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Need S-1 rebuild help

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Dec 2, 2008
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I'm trying to get this newly-purchased airplane flying again and am recovering it plus repairing some ground loop damage. Working off original S-1C prints from Steen plus empennage details from the later prints (couldn't afford both, and my plane is definitely an early (short lower wing) S-1C).

Turtle deck skin: plans seem to show 1/4" ply on turtle deck. That seems ridiculous. Mine has 1/16", with a single piece of Grade A cotton from top longeron to top longeron. Just the cotton tautening wrinkled the 1/16" ply, so that is too thin. 1/8" seems to be the material to use. Yes? AC Spruce aircraft plywood with mahogany face?

Fin and rudder spars: Both are 7/8" tubing with 1" tubing for sleeving at rudder horn and at tail post. However, later plans say sleeve at rudder horn is .049 thick? This gives .027 of slop, and the plans further state "4 rosette welds". Why not use .058 thick sleeving to give a tighter fit and weld the bevelled ends of the sleeve to the spar? Four rosette welds don't seem to be strong enough for the rudder horn on an aerobatic plane.

The 1" tail post is listed as .035 thick; this one gives .055 of slop; again, why so sloppy?

Fin rib stitching: mine was only stitched on top rib, with fabric pulling out by the second rib down. The fabric has a nicely-bowed-out shape, but it might be cleaner if it were stitched on both ribs. ???

Rudder: mine is approx. 1" wider (i.e. from front of spar to trailing edge) than either plan set. Was that in vogue at one time or just something the builder decided to do? Rudder hinges were kind of worn and sloppy; maybe added stress due to larger rudder..... I plan to use the later plans' strap hinges, which I also saw in a picture of a Wolf Pitts in this forum.

Finally: mine has a rather worn Maule solid 6" steerable tailwheel, so I'll either need to replace the Maule or go to one of the lockable tube spring tailwheels. I've flown tailwheeled aircraft all my life and kind of like the way the Maule locks and then breaks on side load or side travel, but Steen seems to think locking/tubular is the only way to go. Without starting a religious war, I'd like to know if keeping the flat spring and a Maule TW is acceptable. Are there steerable tailwheels for the Pitts with the ability to lock as an override? (kind of like a 185).

Rob at Raven also said a 4" tailwheel is fine for an S1, but I think Steen said the 6" was better. Thoughts?

Where can I find another spring set? Mine is 1-1/4" but seems to be tweaked. It has two springs. Just look for a spring set with a hole on each end?

TIA for ideas.


 

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