G04

[aldaeron]

We are working on our Level 3 climber and are quite worried about how to meet Rule G04 (reprinted below).

Obviously no one wants to tumble from Level 3 to the floor, but without power and special tools many of the ideas we have come up with are not looking good. Some of our thoughts (and their downfalls):

- Get a beefy worm gear drive
-> Would need power to reverse it
- Use a good number of CIMs
-> Would back drive when power lost and robot would fall =(
- Use a ratcheting mechanism of some sort
-> Unless we have a really tall person it will be hard to disengage from the floor
- Use a pneumatic piston to drive in a lock somewhere to hold the robot
-> We would have to drain the air and slide the lock out. ALso difficult without a tall person.



There seems to be a direct conflict between keeping the robot locked securely on the pyramid and removing it without power or special tools. Perhaps I am overlooking something simple and maybe you can help.

We are planning to submit a Q&A if we can't think of something good that allows us zero risk of falling off level 3 and meets G04.

-matto-



Rule G04:

After the MATCH, ROBOTS may only be removed from a PYRAMID under the following conditions:

A. by the TEAM while standing on the floor without special equipment,
B. unpowered,
C. and under the supervision of a FIRST Technical Advisor (FTA), FTA Assistant, Referee, or Field Supervisor.


Additionally, if any part of the ROBOT is in Level 3, TEAMS are required to attach a FIRST supplied belay line, detailed in Section 2.2.5, to their ROBOT to spot a ROBOT while the TEAM removes it from the PYRAMID.

Violation: YELLOW CARD

[Jeffy]

You may not need to unreal any sort of climbing mechanism if you use something like a hook to attach to the pole. Just lift up.

Otherwise, make the air release/ratchet accessible from the bottom of your robot and you shouldn't have a problem.

We are hashing out a plan for ours, but it will likely involve a big lever.

[fox46]

I've been waiting to see how this develops as well. I have no clue how they expect to attach a belay line to the top of a robot that is 6ft+ off the ground without using a step ladder. To assert that a step ladder is unsafe and cannot be used by teams but can by field staff seems rather hypocritical. I have the feeling that they haven't quite thought this through.

[Gregor]

I'm curious as to how teams are planning on turning their robot off before disengaging from the tower.

[fox46]

In Q&A -

Q115
Q.Regarding the G4 "A" Update (2013-01-11) - For a robot completely within zone 3, how will the belay be attached if the attachment points are above the reach of the team? And will the belay mechanism allow a robot to be lifted slightly if that is necessary to remove it?

A.If the ROBOT cannot be removed from the PYRAMID under the constraints listed in [G04], the Team would receive a YELLOW CARD.

It would seem that you are not allowed to climb any higher than the tallest member of your team can reach.

G04
After the MATCH, ROBOTS may only be removed from a PYRAMID under the following conditions:

A. by the TEAM while standing on the floor without special equipment,
B. unpowered,
C. and under the supervision of a FIRST Technical Advisor (FTA), FTA Assistant, Referee, or Field Supervisor.

Additionally, if any part of the ROBOT is in Level 3, TEAMS are required to attach a FIRST supplied belay line, detailed in Section 2.2.5, to their ROBOT to spot a ROBOT while the TEAM removes it from the PYRAMID.

Violation: YELLOW CARD


I'm not quite sure what to say about this. I wonder what they consider "special equipment"? Would a 3' stick with a hook to disengage a ratchet be considered "special equipment"?

[Saberbot]

From my interpretation, that is exactly what they mean by special equipment. It look like it's time to recruit a tall human player.

[Garten Haeska]

It's rules like this that makes me glad that I'm 6' 5" and can reach the top bar.

[fox46]

Well since I am not 6'5"+, I consider myself physically handicapped. Good thing I own an artificial limb that measures 3ft long with a hook on the end. :D

[Steven Donow]

I've been waiting to see how this develops as well. I have no clue how they expect to attach a belay line to the top of a robot that is 6ft+ off the ground without using a step ladder. To assert that a step ladder is unsafe and cannot be used by teams but can by field staff seems rather hypocritical. I have the feeling that they haven't quite thought this through.

I wouldn't say it's hypocritical, mainly because odds are, the event staff using a step ladder will be considered "trained staff"

[Qbot2640]

I wouldn't say it's hypocritical, mainly because odds are, the event staff using a step ladder will be considered "trained staff"

I wouldn't count on this...the rule states that the robot will be removed "by the team" and "under the supervision of..." event staff (emphasis mine).

I asked the Q&A question quoted above, thinking that some assistance would be provided, but it seems that (from the response) that will not be the case. I would interpret that a team who needs assistance in any way getting their robot down will be issued the yellow card.

[Taylor]

We are working on our Level 3 climber and are quite worried about how to meet Rule G04 (reprinted below).

Obviously no one wants to tumble from Level 3 to the floor, but without power and special tools many of the ideas we have come up with are not looking good. Some of our thoughts (and their downfalls):

- Use a pneumatic piston to drive in a lock somewhere to hold the robot
-> We would have to drain the air and slide the lock out. ALso difficult without a tall person.


Our plan is to use hooks, as previously noted in Post #2, so the person can simply lift it off the pyramid. To keep the arm locked in place, we'll use something like this (http://www.lowes.com/pd_51080-1277-SP1261_0__?productId=1187149&Ntt=gate+latch&Ns=p_product_price|0), with a 393 motor, an 84-tooth VEX gear, and some fishing line to unlatch it as we ascend.

[Racer26]

The no special equipment rule sort of surprises me. I can remember 1114 in 2010 using a small custom built tool to safely unlatch their one-way latch from the tower without pinching fingers. Is something like that really outlawed in 2013?

[alicen]

as a kind of follow up to everything about the BELAY system; it's not meant to aid you in removing your robot, it's meant to ensure that the robot doesn't fall while you are removing it.

Q. May the belay system be used to lift the ROBOT a small distance to aid in releasing it from the PYRAMID before lowering the ROBOT after the MATCH?

A. No. The belay system is meant as a safety against falling ROBOTS, not a removal tool.

So, I suggest designing a trigger that you can reach to release your robot, and your BELAY attachment points to be closer to the bottom of your robot

[Bob Steele]

As a mentor I really have a problem if a team cannot reach the top of the pyramid to unlock their robot. I would imagine that we will have girl's teams that will have great difficulty with this. The 90" pipe is just that... 90" or 7.5 feet above the floor... I am 5 11 and the tips of my fingers are almost exactly 8' off the floor. For a 5'6" student I am sure they will barely reach the pipe.

I would also like to state that this is a safety hazard, with or without the "belay system" This is the reason we have ladders.

I don't want my students to be put in a situation where they can't reach the third level to unlatch the robot. The

Where is the logic in not allowing a short team to climb the pyramid with their robot just to get a yellow card and then a red the 2nd time? Why design a game like this? (I don't mean students climbing on the pyramid...)

Just lifting a 155 lb weight up by a few inches from a height of over 5 feet is not going to be easy. Of course those of us with big male or female students (over 6 feet tall) can figure out how to do this... but it is inherently unsafe to be under this robot.... that includes the belay.

A belay can slip... it is a human interaction...
Ask any of us who have done climbing...
If a robot comes off the top and starts to drop... I will be surprised if the belay will catch it unless it is attached to the operator's body with a harness AND he/she knows what they are doing...they have to take in slack to their body harness point. Perhaps all of the field personnel will be specially trained and outfitted with the proper equipment to do this... but it is not how it was shown in the video...

If a belay slips.... the students or anyone under the robot gets hurt.

It makes sense to have the proper equipment on the field... such as ladders for the lifters that will put them out from under the robot so they can lift with their legs instead of pushing up with their arms/legs from underneath.

It is a travesty if teams get yellow cards because they are attempting to apply the proper safety precautions.

GDC please rethink this.... what is the point of the yellow card for a piece of safety equipment or any other means that allows the safe removal of the robot? Does it give a team an unfair advantage to do a safe removal?

[sanddrag]

I can see their reasoning here. For whatever reason, there's many dangerous things we can do but ladders are a huge liability and insurance issue. Additionally, allowing unregulated equipment onto the field can cause a safety hazard. I would not want to get whacked in the head by someone's hook removal pole in careless hands and close quarters.

[Jon Stratis]

A belay system that involves a significant mechanical advantage (think pulleys) could be used without much training or other equipment - someone holding it in their hands can reasonably be expected to apply 25-50 lbs of force on the rope to stop a robot.

[Zebra_Fact_Man]

I do find it interesting and slightly disturbing that the rules/GDC is effectively being biased against teams that are vertically challenged, literally limiting their performance capabilities. By which, I mean a team with 1 or 2 tall individuals would have no such problem where a team that doesn't will.

My team is not personally effected by this (we've got tall, strong people), but it still seems unfair nonetheless to teams that don't.

[feverittm]

I agree with this discussion. I think the G04 problem will be a significant issue for some teams.

I also wonder. By Who and When will the belay system be attached to the robot? If by the field personal then they must have a ladder to reach the attach points right? The rule does not state that the belay must be attached by someone from the ground?

[Tem1514 Mentor]

I agree with this discussion. I think the G04 problem will be a significant issue for some teams.

I also wonder. By Who and When will the belay system be attached to the robot? If by the field personal then they must have a ladder to reach the attach points right? The rule does not state that the belay must be attached by someone from the ground?

Part A of the rule

"A. by the TEAM while standing on the floor without special equipment,"

seems very clear to me that the team members do everything from the ground only.

[Taylor]

I do find it interesting and slightly disturbing that the rules/GDC is effectively being biased against teams that are vertically challenged, literally limiting their performance capabilities. By which, I mean a team with 1 or 2 tall individuals would have no such problem where a team that doesn't will.

My team is not personally effected by this (we've got tall, strong people), but it still seems unfair nonetheless to teams that don't.

This is not unprecedented. 2009 featured a game that was biased against people that were colorblind.

[PAR_WIG1350]

Regardless of whether or not there is a precedent for discrimination, complaining here is not the best way to encourage change. Somehow, we need to express displeasure directly to FIRST if we truly want to be heard.

That being said, there is nothing in the rules that prohibits the use of robot parts to remove robots from the pyramid. Any tool that you might need to reach the release could be attached to a length of wire rope bolted to the frame and stowed on the bottom of the robot.

Similarly, fold-down, locking handles to allow shorter people to lift a robot that is otherwise above their reach could be bolted on and then only one person tall enough to release the handles is needed.

After the match the size constraints no longer apply, which gives more freedom in designing the retrieval assisting mechanisms. There is still a penalty in the form of weight and volume occupied by these elements, but any robot that can climb that high will already be devoting a lot of weight and volume to that mechanism. I hope this helps.

[nighterfighter]

Regardless of whether or not there is a precedent for discrimination, complaining here is not the best way to encourage change. Somehow, we need to express displeasure directly to FIRST if we truly want to be heard.

That being said, there is nothing in the rules that prohibits the use of robot parts to remove robots from the pyramid. Any tool that you might need to reach the release could be attached to a length of wire rope bolted to the frame and stowed on the bottom of the robot.

Similarly, fold-down, locking handles to allow shorter people to lift a robot that is otherwise above their reach could be bolted on and then only one person tall enough to release the handles is needed.

After the match the size constraints no longer apply, which gives more freedom in designing the retrieval assisting mechanisms. There is still a penalty in the form of weight and volume occupied by these elements, but any robot that can climb that high will already be devoting a lot of weight and volume to that mechanism. I hope this helps.

The robot could have a folding ladder! Rules against climbing the pyramid exist, but not against climbing the robot...

[Grim Tuesday]

Regardless of whether or not there is a precedent for discrimination, complaining here is not the best way to encourage change. Somehow, we need to express displeasure directly to FIRST if we truly want to be heard.

That being said, there is nothing in the rules that prohibits the use of robot parts to remove robots from the pyramid. Any tool that you might need to reach the release could be attached to a length of wire rope bolted to the frame and stowed on the bottom of the robot.

Similarly, fold-down, locking handles to allow shorter people to lift a robot that is otherwise above their reach could be bolted on and then only one person tall enough to release the handles is needed.

After the match the size constraints no longer apply, which gives more freedom in designing the retrieval assisting mechanisms. There is still a penalty in the form of weight and volume occupied by these elements, but any robot that can climb that high will already be devoting a lot of weight and volume to that mechanism. I hope this helps.

On a similar note, what if your drive team is able to form a human pyramid to allow the top member to release whatever needs to be done? Technically legal but I think would fall under the Head Ref's jurisdiction to penalize unsafe procedures.

[pfreivald]

Keep in mind that while the zone three horizontal bar is 90" off the ground, it is possible* for the robot to have made a valid 30-point climb and not violate any height/volume restrictions, and yet the bottom of the robot is still only 6" off the ground at retrieval time.

*I said "possible"... More likely, you can just barely leave the 60" bar and still be a 30-pointer. A robot 5' off the ground should be manageable by the vast majority of teams.

[johnr]

Why don't they just allow teams to have an extra two people just for robot removal. Some teams won't even need them and this way some teams could have smaller people on drive team. These specialists stay out of the way until match is over.

[Trent B]

I agree that this wouldn't be a bad idea: allowing extras to remove the bot. I tower over all of my students

[Bob Steele]

One team that has a mentor that can handle this is 2122...
See Mark... another reason for you to be around...
Mark is pretty tall....

[PAR_WIG1350]

The robot could have a folding ladder! Rules against climbing the pyramid exist, but not against climbing the robot...

Don't give then a reason to make one, please. :D

[PAR_WIG1350]

On a similar note, what if your drive team is able to form a human pyramid to allow the top member to release whatever needs to be done? Technically legal but I think would fall under the Head Ref's jurisdiction to penalize unsafe procedures.

G04-A, standing on your human player is not the same as standing on the ground. A fold down handle that adds 4" of reach and a 6" pawl poker on 8-12" of wire rope are not outrageous. The fold down handle is just an evolution of the built in handles some teams already use. As long as one uses common sense, there should be nothing unsafe about them. (I do recommend a sturdy lock or latch on any handles so that they don't collapse)

[fox46]

How does one reach said handles to fold them down if the purpose of the handles are to allow you to reach the robot?

A proper solution to this mess would be a simple work access platform about 3'x6' and 3 feet tall with a railing around it which can rolled out throught the field access gates beside the pyramid, casters retracted and stood-upon by team members to reach and lower their robot. It would be a simple item to add to any field setup (have it double as a shipping container for field components). Similar platforms are used in industry for fall arrest mitigation all the time with minimal risk and an excellent safety record. They are far preferred to ladders for tasks such as trying to manipulate a 150lb machine at arm's reach above one's head.

http://agfbrome.com/English/images/Double-acces_001.jpg

The purpose of the pyramid challenge should be to design a robot for the purpose of climbing it, not designing a robot to be removed from the uppermost level without the use of tools/equipment. If the removal process was not intended to be part of the challenge than the pyramid should not have been made 90" tall in this case. It should have been limited to 60", and the robot's height and size restrictions adjusted accordingly to ensure a similar degree of difficulty for the challenge

The GDC has to get it together and think their games through before releasing them. Team Update 3 is a perfect example of this kind of "chasing the bus" situation. Be sure to let them know your opinions when you are emailed the FIRST survey at the end of the year. They do listen- I've been complaining about Motors the past two years and they've responded with a whole family of CIM-variant motors this year!

[Trent B]

With fold down handles you only need one person tall enough to touch the robot and fold them down rather than 2 or 3 to lift it down.

[Chris is me]

Keep in mind that while the zone three horizontal bar is 90" off the ground, it is possible* for the robot to have made a valid 30-point climb and not violate any height/volume restrictions, and yet the bottom of the robot is still only 6" off the ground at retrieval time.

Uh, no, I'm pretty sure it isn't. If the robot is capable of lowering itself without power to six inches after going higher than sixty, then how does it hold itself at the level for scoring? The only way I can think of this being the case is if you had some kind of mechanical device that took 10 whole seconds to disengage a winch's brake, for example.

To answer the OP - worm gears are not the only way to prevent backdriving. They are actually a pretty bad way to do it, as a worm gear that doesn't backdrive is inherently inefficient.

Also, no one said you have to lower your robot with its mechanism to remove it from the tower. If you have a passive hook, just lift it up an inch to take it off and reset your hanger in the pit.

[engunneer]

I am reasonably certain he meant six feet and used the wrong ". (An easy mistake)

[Chris is me]

I am reasonably certain he meant six feet and used the wrong ". (An easy mistake)

OH, wow, I can't believe I didn't see that as a possibility! Sorry for jumping down your throat there, pfreivald.

[pfreivald]

Actually, I meant 6".

I didn't say it was likely, easy, or something to design for -- but it is *possible* to have a robot that lowers itself slowly enough so that you get the points after five seconds, but it's 6" off the ground by the time that the team gets out to retrieve it.