[Jon Stratis]

While we mostly use rivets, we have, on occasion, used bolts as well. Rivets are extremely easy and quick to do, using a small drill bit and a pop rivet gun. Bolts, on the other hand, require larger holes, wrench and Allen wrench, and may not be as quick or easy, depending of familiarity and the exact situation.

For your specific questions, when we use bolts:

1. Most of the time we use long bolts with nuts, although we also utilize rivet nuts quite a bit - they're great, and provide a much better mount than tapping some relatively thin sheet metal.

2. We usually don't need washers- the long bolts are going through gusset plates on both sides, which act, more or less, as large washers themselves. Of course, you want to make sure you aren't over tightening things!. If we are worried about tubing being crushed, we use some plastic/nylon stock, machine it to fit inside the tube, then drill through the whole mess. It gives you support where you really need it, and is fairly light weight!,

3. We always only tap one piece and use clearance for all others. Otherwise, you create the possibility of binding issues and other difficulties putting two tapped pieces together.

4. Unlocks or locktite on everything... These robots move around and rattle so much, anything not properly secured will work it's way loose over the course of competition. And of course, fall apart at exactly the wrong moment!

5. As stated, overall we usually use pop rivets, not bolts. The exceptions being places where we want some added strength (anticipating loads the pop rivets wouldn't be able to handle, in either size or direction) or want a piece to be easily removable/swappable.