pre-charged Pneumatics

[ISGOI Howie]

when we go to mesure the perimeter of the robot can we have a pneumatic piston charged (ie pulling somthing back) or does it have to be empty. thanks for the help guys

[joek]

no, i believe everything has to be uncharged and powered down during inspection, but i'd ask the GDC/ consult the rules first

[ISGOI Howie]

Originally Posted by joek

no, i believe everything has to be uncharged and powered down during inspection, but i'd ask the GDC/ consult the rules first

thanks... the rules arent very specific on that topic

[Peter Matteson]

I disagree. I believe this is perfectly legal for wieghing and sizing.

In the past teams have had srping loaded protrusions and expansions that activated at the start of the match but allowed them to meet size requirements and I see this as no different.

A good portion of this year's ball manipulation devices will be required to be pressurized to size during inspection. Explaining this to the inspectors as a precaution makes sense. Also remember every time you place your robot on the field this devisce will need to be charged fot the same reason.

IMHO you can go through inspection and place your robot on the field with charged pneumatics.

[Al Skierkiewicz]

Peter and Howie,
This is the rule that applies...

<R90> The ROBOT will be inspected for compliance with the dimension constraints specified in Rule <R10> while in its NORMAL CONFIGURATION, by being placed within a FIRST Sizing Device that has inside surface dimensions consistent with the rule. Other than resting on the floor of the Sizing Device, no part of the ROBOT can break the plane of the sides or top of the Sizing Device during size inspection. The ROBOT must be self-supporting while in the Sizing Device.

Inspections are carried out with all systems unpressurized and unpowered for obvious safety reasons. Robot size and weight are tested with the bumpers off and the battery out. Please refer to Rule <10> and <11> as both are referenced in robot size.

The rules for stored energy govern the condition that a robot can be in at the start of a match including air stored in the Clippards. This rule allows teams to pressurize their robot with an off robot compressor but speaks to the start of a match, not to inspection. Please ask the question as we have no guidance to the contrary from the GDC. I expect the pressure vent valve to be open until the "power on" portion of the inspection takes place.

[Peter Matteson]

Missed that one Al.
It looks like a manual "safety" lock is how everyone will have to skirt this issue for inspection.

[MrForbes]

Or have your robot kick the ball without any parts extending past the frame perimeter. It's possible.

http://www.youtube.com/watch?v=Mb0_i3hbVNY

[Jon Stratis]

Originally Posted by Peter Matteson

Missed that one Al.
It looks like a manual "safety" lock is how everyone will have to skirt this issue for inspection.

Everyone really should have a safety lock available anyways. If you are going to be carrying the robot on or off the field with any mechanism "charged" and ready to fire, it needs a secure lock in place to ensure that any jostling doesn't result in someone getting kicked in the gut and dropping the robot on their foot. That is a simple safety practice that every team should have (I would even go so far as to suggest that inspectors should fail teams without it) that can easily prevent real injuries.

Which leads to a question for Al... If a team had such a safety lock that was removed from their robot after placing it on the field, could they use it during the sizing part of inspection, but remove it when weighing the robot? If the safety lock is a few pounds for something real sturdy, it could make a real difference when being weighed.

[Daniel_LaFleur]

Originally Posted by eagle33199

Everyone really should have a safety lock available anyways. If you are going to be carrying the robot on or off the field with any mechanism "charged" and ready to fire, it needs a secure lock in place to ensure that any jostling doesn't result in someone getting kicked in the gut and dropping the robot on their foot. That is a simple safety practice that every team should have (I would even go so far as to suggest that inspectors should fail teams without it) that can easily prevent real injuries.

Which leads to a question for Al... If a team had such a safety lock that was removed from their robot after placing it on the field, could they use it during the sizing part of inspection, but remove it when weighing the robot? If the safety lock is a few pounds for something real sturdy, it could make a real difference when being weighed.

I've always told my team to release the air pressure before lifting the robot off the field. It makes the robot that much safer and doesn't take that much time.

[Jon Stratis]

Ahh, but not all mechanisms are "charged" with air pressure. Teams that utilize springs or surgical tubing with a motor to charge their kicker may, depending on design, leave the kicker in a charged position when the robot is off, while having no pneumatics at all! And other teams will pressurize their robot from the cart in order to save weight (not have a compressor on their robot) - in such a case, you would have to carry it onto the field charged.

[dtengineering]

FIRST provided some good safety guidelines for precharged devices (and this forum came up with some more) a couple years ago for the trackball launchers.

Mind you... if your ball kicker has as much energy stored up as a trackball launcher, you ought to be able to kick balls up into the stands.

My estimate so far is that we are using about 1/4 the force and about 1/2 the stroke on our pneumatic kicker that we did on our pneumatic launcher.

Jason

[joek]

Everyone really should have a safety lock available anyways. If you are going to be carrying the robot on or off the field with any mechanism "charged" and ready to fire, it needs a secure lock in place to ensure that any jostling doesn't result in someone getting kicked in the gut and dropping the robot on their foot. That is a simple safety practice that every team should have (I would even go so far as to suggest that inspectors should fail teams without it) that can easily prevent real injuries.

Which leads to a question for Al... If a team had such a safety lock that was removed from their robot after placing it on the field, could they use it during the sizing part of inspection, but remove it when weighing the robot? If the safety lock is a few pounds for something real sturdy, it could make a real difference when being weighed.

one of the big reasons they put the weight restriction on is because team members are going to be carrying the robot, it's a safety issue.

[Al Skierkiewicz]

Originally Posted by eagle33199

Which leads to a question for Al... If a team had such a safety lock that was removed from their robot after placing it on the field, could they use it during the sizing part of inspection, but remove it when weighing the robot? If the safety lock is a few pounds for something real sturdy, it could make a real difference when being weighed.

Eagle,
The answer would be yes and no. A safety lock could be used but under the rules for start orientation, the robot (not humans) has to be able to remove the lock after the match starts. The robot must be able to hold itself in the same size it did when in the sizing box at the start of the match.

During previous games where mechanisms used considerable stored energy, the team had to demonstrate during inspection, that the stored energy could be released (safely and easily) prior to moving the robot on or off the field. One of the most impressive devices I have seen was on the Baxter robot during Overdrive. It used surgical tubing and a cam type charging device. To move the robot, a team member just needed to back the cam to the point where the tubing was no longer stretched. Those that played against Team 16 that year knows the effectiveness of that ball launcher.

[Mike Betts]

Al,

I have to disagree with you (at least partially) on this one.

If the safety lock, when removed, will cause deployment of a mechanism, I agree.

If we are talking about making a trigger mechanism for a stored energy device absolutely foolproof safe but it's removal does not cause deployment, I not only think it legal but almost mandatory.

We do not want accidental deployment of a mechanism when putting a robot onto or off of the field.

Let's use a theoretical kicker for an example. It has a deflected spring and/or pre-charged pneumatic piston and a trigger that makes it fire. A pin in the trigger, removed after the robot is placed on the field, will prevent accidental firing while the robot is handled.

The pin is never part of the robot during a match. It is in a team member's pocket.

I would call this legal and almost mandatory.

JMHO,

Mike

[Al Skierkiewicz]

Mike,
I would agree on this example provided the robot was able to fit in the box and start the match without said locking device in place.