SECOND shots

[ctshirk7]

thats basicly what we are doing only we took the concept and turned it on its side. we dont have a goal set up yet but we are in the old middle school and use the basket ball goals... smaller target so we dont make them 100% but its amazing. good job with yours

[Eric Scheuing]

Good, accurate shooter. The only thing I don't like is the fact that you can't really go much more rapid fire than that, or so it sounds like by the motors.

[ctshirk7]

that wasnt rapid???

[Alekat]

Originally Posted by ctshirk7

that wasnt rapid???

I don't think this robot will be considered a rapid firing machine comparitively. But definatly the makes of a nice sharpshooter.

[Revolverx7]

As soon as Mark fine tunes the software to re-ramp up the RPM's after each shot we hope to greatly increase rate of fire.

[Mark McLeod]

Full recovery last night under software control took about 1/3 second per ball launched. That means it's capable of 10 balls in under 4 seconds (if we can hand load them that fast).

Back over to Mechanical Engineering

Originally Posted by Rick TYler

Where were your safety glasses?

Mea Culpa. With safety glasses.

[d.courtney]

just a few questions, one how long does it take to start up from nothing, second how much battery comsumption is there, and last a mixture of the two questions, would it be benifitial to quit in the defence, or does it take to long to get up to speed, I can just see how that is going to be a big battery consumtion, then you add the pnumatics, which will take a bunch if it will be feeding only one ball at a time, and then your drivetrain, and the movement of this and last a ball colection of some sort. I see how it is an amazing prototype but your battery will run short I assume every match.

[Ian Curtis]

Originally Posted by d.courtney

just a few questions, one how long does it take to start up from nothing, second how much battery comsumption is there, and last a mixture of the two questions, would it be benifitial to quit in the defence, or does it take to long to get up to speed, I can just see how that is going to be a big battery consumtion, then you add the pnumatics, which will take a bunch if it will be feeding only one ball at a time, and then your drivetrain, and the movement of this and last a ball colection of some sort. I see how it is an amazing prototype but your battery will run short I assume every match.

Where are people coming from with this "OMG everyone's battery is gonna die midmatch!!1!!"? Our 2005 robot, which ran something to the effect of 6 motors, a full pneumatics system and it lasted a good 12 minutes. While this year we'll be running more motors, I still don't see how a good fully charged battery could possibly die mid-match.

While I'm not assosciated with the team that built this launcher, ours reaches top speed in under 3 seconds.

[DarkJedi613]

Originally Posted by iCurtis

Where are people coming from with this "OMG everyone's battery is gonna die midmatch!!1!!"? Our 2005 robot, which ran something to the effect of 6 motors, a full pneumatics system and it lasted a good 12 minutes. While this year we'll be running more motors, I still don't see how a good fully charged battery could possibly die mid-match.

While I'm not assosciated with the team that built this launcher, ours reaches top speed in under 3 seconds.

I agree, as long as the batteries are fully charged teams should have no problem lasting at least a match (and easily 5 minutes). The problem arises when teams do not adequately charge their batteries or do not have enough batteries.

It ramps up in 6+ seconds without feedback, about a second with feedback.

[Henry_Mareck]

have you measured / calculated you muzzle velocity yet?
looks to be about 10-12 m/s

[DarkJedi613]

Originally Posted by Henry_Mareck

have you measured / calculated you muzzle velocity yet?
looks to be about 10-12 m/s

It should be, it was designed to shoot balls at 12m/s. It has not been measured with a speed gun, but it shoots approx. the max distance it should be able to.

[Scott358]

Originally Posted by Henry_Mareck

have you measured / calculated you muzzle velocity yet?
looks to be about 10-12 m/s

Very good estimate. How did you "see" that???

A couple design criteria where:
1. Design to a 13m/s wheel speed, as there will be losses.
2. Design based upon 1/2 max motor speed to accomodate any battery issues, allow for an extra pulse to get back up to speed after a shot, and so we can have some room in case point one above was not concervative enough.

Upon testing, we shot a ball 35' at 30 degrees (with no spin on the ball). Based on this, we're pretty confident that we're at 12m/s, as this was FIRST's indirect measure.

Since then, we've lessened the top drum speed to generate a back spin, giving us much better control at the same type of distance.

In order to get a final number, we'll be looking at a buying a speed gun (which I'll use with the baseball team I coach in the off-FIRST-season).

[LightWaves1636]

Originally Posted by Scott358

Very good estimate. How did you "see" that???

A couple design criteria where:
1. Design to a 13m/s wheel speed, as there will be losses.
2. Design based upon 1/2 max motor speed to accomodate any battery issues, allow for an extra pulse to get back up to speed after a shot, and so we can have some room in case point one above was not concervative enough.

Upon testing, we shot a ball 35' at 30 degrees (with no spin on the ball). Based on this, we're pretty confident that we're at 12m/s, as this was FIRST's indirect measure.

Since then, we've lessened the top drum speed to generate a back spin, giving us much better control at the same type of distance.

In order to get a final number, we'll be looking at a buying a speed gun (which I'll use with the baseball team I coach in the off-FIRST-season).

sorry but finally i found you again, i was trying to figure out which team it was who made that shooter but hey now I know, anyhow my team desperately wants to know how you built that,we hardly have anything, we have replicas but they're hardly working, could you give us schematics of what you did so we could make a similar model. It would help us so much.

[Nuttyman54]

Originally Posted by Scott358

Upon testing, we shot a ball 35' at 30 degrees (with no spin on the ball). Based on this, we're pretty confident that we're at 12m/s, as this was FIRST's indirect measure.

You're probably going faster than 12 m/s in this case, because the FIRST measure excludes air resistance. This is an easy fix however, and it looks to be an impressive shooter. can't wait to see pics of the final 'bot!

[Scott358]

Originally Posted by Eric Scheuing

Good, accurate shooter. The only thing I don't like is the fact that you can't really go much more rapid fire than that, or so it sounds like by the motors.

The current system has no software support to help ramp the motor back up to shooting speed after a shot. As Mark said in the first message of the thread, now it's time for the programmers to do their magic.

We're targeting a minimum of 10 balls in about 7 seconds, which allows an autonomous with 3 seconds of driving, the rest for shooting.