Building the Portcullis

[waffle_dynasty]

FIRST supplied us with some great drawings detailing how teams could build Stronghold’s field elements using easy to obtain materials (plywood, 2x4, etc.). However, I noticed that the Portcullis is not included in these drawings. Does anyone have a plan on how to easily construct the portcullis using easy to obtain materials? If so, could you provide the drawings?

[dhowanetz]

If you go here and open the ‘2016TeamVersions-enc’ Document (password is @Ahead)Together!FRC^2016 ), instructions to build the portcullis are on pages 67-71.

[kindrisana]

I viewed the drawing for the portcullis, but it looks like there is a feature missing from the drawing. In the rules, the picture shoes a small feature before the robot would reach the portcullis; it’s a piece of angle stock with the 90deg pointed up that spans the whole width of the defense. At our local kickoff we took a picture of it, and it looked like it was simply a piece of angle stock that was mounted prior to the portcullis; this is important when designing something to go under the portcullis since it’s not simply a gap to the floor.

[Hallry]

@kindrisana

I viewed the drawing for the portcullis, but it looks like there is a feature missing from the drawing. In the rules, the picture shoes a small feature before the robot would reach the portcullis; it’s a piece of angle stock with the 90deg pointed up that spans the whole width of the defense. At our local kickoff we took a picture of it, and it looked like it was simply a piece of angle stock that was mounted prior to the portcullis; this is important when designing something to go under the portcullis since it’s not simply a gap to the floor.

As mentioned by Dan above, the instructions for building the team version of the Portcullis can be found on pages 67- 71 in the document titled “2016TeamVersions-enc” using password @Ahead)Together!FRC^2016, located in this zip file: http://www.firstinspires.org/sites/default/files/uploads/resource_library/frc/game-and-season-info/competition-manual/2016/frc-field-drawings-2016-enc.zip

The Portcullis, as well as all the other of the Defenses, then lay on top of the Team Defense Platform, which can be built using the instructions on pages 17 - 19 in that same document.

[rsisk]

We built the team version of the Portcullis and it is probably going to be less than useful for prototyping to open the real Portcullis at a competition without some modifications. Particularly matching the 5lb force to lift the gate, how easily the gate will go up/down, etc…

We will probably look at modifying it to be more like the Portcullis that will be used in competition.

[mwmac]

@kindrisana

I viewed the drawing for the portcullis, but it looks like there is a feature missing from the drawing. In the rules, the picture shoes a small feature before the robot would reach the portcullis; it’s a piece of angle stock with the 90deg pointed up that spans the whole width of the defense. At our local kickoff we took a picture of it, and it looked like it was simply a piece of angle stock that was mounted prior to the portcullis; this is important when designing something to go under the portcullis since it’s not simply a gap to the floor.

Are you willing to share your picture?

[ACardinali]

The Portcullis will be hard to accurately prototype dude to the mass of the real game element. Even though it only requires 5lbs of force to lift you need to factor in the true mass you are moving. And form calculations based on what it is made of that mass is a lot more than 5 lbs / 32ft/s^2.

[Vince]

Does anyone have an estimate of the lumber needed to build each “practice field” elements?

While the posted drawings list the BoM, I was looking for a quick summary of how much lumber to purchase for each defense.

Hold Strong!

[Hallry]

@Vince

Does anyone have an estimate of the lumber needed to build each “practice field” elements?

While the posted drawings list the BoM, I was looking for a quick summary of how much lumber to purchase for each defense.

Hold Strong!

You’ll be interested in this thread: http://www.chiefdelphi.com/forums/showthread.php?t=141538

[OldLuke]

Here’s some information about the portcullis that may help. Note all of these calculations are rough:

Mass: 21kg
Effective “Gravity”: 1.0 m/sec^2 (22N/21kg ~ 1.0m/sec^2)

The implications for this is that the Portcullis will fall slowly, about 1.5sec from the top and land with a velocity of about 1.7m/sec. Also means that the Portcullis, will rise a little more slowly than expected as well.

[martin417]

@kindrisana

I viewed the drawing for the portcullis, but it looks like there is a feature missing from the drawing. In the rules, the picture shoes a small feature before the robot would reach the portcullis; it’s a piece of angle stock with the 90deg pointed up that spans the whole width of the defense. At our local kickoff we took a picture of it, and it looked like it was simply a piece of angle stock that was mounted prior to the portcullis; this is important when designing something to go under the portcullis since it’s not simply a gap to the floor.

If you look at page 217 of the field element drawing, you will see the angle shown. It is item 3 on the BOM, described as 1.5" steel angle, .125 wall. On page 219 it is detailed as 50" long, 1" X 1" (not 1.5 as shown on 217).