The Portcullis Mystery
 

I have looked through the field element construction guides, but can't seem to find definitively what the Portcullis door is like. Is it a lattice of solid bars that you can reach through, or is it a solid piece of clear plastic that has lines drawn on it to make it look like bars?

Re: The Portcullis Mystery
 

The door is a solid piece of plastic. So your robot cannot reach through bars to help lift it. The bars are just printed onto the plastic for visibility and theme purposes.

Re: The Portcullis Mystery
 

What I wonder is how solid it is. Can it take a hit from a speeding robot undamaged because I'm sure it'll get smashed into more than once.

Re: The Portcullis Mystery
 

A few people from my team went to the Manchester kickoff and it is Polycarbonate with Bar decals and a 1x1 box steel tubing frame around the whole perimeter of the door on the back side.

Re: The Portcullis Mystery
 

Is it transparent with the bars printed on? Or is it some opaquematerial that has the bars printed on as well?

Re: The Portcullis Mystery
 

The Portcullis is a 5lb steel frame with, from what I have read, 1/8in. thick Lexan covering the gaps so no robot can travel through

Re: The Portcullis Mystery
 

There are pictures of the field in the thread I posted. You can see through the Portcullis.

http://www.chiefdelphi.com/forums/sh...d.php?t=141594

Re: The Portcullis Mystery
 

It's clear polycarbonate with decorations or stickers on it to make it look like bars. It's completely transparent except for the decals which somewhat hinder visibility.

Re: The Portcullis Mystery
 

If it's a similar material to the low side walls, I'd guess it could take quite a hit. Whether the pins holding it into the track can stay together, that remains to be seen.

Is the "printing" sandwiched inside or on one of the outer surfaces? I can see that getting scratched off.

Another question: is their a lip on the bottom of the portcullis door? If so what does it look like? Does a lib stick out perpendicular to the door?

Re: The Portcullis Mystery
 

I suggest you take a look at the Field Components PDF file. The details for the Portcullis are in there. Start at page 211. The polycarbonate is on page 221.

Re: The Portcullis Mystery
 

After consulting the pages you recommend, I still have no insight into the question. It looks like there is a lip on the CAD render, but I don't see any dimensions or reference to it anywhere.

Re: The Portcullis Mystery
 

5 lbs of steel, plus a large sheet of 1/8" polycarbonate. Has anybody build the full device, and if so, are the forces necessary to lift it consistent with what we've been told to expect? I'm thinking 2012, of course. The difference between teams who had access to the full and accurate field and those who built the simple version of the bridge were, well, the difference between winning and losing, mostly.

Re: The Portcullis Mystery
 

Try roughly page 259 in conjunction with 256.

Re: The Portcullis Mystery
 

I see the steel tubing, trying to figure out if it is on the neutral zone or courtyard side.

Re: The Portcullis Mystery
 

Here is a photo I took in Manchester. I was standing in the Neutral zone at the time (sorry about the blurriness - it was a quick grab ...)

As you can see, the steel tubing is on the Neutral zone side ...

Re: The Portcullis Mystery
 

I read the field diagrams that the steel frame and polycarbonate sheet will *mass* more than 5 pounds, but springs in the side channels will reduce lifting force to just 5 pounds. This might be an issue to any mechanism that is trying to lift the portcullis quickly and inertia becomes a factor.

Re: The Portcullis Mystery
 

Are there any bearings used to reduce friction? I'm wondering if the upward force is on a slight angle, how that will relate to the opening force.
Does anyone know?

Re: The Portcullis Mystery
 

Literally every question in this thread is answered in the field drawings. Yes, it is a huge document, and yes, it requires time to read and understand, but it's all there.

Re: The Portcullis Mystery
 

Anyone notice the angle iron on the base of the portcullis? It's on the courtyard side. What purpose do you think it serves?

Re: The Portcullis Mystery
 

Originally I thought the same way, then I saw the pictures posted and the plot started to thicken, I realized there is a conflict. It is possible that the field in Manchester may have had the portcullis mounted the wrong way.

That picture, along with this picture posted on firstinspires.org of the same field appears to conflict with page 214 of the field drawings.


the field drawing shows that the raised lip and the steel box tube are on the same side, with both facing the opposing team's courtyard.

So now I am left wondering if the field was wrong, or the drawings are wrong, both possibilities are supported by the evidence available on firstinspires.org. Personally, I would trust the field drawings, I think they probably just assembled it incorrectly for the physical field, it was probably the first time it was assembled, so mistakes can happen.

Thoughts? I think a Q&A might be in order, but if I have it all wrong let me know.

Re: The Portcullis Mystery
 

I assume that it's reasonably flexible, I don't know anything specific about the material but FIRST has to have accounted for the high-velocity antics of this year. If not, we're in for a lot of penalties.