Wave Pendulum

The holiday season is much anticipated by people of all ages, it is a time for good food, family, vacation, and fun!  But also a time to figure out what to give people... which can prove to be a difficult task.  For me, it's one of those things that I have great ideas for all year round but when the time comes I can't think of anything to give people, especially my Dad.

His christmas list this year consisted of dress socks, ties, and books... boring, boring, boring.  So I was thinking back and remembering the days when my Dad would be delighted to receive a picture I drew or some art project I created for him (this was in the good ol' days when I was 5 or so) and was wishing it could be that easy (and cheap) now! 

That got me thinking... what if I made him something?  He has a large desk at his office, and I wanted to make him something he could display. I thought of a newton's cradle but that was too simple, I was looking for the wow factor. 

After searching on the web I came across this youtube video, pretty neat right?!  Kudos to this website for giving me some information on the apparatus so I could build it!

So that was that, I was going to make him a wave pendulum.  It is unique, a perfect conversation starter, and would look great on his desk... it's also a way cooler gift than a pair of socks :-)  Besides this one looked so neat after it was done that I am in the process of making a mini one for my friend's desk!

Step 1: Materials

Materials:

- Titanium Epoxy (or any type of glue that bonds two metals together)
- Thread (Needs to be thick so the weight of the ball bearings doesn't break it. We used fishing thread for this, and it worked well)
- 15 Ball Bearings (Or any other type of semi heavy ball would work... I think marbles would work as well)
- 15 Gold Brads
- 15 Nuts (as small as you can get them, so when they are attached to the balls they don't take away from the sophisticated finished  
   look)
- Hot Glue
- Wood Glue
- Drill
- Straight edge
- MDF Wood for the base (this is a type of compressed wood, but you can use whatever you would like for the base)
- Bass wood for the legs and top of the structure (4 1/2"x1/2" pieces and 2 1/2"x1/4" pieces)
- Saw to cut the wood (preferably one with fine teeth so you get a more even cut)
- Black acrylic paint for the base (or you can choose to stain it, or paint it a different color, whatever your artistic heart desires!)
- Wood stain for the rest of the structure

Comments

[dovefeeder]

You drilled round holes for the sqaure legs, how do you fit a suare leg into a round hole

[phideon]

What did you use to fasten the brads down and keep the string taught?

[hugskisses13]

cool

[tclemmo]

That is really awesome! Definitely going to be my Christmas holiday project.

[cgreige]

do you remember where you bought the gold brads from?

[SargentPepper]

Hobby Lobby, but I am sure most Craft Store's sell them in the scrap book section.

[Coxster]

Very nice instructable. I also made one of these for my dad recently for his birthday.

My method was slightly different, as the wave was designed to be viewed from above rather than the side. Essentially, I had the constraint that for all pendulums, L*sin(θ) = constant. This is an extra complication for many, I am sure. I will be sure to link to your instructable when I post mine for those who want to take a more straight-forward, side-viewable approach.

Good job! :)

[shazni]

Is each string twisted around a brad and then another string twisted around it and sent down the same hole?
help!!

[SargentPepper]

Sorry for taking so long to reply, the strings are actually pulled through the hole from the bottom and then the brad is put in to plug the string in place. So, at the top you should see both ends of the string poking through. Hope this helps!

[shazni]

Thanks for replying...yes it helps...so did you take a video of your pendulum wave...would love to see how it goes :-)

[shazni]

please may i have close ups of how the strings are fixed? i'm confused..it looks like a 'V'...so how is it done...could you take close ups of the under side and run me through with an from A point to b point to c point .... please pretty please?
is it one long string? how does it go?...down the pole...through the nut..then back through the first hole or 2nd hole? do you knot it or send it down a 3rd hole?
as you can read i'm pretty confused! please help ..i'm trying to make one with marbles .

[SargentPepper]

Here is the photo:

[SargentPepper]

I tried to answer this above, here is a closer picture, I hope the picture makes a bit more clear.

[raiderdk]

Do you think puting something like a guitar tuning key to adjust string legth will be useful?

[SargentPepper]

I never thought of that but that would be a really good idea! That way if it gets "out of tune" so to speak you could quickly adjust it. I glued the strings in place to ensure that they wouldn't move around, but this is a good alternative as well!

[fire_drakon117]

we actually saw a video of this type in my chemistry class. i am forwarding this to him after this comment is posted. awesome job

[SargentPepper]

Thanks!

[Kiteman]

The world demands a video!

[SargentPepper]

Coming soon!

[rjnerd]

I love these. Two points to emphasize for people building their own: Using the double strings (the V) is essential. Use single strings, and they will tangle after about 3 swings. Second, the more rigid the frame they hang from, the longer they will swing.  Yours looks good.  (I built one as a trophy, and used single strings, and a somewhat wobbly frame.  Set it going, and it tangled after the aforementioned 3 swings, and until I stiffened the frame, would damp out after a half dozen swings)

If you want to see one (not this one)  in action, go to  http://www.youtube.com/watch?v=yVkdfJ9PkRQ to see a demo of one built by someone at Harvard.

[SargentPepper]

Great Points! Thanks!