Posted by Brian at 1/14/2001 12:35 PM EST
Engineer on team #226, Tech CReW, from Troy High/Troy Athens.
Does anyone know if there is a problem with the bridge width on the blueprint. If you build it using 16" on center for the supports. The bridge would be 49 3/4" wide including the metal on the outside. They say on the print 3X1’4" on center. Has anyone else had this problem. Thanks.
Posted by Michael Martus at 1/14/2001 12:44 PM EST
Coach on team #47, Chief Delphi, from Pontiac Central H.S. and Delphi Automotives Systems.
In Reply to: Bridge Width Question
Posted by Brian on 1/14/2001 12:35 PM EST:
The Platform is a standard sheet of 4 ft by 8 ft plywood. The ribs ( joists ) are flush with the sides. The ribs (joists ) are standard on center as you would do a wall construction. Addition of plate on side adds no width.
I am not sure how you got a platform larger than the standard width of standard plywood?
The ribs are made from 2 x 8 lumber. (actually 1.75 x 7.25 ). An old system of measurement that dates back to the 1800’s.
Construction hint: Use good plywood not the cheap stuff. Choose 7 ply Birch or Oak. It is stronger, will not warp and cuts and drills well. Avoid particle board centers.
Posted by Brian at 1/14/2001 7:21 PM EST
Engineer on team #226, Tech CReW, from Troy High/Troy Athens.
In Reply to: Re: Bridge Width Question
Posted by Michael Martus on 1/14/2001 12:44 PM EST:
Thanks for the reply Michael. We built the frame under the bridge first and then tried to mate the plywood top to it, which is part of our problem. Our support braces are exactly 16" on center; however, our 2x8 lumber measures somewhere between 1.25" and 1.5". I suppose that I will rip a small amount out of two of the supports under the bridge and call it good. First hasn’t been too good with the blue prints and I am wasting too much time with trying to make everything exact. Thanks for the info.
Brian
: The Platform is a standard sheet of 4 ft by 8 ft plywood. The ribs ( joists ) are flush with the sides. The ribs (joists ) are standard on center as you would do a wall construction. Addition of plate on side adds no width.
: I am not sure how you got a platform larger than the standard width of standard plywood?
: The ribs are made from 2 x 8 lumber. (actually 1.75 x 7.25 ). An old system of measurement that dates back to the 1800’s.
: Construction hint: Use good plywood not the cheap stuff. Choose 7 ply Birch or Oak. It is stronger, will not warp and cuts and drills well. Avoid particle board centers.
Posted by Gary Bonner at 1/15/2001 12:37 AM EST
Other on team #433, MINT, from Mount Saint Joseph Academy and Pew Foundation.
In Reply to: Re: Bridge Width Question
Posted by Brian on 1/14/2001 7:21 PM EST:
16-inch on center studs used in wall construction allows the wallboard joints to occur over a stud. The outer studs would protrude 3/4 inch beyond the edge of the panel. In the case of the bridge, the outer joists are flush with edge of the panel. If you then interpret the 16 inch on center dimension to apply only to the outer joist distance, that leaves 13 inches between the inner joists, the same as the diameter of the small balls. And if we have egg-shaped balls, they could get stuck there. My guess is that they should be evenly spaced, about 15.5 inches.