# What speed is your Boulder launching at

Just wondering what kind of speeds teams are either seeing or expecting their boulders to be flying at?
We used a radar gun on ours this evening and the team as a whole was smiling from ear to ear. 56 mph or 82fps

Is hella an acceptable speed? Our’s moves at about the speed of an unladen swallow.

Over 9000. RPM.

African or European?

Ours currently doesn’t. I haven’t asked just how fast we should actually shoot when we get it built, but a prototype shooting from near the Defenses tried to shoot down any flags that might have been on top of the Tower.

My reason for asking is two fold… One I am curious by nature, second I am curious to know what teams thoughts are on trying to block shots with their robots knowing the speeds that the boulders are being launched at.

One might say…ludicrous speed…

The pool noodle thread I was just looking at comes to mind…it doesn’t take much to deflect even the hardest of shots. Many robots were cheesecaked with pool noodle blockers in 2013, and I expect to see similar strategies employed this year.

We’re somewhere in the range of ludicrous speed to bench grinder.

Speed of light as an acceptable measure of our boulder’s speed

Hrm. I suppose putting it in terms of bench grinders would be more appropriate. I hadn’t thought of that.

2.1 bench grinders. (Spell correct just tried to change grinders to gingers. Silly spellcheck. Gingers aren’t a measure of speed).

We launch ours at 88mph during qualification rounds so that they’ll move forward in time and all get scored simultaneously in the finals.

I hear Gingers are pretty fast.

If we shot the boulder through a Chronograph it would be around “Do we really need this much speed and force?” feet per second. It’s enough to help a five-ounce bird carry a one pound coconut.

enough

Well, the surface speeds on our sets of shooter wheels are 100 and 130 fps at maximum motor output. We generally run it between 60% and 70%. I know we’ve got a lot of slip. So, the answer is just really, really fast.

It’s a fast enough RPM that the difference between VEX hex bearings and VEX ThunderHex bearings may be necessary to investigate.

Sounds like we are pretty far away from the Aim High 12fps speed limit.

You know those gravitational waves you keep hearing about recently? Those weren’t created by colliding black holes, they were created by our boulders colliding with the opposing alliance’s tower.

Im not really sure what ours is running at. It was decent speed when we had mini cims geared 1:1 with 3" of compression, but we put SpinBoxes on the mini cims so its geared 1:1.67 now. The wheels are spinning at roughly 10,000 RPM. We are still working on the final arm/ shooter assembly so we don’t even know how well this will work compared 1:1.

Ours shoots fast enough to take out exit signs and castles at range