Forums > General Discussion   Shooting the breeze...

Long rebound spring

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Created by psychojoe > 9 months ago, 18 Apr 2024
psychojoe
WA, 2234 posts
18 Apr 2024 12:04PM
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I'm making a new flying fox for my kids. About a 20m run and a 3m drop. I've got the steel posts in and the steel cable up. I tried using a cheap pulley but it was crap so I've ordered a quality climbing pulley. I'm sure this thing will be fast now so I've decided I need a nice rebound spring on the end of the cable but I don't fancy paying $200 for a spring. Surely I could source a second hand spring from somewhere. Any ideas?

FormulaNova
WA, 15086 posts
18 Apr 2024 12:13PM
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What is a rebound spring? and maybe a car suspension spring? Leaf or coil.

psychojoe
WA, 2234 posts
18 Apr 2024 12:35PM
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Yeah, coil. It needs to wrap the cable.
Car is probably too wide

IanR
NSW, 1324 posts
18 Apr 2024 4:47PM
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Spring from the front forks of a dirt bike Should be able to get one from a motorcycle wrecker
The climbing pulley will wear very quickly as it's made to run on rope not steel cable

D3
WA, 1506 posts
18 Apr 2024 2:47PM
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Run a tether/retrieval line from the origin point, attach it with a section of bundled bike tubes or appropriate bungee line if you can find it.
Should be able to suspend it in a way it doesn't interfere with the rider

psychojoe
WA, 2234 posts
18 Apr 2024 3:01PM
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IanR said..
Spring from the front forks of a dirt bike Should be able to get one from a motorcycle wrecker
The climbing pulley will wear very quickly as it's made to run on rope not steel cable

I was thinking motorcycle wrecker but the local wrecker is such a douchebag

psychojoe
WA, 2234 posts
18 Apr 2024 3:03PM
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D3 said..
Run a tether/retrieval line from the origin point, attach it with a section of bundled bike tubes or appropriate bungee line if you can find it.
Should be able to suspend it in a way it doesn't interfere with the rider


More hassle than it's worth. The public ones use a spring.

Carantoc
WA, 7186 posts
18 Apr 2024 3:22PM
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Psychojoe said..
.....The public ones use a spring.


Maybe a pair of bolt cutters ?

Then rob the spring from the public one.

psychojoe
WA, 2234 posts
18 Apr 2024 3:36PM
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Carantoc said..

Psychojoe said..
.....The public ones use a spring.



Maybe a pair of bolt cutters ?

Then rob the spring from the public one.


Theirs is more of a damper. I want something that'll push the kids halfway back up the hill.

remery
WA, 3709 posts
18 Apr 2024 3:51PM
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What about using a counterweight, sort of like they have hanging off the railway electric wires?

I'm thinking something that stretches rather than compresses would be better for flinging them back up the rope.

I can't picture how it would work but I'm imagining those ropes that allow a float to go up and down with the tide.

With several pulleys for a sheep shank system.


psychojoe
WA, 2234 posts
18 Apr 2024 4:07PM
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remery said..
What about using a counterweight, sort of like they have hanging off the railway electric wires?

I'm thinking something that stretches rather than compresses would be better for flinging them back up the rope.

I can't picture how it would work but I'm imagining those ropes that allow a float to go up and down with the tide.

With several pulleys for a sheep shank system.



Far too complex. Simple wins today

FormulaNova
WA, 15086 posts
18 Apr 2024 6:51PM
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Kids are too soft these days. Why waste time with a spring. Just a few foam cushions stapled to the post/tree. Make them make their own way back.

Maybe attach a bungie cord to them from the other side and get them to tie the knot at the right length, in case it is wrong.

remery
WA, 3709 posts
18 Apr 2024 9:22PM
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psychojoe said.

Far too complex. Simple wins today


Motorcycle forks have springs, compression and rebound damping for a reason. Simple doesn't work today.

psychojoe
WA, 2234 posts
19 Apr 2024 7:53AM
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My Chinese mate was over at the weekend. He said never buy from Temu unless you absolutely don't care about quality. Apparently they only sell China's lowest quality products.

IanR
NSW, 1324 posts
19 Apr 2024 10:29AM
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Then spend up to a thousand dollars on quality springs
I think your local wrecker has good douche bag radar and treats people the way people treat him

myusernam
QLD, 6154 posts
19 Apr 2024 11:29AM
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Anything with that much energy to stop and then propel basckwards surely has some safety implications? what if they swing up etc? hair fingers? anyway i get a spring to cushion the landing.

remery
WA, 3709 posts
19 Apr 2024 9:32AM
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IanR said..

Remery I don't think anyone is suggesting using the whole fork as your quite right because the rebound is controlled by oil moving through valves


I was imagining the rope going through the fork spring. The would be some cushioning I just don't think it would be progressive enough to send a kid halfway back, like a stretched bungee might. Quality forks like WP only have about 12" of travel and are designed to work with a 200kg bike and 100 kg person.

psychojoe
WA, 2234 posts
19 Apr 2024 4:10PM
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myusernam said..
Anything with that much energy to stop and then propel basckwards surely has some safety implications? what if they swing up etc? hair fingers? anyway i get a spring to cushion the landing.


Absolutely. That's why a want a safe simple spring. But that will have to wait. I had a trial run today, one of the steel posts I fixed to was existing, 6mm steel so plenty strong enough, broke the concrete floor around it. Need to try again, maybe a guy rope.

elmo
WA, 8874 posts
19 Apr 2024 8:47PM
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if you have verge junk pickup in your area grab a cheapo mountain bike and pull apart the front shock theres acompression spring in there which should filt over your rope

CH3MTR4IL5
WA, 938 posts
23 Apr 2024 10:23AM
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psychojoe said..

My Chinese mate was over at the weekend. He said never buy from Temu unless you absolutely don't care about quality. Apparently they only sell China's lowest quality products.


He probably didn't mention the slave labour from Uyghur camps also.

www.nytimes.com/2023/06/22/business/economy/shein-temu-forced-labor-china.html

myscreenname
2283 posts
23 Apr 2024 7:40PM
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psychojoe said..
My Chinese mate was over at the weekend. He said never buy from Temu unless you absolutely don't care about quality. Apparently they only sell China's lowest quality products.

I bought this camping tent from Temu.

myusernam
QLD, 6154 posts
24 Apr 2024 8:08AM
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CH3MTR4IL5 said..

psychojoe said..

My Chinese mate was over at the weekend. He said never buy from Temu unless you absolutely don't care about quality. Apparently they only sell China's lowest quality products.



He probably didn't mention the slave labour from Uyghur camps also.

www.nytimes.com/2023/06/22/business/economy/shein-temu-forced-labor-china.html


You subscribe to the newyork times??!



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Forums > General Discussion   Shooting the breeze...


"Long rebound spring" started by psychojoe