New rule <GS10> is a big change this far into season (and comments on GS11)

[FTC12676]

To add more confusion- interesting to see other linear actuators are considered servos and are allowed. These servos use tiny lead screw and motor exactly like any other lead screw based actuators. Worst is these so called servos comes assembled and are allowed . Here is post

[CoachZM]

I would agree that this is very confusing. FIRST....Your input please?

In the Official Game Forum - Mechanical Section under General Robot Rules: Post 3 is saying they are legal as long as they are constructed by teams themselves and not from a kit. Isn't the Assembled Linear Actuator Kit from ServoCity essentially the same thing as a Linear Actuator from Andymark? The only difference is Andymark's is a servo and ServoCity's is a DC Motor (I guess you could use a Servo) and Andymark's comes in a pretty enclosure/case where ServoCity's is exposed. If ServoCity attached the motor and made an enclosure for it would it then be legal?

Now according to Post 4 in the Mechanical Section under General Robot Rules: Post 4 both the Andymark and ServoCity Linear Actuators should be illegal because they provide both rotational and X/Y movement.

FIRST....BUELLER....BUELLER.....BUELLER

[CoachZM]

New ruling came out in the forums today and Linear Actuator Kits are legal for this season.

[JoAnn]

Here is what I posted in the Coaches Mentors forum.
I cannot post in the game rules Q&A for some reason. So here goes.
"Robots may not obstruct another Robot's path of travel in the area between the Lander and a Crater for more than 5 seconds."
If a robot has expanded to 36" wide and wants to drive between the crater and the lander, do you have have to move to get out of its way since there is no room for them to go around since they are so wide?
If there is room for an 18"x18"x18" robot to go past the lander while you are in the area between the lander and the crater, but they want to go exactly where you are, are you obstructing another robot's path of travel?
In years past if there was another path they could take to get to objects then it was not considered blocking. What is the difference between blocking and obstructing?

Hi Team!

I checked your forum access for FTC12692, and it looks fine from this end. Please shoot me an email if you still can't get in to post to the Game Forum, and I'll troubleshoot it with you.

JoAnn
jhalloran@firstinspires(dot)org

[JoAnn]

I would agree that this is very confusing. FIRST....Your input please?

In the Official Game Forum - Mechanical Section under General Robot Rules: Post 3 is saying they are legal as long as they are constructed by teams themselves and not from a kit. Isn't the Assembled Linear Actuator Kit from ServoCity essentially the same thing as a Linear Actuator from Andymark? The only difference is Andymark's is a servo and ServoCity's is a DC Motor (I guess you could use a Servo) and Andymark's comes in a pretty enclosure/case where ServoCity's is exposed. If ServoCity attached the motor and made an enclosure for it would it then be legal?

Now according to Post 4 in the Mechanical Section under General Robot Rules: Post 4 both the Andymark and ServoCity Linear Actuators should be illegal because they provide both rotational and X/Y movement.

FIRST....BUELLER....BUELLER.....BUELLER

Hello CoachZN,

The intention of rules that prohibit the use of pre-kitted assemblies is to encourage teams to develop a solution that hasn't already been provided for them. For example, claw kits aren't legal, but a team could design a claw mechanism, build it, and it would be perfectly acceptable. It's tricky to write rules for something like this, and sometimes our GDC finds that clarifications or changes to the rules are necessary.

I hope that helps.

JoAnn

[ViperMentor]

I still don't understand making a special exception for the Servocity Linear Actuator kit this season, because it already meets the single-degree of freedom requirement. If this needs a special exception then what about tape measures that have been allowed in previous seasons? Are they allowed because they are single-degree of freedom or because they are not kits?

I think the problem is trying to restrict parts based on "single degree of freedom" when what the GDC really means is mechanisms (either kits or pre-assembled) with multiple moving parts. That would make most things illegal that the GDC wants made illegal. There are already specific exceptions for mechanisms that the GDC would like to allow (for example mechanum wheels, single-speed gearboxes, drawer slides and the Tile Runner kits).

Any kit of individual legal parts would remain legal provided it is not intended to be assembled in one or more predetermined configurations. So for example a Tetrix starter pack would remain legal as intended.

[Alec]

I still don't understand making a special exception for the Servocity Linear Actuator kit this season, because it already meets the single-degree of freedom requirement...

I believe the ServoCity actuator kit was ruled illegal because ServoCity publishes assembly instructions of a non-SDOF configuration of their actuator, i.e, a servo attached to the end of the actuator.

[FTC0417]

Alec : I'm (still :-) confused. Even with the servo attached, the state of the system is still described by a single scalar. And that's a SDOF, is it not?

[Alec]

Alec : I'm (still :-) confused. Even with the servo attached, the state of the system is still described by a single scalar. And that's a SDOF, is it not?

The servo spline follows the motion of the actuator, however, it rotates independently of the motion of the actuator. Unless I am confused, you would need another scalar to describe the motion of system.

[ViperMentor]

Alec - I don't see how publishing instructions for a suggested assembly from legal parts can render those parts illegal. By that logic, SDOF servo block kits are now illegal too.

[Alec]

Alec - I don't see how publishing instructions for a suggested assembly from legal parts can render those parts illegal. By that logic, SDOF servo block kits are now illegal too.

Hello ViperMentor. I believe you are referring to this question:

... If someone publishes an assembly guide to some trivial assembly, does that render the assembly illegal?

This is a rhetorical question. Publishing instructions for a suggested assembly from legal parts does not render the assembly illegal [regardless of the DOF of the assembly]. Thus, it appears that the only thing that makes an assembly illegal is the ability to purchase the parts of the assembly with one click.

Suppose ServoCity (or someone else) published instructions on assembling a nifty 6-DOF arm from legal ServoCity parts. It would be perfectly legal to assemble and use that arm on your bot. Midway through the season, ServoCity decides to allow customers to purchase the parts needed to assemble the arm with one convenient click. As a result, the arm you've used on your bot all season has suddenly become illegal -- just before state championship!!!

The rule boils down to the "one-click rule". The 6-DOF arm is illegal only when the vendor allows you to buy the parts with one click. You may not even need to buy any of the parts of the arm since you already have all the parts needed to assemble the arm from leftover parts from previous seasons. But because the vendor allows customers that need the parts to buy them all with one click, the assembly is illegal.

I agree with JoAnn that it is very tricky to write some of the rules, and I understand and appreciate the intent of the rules. But is the one-click rule actually needed? Teams are encouraged to CAD their bots, but there is no rule that says teams must CAD their bots. The judging process provides sufficient encouragement for teams to CAD their bots. I suggest that the judging process likewise provides sufficient encouragement for teams to develop their own solutions such that the one-click rule is not needed. Further, I believe that most teams take pride in developing their own solutions and need no encouragement at all.