|
Update for October 15
Not much of an update this week
There has been discussion on how to reinforce the bolt-together joint so that it will withstand 500 foot-lbs without distorting .. or at least so that the joint will take the torque without failing.
The suggestions are:
1 - use a large washer to prevent the pull-through that was experienced
2 - use epoxy to bond the short pieces of tube to the longer main tube. This is the weakest point, and could also be bolted to prevent catastrophic failure in the case where the epoxy fails. I know nothing about epoxy beyond using JB weld for many years.
3 - use a welded joint, and test it the same way to see if 500 foot-lbs is a reasonable amount of torque to be requiring, or if the weld has much more strength than that.
The washer idea has had some progress. I cut a 1.5 inch by 1.5 inch square of 1/8 inch steel from some scrap that I have. I have not gotten the holes drilled yet. The aluminum tube used will be new (not recycled from other testing)
I was pointed toward some epoxy, 3M 08115 or 08115, Plexus combined with PC-120 primer, Epovex by Zyvex (can't find much info on that one). So far, no one local sells these. I need to ask the suppliers what they would advise, I guess.
One of the forums suggested JB Weld - but I think that was for an aluminum boat - it may be interesting to make one up with JB Weld for comparison, but I think it makes more sense to do the serious testing first.
|