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?

Yeah, coil. It needs to wrap the cable.
Car is probably too wide

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

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 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 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

psychojoe said.

Far too complex. Simple wins today

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

IanR said..
You can get replacement springs through Temu and Aliexpress quite cheap but I doubt they will bounce your kids half way back up

www.temu.com/ul/kuiper/un9.html?subj=goods-un&_bg_fs=1&_p_jump_id=894&_x_vst_scene=adg&goods_id=601099527598205&sku_id=17592265142026&adg_ctx=a-ad6a1884~c-c9236cb2~f-c0e80054&_x_ads_sub_channel=shopping&_p_rfs=1&_x_ns_prz_type=-1&_x_ns_sku_id=17592265142026&mrk_rec=1&_x_ads_channel=google&_x_gmc_account=710728018&_x_login_type=Google&_x_ads_account=2720833615&_x_ads_set=20878039836&_x_ads_id=157413511615&_x_ads_creative_id=685403347863&_x_ns_source=g&_x_ns_gclid=Cj0KCQjwiYOxBhC5ARIsAIvdH52jGrzOMD3t_rdK0baizkwRSwmiWMRaG9leJnZn2O3vyKBg1zjwCG4aApewEALw_wcB&_x_ns_placement=&_x_ns_match_type=&_x_ns_ad_position=&_x_ns_product_id=710728018-17592265142026&_x_ns_target=&_x_ns_devicemodel=&_x_ns_wbraid=Cj4KCAjw5v2wBhBNEi4AvZ7ZAO_H2W7YyZ-tjG503S7JIoEL7tgm0UnlY_oipoBiQi_njYt574wNXvvUGgIo_w&_x_ns_gbraid=0AAAAAo4mICHLYx4jkHpIoV-o3bsgnLJTK&_x_ns_targetid=pla-2088250705615&gad_source=1&gbraid=0AAAAAo4mICHLYx4jkHpIoV-o3bsgnLJTK&gclid=Cj0KCQjwiYOxBhC5ARIsAIvdH52jGrzOMD3t_rdK0baizkwRSwmiWMRaG9leJnZn2O3vyKBg1zjwCG4aApewEALw_wcB&is_back=1

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

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.

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.

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.

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

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??!