Aftermath of Field Building - Hex bolts and Tee-Nuts

Competition Field Building
1

We finished out Field Build yesterday, and I’m concerned that once we’ve dissassembled and reassembled it a few times, the various connections made with 1/4-20 hex bolts and Tee-nuts won’t line up, or the Tee-nuts will strip or not catch the thread or whatever.

So… I got some 4 inch long 3/8 LAG BOLTS (screws). So the plan is if we can’t make the existing 1/4-20 hex bolt / Tee nut connection work, we just widen the upper hole to 3/8, then use the existing 5/16 lower hole as a pilot hole for the 3/8 lag bolt.

I think for field building in the future, I’ll probably just substitute lag bolts from the start. 1/4 or 5/16 lag bolts would be fine - in the case above, I had to go up to 3/8 because of the pre-existing 5/16 holes.

2

If you’re worried about the ability to take it apart and put it back together multiple times, then lag bolts aren’t the right choice. They’ll wallow out the hole over time and not hold tight. It’s less efficient (which is probably why FIRST doesn’t design for it), but extending the bolts and using nuts on the back side is an easier way to provide repeatability with reassembly.

But honestly, if things lined up once with bolts and t-nuts then they really should line up again. If you’re having trouble then I recommend loosening brackets up and nudging it until every bolt goes back where it came from. THEN tighten everything down.