Interplane Struts Mounting
Great Planes 33% Pitts
by Bob Pastorello
As I prepared to get the beast ready for duty, I struggled a bit in the workshop keeping track of the nuts, washers, spring washers, and 4-40 screws (x 10 SETS) needed to assembly the bird!! You would have laughed to watch all the various parts spinning off under the washer, into the darkest recesses of the workshop....someday, when I REALLY clean up, I'll have 4-40 hardware for plenty....
Anyway - not much to do about using the split and flat washers, as those are what really prevent the screws from backing off, so I started looking at the "nut" side on the wing brackets.
Here's what I came up with - not a clue in the world if it will work - but I'll find out....
1. First, I made 10 pcs,
1/8" Hard Ply, 1/2" square.
2. On my drill press, I drilled centers for 4/40 GP Blind
Nuts (they are 1/8" deep).
3. I made 4 strips of 1/32" ply, 1/2" x
4". These will hold the ply "nut plates" at the correct
spacing for each bracket.
4. I marked ONE hole on each strip near end, drilled
1/8", then CA'd ONE ply plate/blind nut assembly to it. I did this on
each of the 4 strips.
5. For a good fit, I tapered the ply a bit to clear the
screws that hold the brackets to the wings...then attached the interplane
struts, one screw at a time, one strut a time. This permitted marking of
the other end of the strip for THAT strut. Then,
I removed, drilled, CA'd a ply/nut plate to THAT end.
6. Repeated for the other three attachment points, making
FOUR strips of
ply with Hard Ply/Blind Nuts CA'd to them. Trimmed all the strips (and
MARKED each one, JUST in case there was some spacing issues.
After I test fit all of these, I painted them with some Lustrekote that I had, and it was "True Red", with no primer, I can still read the marking of "Forward" and "Wing" I marked on each ply strip.
Here's photos....
 |
 |
 |
 |
| BEFORE | AFTER | Ply Mount Strips | Whole Strut |