I can’t bring myself to think of a landing gear strut as a spring simply because it may flex under some load.
A wing spar may be made of aluminum and flex also but I don’t think of that as a spring either.
What about aluminum frames on trailers…
Isn’t something a “spring” if it remains within its elastic limits in normal use? In other words if it deforms but doesn’t bend under load, & returns to its prior shape or position when the load is removed, then it’s acting like a spring.
That landing gear combines the spring function with the wheel locating function. As said above, if it didn’t flex it’s tear the plane’s frame apart. Click on the blue button to see how much it flexes:
http://www.groveaircraft.com/landing_gear.html
It’s a leaf spring, attached on one end
What about railroad iron?
Or the main support beams on semi-trailers?
Or bridge beams spanning a river or canyon?
At what point is something NOT a spring?
WTH? The landing gear deflects–NOTICEABLY–when the plane sets down, esp. if it wasn’t the smoothest landing. It’s designed to absorb the impact, then redistribute the impact, over time, to protect the airframe. In what way is this substantively ANY different than a leaf spring deflecting when a truck launches off a “whoop-de-doo”?
I believe FAR certifications require the gear handle 500 fpm vertical descent, at max landing weight, without damage. Even on a GA craft, the gear will probably deflect 12" or more. Some cars don’t have that much suspension travel!
@GeorgeSanJose, you can’t use can lids since they can’t be heat treated to increase the yield stress. Does this part have to deflect and return to its original shape, or can it just resist deflection? @wesw 's suggestion of metal washers might be acceptable if you just want them to retain shape. Otherwise, the 22 gauge steel you mentioned might be your best bet. You are most likely to find low alloy grade sheet that is heavily cold worked to provide strength, and heat treating will only soften them.
@ok4450 - here’s the big difference between than landing gear and one of the beams you mention: Let’s take that landing gear and attach the two ends together with a strong bar. Now what happens when they land? CRUNCH - the landing gear is shoved right into the fuselage. Without the spring action of that single-leaf-spring landing gear, the airplane couldn’t land. Not safely, at least…
I thought that I heard my name being whispered…usually I just get yelled at!!!
Sorry I’m late to the party, but I got into a fabrication job that kept me pretty busy the last week.
I skimmed over all these pages and I take it that you want to make coil springs out of tin can lids.
I doubt that you will be able to harden a can lid so that it will retain its shape…as a spring…for long. The first time you stress it (as a kid would do) it will lose shape and over time your spring will get less and less extended. The tin just doesn’t have the correct alloys.
I would suggest that you buy the springs. Any good hardware store will have a good selection of both extension and compression springs. But I’ve never seen that big a spring without it being able to hold up against a heavier weight than what I presume you will be needing.
The only place where I can think of that you could find used springs this size and yet have the ability to compress with a light load would be the coil that keeps a radiator hose from collapsing. I just replaced the upper hose on my Dakota and the coil was almost 30 inches long.
I’ll check out that coil tomorrow and see if /I think it would work out and I’ll get back to you.
Hit the junk yards and look for a truck with a long upper hose and the coil should pull out without much effort.
You could cut this the length and use that.
Thanks to everyone that thought of me!!! I feel wanted…and not just at the post office.
Yosemite
he wants to make a clicker type toy out of two can lids , and use it as a steering wheel on a toy car, I think…
…hey! maybe if you put an actual spring between the lids…
what were you fabbing there , Yosemite?
Here is THE solution to your dilemma … Know the old fashioned style can openers that actually cut with a sharp metal roller…they cut out a rather sharp edged disc when finished? We ALL know this can opener type.
GO buy the OTHER TYPE of can opener…the one that actually cuts the top off of the can from the side…producing no sharp edge at all… Its even demonstrated in the commercial.
It will cut the lid off the can WHILE providing a natural “Rolled” edge to the lid WHICH…will provide much more “Stiffness” to the cut off can lid… The same way we put creases and ribs in steel to stiffen it.
Bet it works for you…
Blackbird
...wood and other materials aren't considered spring material...
Native Americans might argue that point.
;-]
@“Honda Blackbird” , I think you mean the type of can opener that uncurls the rolled edge that seals the top to the side wall of the can. It doesn’t cut anything.
To answer your question @WESW. I was fabricating a cart for someone that would bring his MIG welder, the Plasma Cutter, and a future TIG welder up to a level where the owner doesn’t have to stoop over to see the controls.
It can be wheeled to where it’s stored and be rolled back out when needed.
Equipped with 4 inch casters, all the units will be mounted down, and room for the three shielding gas tanks, all the units will be plugged into a main box.
When you need the unit, roll it out to the work area, plug in whatever of the 40 foot cord you need and plug it in. Air gets plugged into a male chuck on the cart and it then branches off to the plasma cutter and a 20 foot coil for hand tools (cutter, grinder, etc…).
You are then ready to go. All but a welding table.
I still need to install hangers for wire rolls, helmets, and a few other small things.
Yosemite
sounds like something I would build for myself…, nice
bending is to be avoided if at all possible these days…
the casters on my box are 8 inches, tho 
but then again…, I am a fabricator
they are actually 8 inches…, on my box. I needed them for all the weight I pushed around the shop. I made a custom fabricating box with a place for every thing from the mag drill to the 9 inch grinder, every square and hammer known to man and every other thing I needed all hanging or dropping thru racks with holes , even the door when opened had racks for stuff.
12 pairs of eagle beaks , c- clamps…, the whole she-bang.
I could open it up and close my eyes and ask someone to name a tool and I could put my hand on it every time
wes Wilkerson, free range fabricator!
I even had a a round rod coming up about and bent over with a hookat the end from which I hung mylight with a red heat bulb from in the winter. I kept my various squares on top when I fabbed and that light made every tool toasty warm in the frigid winter.
I even took my break at my box , toasty warm.
people would occasionally mistake my box for Mc Donalds tho, and request fries. it was funny every time…
it s in my shed now, some different tools, but still a darned good box.
oh, it also has lifting eyes, and a rod rack type set up on the back for my pony pipe clamps and larger spud wrenches…
I love my box…
The key to even making a clicker type toy out of a piece of steel…like a can lid… Is in the denting or creasing of the steel… This is a rather well known principle… the creases or dimples you incur in the steel make the metal flex, pop or strengthen in different ways. The same way corrugation increases the strength of normal paper… This is basically the KEY to the device that you are making. Don’t take my word for it… Look it up. I’ve discovered this principle as a child…on my own…then began noticing how it was utilized in the world around me…and it just makes sense…
Blackbird
makes sense…