Fin / rudder misalignment
 

Hi all

I have recently started building the TF Spitfire, the first kit back in the hobby after a long break, and have come across a problem.

I am using Robart point hinges of the 1/8" size and the drill jig for these hinge points. I built the rudder and fin, no probs, drilled the holes for the hinge points using the jig and slapped them together to check the fit.

PROBLEM: the rudder now sits a few mm's to the right of the fin (offset). I can only guess that it was the curvature of the fin and rudder trailing and leading edges respectively that threw the jig out???? I did the stab and elevators the same way and perfect.

QUESTION: Will this be a major issue and if so, what would be the best way to go about fixing it?

I hope that all you building pro's can point me in the right direction. The rest of the build (wings, etc) is going swimmingly. I actually surprise myself at how well it's going.

I will try and post a pic if it helps to indicate the issue.

Thanks in advance

Luis

RE: Fin / rudder misalignment
 

Glue the hinges in the rudder.

Drill bigger holes in the fin, fill with epoxy,

Push the rudder into place and hold aligned until the glue in the fin sets.


Ed S

RE: Fin / rudder misalignment
 

Assuming that you didn't permanently glue the hinges in when you saw how far off it was, just fill the bad holes and do new ones a 1/4" to a 1/2" above or below the bad ones.

Highflight

RE: Fin / rudder misalignment
 

I would have to agree with Highflight. It would be easiest to just drill new holes.

RE: Fin / rudder misalignment
 

The problem I have with just drilling new holes is that I might miss the hinge blocks completely. I will have to take a good look and see if I can get away with it as the present holes are smack in the middle of the hinge blocks. It looks as though it might be a dowel fill in job and re-drill.

Fortunately, the hinges are nowhere near to being glued in at present.

Thanks for the input guys.

Luis

RE: Fin / rudder misalignment
 

How about plugging the hole with a balsa plug and a little thin CA. I havent done it with balsa but I have done it with ply, but used epoxy and a dowel. Was able to redrill right on the seam. Only if you're sure you cant move it a little. I've also wallowed out a hole some and filled with epoxy. It worked on a .60 sized plane.
Edwin

RE: Fin / rudder misalignment
 

The dowel and re-drill would probably be the best route.
Dennis-

RE: Fin / rudder misalignment
 

Elongate the holes to fit and then use gorilla glue.
This stuff expands as it dries and will fill any gaps
(it also fills in all the areas between the splines on the hinge points)
You will never lose a hinge with this stuff

Regards,

Tim Hudson

RE: Fin / rudder misalignment
 

There's two problems with Gorilla Glue for that purpose.
First, as a large gap filler, Gorilla Glue can be weak because it may expand, but the glue by itself in the gap ends up being sort of a stiff foam with lots of air bubbles in it.
Second, it DOES expand, and it will run all over the place WHILE it expands and cures. You'll have a real mess cleaning the stuff up, and good luck trying to keep it out of the hinge pin and locking up the hinge.

If moving the hinge point isn't an option, then enlarging the existing (wrong) hole and gluing in a piece of round dowel, and then redrilling correctly, is your best option.

Highflight