All,
Has anyone received multiple FIRST boulders or ones from Gopher and compared the weight? We received 6 of the Gopher balls today and they are different weights and only 1 was close to the official FIRST boulder we received in our Kit of Parts. Some of the weights are so different that we think that they will shoot differently. Let me know your thoughts.
Please post the weights you measured.
Official FIRST boulder - 292 grams
Gopher boulders were 326, 358, 359, 359, 362 and 388 grams.
How do they compare in terms of surface texture, firmness, and size?
perhaps the colors are related to the mass?
This is an issue with frisbees where the titanium in the dye make the white frisbees stiffer.
We are not finding any other real difference other than the weight. We ordered the 6 pack rainbow colored balls the same day of kickoff and they just arrived today. Hoping others can check theirs to compare as well. We would also like to know if teams have a couple of the official boulders to see what the weights are of theirs.
Can you label the weights you posted with that Boulder’s specific color? I’m interested to see if other teams who also bought the rainbow 6 pack find that their respectively colored Boulders weigh the same.
Given the humidity in Duluth is just about zero it’s possible that the one that’s been in town for 2 weeks is much drier than the new ones.
Here are weights by color.
Yellow - 359
Orange - 326
Orange - 362
Purple - 358
Purple - 359
Blue - 388
I take it nobody else has received these yet to compare? Has anyone received multiple gray FIRST boulders yet to compare?
Our KOP ball is 281 grams. We got two more from andymark in week 1, and they weigh in at 289 and 285 grams. I’m surprised that some of the balls could weigh 30% more, pretty interesting. Hopefully the ones at competition will be from the same batch…
We measured our 4 grey boulders at
283 g
284 g
288 g
292 g
Seems like the gray boulders are pretty consistent**(in mass at least)** and the colored ones are different. Anyone else ordered colored balls and measured them?
Here are the weights for ours, our scale only measures to the nearest 5g:
Original in KOP: 295g
New FIRST boulders (grey) recieved yesterday:
285g
285g
300g
Of much greater concern to our team is the remarkable increase in stiffness of all of the new balls. Our shooter compresses the ball, so the new stiffer balls slow the motors more and travel significantly less distance. We set up a jig to measure the force required to compress each ball to 8 inches. Results…
Original KOP Ball:
6,300g
New Balls:
11,860g
11,235g
12,890g
We don’t know how much of this is due to the older ball being broken in, but we don’t believe that it ever flew that poorly even when new. So is it an issue with differences in the foam from batch to batch or was the first ball just an outlier?
We will post a picture of how we measured the compression. If you can obtain data for your own boulders to compare, please post them as well.
Image: to be posted soon
We have not bought any due to the pricing but I am curious as the fluctuation in weight.
We are wondering about the diameter of the balls, having only 1 ball, we can’t compare weights, but the manual says the ball is 10" diameter, but ours is measuring as 9 5/8th.
Anyone else noticed this? We are wondering if it has to do with our altitude, (almost 5000 ft) and how competing at lower altitude could affect our shooter if the size changes this much.
This compression issue arose in 2012. Wise teams will design shooters that hit the target regardless of compression status.
The Yellow and the 2nd Purple ones are good.
For a ball meant for playing dodgeball it seems like a reasonable margin or error.
The solution in my mind is to minimize the projectile weight’s effect on your trajectory. Basically shoot that s.o.b as fast as possible. Then you minimize the arc in the shot and hence minimize the necessity for a perfectly normal weight in your projectile.
Granted, this wont work if your ball is REALLY light or REALLY heavy.
The balls aren’t sealed, or at least ours is not. It has one small (0.1" -ish) orifice in the outer covering, so I would not expect any difference in diameter due to changes in barometric pressure.
The ball that came in our KOP measures 9.7" in diameter at 300 feet above sea level and weighs 290g.
I’ll attempt to weigh and measure my teams boulders but we bought a couple of the gray boulders and not the rainbow pack.