Wood moves, expands and contracts as moisture levels change, whether it is a process of drying out or the humidity levels in the air. The need to ensure that future adjustment - when required - would be easy, has motivated me to redo the end cap bolts for a third time. There will be no fourth time.
The information supplied by WW pointed me in this direction. I have incorporated these features, plus added a design feature of my own (although no doubt this is not new - is there anything "new"? ... probably just re-inventing the wheel).
The probability is that, over time, the bolt and nut will weld themselves together through rust. Tightening the connection will be difficult unless the nut can be immobilised. One way is to remove enough waste to slide in a wrench or spanner. Another is to immobilise the nut from the outset ...
WW suggested a square nut. However, while it has its advantages over the old nut, a square nut still requires spanner to immobilise it. So I have made a elongated rectangular nut, where the shaft runs the length of the bolt hole (and so is restrained by the hole, per se).
Here are the three methods I had used. From the left ... First I tried coach bolts. These were removed as I did not trust their holding ability in end grain. In the middle is the recently removed nut-and-bolt connection. Finally, on the right, is the new system, a bolt and elongated rectangular nut.
http://i13.photobucket.com/albums/a2...uild/bolt6.jpg
The nut plate was made from 1/4" thick x 1" wide O1 steel. Mike Wenzloff gave me an 18" length a few years ago. Nice to add a connection to a friend.
The second feature was the tapered ends to the bolt. Having used them this way now I can confirm that this makes connecting nut and bolt a much easier job.
http://i13.photobucket.com/albums/a2...uild/bolt7.jpg
Here is the set up ...
http://i13.photobucket.com/albums/a2...uild/bolt8.jpg
And here are the end cap bolts installed ...
http://i13.photobucket.com/albums/a2...uild/bolt9.jpg
Tightening now can be done completely from the end cap alone.
Regards from Perth
Derek