Building a claw post-ship
 

My team's robot is coming together, and it looks like we could bag a working robot on ship day (if we wanted to). We will have a mechanism (an arm with a rather simplistic hook) completed, as well as a functioning 6 wheel skid drive.
We plan to keep the control system (cRIO, jaguars, sidecar, etc mounted on a plywood board) to give our programmers a bit more time to refine the code.
I was thinking about using the rest of our withholding allowance and the time between ship and our only competition (DC regional) to give some of the team a chance to develop a claw that they had been pushing for. We used a length of 80/20 for the arm, so attaching a possible claw onto the arm should not be too difficult (although I am an electrical person).
Good idea? Or terrible plan?

Re: Building a claw post-ship
 

Sounds like a good plan to me. The only concerns would be with adding too much weight on the end of the arm and being unable to move the arm as a result. The only other issue (and I don't view this as a problem) is this being considered " un-GP." In my eyes, the period between ship date and competition was made a legal build period for a reason, and you should be allowed to take full advantage of that time.

Re: Building a claw post-ship
 

Do you have a plan for controlling the claw? If you're adding another motor or other device to actuate it, do you think you can make it work quickly enough at the regional to be able to practice using your robot? Same with programming...sure, you can work on code without the electronics installed on the robot, but how will you make it work right once you put it all back together? Unless you have another whole robot to test the code with between ship and comp, you'll probably end up making it worse.

You might be better off finishing the robot as well as you can, and spend a few days practicing using it, and fixing any bugs you find in the code, and maybe getting it to do something in autonomous.

Re: Building a claw post-ship
 

I'm going to these very same questions to the students working on the claw. They seem have a good grasp on how they wish to go about the mechanism but I do have some reservations.
We can rig up another arm to practice with between ship and the regional. Its not ideal, but I think it would work.
There's not much our programming team can make worse, unless they somehow break TankDrive.
I'm trying to keep my team productive between Feb 22 and March 24. If you have any suggestions, I'm all ears. We will be borrowing a Minibot from a FTC team.

Re: Building a claw post-ship
 

Let 'em do it. If the kids want to put in the extra effort of continuous improvement, you should encourage it.

Re: Building a claw post-ship
 

I find that a few weeks of catching up on homework (and sleep) is a good way to fill the time between ship and competition.

Oh....sorting out the extra parts....what you want to take, what you want to leave behind. Getting tools organized. Figuring out how to do scouting.

There are lots of things to do.

Re: Building a claw post-ship
 

I think that might be pushing the "upgrade" section of the rules, our rule of thumb is that if it adds any electronics or coding then it is questionable, we are using the withholding allowance for some better wheels, possibly an upgraded roller for our grabber, but not much else.

Re: Building a claw post-ship
 

By no means is it pushing any rules - it is explicitly permitted.

Re: Building a claw post-ship
 

It is allowed and encouraged. Have your team run with it.

Re: Building a claw post-ship
 

We might do the same. If the kids want to, I would let them do it.

There is nothing against the rules about doing this btw. If anything, it might be encouraged. It shows that the kids can improve on designs and pick out key parts of a design.

Re: Building a claw post-ship
 

agreed, but the point of first is to build a robot in 6 weeks. building a robot and a lift, but not having a claw, is not a robot, it is 2/3 of a robot. i would make sure to have something on the robot, it sounds to me like you plan to simply bring your completed claw, the Manuel says "replacements or upgrades" if it is added without replacing anything then it does not fall into that category.

Re: Building a claw post-ship
 

Just so that everyone is on the same page here.

WITHHOLDING ALLOWANCE – a limited amount of FABRICATED ITEMS that are withheld from the shipping requirements (specified in the 2011 FRC Administrative Manual, Section 5) and retained by the team following the shipping deadlines.

And...

<R24> During the period between ship date and the competitions, all teams may manufacture SPARE, REPLACEMENT, and UPGRADE PARTS, and develop software for their ROBOT at their home facility.
Teams may continue development of any items retained under the WITHHOLDING ALLOWANCE during this period, and then bring them to the competition events.

Please note: This is a reference to items fabricated by your team prior to ship. While you may prototype and plan items for use on your robot, fabrication may take place only at events after the ship date. If in doubt, please ask the Q&A or First for verification.

Re: Building a claw post-ship
 

Thanks for the replies everyone. We plan on having a tube hook ready before we bag our robot, so we're not relying on having this extra time to complete the robot itself.

Re: Building a claw post-ship
 

Go back and re-read the definition of Upgrade Parts. Especially this portion of the definition: "intended to provide additional functionality not currently available on the ROBOT."

I could, if I wanted to, and I was able to do it in under 30 lbs, ship a box-bot, build an arm and a deployment system for it, bring both of those to the event, bolt them on, and I'm legal in terms of build time. Other rules... well, that's what inspection is for.

Al, where did that note of yours come from? I don't remember seeing it in the Manual for this year. Under <R24>, I could manufacture a complete competition system in my shop if I wanted to, unless there's another rule that says otherwise.

Re: Building a claw post-ship
 

i don't believe that a whole arm is an upgrade so much as an addition. i think what they mean by additional functionality would be
a rolling claw vs a clamping claw, or shifters vs single speeds, not a manipulator vs nothing.

Re: Building a claw post-ship
 

Last year the team I mentor brought in the lifting sub-system for the robot at the Hawaii regional and another team built a lifting system before their first regional.

Last year we had ~60 lbs we could keep from shipping, I do not see a difference from last year to this year for the with-holding allowance except for the amount.

I see a claw upgrade, not as a subsystem upgrade, but a host-bot upgrade.

<R24> During the period between ship date and the competitions, all teams may manufacture SPARE, REPLACEMENT, and UPGRADE PARTS, and develop software for their ROBOT at their home facility. Teams may continue development of any items retained under the WITHHOLDING ALLOWANCE during this period, and then bring them to the competition events


<R33> Teams may bring a maximum of 30 pounds of custom FABRICATED ITEMS (SPARE PARTS, REPLACEMENT PARTS, and UPGRADE PARTS, plus all WITHHOLDING ALLOWANCE items) to each competition event to be used to repair and/or upgrade their ROBOT at the competition site. All other FABRICATED ITEMS to be used on the ROBOT during the competition shall arrive at the competition venue packed in the shipping crate or lockout bag with the ROBOT

emphasis mine*

Nowhere does it say that you need to be upgrading a particular subsystem such as a claw.

Re: Building a claw post-ship
 

Could you possibly be looking at this?

"<R25> While at competitions, teams may repair, modify or upgrade their competition ROBOT. To support this, teams may bring SPARE, REPLACEMENT and UPGRADE PARTS and COTS items to the competitions (within the limits specified in Rule <R33>). Work can only be done on-site in the pits or at any facility made available to all teams at the event (e.g., in a team’s repair trailer or a local team’s shop offered to all teams to use). Fabrication may be done when the pit area is open for normal operations during the period starting with the opening of the pit area on the first day of the competition event and ending at 4:00PM on last day of the event. All work must be stopped when the pit area closes each evening. Parts shall not be removed from the competition site and retained overnight after the pit area closes....."

Re: Building a claw post-ship
 

Eric,
Which note are referring to? The sentence immediately following R24 is cut and paste from the manual. The 'please note' is mine. when the manual speaks to upgrade parts I believe it is referring to your decision to beef up a part on a mechanism you designed and built prior to ship but now have second thoughts about.
This also follows R24...
The primary intent of this rule is to allow teams to withhold the ROBOT control system, the OPERATOR CONSOLE, and selected relevant subsystems and access them after the shipping deadline. This will allow teams to have the maximum time possible prior to each competition event to develop and complete the software for their ROBOT while maximizing the potential capabilities provided by the control system.

Emphasis mine.

Re: Building a claw post-ship
 

As someone who is actually withholding my entire arm (since I am lazy and don't want to build yet another arm) I can safely say that this behavior has been the norm for years and is in no way un-gp or "questionable". If you don't like it fine, doesn't mean you have the right to say others can't do it.

Re: Building a claw post-ship
 

From your post:I don't see anything in the manual to support the second bolded line (<R24> specifies that a team's home facility may be used to build upgrade, spare, and replacement parts).

According to the definition of Upgrade Parts, it says COTS or Fabricated Component or Mechanism that is used to improve/add functionality, in effect. It does not say, change how part works. It does not say, you have to have had that part built/on the robot before ship. It says, add or improve functionality.

As such, anything saying "it has to have been on the robot before ship" or "the robot has to have similar functionality already" goes against the Manual's wording. I agree that the intent is to upgrade individual parts--but there is nothing to prevent an entire arm that never saw the robot before ship from coming in as part of the Withholding Allowance or as COTS parts or both and being bolted together at the event. I would, however, apply the general Manual caution against "lawyering" the rules to allow/disallow bringing in any given item.

<R25> refers to at-event work, not Withholding Allowance work.

Re: Building a claw post-ship
 

Eric,
I am reading R23 and R24 together.
Please also read the blue highlight under UPGRADE PARTS for an explanation.
I do not believe it is the intent of the GDC to allow you to continue with building robot subsystems and bring these completed subsystems to a competition if they are less than 30 lbs.
I do believe that the GDC has agreed that a team may design and redesign anything for the robot after ship. A team may also build one of these designs between ship and events. The team may not bring that system to a competition in an assembled form. They may bring parts and materials that can be assembled at the event. In my mind, that is an attempt to give teams the same advantage for building.

Re: Building a claw post-ship
 

If it has the ability to increase robot performance without the risk of compromising the current solution. DO IT!

Re: Building a claw post-ship
 

Last year our team withheld our entire kicker and it turned out to be one of the best decision we made, not that we had much choice since it barely worked on ship day. All I have to say is make sure you have a plan set in stone for when you get to your regional, know exactly how and when you are going to put it together before you get there. We luckily knew exactly what we were going to do and were fairly successful with our new kicker.

I would also suggest keeping your current design in working order in case things don't work out.

Re: Building a claw post-ship
 

It is not the intent of the GDC. I agree with you on that, Al.

So, I can add functionality, or replace it, or otherwise make it better.


Stop work on the robot and ship it at or before the deadline; you have all the calendar time in the build season. Design and fabricate everything.

Between ship/bag and competition, I can build stuff for the robot--spare, replacement, upgrade--without limitation, but I have to bring it in in compliance with <R33>.

The intent is, don't bring in brand-new stuff (arm, deployment system, etc.) that was built after ship. The problem is, it is not prohibited to do so. So, if I were to build a brand-new, not-designed-during-build arm, claw, deployment system, electronics box, or other similar item, that fit into the <R33> allowance, but was built after ship, I can't be stopped under the current version of the Manual, unless it's over the weight of the allowance (and I can probably take it apart to get into that if I need to). Intent of the GDC can't stop anything unless it's in the Manual as a rule, and while it is expressed, it isn't a rule.

I think we're starting to get over into something like the "What is a robot" debate from 2008, so I'll stop there, with the note that I would expect a slightly clearer "intent note" in the Manual next year.

Re: Building a claw post-ship
 

I would like one of the previous posters to ask this on the Q&A. It will make someone's life simpler.

Re: Building a claw post-ship
 

And what part of the manual makes that clear to you at all? This exact practice has been done for years and the GDC made no further effort to stop it this year than before. If that's really their intent, I wouldn't leave the same giant holes in the manual that "let" them happen last year.

Re: Building a claw post-ship
 

The blue boxes, particularly the one after <R24>. Also what Al is saying he's getting from the Manual is that that, or something similar is their intent.

It may be that it's similar to the "what is a robot" debate that we had in 2008: the definition of "Robot" had slipped into such a state that it could be interpreted in a number of ways, which allowed for a very innovative robot to be made illegal by a convoluted process. They may have the intent, but haven't noticed that it's possible to legally get around it. They may also not wish to change it, leaving that to the team's best judgment. If that is the case, they may wish to clarify that in this year's Q&A, leaving it open next year.

Re: Building a claw post-ship
 

Interesting debate, with valid points on both sides.
I've posted this to FIRST Q&A, so hopefully, we will know a definite answer soon enough.

Re: Building a claw post-ship
 

The OP says the arm already has a hook, and since a claw is merely an upgraded hook, it would follow that the claw is an upgraded part since it adds functionality to the robot. If, however, the robot were shipped sans hook, I could see a potential problem.

Re: Building a claw post-ship
 

Can you look an inspector in the eye and say that without laughing?

Re: Building a claw post-ship
 

Please don't let bureaucracy and lawyering trump the engineering...wouldn't an additional part certainly be an UPGRADE to no part at all? Upgrades provide greater performance over the previous model. Having an end effector certainly is a performance enhancer this year over not having one.


My 2 cents.