Post/Pipe Diameter

[DAdams]

This is a technicality but we really need some clarification. And I'm only asking because one of our volunteers, a pipe salesman, brought me up to speed on types of pipe.
The rules state that the tower is made from 1 1/2" diameter pipe. The problem is that the rules don't specify if this is Outside Diameter or Inside Diameter. To be exact, PIPE is always measured by ID, making the OD bigger by a quarter inch. On the other hand, TUBING is measured by OD, making the true outside measurement 1 1/2". But the rules say 1 1/2" PIPE, which is a bit contradictory.
Are we looking at 1 1/2" outside or inside diameter?
Thanks for your help.
DAdams
Team 1828

[Vikesrock]

As mentioned in one of the Team Updates (I forget which one, 3 maybe?) the Field Drawings take precedence over the rules. Track down the proper drawing for the piece you are interested in from the official field drawings and your question will likely be answered.

[MrForbes]

The material specified is structural tubing, NOT pipe! It is actually 1.5" outside diameter, with the specified wall thickness.

One big clue is that they say .083" wall thickness, whereas pipe has a schedule (40 or 80 for example) instead.

(uh....yeah....see if you can find the drawing I copied this from!
http://usfirst.org/roboticsprograms/...nt.aspx?id=452
will help)

[Matt H.]

If you look at the technical drawings found on the competition manual page you can find what you're looking for. After downloading the field drawings take a look at GE-10028_revB.pdf which lists 1-1/2" x.083" Wall 1020 CRS DOM Tube emphasis mine. On later diagrams you can also see the outer diameter listed as 1-1/2".


This being said I would design your grabber such that it can handle small deviations from the norm (perhaps a pipe is distorted).

[MrForbes]

Originally Posted by Matt H.

(perhaps a pipe is distorted).

or a TUBE?



Hi Matt, hope school is going well!