Re: pre-charged Pneumatics
 

Yeah, we do know that. We've seen the videos. Our own design is probably going to work this way. We are going to try our best to keep it inside the frame perimeter at all times, for various reasons. We'll see if we can get the distance we want from it that way....

Re: pre-charged Pneumatics
 

Our design will likely work this way as well. We will also be testing the "inside the Frame Perimeter" version, but we expect we will be going with a version that does utilize the 2 second exception. It will need to be in a partially retracted position for inspection and the start of each match.

A piece of surgical tubing strong enough to restrain the device inside the frame perimeter would slow the kicker down as soon as it reached the frame perimeter, negating the purpose of the extra 3" of travel (as soon as the kicker slows due to a force not part of the collision the ball will be traveling faster and lose contact).

We are making every effort to make this partially retracted state safe, including using a robust latch, but barring circumstances where we are forced to do otherwise we will have a separate safety device restraining the kicker when it is in this position and the robot is anywhere but it's starting position on the field.

It would be preferable to have this safety device in place when sizing the robot, but if that is not we will do what we can to make sure the process is as safe as possible.

Re: pre-charged Pneumatics
 

Ok Jim,
Using your robot as an example, what happens to the kicker when your tubing is not stretched? Does gravity affect it's position? Is it firmly held outside of the frame perimeter even though the tubing is not stretched? If all systems fail on your robot (a hard hit causes your battery to become dislodged and it breaks off a pneumatic fitting), what happens to the kicker? Same scenario but the kicker was not yet in a position to fire?

Re: pre-charged Pneumatics
 

The tubing is always stretched, in the "just fired" position there is a lot of tension on the tubing, pulling the kicker forward.

No.

The current designs have the kicker firmly prevented from moving outside the frame perimeter, because it hits the frame and stops.

That is a good question, we can't answer it because we dont' have the firing system all designed and built. A good answer might be to design it so that it can't fire accidently under circumstances like this, and that is what we're trying to do.

Re: pre-charged Pneumatics
 

I would like to propose another hypothetical: A team's kicking mechanism uses a winch to pull back an arm connected to a torsion spring. To fire, the winch motor is mechanically disconnected (with a dog gear or the like), and the wire allowed to unwind freely. A mechanical stopping device prevents the arm from extending past bumper perimeter. The winch motor does not allow for backdrive.

In this case, the winch must be at least partially winded to fit in the box, but it may do so without power, and it is thus self-supporting. Would this be considered safe for inspection if it was only winded enough to fit in the box? What kind of safety devices should be used with this design, if the intention is to pre-load it before a match?

Re: pre-charged Pneumatics
 

Nadav,
I don't have any direction from the GDC to answer your question at this point. I would have to examine it before I would make a decision to put my hands inside while inspecting.
Jim,
I have considered that some teams would have a design likes yours as well. However, the tension supplied by the tubing at rest, holds the kicker in position against a mechanical stop and it can't be fired from that point. (No threat to human safety should something fail except the damage that would occur if the tubing let go.) If the end of the kicker is inside the FRAME PERIMETER then effectively the robot fits the parameters we have been discussing. If you had answered that the kicker had to be in the firing position to fit inside the box, then Mike Betts and I are in agreement I think, that the robot doesn't fit the criteria of unsupported sizing. I expect that teams are considering the same design criteria as you and coming to the same crossroads. Your answers are encouraging, thank you.

Re: pre-charged Pneumatics
 

hey all
Just have some questions about a latex tube + 1.5" bore cylinder kicker...
we have protoyped it and it seems like a nice and easy mechanism. However it only gets about 10' @ 50psi. we are using a peice of angle alum. to hit the ball, and its doesnt look promising. we found the falcon guys demo video, and it looks very similar, but no where near there results. what can we do to precharge or help a fast release. we have a gate latch, fresh latex tubing, bearing mounts... doesnt seem very active.
any thoughts are appreciated.

Re: pre-charged Pneumatics
 

If you are concerned then it seems to me that you can bring velcro straps with you to the sizing so the robot will be in the "box" as it will be when you are on the field and charged. The difference is that you will not be charged. These can be on the robot for weighing as they weigh nothing.

I have seen too many teams not do something because they were afraid. I say read the rules, have a good argumnet why it is allowed but push the envelope.

Re: pre-charged Pneumatics
 

If you could post a close-up video or series of pictures of your prototype it might expedite the process of understanding what you're doing and result in more focused responses.

~

Re: pre-charged Pneumatics
 

As requested by Mike, we posted the question t the GDC and, i believe, inspired part of update 7 :)

I believe this is exactly the type of guidance the inspectors (and teams!) were asking for in this thread. Inspection takes placed powered down, however if your design requires power to conform to the volume rules, and you have sufficient safety mechanisms in place, then you can be sized in a powered on state, or with significant amounts of stored energy.

This makes designs that have been discussed here legal (where in a powered down state a mechanism would extend past the FRAME PERIMETER) for th purposes of inspection.

However, i would beg ALL TEAMS to show up at inspection fully prepared and ready. If your robot requires power for sizing, tell the inspectors about it first, and demonstrate your safety mechanism before heading over to the sizing box. We all know how crazy it can get when an understaffed inspection team is trying to get all the teams signed off to play - It's up to us to make their job as easy as possible, especially when rule conditions like those discussed here pose potential issues that will slow the process down.