# SG10 on center platform

<SG 10> Don’t clamp your robot to the field.
If a robot is positioned on the center Platform and then extends legs down past the edge of the platform, such that it cannot be pushed off the platform, does this violate rule SG 10?
These legs would not “latch or clamp” to the Field Element, but would limit how far a robot could be pushed horizontally. The robot could be removed from the field by lifting it straight up. And assuming that all other rules such as expansion limitations are met.

Since the platforms are not in the expansion zone, anything that expands vertically past 18" from your robot is violating SG2
From what I understand from your concept is that you wanted to extend vertically however I might be misunderstanding what you are saying.

You are not allowed to clamp on to the center platform, this is because it is a field element, so aslong as you don’t actually touch one of the other sides you would be ok, you have to remember that you are already touching the upward facing side

You can expand vertically, as long as it is not above 18 inches. So if his robot was 10 inches tall to begin with, he could expand 8 inches downward.

You can touch more than one side of the center platform. You just can’t latch or clamp onto it. If those two sides you’re touching meet at an edge, you’re probably not latching/clamping. Interpreting this as illegal is basically interpreting the rules as not allowing you to drive onto the center platform. It’s even possible to touch three sides that all meet at a corner without latching/clamping.

As long as your robot is not the full height before extending downward you should be fine. (Do be aware that since the edge of the platform is curved, you will have to extend about 2 inches downward to get any effect, leaving only 16 inches in height for the rest of your robot.) Just make sure you leave a noticeable amount of space between the platform’s edge and the parts of your robot that extend downward, as shown in the diagram below. Even with this space, your robot will not be able to be pushed off of the platform easily.

While I agree it’s a good strategy, I think you overestimate its effectiveness. No way to push it off? At all? I doubt that.

I fully agree with you here, especially with <G12> voided on the platform. I’m just trying to go along with the idea presented. I’ve edited my wording to better match what I meant.
Another issue with this tactic is the self-inflicted 16in limit on height, which effectively removes 1 ⁄ 8 of the space you have to build your robot. I have no intention of using it myself. (I don’t even plan on parking, but that’s not the point of this thread.)

You also have to be really careful with horizontal spacing since you may well be pushing the 36" limits, depending on how you specifically build those pieces and how they fit on the robot.

The platform is ~24 inches across. To get around it shouldn’t take much more than 26 inches. Even with that, you are well within the 36-inch limit. So expansion really shouldn’t be an issue.

You’re not measuring properly. That’s 36" in any direction, meaning the robot should fit inside a right cylinder with a diameter of 36" standing on its end. The height of the cylinder is based on the robot’s location, either 18" or unlimited.

So let’s look at your 24" + 1" + 1" = 26". That’s on one horizontal axis. Let’s look horizontal and perpendicular to that to see another 26". If those plate by the sides of the platform are your robot’s corners and they drop straight down and they aren’t really long, you’re in good shape. Even if they’re on your robots sides, drop straight down, and aren’t really long, you’re in good shape, though you’re getting closer. But, for example, let’s say you make your four plates really long so that you essentially make a big square that drops down. Now your longest length is 26" * 1.414 = 36.76", and we haven’t factored in parts of a claw or something that might stick out somewhere. Can you go with this design safely? Yes, absolutely. Can you blow through the 36" limit while going with this design and not paying attention to the limit? Yes.

I should have just said “careful” instead of “really careful,” though.

Let’s play a fun game called multiple choice. Which diagram did I post earlier in this thread?

Here’s a hint: It’s B.

I am not measuring incorrectly since I’m not picturing a square around the entire platform, just 4 posts, probably standoffs, sticking down. This would in fact be within the expansion limit. If I’m still thinking about this wrong, please tell me.

(I don’t want to come off as hostile with this response, so please don’t take it that way.)

I wrote one of these:
A) Can you go with this design safely? No, definitely not.
B) Can you go with this design safely? Yes, absolutely.

I’ve seen team build things that seem to be perfectly legal, but when you watch them move their parts they become illegal. All I’m saying is that teams need to be much more careful about things like claws sticking out anywhere and the like if they’re going to then extend to a little over 26" in multiple directions. Even a basic starting robot with a square footprint measuring 17.5" x 17.5" is already roughly 25" across.

For example, consider a 17.5"x17.5" robot with a 10"x10" forklift type claw that folds down in front of it on a linear lift. That’s a reasonable size claw if you’re picking up caps how many teams picked up mobile goals last year. A lot of teams are talking about mounting their claws on one side and their shooters on the other side, so let’s measure that way. The biggest your robot ever measures horizontally is about close to 33" if we line up the robot and claw edges. No problem at all with this basic design an the size rules. Extending minimally that 1" beyond the sides of the platform with only a single standoff on each of the four struts and having them rotate down into position to keep them within the original 18" easily already has the robot around 34.5" mid swing. If they use a few standoffs to give a flatter and sturdier surface like what you drew in B (presumably about 3" wide), that’s about 35.5". And that’s giving minimal room for error between the body and the claw, a small gear or similar for attaching/swinging the standoffs, etc. If your claw shakes at all, if it doesn’t rise and fall so tightly to the body, if you have a nonlinear lift, if you use larger gears for the standoffs, or similar, you’ll go right past 36". That’s why I wrote:

You could easily breach the expansion limit when you consider other subsystems, like a passive cap manipulator that sticks out of the side of the robot. However, I would hope that anybody trying to do this would make sure that doesn’t end up happening. That’s not to say I suggest it. On top of the problems we have mentioned, we did not even address the fact that it would take a motor or piston, both of which would be a heavy price to pay when using the V5.

So to answer the OP’s question, this would not violate <SG10> as long as you are careful. That said, I would not suggest you try it due to the aforementioned problems.

I was considering the same thing. One option would be to put them all on elastics to be released a single time by moving a lift too low compared to normal use or running a motor that is only used in one direction back the other way. There are dangers to that, though, as you can’t pick them back up if you do get shoved off. With the unused single direction of a motor, though, you could set up a slip gear to pull in rope against the elastics to lift them and just pull a little further to slip and release them. If you’re using a piston, it’s just one activation most likely, so that’s not much of a loss since you get unlimited pistons.

Overall, I like the idea behind your design. I would probably only drop them on three sides to provide a spot for my alliance member to potentially climb up and hold on, figuring even if they don’t, they could defend that one side.

Yeah, I thought about an approach that hijacks motor power from other subsystems, but if your team can get that working well, chances are you can build your other subsystems to score more than 6 points in the same amount of time it would take to center park. Even still, it’s fun to think about how you’d put something like that together.

The (4) non-gripping, non- latching legs on the hypothetical robot could be “powered” by rubber bands. Assuming there will be a system to lift and rotate (flip) caps and that there would be no need to flip a cap at 12 inches elevation; the (4) legs would be dropped when the flip is actuated at 12 inches. Or maybe the (4) legs could be raised or lowered depending on the direction of the flip.
There are mechanisms that work one geared system when the motor turns CW and a different geared system when the motor turns CCW. The hypothetical robot could use (1) V-5 motor with clutches that power the (4) legs when CW and through a ball when the same motor turns CCW.

It took me longer to write the above than for (2) others to post reply.
The legs on callen’s hypothetical robot could use CCW (with directional clutch) to power the legs through a full cycle of up and down, stopping the leg in the desired position. And CW to through the ball.