Driving up the portcullis

[staplemonx]

Has anyone tried driving your robot up to the portcullis and putting a driven wheel in contact with the gate, then driving the gate up and the robot under?

[Robomarfa]

Have not tried. How do you get a drive wheel in front of your bumper?

[tindleroot]

Originally Posted by Robomarfa

Have not tried. How do you get a drive wheel in front of your bumper?

A driven wheel is a wheel powered by a motor. Such a device would be allowed as long as it is not extended horizontally more than 15" beyond the frame perimeter and is not extended above the height limit of the robot.

[1452-Leo]

We built a portcullis out of wood (built to the "Team Version" specifications) and I don't think it would be possible to roll it up. However, the actual one might have less friction when applying a force perpendicular to the lexan, so it might be easier.

[RoboChair]

Originally Posted by 1452-Leo

We built a portcullis out of wood (built to the "Team Version" specifications) and I don't think it would be possible to roll it up. However, the actual one might have less friction when applying a force perpendicular to the lexan, so it might be easier.

The portcullis uses ball bearings at the top and bottom of the door in a steel track. So even with huge side loads there should be very little friction(page 253 of 2016FieldComponents.pdf)

[Bob Steele]

Originally Posted by RoboChair

The portcullis uses ball bearings at the top and bottom of the door in a steel track. So even with huge side loads there should be very little friction(page 253 of 2016FieldComponents.pdf)

bearings at the top and bottom... Not sure i understand...
Do you mean the top and bottom of the sides? Probably ...

[RoboChair]

Originally Posted by Bob Steele

bearings at the top and bottom... Not sure i understand...
Do you mean the top and bottom of the sides? Probably ...

Yes, on the sides in a steel track. Consult the 2016FieldComponents.pdf for a visual of the Portcullis as you will see at competition.

[StephenNutt]

We've had the same idea too. There are ball bearings on the sides at the top, and I believe a wheel at the bottom that will roll along a track.

You should allow for more than 5lbs of force - motors should generally be run at under 50% of maximum torque and you should account for some friction too.

Please post back and let me know how things work for you.

[TheGabe]

Our team tried this. We have a few of the four inch anymark wheels (checkered tread) on the frount of our intake mechanism. We decided to try it. Only about half of the wheel is exposed toward the gate so we were able to roll the gate up and it rested on top of our wheels. From there we lifted the intake mechanism up and drove under. Our portcullis is made out of wood and has the 5lb lift force. This is how we plan on tackling this defence during competitions.

[GeeTwo]

Originally Posted by TheGabe

Our team tried this. We have a few of the four inch anymark wheels (checkered tread) on the frount of our intake mechanism. We decided to try it. Only about half of the wheel is exposed toward the gate so we were able to roll the gate up and it rested on top of our wheels. From there we lifted the intake mechanism up and drove under. Our portcullis is made out of wood and has the 5lb lift force. This is how we plan on tackling this defence during competitions.

Great to hear it! We're also planning to double-duty our intake rollers to raise the portcullis. Better go back and check the forces, though!