Dump trailer

[Nat]

I have the hinge done for the dump. The 5" channel subframe web isn't strong enough for the hinge so I had to put a sleeve in it. I have a piece of 1/2 x 4 plate that goes from the top of the mainframe extending down to the bottom of the subframe. I cut a hole in the 5" channel and capped the open side with a piece of 4'' X 4 1/2" X 3/8" plate and welded a piece of 2" ID DOM tube from the channel to the flat plate. I was going to use 1 1/4 shaft for the hinge pin, but decided to use some 2" that I had laying around. The 2" shaft wasn't long enough to extend thru and drill for a cotter key, so I welded a cap on one end and drilled and tapped a hole in the end and will bolt a piece of flat bar to keep the pin in place. It's hard to discribe what I'm talking about, but maybe this pic will Help.

[Nat]

I'm not5 used to this stuff and my shoulders are killing me so I'm going to do something different tomorrow. My axles and tires won't be in till Mom, anyway so it won't hold me up

[GaryM]

Looking very nice Nat. Sounds as though your engineering it as you go along. I guess you have enough experience to do that. [img]/forums/images/icons/smile.gif[/img] I know that I don't. [img]/forums/images/icons/frown.gif[/img]

Are the body sides going to be steel, or perhaps wood?

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] Gary, it's simple: Bore Squared X .7854 X PSI X ELA=Torque. [img]/forums/images/icons/smile.gif[/img] Load weight X ELA = Torque. [img]/forums/images/icons/smile.gif[/img] If the first product is greater than the second, the trailer will dump. If not, then oh well. [img]/forums/images/icons/frown.gif[/img]
(ELA is effective lever arm) [img]/forums/images/icons/crazy.gif[/img]

[Nat]

CJDave, Help me out here a little. I always use the radius squared times pi times pressure per square in to give me the pounds of push. In my case with the 4" diameter of the first stage I'll have 20096 pounds of push, but I don't know how that relates to how much it will dump. The anchor end is 8'9" from the trailer hinge the "live end" is 6' from the hinge end and the anchor end is 11" lower than the "live end". What is the ELA, and where does the .7854 come in. Sounds like you know what you are talking about so it may be something I need to know in the future, Later, Nat

[Nat]

A guy on TBN sent me a link to this website http://www.baumhydraulics.com/cyl_calc_ang.htm
From it it looks like I'll have 6877 lbs of lift at the "live end" of the cyl. That is about 6 ft from the hinge so should be more than I'll ever need. It is a neat site that may come in handy for someone

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] The ratio between the area of a square and the area of the inscribed circle is .7854. A Circle is .7854 of the same size square. So if you have a 4 X 4 post and throw it in a lathe and turn it into a round shape, the new area of the end of that post is 16 X .7854. [img]/forums/images/icons/tongue.gif[/img] What you need to know Nat is HOW HIGH above the pivot pin the live end cylinder trunion is. If you draw a line through the trunion pins of the cylinder, and then drop down and draw a parallel line which goes through the pivot pin of the dump bed, the distance between those parallel lines is the Effective Lever Arm that the cylinder has to work with when the dump is at the bottom. Then figure the load in pounds and the average distance from the pivot pin that the center of load is, and that distance is the Effective lever Arm of the load. So Load (pounds) times Effective lever Arm(inches), equals Torque Required. Then cylinder PSI times Area times Effective Lever Arm is the torque available. Hopefully the "available" is greater than the "required". [img]/forums/images/icons/tongue.gif[/img]

[Nat]

CJDave, I did the calculations you suggested and I come up with some weird numbers. I have 20106 as the (sq of the cyl X the psi ). From the live end of the cyl pin down to the hinge pin of the bed is 10", so 10 X 20106 =201060. The expected load is 6000 lbs so 6000 x 10 =60000. since 60000 is less than 201060 it will work.
So if I subtract 60000 from 201060 and then devide by 11 I get 12823. Is that how much it should dump?
Thanks, Nat

[Nat]

Well, it's do-over time. I gave it a dry run today, by hooking up the hyd. hose and running jumper cables from my truck. My cyl. is to big. I run out of the 2 1/2 gal resavior before it is half way up. I had just measured the ram on my 2 stage cyl, and it was 4". That was fine , except the piston is actually 5". So I don't have enough volume of fluid to use that big of a cyl. It is cheaper to get another cyl, so I ordered it from Northern today. I'll also have to re do the mounts because the cyl I have has a welded end and the cyl. I'm getting is clevis mount. Not a big problem, but stil would rather it worked right the first time., Later, Nat

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] Actually, the Effective lever Arm for the load may be more than 10". Remember that you use the center of load times the distance that the center point of the load is from the bed hinge pin. What was the "divide by eleven".....I didn't get that step. Also, be sure that when you measure the height of the cylinder live trunion above the bed hinge that the two lines are parallel to each other, not level with the earth. The one line goes through both cylinder pins and that gives you the starting point, then the lower line is parallel to that. [img]/forums/images/icons/tongue.gif[/img]