Beta project: More experiments with hardwood "springs"



I guess these aren’t really springs, but I am not sure what else to call it.
Expanded hardwood?
Zigzag hardwood?

Anyway the big one is about 12" tall, and is approaching the practical limits of the technique.
It is very wobbly and the ends rotate easily if you grab them and twist.
It has maple “slats” and plywood for the ends, and is just press fit together without glue.

The small one is only 6" or so and it is surprisingly strong.
I can stand on it as long as I don’t rotate in its vertical axis.
No glue there except in one spot where the maple top piece split along the grain when I was putting it together. (which is why I switched to plywood for the larger one)

Cylindrical structure

Super cool, @jkopel!


I wonder if you set it in a cast ( like liquid resin) base, maybe ½ inch if it would prevent much of the torque. Such an interesting project leading to multiple ideas !! Thanks !!!


Laser “printed” basketball hoop… :ballot_box_with_check:


Why do I feel like trying out some of DaVinci’s lesser known flying contraptions with this technique? Hmmm…


Very nifty, I think the term “expanded wood” best fits. This would make a very nice starter as a waste basket, smaller ones would look real good on a desk for catch alls, or in the kitchen for utensils.

I think we’re all very happy you’ve managed to find some extra time to share your tinker-ings with us.


I 2nd @dan’s comment…
Super cool!


I really like that little one’s edge treatment, and the hardwood makes a nice contrast. Great job! :relaxed:


Thanks for taking the time to share your designs. Something about the shape the expanded wood makes is mesmerizing.


Cool! I wonder what would happen if you added some kind of sheet for an insert.


That’s pretty cool. There are some surgical devices constructed exactly the same way (plastic not wood of course) that you twist, put through a hole and it twists back giving you a nice expanded path to operate through.

Brain is already cooking on using this technique now that I can see it works… Thanks for sharing.


why? because FLYING!!


Looks like a perfect umbrella basket! Nice job!


Yes, flying and space travel fascinate me.


Did you hear that @jkopel? You may have just saved a persons life! :grinning:



Coolness! Wooden torsional spring!


Don’t my stents work “something” like that?


They do have a torsional expansion pattern. They are traditionally metallic although now people are trying PLA stents to biodegrade over several years, and they seem to be doing well.


Wonderful stuff!

One technical term for these “springs” is “flexures”. Flexures are used in high precision stages for sub-micron positioning accuracy, albeit with limited rage, and a restoring force (spring) that has to be dealt with. One way to think of them, in this sort of motion control context (an area of my expertise), is as a frictionless bearing. With the right design, they can serve much the same purpose as roller bearings, for example.


Torsion spring, was that used to measure gravity?