup as the winch tilts it to the full dump position. An alternate to the roller(s) would be to simply leave the pickup in neutral so it can roll back when dumping. The winch has remote control so that I can be in the pickup cab in either case. The advantage of the roller(s) would be that the load could be dumped completely by pulling ahead a few feet with the trailer in the dumped position. Some of this may sound a little silly but I guess the general concept comes from watching trucks unload and reload scrap dumpsters.

I have yet to do any calculations based on geometry but am fairly sure that the 3000 lb winch will more than handle the fairly light load but wondering if you guys have any thoughts on the idea or perhaps have seen something similar that you could share.

 

[npalen]

Edit: Forget to mention that the trailer tires will be up off the ground a couple feet with the trailer in full dump position.

 

[Xfaxman]

Edit: Forget to mention that the trailer tires will be up off the ground a couple feet with the trailer in full dump position.

Like this.



I have had it completely upside down when on the higher front hitch on the MF 240D tractor.

 

[Nooodles]

How about this ejector idea instead. Uo would probably need a little bigger winch though
Easy to build firewood unloader - A step by step guide - YouTube

 

[npalen]

Interesting stuff, guys! Does anyone know offhand what kind of dump angle is needed for general use such as lawn and garden debris? I see know that 60 degrees would be difficult to achieve with my rig but 45 degrees would probably be doable. I am working on a layout which I hope to post.

 

[npalen]

This is a prototype/mockup of what the winch/lift will look like under the 4x8 trailer. The geometry works out fairly well but haven't tried it yet with a load. It does make the HF 3-ton winch groan and slow down when starting the lift but the lever arm (shown with the arrows) increases rapidly as the trailer pivots on it's rear end.

I'm considering adding a drop-down lever arm attached to the tongue. It would drop down when the pin is pulled letting the trailer tilt back to the start position of the winch lift. The drop down lever would have a pad on the end for the cable to seat against during the lift.

The tongue pivot is a little hard to see but consists of a 1" diameter pin welded to the tail end of the 2x2 tubing tongue. It pivots in two bushings welded to the trailer frame. I'm considering improving this by widening out the pivot with a v-shape at the rear of the tongue. (To give the tongue more lateral stability.

Any thoughts, suggestions etc on what might be done to improve this approach?

 

[jaotguy]

you need a new pivot point on the belly of the tongue ....

right now you have a straight pull on the rear of the box to the tongue ... put a "block" between the cable and the tongue... it will change the geometry of the pulling forces ..... think of 2 people holding the ends of a rope, a small child can press in the middle and pull the 2 adults together.

 

[M E Race]

As your pivot point is pushing the bed up, the further ahead of center point the less strain you will have on your winch. A snubbing device would prevent trailer from going completely over in case of a rollback.

 

[BigMike50]

that looks to be a 2-3000 pound winch. There is no way that that wich will lift a 4x8 trailer to dump filled with material at that angle at all. maybe grass clippings. That trailer will easily hold 2 yards of dirt which can weigh over 2 tons. Even if you put only 2000 pounds in that trailer, the way you have it set up would be like trying to pull 4000 pounds or maybe more. For the wich to use its capacity, It would be have to be mounted at the front of the hitch with a boom pole welded just before the bed along with a couple pullies so it is lifting the front of the bed

 

[npalen]

Here's what I've come up with so far:
The winch is a 3000 and, yes, yard and garden residue is probably all it will handle and that is my intention. The black lever added is a piece of 2" SQ aluminum and, yes, it does increase the mechanical advantage considerably. The cable passes thru a small hole in the backside end of the lever and the clamp behind it ensures that the lever will be tucked up under the tongue for road transport and held by the winch.
I'm concerned that I won't be able to get sufficient dump angle because of the 2" ball hitch bottoming out when the tongue is tilted at an angle to the towing vehicle. Will have to do some testing and perhaps some further mods.
I appreciate the thoughts and suggestions. Keep 'em coming!

Edit: I have looked at some of the designs where guys have mounted a post on the front of the trailer with a sheave at the top along with a winch down below. They appear to work well but I don't care for the idea of the long post sticking up in the air.

Edit 2: I did remove most of the extra cable from the winch drum so that it gets more leverage on the cable by applying the load at a smaller radius. Makes me wonder how winches are rated--with a full load of cable or down to the last few rounds on the drum. Makes a big difference although they are probably greatly over rated anyhow.

 

[Xfaxman]

I don't see how the winch pulls the lever down to the starting position, or do you have to push it down by hand?

Notice the black line that I added, you are losing mechanical advantage once the cable gets above a straight line.


But it may not matter, because after the back of the trailer hits the ground, you will have to back up the tow vehicle to get more dump angle, since the winch won't drag the back of the trailer forward.

Winches are rated on the first layer.

 

[npalen]

The lever does have to be pushed down by hand. I realized after running the cable thru a hole near the end of the lever what you're saying on losing leverage and may do that differently. I'm thinking that the winch will drag the back of the trailer forward provided it has enough power. Thought about putting a couple washing machine rollers under the trailer tail end to make it easier on the winch but may just leave the tow in neutral so it can roll back. BigMike50 mentioned that no way the 3000 winch is going to handle the load and he may be right. May have to go to a heavier winch. My biggest concern at this moment is whether or not I'm going to get enough dump angle when the end of the ball hitch bottoms out on the front side of the 2" ball mounting surface on the bumper.
This is one of them "design as you go" projects and it sure helps to have input from you guys out there.

Edit: Would it work to mount a sheave at the front of the tongue where the cable is now attached and then run the end of the cable back to an anchor point next to the winch? That should double the power but cut the speed in half, right.

 

[npalen]

I did a test run yesterday with a near full load of grass clippings. The winch seemed to handle the load easily and the dump angle of about 33 degrees did the trick. Anxious to see what it does with a full load. Had to leave the pickup in neutral so it could roll when dumping as well as when letting the trailer bed back down. Worked OK but still might look at putting rollers under the tail end of the trailer so the tow vehicle could be left in Park when dumping.

 

[Xfaxman]

Glad to hear it worked. How is the hitch ball clearance?

Have you thought about splicing more wire on the winch control, so you could sit in the truck with it in reverse, and help the winch a little?

 

[petegoud]

Have you thought about using a couple of rollers similar to those used on boat trailers in the back of the trailer. Leaving the brakes off during dumping is asking for trouble.

 

[npalen]

Good ideas, guys! Would be easy enough to splice on to the remote. Yeah, I figured I would hear about leaving the brakes off during dumping Hadn't thought of the boat trailer rollers though. I had thought of washing machine rollers but that's telling my age.
The hitch ball clearance is just enough. The 3000 pound winch seems to be adequate so far so the rollers might be the cat's meow.

 

[npalen]

Double post, sorry.