Prangster Problem!

[Tim Morton]

[Plummet]

Posted by Tim Morton on 11/07/2018 12:34:26:

I've not had any problems with keeping the surfaces at 90 degs. Could you explain that a bit please (or some photos if you have)

To explain for those without a Prangster ...

The tailfin and tailplane are made of correx.

There are slots in the fin and the tailplane. These slot into each other at right angles to form the tail surfaces, and they are taped along the join.

The fin is inserted into a vertical slot at the rear of the the fuselage. Two dowels go through the fin to hold it in place.

When in place the tailplane is seated across the top of the fuselage. With use (abuse) the holes around the dowels become looser allowing the tail surfaces to move a bit. As the tailplane seats less firmly on the top of the fuselage it can start to wobble a bit away from the horizontal.

I took an old length of square white plastic drainpipe (perhaps 3 inch square) and cut a slice perhaps half an inch long. I then cut the sides of the slice to create four angle pieces. These I fixed to the upper side of the tailplane and the fin to keep them well square to each other.

Does this make sense?

Plummet

[Tim Morton]

yep - absolutely makes sense now Plummet. I hade that problem with loose dowels on the wing and U/C and on one of the rebuilds / repairs I used some thin ply to support it. so far so good...

My tail plane dowels are still okay - no rattle anyway. I have worn out the underside of the fin though (the tail skid bit ) and the plane became impossible to taxi (or really even take off - it would just immediately veer off to the right due to it being worn / broken / shredded / whatever).

So this repair job actually started with me removing the tail to fit a tail wheel and whilst I was at it I thought I'd have a go at straightening the horiz. stab too.

I'll post another pic of the before and after

[Tim Morton]

[Tim Morton]