i need a hinge
 

ok, need a hinge for a dump bed, but the problem is that it needs to go up then tilt back to clear the rear bumper, not just an arc like a piano hinge crude drawing below, but picture the 2 L's closer together and the top L has to go up vertical as it arcs to the right

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Re: i need a hinge
 

I just went thru this with my Bruder Ram pickup... I ended up making the bumper part of the dump bed
https://live.staticflickr.com/65535/...31fd9267_z.jpg

https://live.staticflickr.com/65535/...31064f97_z.jpg

It wasn't the original plan but it works better than I thought it would.

Re: i need a hinge
 

here's the link to the original thread of the guy who first built it. the bed is too long and low to dump like yours unfortunately. i think i need like a hood hinge that goes up then back

https://www.rctruckandconstruction.c...=4051#post4051

Re: i need a hinge
 

wow 10 years in the making.... This is a truck that needs finished for sure.
I see what you mean now....
Frizzen posted a link for a guy that was making some multi-directional hings for a lowrider .. the concepts might work for you but I can't find the thread he put them in.....hopefully he sees this and can remember where he put them....

https://youtu.be/yvvR_Y7GUC0
A guy is building a radio controlled 1/24 scale mini-truck Radical. First stage is direct-action off a servo

Re: i need a hinge
 

that's funny, i made a lowrider with a tilt and spin bed a long time ago, but never had it dance.

i looked for a linkage designer app and found a couple online, but they were hard to get working right. i may just have to start to experiment with some styrene

Re: i need a hinge
 

Honestly, this may be your best bet -- or do the Cardboard Aided Design thing as a starter. A few thumbtacks as rotation points and you're golden.

I suspect you're looking for like a Z-shaped double hinge, common on lift crane mechanisms. The challenging part is that the two sides are often asymmetrical, like one part of the "Z" is shorter than the other. I generally do all my stuff up in CAD (the computer kind, not the cardboard kind) before moving to the physical world, but the geometry there gets really painful really quick. Stupid irregular triangles and Laws Of Cosines, ugh.

Anyway, this example isn't quite the same, it only has a single hinge point, but you can see how the cylinder drives a set of levers, not a fixed point on the arm to the right. Those levers have to be precisely sized; too long and the cylinder won't push enough, but too short and you won't get enough travel.

I ended up doing trial and error until to make it work =))

https://youtu.be/Up3gK26ORb0

Here's another one I did which is Z-shaped, two hinges, but the two sides (red and darker blue "cylinders") are symmetrical. I could not for the life of me figure out how to have one shorter than the other and still work, when the center bar (lighter blue) is of fixed length and at a fixed position.

http://www.slosh.com/rc/frank/cranedesignup.png

http://www.slosh.com/rc/frank/cranedesigndown.png

Food for thought, anyway, maybe that helps?

-- A

Re: i need a hinge
 

Would it work to have a jackscrew drive the bed aft, up a ramp before it hits a wall that starts the tipping motion?

Maybe something like this hinge?
https://m.youtube.com/watch?v=-McV-N...e=emb_imp_woyt

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Jerry, i think the guy doing the lowrider truck thing might have been a PM instead.
"Fabkingz KustomModels" has some really good build vids on youtube, but more active on Instagram.
"Jevries" usually shows off completed stuff rather than much of the building part.
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It was a Fabkingz video
https://youtu.be/yvvR_Y7GUC0

Re: i need a hinge
 

That's sexy. It's like a W-hinge, only like WW ... wow. Deceptively simple, too, but a beehive to draw up and animate like that.

But, several pieces of cardboard and thumbtacks and I betcha you can find the right radii quicker than a computer =))

-- A