Applied Magnets Forum

aurasarcanus · Joined: 27 Mar 2008 Posts: 3 Location: San Jose, California

I had this crazy idea one day that magnets could easily be used to replace machanical springs in things like airsoft guns and stuff like that. a couple week ago I saw an ad for a new pogo stick that is appearantly really high quality (jumps up to 6 ft.) and holds only a 150 lbs safetly, and it got me to thinking that magnetic springs could, quite possibly, make a pogo stick a whole lot more fun. plus it wouldn't have the tendency to break like mechanical springs would, and could handle much higher weights. I've been putting a lot of thought into it and I'm seriously considering making this idea, and I was wondering if any of you guys had any ideas or suggestions for this kind of project, seeing as how I have only a vague idea of where I'm going with this. Please tell me your thoughts

Guest · Posted: Apr Tue 01, 2008 7:33 am Post subject:

Sounds like a great idea - North to North kind of setup. To be of any use the Mag would probably need to be extremely strong - and for more stability you could use 3 or 4 shafts with a pair in each. Not should how you could avoid the breaking though. They'd have to be rated for maximum weight. If a 200 lb person jumps on it and the mags only support 150, then they will probably shatter anyway - and sometimes it's the pipe that breaks - and not necessarily the spring (I think).

you could always try out a really tiny version to get started (call it the hand pump - or even hand squeezer thing - like those spring based anti-plyers for strengthing hand muscles).
Good luck - and if you ever want to send a free version of any of this that you've built as a thank you - you'll probably find me at rockon1[a]charterinternet[d]com

I say go fo it - start small if you want to save money up front, but go for it!

aurasarcanus · Joined: 27 Mar 2008 Posts: 3 Location: San Jose, California

I tried that, and to be honest, big magnets scare the crap out of me... I have a few that are in the multiple hundreds of lbs pull force and I've seen the carnage they can do. My thoughts are geared more towards a chain of |ns|sn|ns| type set up with a large number of low force magnets as opposed to just a couple of large high force magnets. mainly for the interest of safety, but also due to how magnetism works, being a function of the inverse square of the distance. So with 2 1" thick magnets, if my understanding of magnetism works is right, on contact there will be approximately 450lbs of repulsive force, at 1" of seperation, the force drops to 112lbs, at 3" seperation, its all the way down to 28lbs. it makes to hard of a stop for the distance, too much sudden impact force on the legs. just way too much for me.

drewideth · Joined: 15 May 2008 Posts: 2

I think that the idea is quite feasible. You might possibly want to look into using an electromagnet type of application to reduce size. And if the coils are wound properly it most likely could be ran off of a 9 volt battery or comperable.

billfunk29 · Joined: 23 Jun 2008 Posts: 1

I've been planning on building a magnetic pogo stick. I found this site in my research. I have two 2" dia x 1" thick magnets that I ahve played with. They are scarry. I usually keep one at work and one at home to prevent accidents.

My initial plan is to stack several (5?) of these in a plastic tube. Some sort of steel or aluminum tube will house the magnet tube and mount the foot/hand pegs.

The questions I was looking to answer are:

What is the efficiency of the compression/ extension cycle. How does it compare to steel springs?? Bungy cords??

What would happen if I surounded the magnet tube with liquid Nitrogen?

Can you wrap a coil around the tube and use capicitors to control the rebound?

My background is aerospace so I'm a little weak on the physics here.