Superduty dump build

[powerstroke444e]

Well usually don't post till the project is finished but thought everyone on here would get a kick out of this.
Started as a 97 superduty ief450 with a 12 foot flatbed with tool boxes on it.
Great truck but couldn't pull my gooseneck and I really needed a dump bed, and I had a pile of metal laying in the barn and a big cylinder lay next to it screaming build a dump.
I dont have the all the photos on this computer but here is the before and where I am now and some in between shots.

New bed is 8 foot wide with 6 foot between toolboxes and 10 foot long. pretty much a service truck that dumps, most of the time will be used for hauling pea gravel or the clean up mess left over on a job sites. Not for daily trips hauling to the quarry.
Yes I know the tools in the boxes will slide to the end when it dumps I am putting dividers in the boxes for that and still better than using a shovel.

 

[2458n]

How does the bed height compare with a regular truck ? Are you able to use your gooseneck trailer with other trucks? Super nice build. Had a truck like this when working for a pipe line company , always finding uses for it on jobs.

 

[LD1]

Nice build.

I did one on an old dodge 1 ton about a year and a half ago. Only I used two cylinders outside the frame. I couldn't come up with an easy way of getting around the driveshaft with the cylinder and cross peices without spending big $$$ on a telescoping cylinder.

A few questions for ya as I am just curious

What are you using for hydraulics??

And have you calculated the dumping force yet?

 

[powerstroke444e]

The bed is actually about 1.5 inches lower than the flat bed I had on it. The cab to axle is 84 inches and I had to cut about 2.5 foot off the back of the frame so I could get the gooseneck to clear the back and keep the gooseneck ball about 6 inches in front of the axle. With the tool box on the side I will be about 2 inches higher than my other trucks with a regular bed on it. Most of the time it will have a pintle hitch trailer on it but I wanted to be able to use the gooseneck if needed.

The cylinder force my math says if it wont dump it its way overloaded. As I have a 5 inch 1st stage and 3 or 2.5 second. The most that should be on the truck is about 6,500lbs to stay in side of max gvw 15,600. Which only about half of that is what the cylinder needs to lift due to being at the front so it really over built, but figured some day may put the bed on something bigger.
Using a 12v pump and it takes about a minute to go up and a little longer to go down. Reason I used what I did is it was I didn't want to spend much on it so just used what was laying around.
Hope to have it ready for paint in next week or two.

 

[LD1]

The reasone I asked about the force is because it looks like the cylinder is mounted on a pretty good angle when the bed is down. But I could be wrong. This greatly diminishes the starting force. And the little 12v self-contained units are usually only 1600psi or 2000psi.

Would have to know what angle the cylinder is on in relation to the bed to accuratly figure it.

 

[powerstroke444e]

The reasone I asked about the force is because it looks like the cylinder is mounted on a pretty good angle when the bed is down. But I could be wrong. This greatly diminishes the starting force. And the little 12v self-contained units are usually only 1600psi or 2000psi.

Would have to know what angle the cylinder is on in relation to the bed to accuratly figure it.

Back pin is 15 inches below top pin 36 inch closed length? Pump is set @ 2500 but I think I am going to back it down as I don't think I should need but 1500 or so at max load. Figure away but didnt want to use to cylinders as takes to much fluid and had to work around drive shaft and fuel tank. My best guess is it still beats a shovel.

 

[LD1]

Back pin is 15 inches below top pin 36 inch closed length? Pump is set @ 2500 but I think I am going to back it down as I don't think I should need but 1500 or so at max load. Figure away but didnt want to use to cylinders as takes to much fluid and had to work around drive shaft and fuel tank. My best guess is it still beats a shovel.

That is only half the battle. being 15" below the top pin is only half the battle.

Assuming you used the deck as a reference point, that puts the cylinders on a ~24 degree angle to the deck. But you need to know the angle in reference to the deck pivot.

IE: draw an imaginary line from the rear bed pivot to where the cylinder hooks up. This is the "actual" line the bed pivots on.

So basically, if you could measure the distance between these two points, AND how far down from the top deck they are, I could calculate that angle, and take it off of the 24 degrees, and be all set.

But you should be fine either way. Even if it comes up to a 15* effective angle for the cylinder, that is still 25% of the force lifting.

And a 5" cylinder @ 2500psi x .25 is still ~ 12000lbs.

 

[powerstroke444e]

But you should be fine either way. Even if it comes up to a 15* effective angle for the cylinder, that is still 25% of the force lifting.

And a 5" cylinder @ 2500psi x .25 is still ~ 12000lbs.

I did the math on it when I started cant find figures but it was something like around 18 degrees and once I noticed I was in the 10000lbs plus on 1st stage range figured all was good I know second stage is good for about 15000lbs when its all the way out. even if I put this bed on a f650 I still have more bed than truck.

 

[Iplayfarmer]

Back pin is 15 inches below top pin 36 inch closed length? Pump is set @ 2500 but I think I am going to back it down as I don't think I should need but 1500 or so at max load. Figure away but didnt want to use to cylinders as takes to much fluid and had to work around drive shaft and fuel tank. My best guess is it still beats a shovel.

All of the math boils down to this simple equation... To find the portion of the force that is vertical, divide the vertical distance between the top and bottom pin (15" in this case) by the closed length of the ram (36" in this case). So, 15/36 or about 0.417

Multiply this number by the ram force and you get the force that is acting directly upward on the bed to dump the load. In this instance the 5 inch ram with 2500 PSI has 49,087 pounds of force. Multiply that by the number from above and you get 20,469 pounds of force acting vertically to dump the load.

Now, there's a whole other set of equations to determine how much force is required in a rotational direction to dump a load. That's where LD1 needs the distance from the dump pivot to the ram pin, how far the bed sticks out behind each point, etc.

 

[LD1]

All of the math boils down to this simple equation... To find the portion of the force that is vertical, divide the vertical distance between the top and bottom pin (15" in this case) by the closed length of the ram (36" in this case). So, 15/36 or about 0.417

Multiply this number by the ram force and you get the force that is acting directly upward on the bed to dump the load. In this instance the 5 inch ram with 2500 PSI has 49,087 pounds of force. Multiply that by the number from above and you get 20,469 pounds of force acting vertically to dump the load.

Now, there's a whole other set of equations to determine how much force is required in a rotational direction to dump a load. That's where LD1 needs the distance from the dump pivot to the ram pin, how far the bed sticks out behind each point, etc.

You are half right.

Assuming the bed is level AND the rear pivot of the bed is on that same "level" plane, the vertical componet acting on the bed IS indeed 15/36 of the total force.

BUT since the rear bed pivot is BELOW this plane, the resulting "effective" angle of the bed that the cylinder is pushing on is a line drawn between the rear pivot and the cylinder mount-bed pivot.

So what you have is a cylinder mounted at ~24* angle pushing on a bed that is level on the top, in reality is actually ~ 10* angle.

Se my attached crappy paint drawing.

The angle needed to be used is the angle from the green "imaginary" line to the cylinder. And NOT the angle from the cylinder to the bed.

This will give the vertical lift at THAT point. But then theres the whole issue of how far forward on the bed the cylinder is mounted in relation to the rear pivot and CL of the bed itself. If the bed is 100" long for example, and the cylinder is hooked @ 50", the dump capacity would simply be the SIN of the angle mentioned above x the cylinder force. BUT if the cylinder is mounted farther forward of the rear pivot, like at 60", this increases the capacity by 6/5ths. And if farther back, it reduces capacity.