Dump wagon build

[CDN Farm Boy]

Correct me if I'm wrong, but location matters. The closer the cylinder attaches to the front of the box, the better. Lifting at the front edge of the box would need a lot less lift than lifting from the middle. Turning the cylinder and pushing from the back should or at least could, make for a more forward lift point on the box. A good thing. Course, this would also mean longer cylinder travel to achieve the same angle of dump. Seems like a longer cylinder would be easier and cheaper than building for less travel but higher total forces.
Or not.

That's exactly what rswyan was suggesting, but if my math was right, not quite that simple. At the same heights as I have now, with just reversing the mounting, due to the reduced effective angle of the cyl, would only have a net gain of about 550 lbs. Raising the bed 4" relative to the lower cyl and reversing the cyl would make a significant difference.

As for dump angle, this orientation would actually gain about 5 deg of dump with the same cyl.

Something still seems wrong with orienting the cyl this way to me. Aside from a couple people here, I've never seen one like this. Why are they not a more common design?

 

[rswyan]

That's exactly what rswyan was suggesting, but if my math was right, not quite that simple.

Without seeing exactly what you did for "math", I'd have no way of knowing.

At the same heights as I have now, with just reversing the mounting, due to the reduced effective angle of the cyl, would only have a net gain of about 550 lbs. Raising the bed 4" relative to the lower cyl and reversing the cyl would make a significant difference.

Just so we're clear here. when I say "reverse the cylinder" I'm talking about pushing the front of the deck up - not simply flipping the cylinder around on it's current attachment points.

IOW: new attachment points to push the deck up from it's front.

As for dump angle, this orientation would actually gain about 5 deg of dump with the same cyl.

Which orientation ?

Something still seems wrong with orienting the cyl this way to me. Aside from a couple people here, I've never seen one like this.

Really ?

Why are they not a more common design?

Might be more common than you're thinking ...

 

[CDN Farm Boy]

Without seeing exactly what you did for "math", I'd have no way of knowing.

I'll try to clarify...see next post. I'll have to condense my CAD drawings and hen-scratching to something more post-friendly but the results are in post #39

Just so we're clear here. when I say "reverse the cylinder" I'm talking about pushing the front of the deck up - not simply flipping the cylinder around on it's current attachment points.

IOW: new attachment points to push the deck up from it's front.

Yes, I thought I followed. 180 the cyl within the current mounts would do nothing but need longer hoses. Bed side cyl mount would be at the front of the bed but that would place the base end of the cyl at mid-point of the reach similar to Steve has in post #36.

Which orientation ?

As noted above vs my current setup. See drawings in next post

Really ?

View attachment 406166

Might be more common than you're thinking ...

Not the same orientation as I understood from your suggestion. That has both ends of the cyl at the front of the bed it is pretty much a 90 deg lift. Obviously the way to go to get the most force out of the cyl but you need a much longer cyl to do it. I'd need a 64" stroke cyl to get the same amount of dump angle that I have now from my 30" cyl. At a 90 deg lift, I could get by with a 2" or 2.5" bore cyl giving 6900 or 10800 lbs respectively of lift to get in the same effective lift area as with the 4" cyl mounted on the angle. Upside to this design is horizontal forces are eliminated but would require a TALL tower at the front of the wagon to mount the cyl, even with using a telescopic cyl.

 

[CDN Farm Boy]

As built:



As per my understanding of rswyan's (and others') suggestion:



Omitted from the drawing for clarity is that there is also 12" of rear overhang past the hinge and 21" of front overhang past the base cyl mount. Since these affect both designs equally, I left them out of the drawings. 4" bore cyl with 30" stoke running a guess of 2200 psi as that is my understanding of the factory setting of the relief valve on my tractor

 

[CDN Farm Boy]

The cold finally let up a bit and made it up to -8 today so I took the time to get some measurements and plug them into CAD to get the cyl angle. My 10 deg guess was pretty frickin close. Cad says 10.38 deg at rest. So using the link from Surplus Center forces go something like this:

Current:
10.38 deg = 4981 lbs of lift 4' from the box pivot
Lift whole thing 4": 13.39 deg = 6398 lbs of lift
Lift whole thing 6": 19.44 deg = 9201 lbs of lift - really don't want to raise it this much

If I were to reverse the mounts as rswyan suggests:
At existing height: 5.74 deg = 2765 lbs of lift 8' from the box pivot
Lift whole thing 4": 11.5 deg = 5512 lbs of lift

With factoring in the mechanical advantage of the lever of the box (if I"m calculating right), the second way would give me an extra 549 lbs of lift BUT also an extra 2216 lbs of horizontal push now trying to push the box off the front of the frame rather than the back. I'm not sure this is an improvement. Now if I were to reverse the cyl AND lift everything 4" I could gain 4626 lbs of effective lift for a total of 11024 lbs by comparison. This is obviously a big improvement but has the challenge of the cyl base mount being in the middle of the reach which is it's weakest point rather than now with it on the front frame. Anyone know how much force is required to bend a 3" pipe pushing in the middle of a 8' lenght?

If I got this right, I'm either going to weld it solid to the wagon frame at it's current height or raise it 4" and weld it solid. If that doesn't work, I'll incorporate a scissor lift once I look at the geometry a bit more.

In these calculations I made an error as to the length of the lever and the ratio between them. The second option should have had a factor of 1.8:1 not 2:1 for calculating equivalent lift. Lever length for the first (as built)option is 48" while the (my understood) proposal has a length of 86.5"

So to re-calculate the proposed layout:
5.74 deg = 2765 lbs of lift @ 1.8 lengths of the original lever (86.5 vs 48) = 4977 which is pretty much exactly what I have now. 2765 lbs of lift on a 86.5" lever is the same as the 4981 lift on the 48" lever. Please correct me if I'm wrong.

 

[Steve_Miller]

Something still seems wrong with orienting the cyl this way to me. Aside from a couple people here, I've never seen one like this. Why are they not a more common design?

Company Normand - Farm Dump Trailers

I did the same thing as these guys. I'm no engineer but it seems that you would need less push force the farther you move forward but it comes at adding cylinder length. My methology (brain says this should work) says that less force equals smaller cylinder size. I used the link someone posted here earlier to calculate forces needed. I worked out how far down I could go to the bottom cylinder mount and went from there to calculate length and cylinder size. Their pictures are not very big but you can see how the cylinders are mounted.

Steve

 

[CDN Farm Boy]

Interesting. I've only ever seen a Normand with the vertical front mount cyl.

There's no question that lifting at the front will take less force than lifting in the middle. The difference is if the design will provide the additional force or not. Within the constraints of my build, I don't have enough height to get enough effective angle to make it worth the redesign.

It probably works in yours because you planned it that way from the start. Still seems backwards to me but apparently it works

Once I figure out how to best get my lower frame rails anchored I will be able to properly evaluate if my setup actually works since it was the anchoring that was the weak link that failed. I don't even know for sure if I have enough lift or not. If then find my current setup doesn't work, I'll likely rebuild with a telescopic cyl mounted vertically at the front like a dump truck

 

[bcp]

If then find my current setup doesn't work, I'll likely rebuild with a telescopic cyl mounted vertically at the front like a dump truck

If you are buying a telescopic cylinder, get one to mount under the center of the bed. Then, by arranging latches and pivots, it can dump to either side or the rear.

Here is the first example I found:

3-Way Dump Trailer | Marvel Construction & Equipment Rental | Valparaiso, IN

Bruce

 

[CDN Farm Boy]

If you are buying a telescopic cylinder, get one to mount under the center of the bed. Then, by arranging latches and pivots, it can dump to either side or the rear.

Here is the first example I found:

3-Way Dump Trailer | Marvel Construction & Equipment Rental | Valparaiso, IN

Bruce

Those are neat, never seen one as a trailer, only as small tracked or wheeled buggies on construction sites. To use that idea, might as well start from scratch. Too much redesign for what I have now. Not to mention, too much vertical underbed height is needed for my tastes

 

[rswyan]

I'll try to clarify...see next post. I'll have to condense my CAD drawings and hen-scratching to something more post-friendly but the results are in post #39

Ok.

Yes, I thought I followed. 180 the cyl within the current mounts would do nothing but need longer hoses.

Actually just reversing it using the same mount points would reduce the force ... because the rod side of the has less surface area for the fluid (under pressure) to act on.

Bed side cyl mount would be at the front of the bed but that would place the base end of the cyl at mid-point of the reach similar to Steve has in post #36.

Correct.

As noted above vs my current setup. See drawings in next post

Ok.

Not the same orientation as I understood from your suggestion. That has both ends of the cyl at the front of the bed it is pretty much a 90 deg lift. Obviously the way to go to get the most force out of the cyl but you need a much longer cyl to do it. I'd need a 64" stroke cyl to get the same amount of dump angle that I have now from my 30" cyl.

Fab a scissor lift at the front that points rearward.

When the bed is full down, the scissor lift is already partial open.

Make the lower arms/rails for the lift somewhat longer the ones for the top (the top arms will sit "level", the bottom arms will already be angled upward)

Attach your cylinder to the hinge pin that connects the two sets of arms (or thereabouts)

Push the scissor lift open to raise, pull it closed to lower.

At a 90 deg lift, I could get by with a 2" or 2.5" bore cyl giving 6900 or 10800 lbs respectively of lift to get in the same effective lift area as with the 4" cyl mounted on the angle. Upside to this design is horizontal forces are eliminated but would require a TALL tower at the front of the wagon to mount the cyl, even with using a telescopic cyl.

I only posted the picture to illustrate the point being pushed/acted upon (the front), not necessarily the type of cylinder or it's orientation.