Sheet Metal Trampoline for Goats 2

[Berniedog]

I want to design a sheet metal trampoline for my daughter's goats. See the following link:

https://youtu.be/dYhXPbxt9Sc.

Does anyone have experience is sheet metal design and can tell me how to proceed?

 

[BAretired]

The goats seem to be having a lot of fun. Show the video to the sheet metal supplier and get their ideas. The design looks pretty simple. You have to make sure you provide a reliable hinge support at each end. The only other thing is to make sure you get the proper gauge of sheet metal, which you can do by experimenting right in the sheet metal shop.

BA

 

[oldestguy]

The question was someone with experience with sheet metal design. So far no answers. This post may not meet the rules here.

 

[Ron247]

This appears to be more of a "Beers and Friends" type design.

 

[drawoh]

Berniedog,

I have a lot of experience in sheet metal design, but not a whole lot of experience with the flexible mounting of goats. If the electronics I am accustomed to mounting were to jump on and off their mount and bounce all over the place, people in the aircraft would be alarmed.

The thing is a curved beam, and it is highly deflected. I assume you can determine the weight of your goats. You can study that video and work out how high they jump, and what energy they will impose on that piece when they land on it. You should be able to do the analysis. It looks like it is anchored to the ground somehow. Don't forget to account for the folded over safety edges on the sides.

--
JHG

 

[oldestguy]

No experience with goats, other than some "friends". However in highway construction arched culverts are common. This example seems to be one of those. Go to supplier of culvert pipes. One such supplier used to be Armco. Ask at your county highway dept for them.

 

[robyengIT]

IMHO, suggestions to start with : steel S275JR thickness 2.5-3 mm diam 2000 mm (half circle structure) pay attention to sharp edges on the sides you could add some stripes of thin wood/rubber perpendicular to the long axis (to avoid sliding)

 

[WARose]

Arches are a favorite subject of mine......but I have to question the ethics of doing something like this. Not only are you talking about animals potentially falling off this thing......you are also talking about them possibly cutting themselves on the edges. Sheet metal can have some sharp edges.

 

[BAretired]

Maybe a little duct tape on each edge would alleviate your concern.

BA

 

[JoelTXCive]

I wonder if there is a cable or set of tension type ties across the bottom in the grass? The ground doesn't seem disturbed, but something must be holding the arch together.

I think the goats are okay falling off. They are less than 48" so no OSHA rail required. They might need and IBC rail though.

 

[Berniedog]

robyengIT

Is there an equivalent USA specification for S275?

Good comments people. I can't find any information anywhere on what material they used. Two fabricators I spoke with believe it is some kind of spring steel.

 

[Compositepro]

Find an old above-ground, round swimming pool and use the walls. Sheet metal will get permanently deformed easily unless it is heat treated and has adequate thickness. The fabric reinforced PVC walls that are about 1/8" thick will work for you. Culvert pipes are corrugated so that they will not flop around like the sheet in you video. A sheet of flat fiberglass would work well, but that would be expensive to buy new.

 

[dhengr]

I believe that is called a Flexibly Arched Goatoline. They are going to be offering a three semester course in their design at the Uni. next year. They could already model and reproduce the motion with their arch design software, and were quite proud of themselves, even though they didn’t have practical purpose for them, until the old goat down the hall (the school dean) came along and said ‘I gots young goats at home, I’ll take that.’ We used to call that arch buckling, but that was back in the days of the slide rule and such. I would start with about a 3 or 4’ wide, 10’ long, by .125” thk. piece of sht. metal, and go from there. For WARose’s and the goats benefit, grind the sharp edges on the sheets. There may actually be some benefit in hemming the edges to prevent local (sine wave) edge buckling of the sheets, although that might make the edges to stiff. There may also be some benefit to keeping the sharp edges. Every day you could go out there and pick up some thin sliced goat flank steaks.

 

[r13]

I think you can setup a curved beam using short discrete plate/line element, and load it by trails to generate acceptable deformed shape. The stress in the element should be kept within elastic range. The thickness of element should be as thin as possible, yet strong enough to support the weight of goat (plus thrust) without excessive deflection between B and C.

 

[robyengIT]

Berniedog : could be either SS grade 40 or SS grade 50

 

[robyengIT]

my suggestions are based on this experience (watch video): steel S275JR thickness 2 mm diam 1800 mm width of steel coil 1500 mm (spirally welded to make a steel cylinder with length 6000 mm)

 

[Berniedog]

Thanks for all your input.

 

[dauwerda]

Looks like some type of plastic to me.

 

[Berniedog]

Yes that is what one of my Fabricators said.

 

[BAretired]

Really? It sounds metallic to me. Buying a cylinder of that stuff would eliminate the need to provide hinges at each end. Just fasten the cylinder to the grade.

BA