threads
Page 4 of 7
Mazda Projects \  dump bed from hell

dump bed from hell

Mazda Projects
views 5994
replies 60
following 7
 
mazdaman82   +1y
i had mine right on top of the frame rails and it didnt hit....need to bring yours down to that atleast
fattirebicycles   +1y
No, it won't. It all comes down to simple mathematics. tricky shaped hinges don't do shizz. when your pivot is higher up, the distance from your pivot point to the lower corner of the bed is longer than the distance from the pivot point to the cab. that is why you hit. you must move the pivot point so that the distance between your pivot point and the lower corner of the bed is less than or equal to the pivot point to the front of the bed. pic to come.
blackhulk   +1y


dude this was amazing...it worked...so im gonna cut them down 2 inchs and move them back 2 inchs and them that should fix my problem...this weekend i will do it up if the weather anit pissing down rain
mazdamandan   +1y
OK so I missed a few details there, lol

The top pivot for what I will do, serves the purpose of having to manually lift for the first few inches , then you see where it will bottom out and thats the point where the shock will help and push the rest of the way, not much weight to my box anymore its only sides now, lol

And as for pointless shape of the hinge arm, its about a few things, strength, replacing that with a right angle, will put major stress on those corner welds, so ya gussett like mad , and thats still a lot of work, I will be using 3/16 plate and tubing where the holes are, besides it'll look better and never fail.lol
Cantilever suspensions use these types of parts as do airplanes, etc.
Lever advantage also with 2 pivot points combined. It will be easier to lift

This is just a fancier way of building a hinge for sure, but it willpull the box back, and upthat is the point.

thread post photo


The shock will limit the travel, but it will do a full 90 degree without touching the ground when at full drop, and also the 2 pivot hinge will act as a safety feature, the box will not pop up because the 2 pivot/funny shaped hinge / shock combo will prevent it .

I can only go so far illustrating this in words till I build it.
fattirebicycles   +1y
"dude this was amazing...it worked...so im gonna cut them down 2 inchs and move them back 2 inchs and them that should fix my problem...this weekend i will do it up if the weather anit pissing down rain"

Your plan should work. for further education, I will continue.
Okay, here goes. The lines on the pic represent the bottom corner of the bed relative to the pivot point. Every single line in this picture is the same length. see how the blue example never hits the cab, but the red one does? It is because the pivot is lower, making the distance from the pivot to the bottom corner the shortest distance in the picture. if the distance between cab and pivot is longer than the distance from bed corner to pivot, the bed never hits.
thread post photo
Post was last edited on May 04, 2010 04:05. This post has been edited 1 times.
fattirebicycles   +1y
"The shock will limit the travel, but it will do a full 90 degree without touching the ground when at full drop, and also the 2 pivot hinge will act as a safety feature, the box will not pop up because the 2 pivot/funny shaped hinge / shock combo will prevent it . "


I like the cylinder on the hinge better. but what is going to keep your bed from pivoting on the upper pivot? the front of the bed will not lift because the upper pivot allows the bed to rotate on it. the rear of the bed would lift up and away, but the front would stay down, because there is nothing keeping it stationary. if there were no upper pivot, and your hinge were welded diirectly to the bed, then it would work as you envisioned.
mazdamandan   +1y



I believe the point was, made, lol
mazdaman82   +1y
i get it mazdamandan...im with you
and i under stand what you are saying too fattire
blackhulk   +1y
well i diffiently learned alot more tonight....i should of asked this b4 i build mine...would of saved me so much time..now i will have to cut them out and repaint my rear bar after..no biggy...live and learn
mazdamandan   +1y
A solenoid will be wired with the module from the shaved doors with a heavy pin as well, but the weight of the box and the direction of the shock pressure will hold her there too, clear as mud ?, lol

the top pivot will bottom out on the frame/ understructure of the box

the idea of the 2 pivots also serves the ease of lifting, thats where the mech advantage meets with the shock under pressure and will help to lift.

BTW just a regular auto shock is used here.
Oh and I totally screwed the first pic up I meant to do it like the other pic shows as far as the position of the shock.
was rushing ,lol