Actual Composition of Orbit Balls!

I attempted to make one ball… with polycarb. (or lexan… I’m not sure because it was a scrap from the work area) and it was way stiffer and heavier than an actual orbit ball. Since they are becoming near-to-impossible to find anywhere… and we are worried about using non-spec orbit balls because of their differences from real orbit balls…

I got a section of an actual orbit ball submitted for Fourier Transform Infrared (FT-IR) microscopy. The results are as follows…

Plastic Loops = Polypropylene
White Bit Inside of Fabric Layer = Polyester/Polyester-diisocyanate(urethane) like Lycra® spandex
Outside of Fabric = Nylon (polyamide)

I have not done any in depth research yet, but it looks like you can buy sheets of polypropylene in the right thickness for orbit balls online.

Stiff clear bands.doc (23.5 KB)
White fibers from green spongy mat’l.doc (23 KB)
Green, spongy material.doc (24.5 KB)


Stiff clear bands.doc (23.5 KB)
White fibers from green spongy mat’l.doc (23 KB)
Green, spongy material.doc (24.5 KB)

Great info! Our homemade orbit balls are also much stiffer than the regulation ones. They behave quite differently in our scoring mechanism as a result. We will look into polypropylene for any more balls we try to make.

By the end of the year, I have a feeling that I’m going to know much, much more about the intricacies of orbit balls than I ever wanted to.

great job!

FT-IR is a very cool method of determining material composition

Sigh…now she tells us… :o

Thanks Ducky!

We are still optimistic that the homemade balls will give the Rochester area teams a good testing at our pre-ship rally, but it sounds like its good that we do have a reasonable supply of the “real” ones for teams that it might impact. I’d be interested to hear the experiences of teams who have found a difference in their robot’s function from using store bought vs homemade balls. Give a few more details than just a statement of they didn’t work the same. Was it because of compression, size, stickiness, stiffness?

Now that’s the way to do research! :slight_smile: Thanks for the info, it should help many teams.

MILFORD DE 19963 (302)422-2854 6
REHOBOTH BEACH DE 19971 (302)644-8014 3
SEAFORD DE 19973 (302)628-1668 5
GEORGETOWN DE 19947 (302)854-9454 2
WILMINGTON DE 19808 (302)683-9312 13

I assume you already cleaned these Walmart stores of their inventory? The 1/21/2009 inventory list showed three balls in stock at our local store, and they were there last Friday, so we bought them…

Jim:

Thanks for the Orbit Ball Delaware Wal-Mart Update! We and some other local teams cleaned out most of the Delaware stores. There still might be an Orbit Ball or two in hiding.

All the best during crunch time!

One of the first things I noticed about the sample in the KOP was a little tag saying it contains PU Foam, which I assumed meant Polyurethane foam. But when we dissected one of the balls, the substance lining the fabric didn’t look like foam. So it sounds like the ball label was correct; FT-IR trumps eyesight!

I thought the plastic seemed like the kind milk jugs are made of, but that’s polyethylene, not polypropylene. Nevertheless, I’m kinda hoping that next year FIRST will just have everyone rinse and dry their 1-gallon plastic milk jugs for game pieces-- then we won’t have this year’s supply lunacy.

I believe they are made of Unobtainium. Good work on the research and thanks for posting.

Jason

I agree completely…

BTW Does anybody know when IFI’s stock of magic will be in stock and no longer back ordered?

Thanks so much for this info, i’m currently working on attempting to make some in New Zealand before we start on our build and this was so much help.

what are the measurements of each strip? I heard the balls are a 9" diameter and believe this would make each strip about 28.3" long, yes?
I’m guessing about 1" wide, but does someone have confirmation on the width?
and how thick are the sheets of polypropylene used in the official ones, does anyone know?

thanks,
Steph

Steph: Check out the instructions here!

http://www.chiefdelphi.com/forums/showthread.php?t=71591

Substitute the polypropylene (1/16 inch) for the polycarbonate and you should be close.

Brilliant, thank you very much