Thin-walled tube of soft metal when you try to bend often creased. To avoid this, they are usually pre-stuffed with sand.
With the same purpose, you can use another method: navit on the future site of bend copper or aluminum wire – turns will not allow the tube to wrinkle at the bend.
The same result can be achieved using a suitable inner diameter of the spring.
Recommend to read
ALL-TERRAIN AMPHIBIAN
The amphibious all-terrain vehicle was built over five years and first left the garage in 1969. Traveled more than 1000 km. Tested on rough terrain, on snow, on water, on marshy, sandy,...
COVER FOR MAT
Just note - it's not my idea, I offer only the version of her performance. Came across this idea in some military magazine. The conversation was about the Mat-foam: "...However, such...
