Deciding on the best method of tipping a dump box

[bcp]

Unless there are reasons not to, build the bed (or sides) a couple of inches wider in the rear to ease dumping.

Bruce

Sorry Bruce. i don't quite comprehend what you are saying. The bed is going to be 42 inches wide. What are you suggesting?

If the bed tapers a bit, the load will come out easier without sticking to the sides as much. Won't matter much with sand or gravel but helps with anything sticky.

The bed could be a rectangle, but the sides could have a spacer on the front post to narrow it a bit.

Bruce

 

[hydriv]

OK... thanks for the clarification.

 

[J_J]

I would recommend building the bed straight.

If you want material to slide out better, just add wood guides in the front at a angle, or make a half circle with some kind of material so there are no corners for material to stick.

 

[hydriv]

My sincere thanks to all who took time to post in this thread.

 

[dfkrug]

Leejohn - according to the other thread that I read on this site, it is essential to take into consideration the
angle of the cylinder at the start of the lift because the push needed at a low angle is much greater than
what is needed as the cylinder lifts the box to where the angle is around 90 degrees.

Yes, you should design for the greatest force needed: when the bed is down. You need to use a little
trigonometry to figure out that force from the angles involved. I don't know which thread you viewed, but
I posted something recently on a designing the hydraulics for a simple one-cyl, direct-acting dump bed.
The force calcs are a little more complicated for a scissors-style dump.

See posts 28-29:
http://www.tractorbynet.com/forums/...ydraulic-dump.html?highlight=homemade+utility

 

[SATOHBULL]

From the description in the first post, it sounds like a Case/Ingersoll hyd system. If it is, consider this: Usage of a larger cylinder would allow connecting it to the lift circuit. That would provide a much more controllable flow. If necessary the relief can be adjusted upward to provide more power. I think most are at around 575. On my own machine I wouldn't hesitate to go up to 750. If you install an isolation valve so that the mid lift doesn't see the pressure, 1000 wouldn't be an issue.

 

[hydriv]

From the description in the first post, it sounds like a Case/Ingersoll hyd system. If it is, consider this: Usage of a larger cylinder would allow connecting it to the lift circuit. That would provide a much more controllable flow. If necessary the relief can be adjusted upward to provide more power. I think most are at around 575. On my own machine I wouldn't hesitate to go up to 750. If you install an isolation valve so that the mid lift doesn't see the pressure, 1000 wouldn't be an issue.

You are correct with respect to the tractor choice. However, cylinders over 2 1/2 inches in diameter become very pricey. Secondly as you pointed out, in order to effectively use the lift circuit to operate the trailer cylinder, a 4 port Selector Valve would be needed to isolate the mid-lift cylinder. In addition, lines from that Selector Valve would be needed to run to the quick connects at the rear of the tractor. All of this adds to the expense. Since he has a rear PTO kit on this tractor, he can use a cylinder that costs less than $90.00 from Surplus Center and eliminate the cost and work involved to make use of the mid-lift circuit.

Thanks all the same for the suggestions.