Bot Blockers

[Jeff Waegelin]

Does anyone know how thick the botblockers are, and how big the holes on them are? We'd like to build one, but the drawings we have only have simple measurements for the length and width.

[Mike McIntyre]

The blockers are made from fiberglass mailposts that we bought at Home Depot for $19.25 each. They are 48" x 4" x 4" and .25" thick as purchased. We drilled four 2.375" holes in them on opposite sides, approximately evenly spaced (although the holes tend to be a little closer to each other than they are to the end of the post). The other set of opposite sides have a single, centered hole on each.

[Jeff Waegelin]

I appreciate your help, but is there any way to obtain an exact measurement of the hole spacing? Our design could be adversely affected by incorrect spacing, so I would really like some actual measurements. If not, we will be ok, but I would appreciate more accurate measurements on the holes.

[Mike McIntyre]

Do not design your robot for a perfect fit: allow for a slight variation. While the holes average around 7.25" apart, there is a .125" plus/minus.

[Jeff Waegelin]

Okay. That sounds good. Thank you for the information. We weren't planning on a perfect fit, but I wanted to know if we were looking at a huge variation or small variation in spacing.

[Mike McIntyre]

When the 'bot blockers were made, the students measured all holes to be 9.25" apart on center, and the center of the end holes was 9.25" from the end of the blocker. The actual drilling, however, had a few that are a little off (less than .25" error); most are very close to that spacing.