Hello;
There's been discussion on the grain orientation in shear webs of the spar, now how about the spar caps.
I have seen some pictures (and one accident report) that showed that the builder didn't orient his plies in the laminated spar caps correctly, and this was part of the reason for failure.
Let's say we build a set of spar caps that have 1/4 inch think wood. I would have assumed that you'd lay these on top of each other so that the glue joints end up horizontal in the spar. However, in this particular accident report, it indicated that it was done this way, instead of vertically as called for in the plans. I think it was an I-beam type of construction, not a box beam, and there were other problems too, such as shear web too thin.
Does anyone have specs on whether a typical spar cap has horizontal or vertical glue joints, or does this vary with the designer's wishes?
Again, my assumption would have been to lay these up with horizontal glue lines when completed.
Thanks, Tom.
There's been discussion on the grain orientation in shear webs of the spar, now how about the spar caps.
I have seen some pictures (and one accident report) that showed that the builder didn't orient his plies in the laminated spar caps correctly, and this was part of the reason for failure.
Let's say we build a set of spar caps that have 1/4 inch think wood. I would have assumed that you'd lay these on top of each other so that the glue joints end up horizontal in the spar. However, in this particular accident report, it indicated that it was done this way, instead of vertically as called for in the plans. I think it was an I-beam type of construction, not a box beam, and there were other problems too, such as shear web too thin.
Does anyone have specs on whether a typical spar cap has horizontal or vertical glue joints, or does this vary with the designer's wishes?
Again, my assumption would have been to lay these up with horizontal glue lines when completed.
Thanks, Tom.
