to anyone mechanically inclined

ch_2005 · Post by **ch_2005** » Sat Dec 31, 2005 2:47 am

Ok Guys;

I'm building a 2' bucky ball out of 1/4" copper refrigerator tubing. I want to flatten the ends of the tubes for the joints. For the joints I want to rivet the tubes to some sort of round metal piece such as a washer.

It would have to be some sort of fairly large washer such as a fender washer. However, since most fender washers are varying types of Steel they would be difficult to drill holes in (5 or 6 depending on the vertex).

So what I want to know is if you have any ideas for a source of copper or aluminum round flat things about the size of a silver dollar or half dollar. I will need about 100 of them so they can't be too expensive.

If they have a hole in the middle that's fine. Or if they have 30 holes around the outside edge that would be cool too because then I could use them as hubs for the verticies with 5 or 6 struts.

I've been racking my brain for all things plumbing, electrical, automotive, and I havent come up with exactly the right material to use or source to get it.

Thanks,

CH

Post by **Phineus** » Sat Dec 31, 2005 3:04 am

Places that do punch pressing throw stuff out like that by the ton

Home depot

The round knock outs in electrical utility boxes

aol sign up cds

silver dollars

slot machine slugs

http://www.google.com/search?q=nuts+bolts+and+washers

The side off your computer and a pair of sheet metal sheers.

PS. What's a bucky ball ?

Malibu350 · Post by **Malibu350** » Sat Dec 31, 2005 3:12 am

I first tried to make a bucky ball back in 83.... never again.

good luck with it CH.

SLO_SCATTER · Post by **SLO_SCATTER** » Sat Dec 31, 2005 11:18 am

Ok, dumb question time. What is a bucky ball???

NIR_PitBull · Post by **NIR_PitBull** » Sat Dec 31, 2005 12:58 pm

SLO_SCATTER wrote:Ok, dumb question time. What is a bucky ball???

lol. Good question....

Cale · Post by **Cale** » Sat Dec 31, 2005 9:31 pm

http://en.wikipedia.org/wiki/Bucky_ball

Very cool stuff.

Malibu350 · Post by **Malibu350** » Sat Dec 31, 2005 11:13 pm

I'd use some 6061 or 7075 aluminum (aircraft grade). it's easy to drill, very strong, bendable and can be polished to a high gloss.

If you have a band saw and a local scrap metal outlet in your area you could by a rod of aluminum and saw wafers from it then drill away for about ten or twenty bucks.

Another option would be a plastic rod stock from a industrial supplies store. Get either a Nylon or Acetel (non glass filled) material to work with for strength and ease of machining.

There is also a large variety of sizes of Nylon washers out there but I don't have any sources handy at the moment.

I can hook you up with just about anything if you have trouble finding what you need... let me know, I have a full machine shop and tons (literally) of materials.

ch_2005 · Post by **ch_2005** » Sun Jan 01, 2006 6:09 am

I do not have a band saw. I'd be stuck with a hacksaw or compound miter saw. Neither of which would be a great tool for slicing up an aluminum rod into 100 pieces.

The right nylon washers would be good. 1.75" outside diamater and approx. 1/4" or less inside diameter and about .050" thich would be nice. Having trouble finding a supplier online. I'd probably be better off finding an actual sho around here (RI) wouldnt I? If i find somone in the field then if they dont have it they would probably know somone who does.

For drilling the little suckers I suppose I'd have to go use a friend's drill press. Stack them and then dril the holes. Or, if it was a rod then i could drill the holes beofore i slice them up. I do have a friend with a band saw I could probably use.

Maybe my best bet is a nylon or acetal rod.
http://www.onlinemetals.com/merchant.cf ... its=inches
http://www.onlinemetals.com/merchant.cf ... its=inches

Looks like Acetal and Nylon are about the same price. Which do you reccomend?

I should be confident in getting 100 wafers out of a 10" piece That's allowing about half loss to saw cuts. A normal bandsaw should be less than .050" right?

It's actually hard to find plastic or 7075 aluminum discs for cheap. I guess they are usually considered a byproduct that either goes in the trash or to to be recycled. I'm sure somone has a ton of them somewhere. I just want 100. sigh.

I also noticed that they sell hex rod but no pent rod. Must be cause it's hard to make a wrench for a hex nut. Probably why you see hex nuts on fire hydrants.

Dang it's getting late/early.

What an odd way to spend the first 6 hours of the new year - scouring the internet for metal and plastic stock.

Well I'd better get some sleep. My favorite breakfast place closes around 2pm. I dont want to miss that. Not a good way to start out the year.

Talk to you guys later.

P.S. Here's a famous bucky ball:

(Puzzle: I spy with my little eye one of 20 pentagons on that sphere)

Malibu350 · Post by **Malibu350** » Sun Jan 01, 2006 3:25 pm

Try this place CH... http://bokers.com

That would be my first resource option.

Aluminum would be my first choice of material, but it will be the most expensive. Nylon and Acetel are both very good choices as far as strength goes. Nylon offers a higher heat stability but it's a tad on the soft side so if there's a sustained amout of lateral pressure you may get some cold flow resulting in joints coming loose over time. Acetel has a higher durometer index so it'll hold it's shape better longer but not by much. Either would do a good job but Nylon is far more common when it comes to readily available washers and spacers.

let me know how it goes, I have other options if need be.

ch_2005 · Post by **ch_2005** » Tue Sep 05, 2006 9:47 am

Well, I finally built it.
I ended up using 7/16"x1-1/4" stainless steel washers. They were slow to drill but it worked.
Took my friend and I a week to make.
902 pieces.
92 washers
270 pieces of tubing
540 rivets
1080 holes between the wasers and the tubes that is.

Managed not to break any drill bits either!
lol. Fortunately we had a drill press. Other than that just hand tools.
Cut the tube with bolt cutters:
http://ch.mtm2.com/misc/sphere/tube-cut-jig.jpg
Flattened each tube with a hammer.
Clamped each tube in an aluminum jig for drilling:
http://ch.mtm2.com/misc/sphere/tube-drill-jig.jpg
And here's the finished product:
http://ch.mtm2.com/misc/sphere/Atlas1.jpg

Enjoy. Let me know if you can think of something useful to do with it.

Post by **Phineus** » Tue Sep 05, 2006 11:37 am

Enjoy. Let me know if you can think of something useful to do with it.

That was going to be my question.

I glanced over the above posts but nothing jumps out at me, so I'll risk asking: why did you do this again?

Anyway, nice job of patience and determination. How strong is it? Obviously it wouldn't survive a 16 ton anvil being dropped on it, but I wonder if there's any risk of it accidentally meeting with a bad end.

Maybe you could now make a 3D scanner and turn it into a track model.

Cale · Post by **Cale** » Tue Sep 05, 2006 5:06 pm

2 words:

Battlebot Soccer.

ch_2005 · Post by **ch_2005** » Wed Sep 06, 2006 1:17 pm

It's pretty strong.
I can pull on opposite sides of it as hard as possible and there's bsaically no deformation. It could probably handle a few of me pulling on it.
I haven't tried crushing it. I'm guessing it could take quite a bit. Around 30lbs at least it feels.
I've rolled it all over the yard for fun. It doen't crush itself being that it only weighs 8lbs. It should survive a fall off a table pretty well. If anything happened i'm guessing only a few pieces would bend and could easily be replaced.

My gf might make some stained glass pieces to put in it. It might turn into a lamp some day.

Next time i have my r/c trucks out I'll try using it as a bot ball :-)

If i get some <a href="http://www.amazon.com/exec/obidos/tg/detail/-/0520239318/qid=1061516424/sr=1-3/ref=sr_1_3/102-9616182-0580910?v=glance&s=books" target="_blank">book</a>s on geodesics I could approximate it in x,y,z coordinates i think. That's a project for another week.